cclxxxvi GENERAL SUMMARY OF SCIENTIFIC AND 



an'ulcs. The bulk is augmented proportionably to the 

 weight. The same writer points out very clearly the evils 

 attending this excessive adulteration. The chemical and 

 physical properties of the silk thus treated are material- 

 ly modified. What is sold as silk is, in reality, a mere ag- 

 glomeration of heterogeneous matters devoid of cohesion, 



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held together temporarily by a small portion of silk. The 

 strength and elasticity of the fibre are likewise reduced. 

 From beins: in its natural state one of the most stable of 



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substances, and but slightly combustible, in its adulterated 

 state it burns like tinder if touched by a flame. It is like- 

 wise affirmed to be liable to undergo spontaneous decompo- 

 sition, and to absorb gases with the evolution of heat which 

 sometimes leads to actual combustion. The adulterated silk 

 when burning scarcely gives off the characteristic odor of 

 animal matter. 



It is of interest to supplement our notices in last year's 

 Record of the artificial production of vanillin the active 

 principle of the vanilla bean (which is now a commercial 

 operation) by reference to a suggestion for obtaining it 

 largely by another process. In several manufacturing oper- 

 ations pine-wood is treated in iron boilers, under high press- 

 ure, with a solution of caustic alkali. The resulting liquid 

 contains various salts of soda, and, if the temperature has 

 not been too great, among them the soda salt of vanillin. 

 Experiments made with the view of establishing this fact 

 are conclusive, its presence being demonstrated by the pres- 

 ence of an intense vanilla odor, which becomes more promi- 

 nent when the liquid is treated with an acid and left stand- 

 ing for several days. It has thus far, however, been found 

 impossible to extract the crystallized vanillin from the 

 above-named liquid, though in all likelihood this consumma- 

 tion will not be long delayed. 



M. Gerard gives the name of Apparatine to a colorless, 

 transparent substance which he obtains by heating starch, or 

 substances rich in starch, with caustic alkali. The product 

 resulting from this treatment is said to be excellently adapted 

 as a dressing for all kinds of textile fabrics cotton, woolen, 

 or silk to which it imparts a velvety gloss impossible to 

 obtain by any other mode of treatment. 



M. Paulet's observations upon the chemical operations in- 



