Popular Science Monthly/Volume 28/March 1886/Sketch of Sir John Bennet Lawes
|SKETCH OF SIR JOHN BENNET LAWES.|
IN John Bennet Lawes, said "Nature," more than ten years ago (December 9, 1875), "we have a private individual who, unaided by the state, or by any scientific body, has made a greater number of useful experiments than all the experimental farms of European governments put together." The work referred to in such terms of praise was performed on Mr. Lawes's private estate at Rothamstead, in Hertfordshire, England, to which he succeeded as heir in 1822, being eight years of age, and on which he began his famous experiments in 1834, when he entered upon actual possession of it.
Mr. Lawes was born in 1814, and acquired his school education at Eton College and Brasenose, Oxford, where he was a student from 1832 to 1835. His favorite work during this time was in the laboratory; and after leaving the university he spent some time in London, in the study of practical chemistry. His situation and surroundings were particularly favorable to his giving his whole attention to the pursuit to which his tastes inclined him, and for which he had qualified himself by his studies. Possessed of independent means, a handsome property, and a beautiful old manor-house and domain of about five hundred acres, he at once interested himself in agriculture; and from the year he entered upon manhood till now, or for more than fifty years, he has been unceasingly applying his scientific knowledge to the solution of questions affecting the practice of that art. "In the commencement of his experiments," says his biographer in the London "Times," "among other subjects, the effect of bones as a manure on land occupied his attention for some time. A friend and neighbor, the then Lord Dacre, particularly directed his notice to the fact that bones were very variable in their effect on different soils. Several hundred experiments were accordingly made, some upon crops in the field and others with plants in pots, in which the constituents found in the ashes of plants as well as others were supplied in various states of combination. Striking results were gained from these experiments, in which the neutral phosphate of lime in bones, bone-ash, and apatite was rendered soluble by means of sulphuric acid, and the mixture applied for root-crops. The results obtained on a small scale in 1837-'39 were such as to lead to more extensive trials in the field in 1840-'41, and to the final taking out of a patent early in 1842. This being done, Mr. Lawes established large works in the neighborhood of London, for the manufacture of superphosphate of lime, by which name the manure is known, which has produced such a revolution in the science of agriculture."
In 1843 Mr. Lawes associated with himself Dr. J. H. Gilbert, whose name has since been connected with his in all the researches prosecuted at Rothamstead, as a practical chemist; and together they undertook a series of agricultural investigations in the field, the feeding-shed, and the laboratory. The laboratory was at first located in an old barn; but in 1854, when the friends of Mr, Lawes proposed to present him a service of plate in recognition of their appreciation of his work, he suggested that a new laboratory building would be a more appropriate and enduring as well as useful testimonial, and the money was applied for the purpose of erecting one.
The place, identified with Mr. Lawes's experiments, Rothamstead, the patrimonial estate of the investigator, is situated some twenty-five miles from London, in Herts, and is easily accessible to visitors from the Harpenden Railway station. The manor-house is described as being a remarkably fine specimen of Old English architecture, while the domain surrounding it contains some magnificent timber, including an avenue of lindens, which, for size and regularity of dimensions, are perhaps unsurpassed in the south of England. Around the family mansion lie the five hundred acres that form the experimental station, which is entirely maintained by Sir John. For the benefit of the large number of laborers whose services are required in the management of the station, Mr. Lawes many years ago formed an allotment club through which small gardens of about an eighth of an acre each can be rented. For this purpose, in 1882, sixteen acres of land had been allocated, and the whole number of allotment gardens then in cultivation was one hundred and seventy-four. The allotment area is furnished with a club-house.
