SCIENCE- GOSSIP. 



189 



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v'h. 



CHEMISTRY 



CONDUCTED I'.v HAROLD M. READ, B\C.S. 



Artificial Silk.— During- recent years an 

 industry which shows signs of being considerably 

 developed in the near future has sprung up in the 

 manufacture of artificial silk. Although the idea 

 of making this article dates back to Reaumur in 

 1734, it took no practical shape until the demand 

 arose for filaments for incandescent lamps. At the 

 present time there are four main classes of artificial 

 silk on the market: — (1) That made by de nitrating 

 nitro-cellulose, the denitrating being usually car- 

 ried out with sulph-hydrates as originally recom- 

 mended by Bechamp. The product thus obtained is 

 highly lustrous and supple, resembling silk in its 

 affinity for basic colours, and cotton in its composi- 

 tion. (2) " Glanzstoff " or lustre-cotton, made by 

 dissolving cellulose in ammoniacal copper, and 

 precipitating by the addition of an acid. (3) 

 Lustre-cotton, made by treating cellulose with 

 caustic soda, washing, dissolving in zinc chloride 

 solution in the cold, and then precipitating, (4-) 

 Viscose Silk, the cellulose xanthate patented by 

 Cross & Bevan, made by treating sodic cellulose 

 with carbon bisulphide. The viscose is forced 

 through capillary holes into ammonium chloride 

 solution, and the thread wound on to reels In 

 this connection it is of interest to note Dr. Lieb- 

 mann's remarks at the recent Bradford meeting of 

 the British Association. Dealing with the danger 

 likely to ensue from the extremely ready com- 

 bustion of artificial silk, he pointed out that this 

 drawback has now been overcome, and at the same 

 time the lustre even surpassed that of natural silk. 

 Unfortunately the use of the artificial product is 

 still limited ; for example, dress goods made entirely 

 of this article are very brittle while clamp, and it 

 cannot be used for warps, but as yet only as weft 

 for silk and cotton fabrics. 



Synthetic Perfumes.— The artificial produc- 

 tion of the odorous constituents which characterise 

 both the animal and vegetable worlds goes on 

 apace ; and while, from a chemist's point of view, 

 the compositions of both pleasant and disagreeable 

 perfumes are equally important, from the popular 

 and money-making side the preparation of the 

 agreeable odours places the chemist's aspect of the 

 question in the shade. A few years ago Tiemann 

 succeeded in building up chemically ionone, the 

 perfume of orris root, while the recent litigation 

 through the rival claimants to the synthesis of 

 musk is still fresh in our memories. The latest 

 addition is artificial " otto" of rose, which appears 

 on the niarkei simultaneously with a paper in the 

 Berichte of the German Chemical Society by 

 Walbaum and Stephan. The research has been 

 carried out in the laboratories of Schimmel & Co., 

 and it appears that German otto of rose consists 

 essentially of a mixture of nonyl-aldehyde and 

 laevo-citronellal with the aldehydes and alcohols 

 normally occurring in such perfumes as bergamot, 

 cassia, and others. 



A New [ndicatob. In a recent issue of the 

 Zeiticlvrift fii/r AnalytiscJie Chemie a new indicator 

 Eor both acids and alkalies i- described under the 

 dame of "Alizarin-green li." It occurs as a 

 greenish-black powder, easily - 

 and i" long - to the -groups of I h i thiazim 3. I >n 

 the addition of acid- to 1 he 1 ion there 



is produced a fine red coloration, which reverl 

 green on 1 he addil ion of 1 raci - of alkali. 



The Nati re of Alloys.— The report of the 

 committee appointed to considi r 1 he _ 

 alloys presented it- report to the British Assi 

 tion a! its recent meeting at Bradford. Up to 



within quite recenl \< ars th< 



proving the formation of the definite compounds 

 which mosl chemists considered present has been 

 the abstract ion of the particular compound. Ordi- 

 nary chemical methods are of no avail; fractional 

 solution has been partially successful, such distinct 

 compounds as copper-tin, platinum-tin. zinc-copper 

 having been isolated. Professors Roozeboom and 

 Le Chatelier have now shown that careful deter- 

 minations of the - freezing-point," supplemented 

 by examination under the microscope, reveal the 

 presence of compounds v> hose existence was hitherto 

 unknown. A long list of known and supposed 

 alloys was given, and it was stated that the ordinary 

 atomic relations do not hold in the case of alloys. 



The Universal Eudiometer. — A new eudio- 

 meter is described in a recent number of the 

 Chemical News. It has been designed by Dr. 

 G. Woollatt, and has been found to be of great 

 advantage in lecture demonstrations, giving a 

 rate results with very little trouble and over a 

 wide range of conditions. There is certainly much 

 to commend it, and it is suitable not only for the 

 demonstration of Boyle's and Charles' laws, for 

 which it was primarily designed, but also for the 

 analysis and synthesis of gases. We recommend 

 it to the notice of lecturers. It is being made by 

 John J. Griffin & Sons, Limited, of London. W.Q. 



Explosion of Magnesium. — From time to time 

 we are startled by the want of care on the part of 

 experimenters ; one of the most recent instances 

 occurred on September 3rd at the offices of the 

 Phoio-Program me, 29 Rue du Mail, Paris. It appears 

 that M. Jean Larcher (director of the Programme, 

 which is a well-known illustrated review) was 

 engaged with two assistants in developing some 

 negatives in a dark-room attached to his offices. 

 One of them carelessly struck a match to light a 

 cigarette. He happened to be near a big jar of 

 powdered magnesium, and the latter exploded. 

 The house was shaken to its foundations, all the 

 windows were blown out, and a perfect panic 

 seized the inhabitants of the house, as well as the 

 neighbours, for the Rue du Mail is a narrow 

 thoroughfare in a busy quarter, and all the house- 

 are five or six stories high, and let off in flats. 

 When assistance came the men were discover, d 

 severely injured, and they were conveyed to the 

 nearest hospital. The other people who suffered 

 personal injuries by the explosion were a M. Pozi- 

 nioiiin, who was passing the house and received 

 broken glass on his head. A tenant. Mine. Char!": 

 happened to be standing at a window when the 

 accident happened, and she was knocked down 

 and sustained some nasty bruises, but a clerk who 

 was in the next room to that in w Inch the explosion 

 occurred was lucky enough to escape with no 

 iniurv beyond the shock. 



