Popular Science Monthly/Volume 49/October 1896/The Vivisection Question II

by C. F. Hodge

Layout 4

THE VIVISECTION QUESTION.

By C. F. HODGE, Ph. D.,

ASSISTANT PROFESSOR OF PHYSIOLOGY, CLARK UNIVERSITY.

III.—THE UTILITY OF VIVISECTION.

ASIDE from the highest "use of science," its satisfaction of man's intellectual wants and its influence upon his character, science has many "practical" values connected with its development. And it is to these "uses" of physiological research that we will confine attention, bearing in mind that we are addressing those who believe that, after duty, human health and happiness are the highest values in the world, and that the greatest evils in the world, after moral evil, are human suffering caused by disease and premature death.

How much "use" humanity has for help in these regards may be seen from a glance at vital statistics. "Of 1,000,000 people starting out in life, 407,000 will die, almost all from disease, before reaching the age of forty-one."^[1] We are losing yearly in this country over 302,806 children under five years of age.^[2] There certainly is no "use" in this.

A recent writer^[3] has actually cited mortality statistics to prove the futility of vivisection. The figures do show that in England since 1850 certain organic diseases have been on the increase, despite the slight advance in our knowledge of them. At first blush this table given by Leffingwell strikes one as a serious argument against the utility of research. On closer inspection, however, it only reveals the astute cunning of this author in the selection of his diseases. Almost without exception these maladies lie very deep in the hereditary tendencies of the race, and we could not expect them to be checked and reversed in so short a time. With increase of wealth and advance in civilization the chance that defectives may leave enfeebled progeny is greatly increased, and that there has not been an even greater increase in these diseases is cause for congratulation. But even if the statistics would support the significance Leffingwell attaches to them, what are we to do about it? The only courageous course would seem to be to acknowledge the extreme difficulty of the problems involved and attack them with redoubled energy. Over two thousand years of clinical observation and empiricism have probably about exhausted possibilities in these directions, so that our only hope would seem to lie in experiment; and the less preliminary experimenting on men, the better. If Leffingwell had been able to prove from statistics that there is no curable disease in the world, he would have had a strong argument. As it stands, however, it must be acknowledged to be the strongest possible argument for the side of research.

The chief point of unfairness of the table lies in Leffingwell's selection of diseases. Why confine attention to statistics of organic disease? In acute diseases, where we would naturally look for the first fruits of scientific work, the gain has been considerable.

In support of this, we may quote a few passages from Newsholme's Vital Statistics. On page 273 he says: "If these children" (the 858,878 born annually in England) "be traced through life, the changes in the death-rates occurring 1871-1880, as compared with 1838-1854, would result in an addition of 1,800,047 years of life shared among them; and since this number of births occurs annually, it may be reasonably inferred that there is an annual addition of nearly 2,000,000 years of life to the community, the greater share in which must be ascribed to sanitary measures. . . . In the decennium 1871-1880, the death-rate from fever fell from an annual average of 885 per million to 484, a decline of forty-five per cent" (page 183). For scarlet fever the decline between 1875 and 1885 was forty-nine per cent (page 185).

From tables, page 101, we see that the death-rate per 1,000 in 1838-'40 was, for males, 23·3; in 1887, only 19·8; for females, in 1838-'40, 22·5; in 1887, only 17·8.

From comparing death-rates for the ten years before and after 1872, the year of the passage of the Public Health Act, we find that "no less than 392,749 persons who, under the old régime, would have died, were, as a matter of fact, still living at the close of 1881. . . . Add to these saved lives the avoidance of at least four times as many attacks of non-fatal illness, and we have the total profits as yet received from our sanitary expenditure" (p. 127). "We may add that if the death-rates between 1881-1888 are included, the improvement becomes even more striking." Thus:

		Record of years		Mean annual death- rate per 1,000
Public Health Act, 1872.	Ten	years,	1862-'71		22·6
	Four	"	1872-'75		21·8
	Five	"	1875-'80		20·79
	"	"	1881-'85{		19·30
			1886		19·8
			1887		18·9
			1888		17·83[4]
For Boston,			1892		23·3
⁠"⁠London,			1887		19·6
⁠"⁠Lowell, Mass.,			1892		26·6
⁠"⁠Massachusetts,			1892		20·6[5]

We are frequently met here by the statement that improved sanitary measures have nothing to do with vivisection. But, in order to gain the passage of costly sanitary measures, sound reasons must be given; these are drawn almost wholly from the pure sciences of physiology and hygiene, and in just those points which bear on public sanitation science owes much to experiment as an essential part. The truth of this we shall see more and more clearly as we proceed.