The scientific discovery, says an English biographer, around which all Mr, Lawes's subsequent work centered was the disprovement of Liebig's mineral-ash theory. It was generally supposed at the time his experiments were begun that certain saline bodies; so-called mineral constituents, were essential to the growth and development of the plant, and that such substances must be furnished to it by the soil. The necessity of a certain quantity of nitrogen was recognized; but it was imagined, since wild plants could thrive without any artificial supply of nitrogen, that a sufficient amount of that element existed in the atmosphere to render it unnecessary to take any steps for increasing the supply. The cardinal discovery made by Mr. Lawes of the absolute necessity of the presence of nitrogen in the soil in order to maintain its fertility was a contradiction of this view, and led to the opening of a new field of agricultural investigation. In connection with the belief in the sufficiency of the atmospheric sources of nitrogen, it was supposed that the fertility of a soil might be maintained for an indefinite period if the different mineral constituents carried off by the crop were annually returned in duo quantity as mineral manure to the soil. Respecting these two points, and regarding the sources of nitrogen, Mr. Lawes has said: "I maintain that the amount of nitrogen supplied to our crops from the atmosphere, whether as combined nitrogen brought down by rain or that absorbed by the soil or the plant, constitutes but a very small proportion of the total amount they assimilate, and that the soil itself (or manure) is practically the main source of their supply. Indeed, it is a question whether on arable land as much or more may not be lost by drainage or otherwise than is supplied by the atmosphere." The field experiments on which these conclusions rest have formed Sir John Lawes's principal work. Favored by position and circumstances, he has been enabled to carry out on a large scale most important operations. His general plan has been to select fields in a condition of agricultural exhaustion, that is, in a state in which a fresh supply of manure was needed to fit the soil for the growth of another crop. Upon this exhausted soil each of the most important crops in the rotation was grown year after year upon the same spot, in plots without manure, and in other plots in which various kinds of manure, but usually the same to each, were applied yearly. Thus it became possible to determine the point of relative exhaustion or excessive supply of any of the constituents of the manure. The details of this method are given an exemplary explanation in Mr. Lawes's "Report of Experiments on the Growth of Barley for Twenty Years on the Same Land," published in 1874, when the experiment was still in progress. The field had been divided into plots of about one fifth of an acre each. Some of these had never received any manure during the twenty years; the others received some one or more of the food constituents which barley requires. Thus, one was manured with phosphates, a second with alkalies, a third with ammonia, a fourth with ammonia and phosphates, a fifth with ammonia, phosphates, and alkalies, etc., every year in succession. At harvest the crops were carefully weighed, and were then analyzed in the laboratory under the superintendence of Dr. Gilbert, when the amounts of dry matter, ash, and nitrogen, were determined.
"The advantages of this systematic mode of experimenting," says an English review of the report, "are very great. Carried on in the same manner for so many years, these experiments answer questions relating to the exhaustion of the soil, to the permanent effect of manures, to the effect of season upon the produce. With the aid of the laboratory investigations they teach us what proportion of the various ingredients supplied in the manure is recovered in the crop, and how the composition of the plant is affected by the various conditions of the soil. In conjunction with analyses of the soil and of the drainage water, we learn what becomes of the manures supplied, how deeply they have penetrated into the soil, what is the loss suffered through drainage, etc. A single field experiment, thus thoroughly and patiently carried out, touches half the domain of agricultural chemistry, and supplies information of the most solid and valuable kind."
Mr. Lawes addressed himself with great skill and success to the task of perfecting the methods of analysis; but, even after all his investigations, he believes that the elucidation of agricultural principles must be looked for from a due consideration of vegetable physiology as well as chemistry, and of the special functional peculiarities and resources of different plants as well as their actual percentage composition. The explanation of the distinctive functions of crops grown in rotation is found, in his view, in the character and length of life of the different plants; in the character of the roots in regard to number, size, etc., and to their aptitude to derive more of their food and moisture from the surface, or from the subsoil; and in the greater capacity of some for liberating and assimilating food not available for others, or for arresting food which would otherwise be washed out of the soil. In brief, his investigations have embraced researches into the exhaustion of soils, including experiments on crops; on the principles of rotation and fallow; on the mixed herbage of grass-lands; on the progress of vegetation generally, including researches on the action of manures; on the origin of nitrogen in plants; on the feeding and fattening of cattle, and generally on stock as meat-producing and manure-making machines; on rainfall and drainage; on botanical characteristics; and on the chemistry of the malting process, and the comparative value of malt and barley as food for cattle. Mr. Lawes also, in conjunction with Professor Way, acted upon a royal commission from 1857 to 1865, in the investigation of the effect of the application of town sewage upon grass and other crops; and in the institution of comparative experiments on the feeding qualities of the differently grown crops, to be determined by the amount of increase yielded by oxen, and the amount and composition of the milk yielded by cows.
