SCIENCE- G OSS J J \ 



93 



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i#' CHEMISTRY 



■ .Mil! U^^SJrte 



CONDUCTED BTi HAROLD M. READ, P.C.8. 



Manufacture ok Artificial Pearls. — In 

 view of the enormous trade now carried on in 

 artificial pearls, the method of preparing the 

 mother-substance for their manufacture is of 

 interest. This mother-substance is worked up in 

 the Lauscha district, and other glass-making 

 centres of Tinning a. from fish-scales imported 

 from the Baltic. The scales are firsl thoroughly 

 washed with fresh water to remove impurities, 

 then shaken up with a further quantity of water 

 for about two hours, and finally the whole is sub- 

 jected to pressure in a linen bag. The silvery 

 lustrous runnings are collected and set aside. 

 This treatment is repeated until the scales have 

 lust their silvery appearance, become transparent, 

 and hard to the touch. The runnings are put aside 

 to clarify, while, to prevent putrefaction, ammonia 

 [s added and the mixture kept at as low a tempera- 

 ture as possible. The sediment is now washed 

 repeatedly with water, until the washings are quite 

 clear. Thereupon the lustrous residue is bottled 

 off, and the water gradually removed by successive 

 washings in alcohol. During this treatment the 

 extract assumes the consistency of butter, but it 

 still retains its pearly lustre. For use, the butter- 

 like mass is mixed in small quantities with a hot 

 aqueous solution of gelatine. If the " pearls " are 

 to be coloured, a spirituous solution of an aniline 

 - incorporated with the gelatine. 



Sugab an Aid to the Growth of Plants. — 

 During the last two years some most interesting 

 work has been carried out at Nottingham College, 

 by Mr. J. Golding, on the influence of saccharose 

 or cane-sugar on the growth of plants. The aim 

 of the experiments — the results of which have 

 recently been published — was to compare the 

 increased yield produced by sugar on plants draw- 

 ing all their nitrogen from the air, with that 

 obtained in the case of plants drawing their nitro- 

 gen in a combined form from the soil. If the energy 

 for the nitrogen-fixation comes from the break- 

 ing- u]i of the sugar, those plants which have to fix 

 all their nitrogen might naturally be expected to 

 benefit more by sugar applied to their roots than 

 those which have their nitrogen presented in a 

 combined, and hence more readily assimilable 

 form. Briefly stated, the results of the investiga- 

 tion show that the leguminous plants with healthy 

 root-nodules or nitrogen-fixers benefit by the 

 application of small quantities of sugar to their 

 roots. Further, even in the case of those plants 

 which are devoid of root-nodules, but are supplied 

 with an abundance of combined nitrogen, an in- 

 creased yield is noticed after the application of sugar 

 to their roots. At the same time, it is found that 

 where the plans are starving for want of nitrogen, 

 the addition of sugar is actually injurious ; in fact 

 it is possible to kill plants by the use of too much 

 sugar. These results confirm those obtained some 



months ago bj Winogradskj and OmeTiansky, who 



found that one pari of | I in 500 entirely 



ented nitrification. 



Professor Nilson.— On July 5th the Chemical 

 Society paid fitting tribute to one of their distin- 

 guished members, the late P Nilson, in a 

 memorial address delivered by one of hi- co- 

 worker.-. Professor Otto Petterson. The lecture 

 was delivered in English, and in a style which 

 mighl well be emulated by many Englishmen. 

 Nilson's life was sketched from his leaving his 

 father'- farm in Gottland, a detailed account being 

 given of his braining with the greal Swedish 

 phemisl Berzelius, his r< in pure chemistry 

 at Upsala University, and hi-- work as Director of 

 the Agricultural Department of the Swedish Go- 

 vernment. It was in tin- latter office thai Nilson 

 showed not only bis exceptional capacity as a 

 thinker, but also his skill as a chemist, and hi^ 

 patriotic enthusiasm for his motherland. 



Conversion of Phosphorus into Arsenk 

 Last month I referred to a paper by Fifties dealing 

 with the alleged preparation of metallic arsenic 

 from phosphorus. A scathing criticism of Fittica'e 

 work by Dr. Clemens Winkler has appeared in the 

 " Berichte," and an excellent translation of this 

 paper is published in the " Chemical News." After 

 pointing out the utter fallacy of Fittica's assertions, 

 and the fact that the percentage of arsenic obtained 

 corresponds almost exactly with that ordinarily 

 found in commercial phosphorus, Dr. Winkler con- 

 cludes with a paragraph which will be heartily 

 welcomed by all students whose efforts are directed 

 towards the discovery of truth. The remarks may 

 so well be applied, not only to chemistry but t< > 

 every branch of science, that I reproduce them : — 

 " It would appear as if in inorganic chemistry a 

 dangerous tendency showed itself of late to enter 

 into speculations without those careful investiga- 

 tions wdiich have hitherto distinguished German 

 chemists. Cases are multiplying winch tend to 

 show that a theory is first formed, and that one 

 seeks to find what one wishes to find; or that, 

 in the words of the physiologist Czermak. one 

 starts from ' erroneously observed facts,' and 

 thus falls into mistakes. The reason must 

 be sought, to a great extent, in the fact 

 that the art of analysis is being regrettably 

 neglected. I intentionally say the 'art, 1 for 

 between analysing and analysing there is the same 

 difference as between artists' and stonemasons' 

 work. One cannot expect analytical aptitude 

 from the physicist, whose field of investigation 

 begins more and more to extend to inorganic 

 chemistry as electrolysis develops ; and he. within 

 his field of investigation, is able to discover useful, 

 even great, facts. But physical chemistry is in no 

 way synonymous with inorganic chemistry: for 

 the latter, far from being a finished department of 

 science, embraces problems in infinite number 

 which must be solved upon an entirely different 

 road from that indicated by the ion theory. The 

 really successful carrying out of inorganic chemical 

 investigations is possible only to him who is not 

 only a theoretical chemist, but also an accomplished 

 analyst: not only a practical, mechanical work- 

 man, hut a thinking and forming artist, wl 

 clearly the theories of the operations, to whom 

 the knowledge of proportion is a part of himself, 

 and who in all his doings is led by a Bense of order 

 and neatness, but especially by a desire for 



truth." 