The most encouraging feature in the comparison of the new with the old tables of vital statistics is the decrease in child mortality. Newsholme, page 101, gives tables of annual death-rates by age-groups from 1838 to 1887. From this we see that whereas in 1838-'40, in every thousand infants born, 72·6 died under five years of age, in 1887 only 57·8 were lost—a gain of over twenty per cent. Abbreviating the table, we have, per thousand births:

Age—	to 5 years.	5 to 10 years.	10 to 15 years.
1838-'40, died	72·6	9·7	5·3
1887, died	57·8	4·9	2·9
⁠A gain of	20·5	49·5	48·2

These things give us ground for courage and hope, but not for rest—not as long as diphtheria is annually taking from the homes of this country its 49,677 children; not while fevers are yearly "baking to death" 126,332 of our people; and while consumption is causing years of suffering and the loss annually to this country of 102,199 valuable lives.

Were this wholesale slaughter the work of a national enemy or of visible wild beasts, the public would not be slow in its appreciation of any attempt to meet the common foe. But the struggle is none the less real, and the intelligence and often the courage and self-sacrifice required to carry it on are no whit less than in the struggles of a race to subdue a savage continent or a human enemy. With the conquest of all the continental areas assured to man, if war, according to the hopes and theories of some, were a thing of the past, the next great step in the development of the race must be this conquest of the forces of disease. A comparatively small branch of the human race has come to face the issue squarely on experimental lines, and to realize the fact that success can be achieved in no other way. The fate of the Hindus stands as a warning that even an Aryan strain may lapse into the abject imbecility of zoölatry and mysticism. The race that meets this stupendous issue, that succeeds in giving to men the laws by observance of which can be attained, not only freedom from disease, but also the development of the highest type of man, that race alone can carry out to its full perfection the evolution of mankind. In course of its development this race will be able to bestow incalculable benefits upon other races and upon even the animal species which it finds useful to preserve.

 

IV.—THE ARGUMENT AS TO THE UTILITY OF VIVISECTION IN SPECIAL CASES.

Attempts to prove or disprove the utility of vivisection by special cases have needlessly complicated and embittered the discussion. Matters involved in the warmest medical controversy have been freely introduced, and naturally an abundance of strong language has been at the disposal of either side. It must therefore be distinctly understood as we proceed that this is not the place to settle medical controversies nor to write a complete history of useful medicine. We are to deal not with medical controversy nor with medical history, but with pure argument—argument to prove from special instances the use to humanity of vivisectional methods of investigating the processes of living Nature. This being our purpose, we must leave to experts all discussions of such things as antitoxine, hydrophobia inoculation, etc., and confine our attention to cases about which there is the least medical controversy and about which people generally agree. We will thus select classical cases, the older the better, and only so many as will serve to render the argument clear and to illustrate best the methods of vivisectional work.

The special cases of Harvey, Charles Bell, Magendie, and Claude Bernard have come to be an established feature in every discussion of this subject, and so many wrong impressions regarding them remain uncorrected that we must consider their work at some length,

A knowledge of the circulation of the blood, no intelligent person can deny, has been of great practical value to men. It affords a foundation for all laws of hygiene and for the practice of surgery and medicine.

