# Popular Science Monthly/Volume 16/March 1880/Correspondence

CORRESPONDENCE.

Messrs. Editors.

IN a good but caustic review of Mr. Mallock's book—"Is Life worth Living?"—you make use of a sentence which would seem to reflect on all alike who are engaged in the study of theological problems: "We have here the last brilliant exploit of the theological mind in its warfare with modern science." Permit me, as a student of theology and a lover of modern science, to read you a short lecture. Many of the young ministers to-day are firm believers in evolution, and preach it. This theory is by no means a hindrance in our study of theology, but the best instrument which has so far been placed in our hands. If on our desk the Bible lies, so also do Spencer's "First Principles" and his "Sociology." If we respect and study Jesus, so do we Spencer and Tyndall and Clerk Maxwell. These have a gospel for us—they have a hope. The young theological mind is very far from engaged in a warfare with science; it is anxious, and hoping, for firmer ground than we now have. If science can help us, and it can and does, in making this life more valuable, the future brighter, and ourselves better, we welcome it. We are not troubled about reconciling theology and science; we take what we can in both, after honestly and carefully investigating for ourselves, and then allow them to reconcile themselves. What we have to do with is the truth pure and simple. Some of us will not pledge ourselves to any "body of divinity," either ancient or modern; we will not swear by Bibles, old or new, nor believe all the spirits, either in the Gospels or the biologies. The writer of the preface to the American edition of Spencer's "First Principles" tells us that his hope is in the young men. Many of them are with him. We now only ask you to remember this, and let us investigate in our own fields, mindful of the fact that we are each doing our best to find the truth. We are side by side oftener than we imagine, even if some college presidents will not see it. None are so blind as those who will not see.

It would not be out of place if in the "Monthly" you would give an article, now and then, bearing directly on the theological questions—the higher theological questions, not the petty disputes of the sects.

 ⁠You have our hand. A Young Theologian.⁠ ⁠Keene, N. H., January 21, 1880.

THE AGE OF ICE

Messrs. Editors.

An article under the above title, published in the October number of the "Monthly," appears to have brought upon its author the charge of plagiarism. But his own note with the accompanying editorial, published in the February number, not only completely exonerates him, but actually converts the charge into an encomium. For the writer of the article in question can scarcely fail to appreciate the compliment of being charged with borrowing, from so reputable an author, ideas which prove to have been made public before the able work of Mr. Croll had seen the light.

But, if the accusing party had carefully and understandingly read the article of Mr. Norton as well as those which he charges Mr. Norton with plagiarizing, he would never have made the charge. For he would have discovered in the former article statements quite excusable, when the date of their writing is known, but which would never have been made had Mr. Norton read cither the work of Mr. Croll or the articles of Mr. Merriman. The object of the present writing, however, is neither to vindicate nor to criticise.

But, since the "Monthly" is almost solely relied upon by so many readers as an exponent of the latest scientific discoveries and opinions, the publication of Mr. Norton's article, so long after it was written, seems liable to mislead this class of readers. The conductors of the "Monthly" may not, therefore, deem it inappropriate to give place in their columns to a very brief statement of the points in which the article is likely to convey an erroneous impression:

1. In the published abstract the author says: "The southern hemisphere has at present a winter of 187 days and a summer of 179 days. We may justly infer that during this winter more snow and ice accumulate than the shorter summer is able to melt."

In the lecture this statement may have been accompanied by such an explanation as to prevent a misconception; but, as published, it must leave on the popular mind the impression that, because the summer is shorter, therefore the heat received from the sun is less—an impression which many have received; whereas it was long since shown that the earth receives from the sun exactly the same amount of heat from the vernal to the autumnal equinox as from the autumnal to the vernal, whatever may be the position of the apsides, and whatever the eccentricity of the orbit.

2. In speaking of the variation in the eccentricity, the author says: "There is one more factor in this problem which must be considered, and that is the periodical variation in the eccentricity of the earth's orbit. Sometimes the line of the apsides is longer than at other times."

I am at a loss to account for this last statement. The author must have known that the mean distance of a planet from the sun is one of the two invariable elements of the planetary orbits. Of course the line of the apsides, which is the major axis of the orbit, and therefore twice the mean distance, can not vary. The eccentricity is increased or diminished by diminishing or increasing the minor axis, the major axis remaining always the same.

