Part 39

Gilbert, however, would not listen to any such heresy, as he considered that the question of the assimilation of the free nitrogen of the air by plants had been finally settled by the experiments of 1857-60. It was therefore a most happy chance that Gilbert was present at the scientific congress in Berlin in 1886 when Hellriegel described his experiments on leguminous plants, showing that the formation of nodules on these plants was associated with the fixation of atmospheric nitrogen. In commenting subsequently on these experiments, Gilbert said, "It must be admitted that Hellriegel's results, taken together with those of Berthelot and others, do suggest the possibility that, although the higher plants may not possess the power of directly fixing the free nitrogen of the air, lower organisms, which abound within the soil, may have that power, and may thus bring free nitrogen into a state of combination within the soil in which it is available to the higher plants--at any rate to members of the Papilionaceous family. At the same time, it will be granted that further confirmation is essential before such a conclusion can be accepted as fully established."

This comment reveals the essential conservatism of Gilbert's mind, but the true greatness of the man is seen when we find him, at the age of seventy, repeating the experiments of Hellriegel and Wilfarth, and himself supplying the confirmation of their results which he considered essential.

The results of these experiments, contributed to the Royal Society in 1887, 1889, and 1890, fully confirmed the theory that leguminous plants are able to assimilate the free nitrogen of the air by means of the micro-organisms contained in their root nodules, and also explained the failure in the 1857-60 experiments to demonstrate nitrogen fixation by leguminous plants owing to the use of calcined soil by which the inoculating organisms present in the soil were destroyed.

Gilbert's investigations from 1871-75 showing that the drainage waters from the experimental fields of Rothamsted contained more nitrates as the amount of ammonium salts applied to the soil increased, have been quoted by some writers as being the basis of the modern theory of nitrification. It must be remembered that Gilbert was at first actively hostile to the bacterial theory of nitrification, and the credit and honour of the work done at Rothamsted on the nitrifying organisms belongs entirely to Warington.

A few words must suffice for an account of the series of Rothamsted experiments on animals. Series II deals with "Reports of experiments on the feeding of animals, sewage utilisation, &c. Published 1841-1895 inclusive," and contains 31 papers. Among the points investigated may be mentioned--the composition of foods in relation to respiration and the feeding of animals; experiments on the feeding of sheep and the fattening of oxen; some points in connection with animal nutrition; the feeding of animals for the production of meat, milk and manure.

The work on the part played by carbohydrates in the formation of animal fat led to a keen controversy with foreign investigators. Lawes and Gilbert had satisfied themselves by their experiments on pigs that fat was undoubtedly produced from carbohydrates. The German physiologists doubted this, and for some time there was a wordy warfare between the rival camps. Gradually the experimental evidence for the formation of fats from carbohydrates became overwhelming, and once again the Rothamsted position was vindicated.

Gilbert maintained throughout his life a close connection with foreign workers, and his holidays were frequently employed in visiting institutions and attending scientific meetings on the Continent. He made three visits to the United States and Canada and delivered several lectures there.

As he passed into old age his powers seemed to suffer little diminution, and his appearance at the age of eighty showed little indication of physical weakness. The death of Sir John Lawes in August 1900 was a severe blow to him, and soon afterwards his energies began to fail. He had a severe illness whilst away in Scotland in the autumn of 1901, but he recovered sufficiently to be able to return to his work for a short time. With the indomitable tenacity which had characterised him throughout life he continued actively at work for a few more weeks, eventually succumbing on December 23rd, 1901, in his eighty-fifth year.

Thanks are due to Dr J. A. Voelcker for kind assistance; and to the Royal Agricultural College Students' Club, Cirencester, for permission to reproduce the accompanying photograph.

WILLIAM CRAWFORD WILLIAMSON

1816-1895

BY DUKINFIELD H. SCOTT

Early exponents of Fossil Botany--Witham of Lartington--Edward William Binney--William Crawford Williamson--early influences--first contribution to science--studies medicine--work on Foraminifera--appointed Professor at Manchester--successful popular lecturer--his influence in Natural History--investigation of the Carboniferous Flora--controversy with French palaeo-botanists--the magnitude of his output--defects in his work--later work at Kew--personal traits.

During the last forty years the study of fossil plants has come to be a specially vigorous and characteristic branch of British botany. The proper subject of my lecture is Williamson, the man to whom above all others the present strong position of the subject is due. But "there were brave men before Agamemnon," and there are two of the older masters, Witham and Binney, whom I cannot wholly pass over. I ought really to include others, and notably Sir Joseph Hooker, to whom we owe our first clear understanding of Stigmaria and of Lepidostrobus, but this course does not extend to those who, like Sir Joseph, are still living among us and still in active work.