The first great step in the line of this discovery was made by Galen. "By ligating in a living animal an artery in two places, and opening the vessel between the ligatures, Galen demonstrated that the vessel contained blood. Thus by an experiment upon a living animal, a vivisection, the first great source of error, the supposition that the arteries contained air, was removed, the true nature of an artery demonstrated, and the modern theory of the circulation made possible."^[6]

Whatever may be the claims of Servetus and Cæsalpinus, there can be no doubt that the one man to unite the observations of his predecessors into an intelligible whole, to found his own observations upon experiment, in short, to discover the circulation of the blood as we now understand it, was William Harvey.^[7]

The claim is often made that Harvey discovered the circulation by "thinking," by "inductive reasoning," and not by vivisectional experiment. As well say that Columbus discovered America by thinking and not by experiment. Harvey not only thought out the circulation, which is a very small matter, but he demonstrated it to be a fact by innumerable experiments upon living animals, which is a very great matter. Here, again, we must emphasize the fact that Harvey did not study, and could not possibly have studied, in dead animals "the motion of the heart and blood in animals." To found his great thesis on a broad basis of experiment, Harvey vivisected a great many kinds of animals, from his own person to "shrimps, snails, and shellfish."

⁠Chapter I of Harvey's great work, De Motu Cordis et Sanguinis in Animalibus,^[8] begins, "Cum multis vivorum dissectionibus (uti ad manum dabantur) animum ad observandum primum appuli quo cordis motus usum," etc.
⁠Chapter II is entitled Ex vivorum dissectione, qualis sit cordis motus.
⁠Chapter III is entitled Arteriarum motus qualis ex vivorum dissectione.
⁠Chapter IV is entitled Motus cordis et auricularum qualis ex vivorum dissectione.

The argument that Harvey was led to his discovery by "reasoning upon the valves in the veins," as stated by Boyle, is well answered by his translator, Willis,^[9] who points out at some length that "when we turn to Harvey himself, in his works we nowhere find that he approaches his subject from the quarter now particularly indicated" (i. e., from the purpose of the valves in the veins).

Even Harvey was attacked during his life on the ground that the discovery of the circulation was of "no use" (Willis, p. 358), "because men still continued to die."

For Harvey the blood passed through the flesh (per partium porositates), and not until the microscope was available was it possible for Malpighi to discover the capillary circulation in 1661. This he did in the exposed lung of a living frog.

In recent years Claude Bernard^[10] greatly advanced our knowledge of the circulation by demonstrating, wholly by vivisectional methods, that the flow of the blood is regulated by a nervous mechanism continuously acting to contract or dilate the vessels according to the requirements of each organ or part of the body. Thus it is seen that every important step in the advance of our knowledge of the circulation of the blood has been made by vivisection and could not possibly have been made in any other way.

Similarly, the testimony of Sir Charles Bell is constantly adduced to prove the futility of vivisection. Bell is the anatomist to whom, with Magendie and Johannes Müller, we owe the first great advance in the experimental study of the nervous system. He first demonstrated, though in no thoroughly satisfactory manner, the twofold function of the spinal roots. It is true that Bell did say some things derogatory of physiological experiment about the beginning of this century. But it is also true that his actions speak louder than his words. By reference to his works, we find that Bell made this great discovery in the only way possible—viz., by means of vivisectional experiments. He actually vivisected asses, kittens, rabbits, fowls, monkeys, and dogs, performing the same experiments for which Magendie has been so severely criticised.^[11] Charles Bell was exceedingly sensitive upon the point of causing pain to animals, as is shown by several passages in his works; and it is certainly a strong argument for the necessity of vivisection that a man of his sensitive nature should be compelled to resort to this method in order to demonstrate the truth of his theories. It must be remembered that he had no anæsthetics, and therefore his position can not apply to the present discussion of the subject. Were he operating to-day, with chloroform, ether, morphine, chloral, paraldehyde, cocaine, and other anæsthetics at his disposal, he need have had no twinges of conscience about the pain his experiments occasioned.