3. In discussing the displacement of the earth's center of gravity by an accumulation of ice at the pole, it is said, "Now push the center of gravity 2,000 feet toward the north, and the Arctic Ocean would be so much deeper over the pole, and the water would be about 1,000 feet deeper at the latitude of 45°. To accomplish this result, we must calculate that the space within the Arctic Circle was covered by an ice-cap averaging, perhaps, 8,000 feet in thickness—an entirely supposable case."

By calculation, I find that, if all the water to form this ice-cap were taken from within the Antarctic Circle, and if the density of ice were equal to that of the earth, the above statement would be approximately correct; but, allowing for the difference of density, the cap must be more than eight miles in thickness; and, if the water to form the cap were taken equally from all parts of the earth's surface, the thickness must be more than sixteen miles.

Perhaps it should be said, however, that, according to Mr. Croll, no such amount of displacement is required. He estimates that the transfer of an ice-cap two miles thick from the southern to the northern hemisphere, which would displace the center of gravity about 380 feet, would satisfy all the demands of the glacial phenomena.

4. But, if Mr. Norton's article should be received as an exponent of the present views of those who advocate this theory, it would be most seriously misleading in the date to which it refers the age of ice. It is said: "Unless astronomical calculations fail, the last great summer of the northern hemisphere commenced some 6,500 years ago. When it began, northern America, Europe, and Asia were frozen and deluged. The Arctic Ocean extended to a line south of the present bed of the Great Lakes. The Alps and the Altai were also southern boundaries of this ocean. Europe was the home of a swarthy, dwarfish race, who hunted the aurochs and great hairy mastodon at the foot of the glaciers that then half overflowed the continent."

Thus the age of ice is referred to the last mild aphelion winter, when the earth's orbit was but slightly more eccentric than at present. But both Mr. Croll and Mr. Merriman, from whom Mr. Norton is accused of plagiarizing, refer the glacial epoch to a period of great eccentricity, from 80,000 to 240,000 years ago.

Indeed, the warmest advocates of the great year theory freely admit that, with the eccentricity no greater than it has been at any time within the last 80,000 years, the age of ice could not have been the reuslt of such a cause. It scarcely need be added that some refer the ice age to a period of still greater eccentricity, some 800,000 years ago

 M. Lyford.⁠ ⁠Waterville, Maine, January 26, 1880.

ARSENIC IN KINDERGARTENS.

Messrs. Editors.

There has been of late, in the local newspapers, a good deal of discussion, pro and con, concerning the merits and demerits of the Kindergarten system. Without presuming to decide whether the system is good or bad, I wish to bring under the notice of your readers a simple fact in connection with it that is of more than local interest. A friend of mine in Pittsburg, who has a little daughter being instructed (or amused) in one of the Kindergartens here, recently handed me some pieces of a green-colored paper which the child brought home from the institution, and told me that one of the amusements of children in such institutions was to cut figures out of various colored papers and fashion them into designs of different kinds, the aim of such amusements being to instruct in distinguishing various shades of color and differences of form. The green paper above mentioned I have very carefully examined, and I find that it contains an abundance of arsenite of copper, which most people nowadays 'know to be poisonous. In these days of reckless assertion by pretended men of science, it may be well to fortify my statement, and I accordingly send you two hermetically sealed tubes, one of which contains a mirror of metallic arsenic, and the other a ring of crystals of arsenious acid, both of them derived from the green paper, of which I also send you a sample. Several mirrors were obtained from a fragment of paper half the size of the piece inclosed, and material enough was procured from it to produce several more. The crystals can be recognized, under a three-hundred power of the microscope, as octahedra. Knowing well that such paper is used in all other Kindergartens throughout the country, and knowing also the habit of children putting everything available in their mouths, and especially of swallowing paper, I think the use of a sort colored with an arsenical pigment deserving of the severest reprehension. You may, if you please, show these tubes to any of the able chemists of your city, or describe them as you may see fit.

 Yours truly, ⁠George Hay, M. D., Analyst, Analytical Laboratory. 45 Diamond St.Alleghany City, Pa., January 16, 1880. ${\displaystyle {\begin{matrix}{\big \}}\end{matrix}}}$