In 1872 Mr. Lawes announced his intention of placing in trust his laboratory and experimental fields, with an endowment of £100,000, the interest of which, after his death, should be applied to the continuance of the investigations carried on there. "It is seldom," "Nature" remarked, in noticing the fact at the time, "that we have to record an act of so great munificence directed in a channel calculated to bring about such important results to the scientific departments of agriculture."
Mr. Lawes was elected in 1854 a Fellow of the Royal Society, whose royal medal he received conjointly with Dr. Gilbert in 1807; he has also received a gold medal from the Imperial Agricultural Society of Russia; in June, 1881, the Emperor of Germany by imperial decree awarded the gold medal of merit for agriculture to him and Dr. Gilbert jointly, in recognition of their services for the development of scientific and practical agriculture; and in May, 1882, Mr. Lawes was created a baronet, and became Sir John Bennet Lawes. he is also a Fellow of the Chemical Society, and an LL. D.
The results of the Rothamstead investigations of Sir John Lawes are to be found in the journals of the Royal Agricultural Society, the reports of the British Association, the Journal of the Chemical Society of London, The Transactions of the Royal Society, the Journal of the Society of Arts, the Journal of the Horticultural Society of Loudon, the "Edinburgh Veterinary Review," the reports of the Royal Dublin Society, the "Philosophical Magazine," the "Agricultural Gazette," the "Chemical News," and in official reports and scattered pamphlets and newspaper letters.
Of the value of Sir John Lawes's work at Rothamstead as a whole, we find the judgments recorded in scientific reviews of its results, that "it is not to be equaled by that of any of the foreign stations; indeed, in several departments of investigation it might safely challenge comparison with their united efforts"; and that "he has obtained a larger body of facts in relation to manures and cropping, and the feeding of animals, than all the agricultural societies in the empire put together."
We also find some lessons suggested by it in the same reviews, the bearing of which seems to have escaped, the notice of the reviewers themselves, for they forthwith proceed to draw from them the opposite conclusions to the true one: "The whole is the work of the man himself. He has had no aid from the Government or any agricultural society, and no advice from any committee or public body." "Of the indebtedness of science to Mr. Lawes's unique and costly experiments we need not speak, the facts are so plain that they speak for themselves. Nor need we state the moral. The addition to the national wealth which has accrued from the discoveries made by Mr. Lawes is already enormous. It must be borne in mind that this benefit has arisen from accidental researches, for Mr. Lawes was not compelled to take them up, nor is he bound to continue them."
The secret of this great merit is also given; for while Mr. Lawes has not had an unqualified success, especially in drawing inferences from his facts, "his writings afford ample evidence of great earnestness of purpose. His manly, outspoken language shows that he loves truth for its own sake. He has had ample resources; and he has had the motive of self-interest, as well as love of knowledge, to stimulate him in his investigations."
In this splendid example, as in so many others, we have illustrated anew the fact that the best scientific results and the most important advances in discovery are the fruit of earnest individual work, prompted by love of the pursuit and carried on in a spirit of self-reliance; that investigation can and will make its own paths and find its way to its own ends, and be more vigorous and active for the effort; and that the time has not yet come when, in Anglo-Saxon countries, science has so declined that it must be coddled by official patronage.