Magendie completed Bell's work, placing it upon a firm basis by means of experiments for which he has been accused of most atrocious cruelty. It is sufficient to reply that Magendie, too, worked before anæsthetics were discovered, and when people's ideas about physical pain were very different from our ideas at present. And Magendie was, to say the least, as oblivious to his own suffering as he was to that of the animals he experimented upon. When cholera broke out in France, in 1832, he went as a volunteer into the center of the afflicted district, and afterward served in the great cholera hospital, the Hôtel Dieu, during the epidemic in Paris, and for his heroism received the cross of the Legion of Honor^[12]—"The fiend Magendie."

Take, for example, another great line of physiological work than which few discoveries have been of more practical value to human life. Upon a knowledge of the physiology of respiration we build and ventilate, or ought to, at least, dwelling and school houses, audience rooms, and hospitals.

The first important discovery in this line was made by Sir Robert Boyle (1670), who found, by the use of his air pump, that if he deprived animals of air they died. He vivisected in this way kittens, birds, frogs, fish, snakes, and insects.^[13] Boyle also discovered that by keeping animals in a closed reservoir the air became unfit to sustain life.

Priestley, a century later (1772), continued Boyle's experiments by keeping mice in air-tight receivers until the air was vitiated and would no longer support life. He then tried to restore the air to its former condition: he rarefied and condensed it, heated it, exposed it to water and earth, and treated it in many other ways, each time testing it with living mice to ascertain whether it would again support life. All this was to no effect. In every case the mice died. Finally, he found that after plants grew for a while in the vitiated air, mice could again live in it. Thus was discovered the important relation between animal and vegetable respiration, and we now plant trees and lay out parks, and call them the "lungs of our cities." Two points must be emphasized here: first, that Priestley could not have done this with dead mice; and, second, that no one except Lawson Tait and Miss Cobbe would have the hardihood to claim that he ought to have used live men instead of live mice, on grounds of moral rights, and from the fact that the physiology of man is "so different" from the physiology of the mouse.

Turning to still another important line of scientific work, diseases of microbic origin are said to cause four fifths of the sickness in the world. As an example of researches in this field, we may cite the classical work of Edward Jenner.^[14]

Jenner began to study in earnest the disease cowpox, and its relation to smallpox, in 1775. For twenty-one years he patiently investigated the subject, and found that no one who had once suffered an attack of cowpox was taken with smallpox, although frequently exposed. "Legends of the dairymaids" had told for generations that an attack of cowpox conferred exemption from smallpox forever after. Jenner might have told the same story; but, if he had not proved the truth of his assertion by experiment, we might still have nothing but "legends of dairymaids" and no vaccination.

In May of 1796 Jenner began his experiments. He says (page 29): "The more accurately to observe the progress of the infection, I selected a healthy boy, about eight years of age, for the purpose of inoculation for the cowpox." This inoculation was followed by an attack of the disease. But Jenner does not stop here. Again, he says: "In order to ascertain whether the boy was secure from the contagion of the smallpox, he was inoculated the 1st of July following with variolous matter immediately taken from a pustule. Several punctures were made in both arms, and the matter was carefully inserted, but no disease followed."

Some might have called the discovery complete at this point, but Jenner realized that one case is not every case, and that he must repeat the experiment, which he did scores of times, even going so far as to endanger human life in order to establish the truth of his discovery. For he goes on to say (page 41): "To convince myself that the variolous matter made use of was in a perfect state, I [at the same time that he inoculated a patient previously inoculated with cowpox] inoculated a patient with some of it who had never gone through the cowpox, and it produced the smallpox in the usual regular manner."

Previous to the introduction of vaccination in London the average annual death-rate per million from smallpox was (Newsholme, table, page 192):

1728-'57		4,260
1771-'80		5,020
1801-'10		2,040	beginning of Jenner's work.
1872-'82		262
1885		1,419
1886		24
1887		9

Germany now has the most efficient laws of probably any country for making not only vaccination but repetition at stated intervals obligatory. As a result smallpox is rapidly disappearing. In 1888 the deaths from smallpox in the entire empire amounted to one hundred and ten, less than 2·5 per million, and the majority of these occurred on or near the boundaries of other countries. We can easily appreciate the usefulness of this. Still, during this work Jenner was persecuted and abused.