I am indebted to Mr Philip Witham, a member of the family, for some information about Henry Witham, of Lartington, the first Englishman to investigate the internal structure of fossil plants.

Henry Witham was, by birth, not a Witham, but a Silvertop, having been the second son of John Silvertop of Minster Acres, Northumberland. As Henry Silvertop he came in for the Lartington property. He was born in 1779 and married Miss Eliza Witham, niece and co-heiress of William Witham of Cliffe, Yorkshire, when he took the name and arms of Witham.

The method of cutting thin sections of rocks and fossils had just been invented by Nicol, and this gave Witham the opportunity for his investigations. His papers are illustrated by the botanist McGillivray, to whom he may have owed some further assistance. Indeed he made little pretension to botanical knowledge, but the opinions which he expresses strike one as remarkably sensible, and he must have been a man of sound judgment, at least in scientific affairs.

Witham was the first investigator of that most famous of fossils, Lepidodendron Harcourtii; of the Craigleith tree (now Pitys Withami), of the Lennel Braes trees (Pitys antiqua and P. primaeva), of the Wideopen tree (Pinites, now Cordaites Brandlingi) and of Anabathra pulcherrima. It is curious to notice that the Craigleith tree, a manifest Gymnosperm, was at first (1829) regarded even by the great Brongniart as a Monocotyledon, while others imagined it to be a Lycopod. Witham, however, soon set this right. He always speaks with great respect of Brongniart, then just becoming the recognised leader of fossil botany. The following passage from Witham's memoir on the vegetable fossils found at Lennel Braes, near Coldstream, is of interest.

"Now, according to that gentleman's [Brongniart's] opinion, out of six classes ... only two existed at that period [Carboniferous], namely the Vascular Cryptogamic plants, comprehending the Filices, Equisetaceae and Lycopodeae, and the Monocotyledons, containing a small number of plants which appear to resemble the Palms and arborescent Liliaceae. The existence, therefore, of so extensive a deposit of Dicotyledonous plants, at this early period of the earth's vegetation, appears to demand the attention of the naturalist."

Brongniart's "Monocotyledons" were no doubt Cordaiteae. Witham, we see, set the great man right as regards the antiquity of Dicotyledons, in which, of course, Gymnosperms were then included.

Witham's earlier papers were embodied in his book: The Internal Structure of Fossil Vegetables found in the Carboniferous and Oolitic deposits of Great Britain, described and illustrated, 1833. It is dedicated to William Hutton, author, with Lindley, of the Fossil Flora of Great Britain.

A passage from the dedication shows that Witham took his work seriously--"To lend my aid in bringing from their obscure repositories the ancient records of a former state of things, with the view of disclosing the early and mysterious operations of the Great Author of all created things, will ever be to me a source of unalloyed pleasure."

Witham thus fully realised the important significance of the work on which he was engaged. He must have been an interesting person of a somewhat complex character, and I wish we could know more about him. He died on Nov. 28th, 1844. Like all his family, he was a Roman Catholic.

Witham's localities on the Tweed remained practically unvisited until Mr Kidston re-explored them eight or nine years ago, with brilliant success--the results, however, are still unpublished.

* * * * *

Edward William Binney, the first investigator of the Lancashire coal-balls, was born at Morton in Nottinghamshire in 1812, and was thus only four years senior to Williamson. He settled in Manchester in 1836, and practised as a solicitor. He early showed scientific tastes; the Manchester Geological Society was started, chiefly by his influence, in October 1838. He was concerned in the discovery of the famous St Helen's trees, which first proved the connection between Sigillaria and Stigmaria. "Binney completed the proof that all coal-seams rest on old soils which are constituted entirely of vegetable matter; this was the seat-stone of a seam of coal" (Robert Hunt). He gave up the practice of Law, and, devoting himself to science, became a leading authority on northern geology, and rendered important aid to the Geological Survey by his long experience of the coal-fields of Lancashire and Cheshire. He assisted in the discovery of the Torbane Hill mineral or Boghead Cannel, a deposit once notorious as a subject of litigation, and more recently as a bone of scientific contention. Binney died on December 19, 1881. Etheridge said of him: "He was a man of the highest honour and remarkably outspoken; his sturdiness and strength of character being rarely equalled."

Binney was the discoverer of some now famous fossils, notably Dadoxylon (now Lyginodendron) oldhamium, and Stauropteris oldhamia. His best known work is the monograph, Observations on the Structure of Fossil Plants, in four parts, published for the Palaeontographical Society, from 1868 to 1875. Thus his work on coal-plants overlapped that of Williamson.

The first part is on Calamites and Calamodendron--the names are used in the old sense, for Binney kept up Brongniart's distinction, though apparently not convinced of its validity. In this memoir he described the "cone of Calamodendron commune," now known as Calamostachys Binneyana.