194 



NATURE 



[October 17, igi: 



Another important feature of the work of this 

 congress was the delivery of four lectures of 

 general interest by eminent chemists representing 

 France, Germany, Great Britain and Italy. The 

 great hall of the college of the city of New York, 

 having a seating capacity of 3000 persons, was 

 available for this purpose and for the general 

 meetings of the congress. 



Prof. Gabriel Bertrand spoke on the part played 

 in agriculture by the minor constituents of plants. 

 It has been demonstrated that the element man- 

 ganese, present only in minute quantities in plants, 

 enters into the composition of laccase, an enzyme, 

 first extracted from the lacquer tree, which is 

 capable of bringing about an assimilation of 

 atmospheric nitrogen. Small additions of man- 

 ganese have been found to increase crops to a 

 considerable extent, and similar effects have been 

 produced with other of the less common elements. 

 These results lead to a new class of fertilisers — 

 the catah'tic manures — which are capable of 

 modifying favourably the fertility of the soil. 



Dr. Carl Duisberg lectured on the latest achieve- 

 ments and problems of the chemical industry. 

 The problem of the utilisation of peat has received 

 a solution in Frank and Caro's process of pro- 

 ducing peat gas for heating purposes with recovery 

 of the nitrogen as ammonia. Great strides have 

 been made in the manufacture of refined steels 

 containing other elements besides iron and carbon. 

 The nickel alloys are of great value ; those contain- 

 ing 23 per cent, and upwards of this metal are 

 non-magnetic, whilst the 45 per cent, alloy has 

 a coefficient of expansion not greater than that 

 of glass. Steels containing chromium and molyb- 

 denum are remarkably resistant to mineral acids ; 

 the alloy containing 60 and 3 per cent, of these 

 metals respectively is not appreciably attacked by 

 Ijoiling aqua regia. Steels containing chromium, 

 tungsten and vanadium have a high degree of hard- 

 ness. Vanadium steel is emplo\ed in forging high- 

 speed tools, and the firm of Krupp have patented 

 a steel which can neither be drilled, nor disin- 

 tegrated by explosives, nor cut by the oxyhydrogen 

 or oxyacetylene flame. Electrolytic iron, which is 

 now manufactured free from hydrogen by electro- 

 lysis in hot solutions, can be magnetised and 

 demagnetised more readily than ordinary iron 

 containing carbon and silicon. Electromotors in 

 which this material is used are two-and-a-half times 

 as efficient as those constituted of silicon iron. 

 The lecturer reviewed the recent developments in 

 colour synthesis, pharmaceutical chemistry and 

 chemotherapy, the treatment of infectious disease 

 with chemical compounds. The production of 

 non-inflammable kinematograph films ("cellite") 

 and non-inflammable celluloid ("cellon") from 

 acetylcellulose are valuable improvements which 

 must eventually promote greater security of life and 

 property from fire. 



A controversial topic was reached when the 

 lecturer dealt with the problem of the manufacture 

 of artificial rubber. He asserted that F. Hoffmann, 

 of the Elberfeld factor}', is to be regarded as the 

 real discoverer of synthetic ruliber, this investiga- 

 NO. 2242, VOL. 90] 



tor having polymerised isoprene to rubber in 1909, 

 a discovery vihich has been followed by the produc- 

 tion of certain homologues of natural rubber. 

 This view of the synthesis of rubber was subse- 

 quently refuted by Prof. W. H. Perkin in a 

 lecture on the polymerisation of butadiene and 

 isoprene, when reference was made to Tilden's 

 discovery of nearly thirty years ago that isoprene 

 polymerised to a substance identical with natural 

 rubber. Specimens of Tilden's preparations were 

 exhibited, and the lecturer gave an account of 

 recent successful experiments on rubber synthesis 

 starting from amyl alcohol made by a group of 

 English chemists in collaboration with the French 

 bacteriologist Fernbach. 



The third general lecture was delivered by 

 Prof. Perkin, who described the experiments 

 which led to the fireproofing of the very 

 inflammable material flannelette with precipitated 

 hydrated stannic oxide, a treatment which renders 

 the fabric (" Non-flam ") permanently fireproof with- 

 out affecting the colour of the dyed cloth, while its 

 strength is increased by 20 per cent. 



The fourth general lecture was delivered by 

 Prof. G. Ciamician, who spoke on the photo- 

 chemistry of the future and advocated the utilisa- 

 tion of radiant solar energy either directly in pro- 

 moting photochemical change or indirectly by the 

 intensive cultivation of plants yielding industrially 

 valuable products, the harvested plants being 

 subsequentlv converted economically into gaseous 

 fuel and their mineral ash and recovered nitrogen 

 being restored to the soil. 



Closely allied to the subject of intensive cultiva- 

 tion were two addresses dealing with the fixation 

 of atmospheric nitrogen. In the first of these 

 discourses Dr. S. Eyde, who referred to the 

 oxidation of atmospheric nitrogen, described the 

 remarkably rapid growth of the synthetic nitrate 

 Industry of Norway and the methods employed in 

 utilising the water-power of that countr}'. In the 

 second address Dr. H. A. Bernthsen gave an out- 

 line of Haber's process for synthesising ammonia, 

 now being developed on a manufacturing scale by 

 the Badische .Anilin und Soda- Fabrik. 



By operating- with purified hydrogen and nitro- 

 gen under high pressure (200 atmospheres) 

 at 650-700° C. in the presence of a suitable 

 catalyst (iron, manganese, molybdenum, tungsten, 

 uranium carbide, &:c.), about 8—10 per cent, of the 

 gaseous mixture is converted into ammonia, which 

 is either separated by liquefaction or dissolved out 

 by water. 



In addition to the general lectures and sectional 

 meetings, the social side of the congress was fully 

 developed, and a special entertainment programme 

 was arranged for the ladies accompanying the 

 members and delegates. 



At the close of the congress nearly 300 of the 

 members proceeded on one or other of two tours 

 arranged by Drs. Rosengarten and Day and other 

 members of the special transportation and factory 

 inspection committees. Two special trains were 

 provided, and at each stopping-place local com- 

 mittees had been organised, the representatives 