Jenner's experiments belong to the class of investigations which since 1850 Thiersch has made for cholera. Lister for inflammation of wounds, Pasteur for rabies, Koch and Pasteur for splenic fever, M. Freire for yellow fever, Koch later for cholera, and has now begun to make for consumption.

Thiersch's experiments on cholera, which caused the death of fourteen mice and proved that cholera is communicated by swallowing particles of cholera discharge, have been an important factor in the sanitary legislation of every civilized country.

Two of the London water companies experimented with cholera-polluted water upon 500,000 people, causing the death of 3,476 human beings in 1853-'54. This is the popular accidental experiment which antivivisection writers tell us to wait for, and which they say is sent by Providence to teach men physiology. Thiersch made the same experiment upon fifty-six mice, the conditions being accurately determined and scientifically controlled, and with the death of fourteen mice gave the world more exact information about the contagion of cholera than all the cholera epidemics recorded in history. This is the scientific experiment which we are told should not be made.^[15]

The antiseptic method, which we owe in so great a measure to the vivisectional experiments of Joseph Lister, is past all reasonable controversy and we may refer to it here. It has come to be used in hospitals generally, and has reduced mortality from surgical operations to one tenth of what it was before. Any one who has seen even a few cases of antiseptic surgery will readily agree with Dr. Keen when he says: "Sir Joseph Lister has done more to save human life and diminish human suffering than any other man of the last fifty years."^[16] Still, Lister was obliged to leave England to continue experiment in his merciful work after the passage of the restrictive law in 1876.

In the Tübingen Hospital died from amputation before introduction of Lister's method and after:

	Per cent.	Per cent.
Of lower limb	43·5	3·2
Of upper limb	30·6	2·9[17]

We might extend much further the list of useful discoveries which have depended for some essential part of their development upon vivisectional experiment; but such is not our present purpose. The reader can find these amply discussed elsewhere. We would, however, at this point call special attention to the way in which a discovery of this kind is received. Jenner's smallpox inoculation was obliged to run the same gantlet of popular and professional favor and disfavor as Lister's discovery, as Koch's and Pasteur's are running now. Such discoveries are in even greater danger from ignorant and enthusiastic supporters than from learned opponents. The problems involved are very complicated. Exceptions of every kind occur—e. g., a person may have smallpox twice, and so, although vaccination protects in most cases, it does not in all; and, further, as Jenner himself says, "inoculation sometimes under the best management proves fatal."^[18]

In the case of one of these complications in London, Jenner has himself left a record in strong English of the way he felt. Writing to Moore in 1811 he says: "The town is a fool, an idiot, and will continue in this red-hot, hissing-hot state about this affair until something else starts up to draw aside its attention. I am determined to lock up my brains and think no more pro bono publico, and I advise you, my friend, to do the same, for we are sure to get nothing but abuse for it."^[19]

We are, however, discussing the utility of a method, and while we will not introduce Koch's treatment as an argument for the utility of vivisection until it has been perfected and the medical profession has reached a decision as to its value, we can hardly find a better example of the vivisectional method. Koch's method is that of Jenner perfected by using animals instead of men. His discovery in 1883 of the tubercle bacillus has already become of inestimable value in directing sanitary measures and in recognizing the earlier stages of consumption while cure is possible. This, we are told by an antivivisection writer, "was discovered by the microscope, not by vivisection."^[20] How did Koch make this discovery?

It is true the microscope assisted as spectacles help to read. But Koch, in the examination of tuberculous matter, discovered a number of germs with the microscope. Which one of these caused consumption no number of microscopes could tell him. This had to be settled by most careful experiments. There are several steps in the process. The first is to identify all the different kinds of microbes found constantly in tuberculous bodies. For convenience we will call these microbes a, b, c, d. These are mingled together. The second step is to cultivate these germs in one test tube after another until perfectly "pure cultures" are obtained—i. e., nothing but a's in one, nothing but b's in another, and so on. Up to this stage he has not the least idea which of these is the germ of consumption. The only way he can determine this point is by experimenting upon living animals. He must then inoculate a number of healthy animals, one with germ a, another with germ b, another with germ c, another with germ d. The four animals are now watched carefully. The animal inoculated with germ a, we will say, sickens and dies with unmistakable symptoms of tuberculosis. Those inoculated with germs b, c, and d are not affected. He repeats the experiment several times, and if each time with the same result is justified in concluding that germ a is the cause of tuberculosis, while the other germs are harmless.

