ACHIEVEMENTS OF CHEMICAL INDUSTEY DUISBERG. 241 



which must be converted into marketable tin by costly smelting 

 operations, the new process yields an anhydrous tin chloride, which 

 is used in large quantities for weighting silk. The detianing with 

 chlorme is not carried out with cuttings, as m the electrolytic process, 

 but with waste pressed in hard packages, so that 20 times as much 

 material can be treated in the apparatus at the same time. In the 

 United States this process is operated by the Goldschmidt Detmning 

 Co. of New York. 



REDUCING AND OXIDIZING AGENTS. 



One of the most brilliant successes in applied chemistry has been 

 achieved by the persevering experunents of some chemists with a 

 long-neglected substance, the constitution of which had never been 

 properly understood. The old hydrosulphite of Schiitzenberger, 

 rendered stable and easily transportable in powder form as an anhy- 

 drous sodium salt or as rongalite in combination with formaldehyde, 

 has now become a most important article of commerce. It is chiefl}^ 

 used in vat dyeing and for reducmg purposes m general, such as 

 stripping dyed fa]:)rics and as decrolin for bleaching sugar. 



PEROXID OF HYDROGEN, PERSULPHATE, AND PERBORATES. 



Peroxid of h3'drogen and its derivatives at present find less favor 

 in commerce, although their future appears to be very brilliant. 

 Eecently the Farbenfabriken vorm. Friedr. Bayer & Co. succeeded 

 in rendering this important oxidizing agent, which easily decomposes 

 and which can be marketed with difficulty only m watery solution, 

 solid and stable by the addition of urea. 



This i)owder is in the market under the name of Ortizon, but on 

 account of its relativel}^ high cost it is intended not so much for 

 technical as for hygienic and pharmaceutical purposes. 



The mteresting manufacture of sodium peroxid horn, sodium 

 and the many scientific investigations of the persalts, have not 

 been followed by great commercial success. The persulphate and. 

 perborate, however, the latter under the name of 'Tersil," are being 

 manufactured on a large scale. The reason of this failure seems to 

 be the high cost of production. 



RARE METALS. 



The most interesting alloys discovered by Muthmann and Auer 

 have found little application in the arts, and the use of cerium and 

 thorium preparations is still confined to the incandescent gaslight 

 industry. Only the "Auermetal," consisting of 3.5 per cent iron 

 and 65 per cent cerium, is employed and this only to a limited 

 extent for the manufacture of pocket cigar lighters. 



