January 2, 1902] 



NATURE 



205 



faults and disturbances observed in the coalfield near 

 Swansea ; and important suggestions are made regarding 

 the subdivisions recognised in the Upper Coal-measures 

 of North Staffordshire and their extent westwards across 

 the Cheshire plain, and south-westwards into the Bir- 

 mmghani area. 



The discovery of Rh;etic, Liassic and Cretaceous fossils 

 in rocks, preserved within an old volcanic vent in the 

 Isle of Arran, is of especial interest as indicating the 

 former extent of these Secondary strata. The Cretaceous 

 rocks of the south of England have received attention, 

 rnore especially as regards the Lower Greensand of parts 

 of Sussex and the Isle of Wight, the subdivisions in 

 which are compared. 



Students of Tertiary strata will find interesting refer- 

 ences to the successive overlaps of the London Clay and 

 Bagshot beds on the western side of the Hampshire 

 Basin. The volcanic series of Arran and of Skye come 

 into notice also in the portions of the Summary which 

 deal with Tertiary times. 



In various parts of the country observations have been 

 made on Pleistocene deposits, the most important being 

 the full account of the glacial phenomena in the Maccles- 

 field district. 



The petrographical work includes a particular account 

 of the marbles of Assynt, which have resulted from contact 

 metamorphism produced by igneous rocks on surround- 

 ing dolomites. The palKontoIogical work includes im- 

 portant catalogues of type-specimens of Pleistocene, 

 Pliocene and Devonian fossils preserved in the Museum 

 of Practical Geology ; and there are special notes on 

 Carboniferous plants from Berwickshire and on the fossil 

 fishes from the Silurian rocks of the Lesmahagow district. 

 In this brief abstract of some of the results of a year's 

 work on the Geological Survey we have refrained from 

 mentioning individuals, but the work of each has been 

 carefully indicated in the memoir. It is satisfactory, 

 moreover, to note the assistance that has been rendered 

 by Mr. R. Kidston, Ur. R. H. Traquair and Dr. G. J. 

 Hinde in the identification of particular groups of organic 

 remains. 



SIR J. HENRY GILBERT, LL.D., F.R.S. 



' I 'HE names of Lawes and Gilbert have been " house- 

 ■*■ hold words" in the mouths of English students of 

 agriculture during the past half century. Sir John Lawes 

 departed from amongst us last year, at the age of eighty- 

 five. His colleague, Sir J. H. Gilbert, has also now 

 finished his labours ; he died at Ilarpendenon December 

 23, at the age of eighty-four. 



Joseph Henry Gilbert was the second son of the Rev. 

 Joseph Gilbert, a nonconformist minister at Hull. He 

 was born at Hull in 1817. His mother, Ann Gilbert, 

 was a daughter of the Rev. Isaac Taylor, of Ongar, and 

 thus belonged to a well-known literary family ; she was 

 herself the authoress of numerous poems for children. 

 While at school young Gilbert met with a serious acci- 

 dent, and practically lost the sight of one eye. His great 

 pluck enabled him to accomplish his life's work with 

 little apparent hindrance, but the disadvantage of weak 

 sight was very real, and much of his subsequent literary 

 work had to be dictated. He went from school to 

 Glasgow University and studied chemistry under Dr. 

 Thomas Thomson. From thence he went to University 

 College, Lortdon, and commenced working in the labora- 

 tory of Dr. Antony Todd Thomson. Here apparently 

 he first made the acquaintance of Mr. John Lawes, who 

 was a frequent visitor to the laboratory. He next pro- 

 ceeded to (iiessen, where Liebig was then professor of 

 chemistry, and took the degree of Ph.D. in 1S40. Dr. 

 Gilbert then acted for a short time as assistant to Dr. 

 Antony Todd Thomson, and afterwards left to take up 



NO. 1679, VOL. 65] 



calico printing and dyeing in the neighbourhood of 

 Manchester. 



It was in 1843 that Dr. (lilbert's services were engaged 

 by Mr. Lawes for the agricultural investigations then 

 commencing at Rothamsted. We have already noted in 

 these pages (Nature, September 13, 1900, p. 467) the 

 foundation of the Rothamsted agricultural investigations 

 by Mr. J. B. Lawes, their rapid development at his sole 

 expense, and their subsequent liberal endowment by him ; 

 we have now to mention the important part taken in the 

 work by his collaborator. Dr. Gilbert. 



The two investigators were, to a considerable extent, 

 well matched, each supplying some deficiency in the 

 other. .Sir John Lawes brought to the work a very 

 original mind, an enterprising spirit, and a thorough know- 

 ledge of the facts of practical agriculture ; and this 

 practical knowledge served to inform his judgment and 

 enabled him to test the truth of many of the scientific 

 theories which came before him. Sir J. H. Gilbert, on 

 whom the details of the work devolved, brought to his 

 task a more exact knowledge of science and of methods 

 of investigation, an acquaintance with foreign chemists 

 and foreign literature, and, above all, methodical habits 

 of work, which proved of immense value in planning and 

 carrying on through fifty-eight years the field experi- 

 ments which became such a striking feature in the 

 Rothamsted investigations. He was an indefatigable 

 worker, and loved to accumulate an immense mass of 

 results, frequently of a similar kind ; and a reader of 

 Rothamsted papers is sometimes so overwhelmed by 

 numerical statements that, to use a familiar simile, "he 

 finds it difficult to see the wood for the trees." 



The Rothamsted investigators soon found themselves 

 engaged in controversy with German men of science, and 

 Sir J. H. Gilbert at once proved himself to be a warm 

 and untiring antagonist. The first subject of dispute was 

 the so-called " mineral theory ''of Baron Liebig. Liebig 

 held that the atmosphere supplied in sufficient quantity 

 both the carbon and nitrogen required by crops, and that 

 the proper function of manure was to supply the ash con- 

 stituents of the crop it was intended to grow. On the 

 other hand, the Rothamsted field experiments with wheat 

 and barley proved unmistakably that ammonium salts 

 and other nitrogenous manures had afar greater effect in 

 increasing the produce than any application of phos- 

 phates, potassium salts, or other ash constituents. So 

 long as the question was confined to the cereal crops, 

 Rothamsted was triumphant ; but when leguminous crops 

 became the subject of experiment the answer was 

 doubtful, and in many cases the manures supplying ash 

 constituents proved the most effective. It has taken 

 many years, and tasked many investigators, to elucidate 

 this part of the subject. We now know that the roots of 

 leguminous plants become the habitation of certain 

 bacteria, and that by means of these the plants are fed in 

 a special manner with nitrogen from the atmosphere. 



The subject of the assimilation of nitrogen by plants 

 led to one of the most highly prized of the Rothamsted 

 investigations, in which plants were grown from seed in 

 soils destitute of nitrogen, but supplied with ash con- 

 stituents, and in an atmosphere free from ammonia, the 

 object being to ascertain in a rigorous manner if an 

 assimilation of the free nitrogen of the air took place. 

 The work lasted three years, and was made the subject 

 of a communication to the Royal Society by Lawes, 

 Gilbert and Pugh. The chief honour of the work belongs, 

 in this case, to the last-named author. Pugh was an 

 .\merican studying in Germany, and when the controversy 

 on nitrogen assimilation between Boussingault and Ville 

 was at its height he offered to come to Rothamsted and 

 help to solve the question. His offer was accepted. 

 The whole of the experimental work was conducted by 

 Pugh with an ingenuity and accuracy which were justly 

 admired. 