This is but the first stage in the investigation. After the discovery of the cause comes the question, How can this cause be controlled? How can its action be prevented? Here, as Koch says, men have begun at the wrong end of the problem. Since the beginning of medicine the doctors have been experimenting upon men to find a cure for consumption. The problem here is too complicated, and in consequence little has been learned. Experiment must begin, he says, with the bacillus itself. We must grow it first in pure cultures in test tubes, in all manner of different culture media and under all conditions of temperature and light, in order to ascertain under what conditions it grows best and under what conditions it can not grow. We must next subject it in the test tube to the influence of different chemical substances, and when some compound is discovered to Mil or hinder the growth of the bacillus in the culture, then the substance must be tried upon tuberculous animals to ascertain whether in their bodies as in the test tube it will act to kill the bacilli without injuring the animal. When a substance fatal to the bacillus and harmless to the animal is found, with all due allowance for differences between the animal and man, it may be tested on man.

This, in brief, is but one important line of research, and clearly it should be carried out thoroughly for every infectious disease. A single link in the chain of procedure requires absolutely to be welded by experiments upon living animals. With millions on millions of human beings and animals suffering and dying yearly for lack of this knowledge, no truly humane person can for a moment deny to an investigator the right to complete his work by introducing this link.

In view of the stupendous values involved it is clear that any amount necessary of animal or human sacrifice and suffering is wholly justified. Whether unnecessary suffering is inflicted is a question which only the highest experts can adequately decide. Prof. Bowditch^[21] has so thoroughly discussed the subject of pain caused by vivisection that we would pass it by without mention, were it not for the fact that the public mind has been of late so much abused by misstatement and exaggeration on this head. Prof. Yeo's estimate, the most reliable we have, is that in every one hundred experiments seventy-five are "absolutely painless," twenty are as "painful as vaccination," four, as "painful as the healing of a wound," one, as "painful as a surgical operation." The pain of vaccination is altogether trifling, and that of the healing of a wound after antiseptic treatment is also practically nil. This leaves but one per cent of all experiments as painful to any serious degree. During over ten years' active experience in three laboratories in this country and a number of the leading laboratories abroad, I have never had occasion to perform or witness an experiment of this painful class. Discovery of new anæsthetics and more recent methods of operation have doubtless reduced the pain of experimentation even below Yeo's estimate. In all laboratories in this country, and equally abroad, I have always found anæsthetics adequately and uniformly employed.

In the recent discussions before the House Judiciary Committee of Massachusetts upon the bill relating to inspection of vivisectional experiments in the medical schools and universities of the State, none of the petitioners for the bill were able to cite a single case, or the reasonable suspicion of a case, of abuse of vivisection, as having occurred within the State of Massachusetts, In order to obtain as reliable data as possible upon this point, I sent blank tables, arranged according to the table below, to all the laboratories in Massachusetts where vivisectional experiments were likely to be made. Returns were kindly sent in from all the laboratories, and may safely be taken to represent the experimental work in the State during the year 1894-'95.

Animal	Number used.	Painless.	Painful as
			Vaccina- tion.	Healing of wound.	Effect of poison.	Disease.
Frogs	866	845	4	. .	17	. . .
Pigeons	23	19	. .	4	. .	. . .
Rats	25	25	. .	. .	. .	. . .
Rabbits	146	61	50	. .	5	30
Guinea-pigs	465	. .	150	. .	. .	315
Cats	22	18	. .	. .	4	. . .
Dogs	95	91	. .	2	2	. . .
Mice	30	10	. .	. .	. .	20
Squirrels	3	3	. .	. .	. .	. . .
⁠Totals	1,675	1,072 (64%)	204 (12·2%)	6 (0·4%)	28 (1·6%)	365 (21·8%)

Contrast with this the 34,419 human beings who die of disease annually in Massachusetts.

A general principle underlying vivisectional work is also revealed in the table, viz., that the lowest animal adequate for the purposes of the research be employed in preference to one more highly organized. This entirely negatives an assumption often advanced that animal vivisection tends toward human vivisection. The whole tendency of modern physiology has been exactly the reverse. Animals have come to be used in order to save human beings from abuse.^[22] In the very beginning of medicine every attempt to cure disease or alleviate suffering must have been, in the nature of the case, an act of human vivisection. A large proportion of modern medicine at present is equally in essence nothing more nor less than human vivisection, and it is only gradually, as elements of experiment and uncertainty are eliminated from remedial measures by more exact knowledge, that the practice of medicine becomes anything more than human vivisection.^[23]

A further argument against the utility of animal experimentation is based on differences between animals and men, which make it unsafe to apply results directly from the animal to man. A logical error is here involved; for, while there are physiological differences between different animals, to one point of difference there are many points of close similarity. A difference in physiological function is technically known as an idiosyncrasy. These differences exist between individual men as well as between different species of animals. A man who has had smallpox or measles acquires an idiosyncrasy which protects him from having them again. In some cases this difference exists from birth; in others it is impossible to acquire it. Man himself begins life as a microscopical speck of living matter, and in his physical development passes through and beyond the lower stages of organic life. Hence the fundamental physiological processes and functions he has in common with the great body of living things beneath him. On this wider view physiological idiosyncrasy becomes the strongest possible incentive to experiment. How is it that certain species have become wholly immune from certain diseases? With the secret of this immunity discovered, it may be easy to induce a similar immunity in another species or in man.

The conclusion which follows from the foregoing chapters bears directly upon a topic of considerable present importance, viz., that of legislative interference with scientific work.^[24] With due appreciation of scientific achievements in the past, we must keep ever before us the fact that the hardest labors and richest harvests in science are still in the future. And every consideration of religion, morality, altruism, humanity, and utility urge to

the prosecution of physiological education and research with unabated energy. Hence no legislative action should be taken which could possibly offer hindrance or annoyance to either teachers or investigators.

In accordance with the pernicious principle that a law can do no harm except to offenders, the English Parliament, in 1876, passed an act severely restricting vivisectional work. This action of England was promptly reversed by every other European nation where the subject was agitated, and by every State Legislature in this country to which the matter has been referred. Within the past year this reversal has been reaffirmed in Switzerland and in Massachusetts. The restrictive act in England served not in the least to abate the agitation and protect physiologists in their work, as was intended; but, as an eminent English physiologist puts it, has "only tended to encourage the opponents of science in their vexatious interference." English antivivisectionists under this encouragement have shifted position from restriction to total abolition, and have increased the agitation. We have in this country at least three societies organized on the platform of total abolition of physiological experiments. The legislative measures advanced thus far by these organizations have been mild in the main; but while they emphasize before the public the fact that their laws do not aim to "prohibit" experiments, they are also unguarded enough to speak of them as "the entering wedge for more radical measures in the future."^[25] Clearly, for medical and scientific faculties, for medical societies, and for all who have at heart the advancement of humanity and science, the strategic point at which to meet the enemy is the point of "the entering wedge."

After conscientiously reading their literature for the j)ast five years I feel warranted in saying that science has little to fear from the efforts of the antivivisection societies. Their methods of agitation would sink even a worthy cause. The real danger lies with scientific men themselves who entertain ideas of conciliation and compromise which will admit the point of the "entering wedge." Prof. Michael Foster has had the benefit of twenty years' experience in conducting a laboratory under restrictive legislation, and his advice should certainly carry great weight. He writes as follows: "My earnest advice" (to us in America) "is to straighten your backs, and, knowing that no legislation is necessary on grounds of humanity, and that all legislation is bad for science, strain every effort to defeat the agitation."^[26]

1. Albert Buck. A Treatise on Hygiene and Public Health, vol. ii, pp. 328, 329.
2. Tenth Census Compendium, p. 1707.
3. Albert Leffingwell. Vivisection, p. 75, Boston, Mass., 1889 (date of introduction).
4. Arthur Newsholme. The Elements of Vital Statistics. London, 1889.
5. A Summary of the Vital Statistics of the New England States for the Year 1889. Boston and London.
6. H. C. Chapman. History of the Discovery of the Circulation of the Blood, p. 12. Philadelphia, 1884.
7. Read J. H. Baas. Outlines of the History of Medicine. New York, 1889, pp. 527-530. Also Sprengel, in his Geschichte der Arzneykunde, gives Harvey the frontispiece in vol. iv, and devotes forty pages (50-89) to his work of discovering the circulation of the blood. Also Haeser, Lehrbuch der Geschichte der Medicin, vol. ii, pp. 252-262, devotes eleven pages to "Discovery of the Circulation, Harvey." And when a man comes forward and says, "It is only our insular pride which has claimed for him the merit of the discovery," he brands himself as a person with whom it is impossible to reason (as does Lawson Tait, Uselessness of Vivisection upon Animals, p. 6). Any one desirous of investigating the trustworthiness of Tait in such matters can find him fully discussed, in a way he has not been able to answer, in the book Physiological Cruelty, by "Philanthropos," Appendix E» and also in Heidenhein, Vivisection, Leipsic, 1884, pp. 85 if.
8. Harvei Opera, 1737, or The Motion of the Heart and Blood m Animals. Sydenham edition, London, 1847.
9. Willis. William Harvey, a History of the Discovery of the Circulation of the Blood. London, 1878, pp. 301 ff.
10. Cl. Bernard. Leçons sur le Diabète. Paris, 1877, p. 43.
11. Charles Bell. Idea of a New Anatomy of the Brain. London, 1811. Transcribed by H. U. D., 1813. Also, Nervous System of the Human Body. London, 1830.
12. J. C. Dalton. Magendie as a Physiologist. International Review, February, 1880, p. 120. The story of Magendie's repentance and distrust of vivisection, shortly before his death, has often been adduced against this method of research. After careful search through all the accounts of Magendie's life (thirteen in number), Dalton is able to say that there is no intimation of any ground for this idea.
13. Boyle. Philosophical Transactions, vol. v, pp. 2011-2055.
14. Edward Jenner. An Inquiry into the Causes and Effects of the Variolæ Vaccinæ, December 20, 1799, London, 1801.
15. John Simon. Experiments on Life. London, 1881.
16. W. W. Keen. Our Debts to Vivisection. Reprint from Popular Science Monthly, May, 1886, p. 15.
17. Heidenhain. Die Vivisection, p. 34.
18. Jenner, loc. cit., p. 57.
19. Crookshank, op. cit., fol, i, p. 139.
20. Ernest Bell, M. A. Weighed and Found Wanting, Victoria St. Society publication.
21. H. P. Bowditch. The Advancement of Medicine by Research. Science, July 24, 1896.
22. The recent action of Dr. J. S. Pyle (A Plea for the Appropriation of Criminals condemned to Capital Punishment to the Experimental Physiologist, Canton, Ohio, 1893), so far as I have been able to ascertain, is an individual matter, and can not be taken to represent in the slightest degree the tendency of experimental medicine or the attitude of experimental physiologists in this country.
23. The Zend-Avesta permitted a doctor to practice his art upon three heretics. If these all died or were made worse by his treatment, he was forbidden, on penalty of death, to follow his profession further. If they recovered, he might begin practice upon the faithful.—Sprengel. Geschichte der Arzneykunde, vol. i, p. 126. (Refers to Zend-Avesta, Part III, p. 336.)
24. For fuller discussion of this topic see Bowditch, he. cit., pp. 8-16, and appendix.
25. Antivivisection, June, 1896, pp. 9 and 13. Aurora, Ill.
26. Private letter from Prof. Foster to the writer, under date of February 1, 1896.