502 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



connection with the manufacture of aniline and alizarine. 

 8 (7, XII., 254. 



MODIFICATIONS OF CHKOME-ALUM. 



Gernez states, as the result of experiments, that solutions 

 of chrome-alum which have been converted into the green 

 modification by heating to 212 never crystallize, even if 

 supersaturated, if care is taken that not a trace of violet 

 chrome-alum or any other alum is present, and also that they 

 retain their green color, and it is never assumed by solutions 

 prepared cold. Upon slow evaporation a green transparent 

 mass is left, which gradually fills with cracks. If, however, 

 a fragment of crystallized chrome-alum, or other alum, is in- 

 troduced into the above solution, crystallization instantly be- 

 gins, and gradually violet chrome-alum crystallizes out. 15 

 (7, XXX., 48. 



KEMOVING VEGETABLE SUBSTANCES FROM WOOL. 



Messrs. Barral and Salvetat, in a memorial presented to the 

 Academy of Sciences of Paris, refer to the fiict that a large 

 proportion of the wool imported from Australia and South 

 America contains a greater or less j^ercentage of vegetable 

 matter mixed with it, which, of course, is injurious to its 

 quality, and which usually resists the mechanical means of 

 separation. An important problem, therefore, has been the 

 destruction and elimination of the vegetable fibre by agen- 

 cies that do not affect the wool. In summing up the results 

 of their experiments, and considering those of others work- 

 ing in the same field, Barral and Salvetat remark that the 

 cellulose and Avoody fibre can be decomposed under the 

 action of several chemical agents, provided that the tissue, 

 dried in the air after soaking, is then raised in a stove to a 

 temperature of about 350 Fahr. These agencies are sul- 

 phuric acid, hydrochlorate of alumina, hydrochloric acid, ni- 

 tric acid, chlorides of zinc, of iron, of tin, and of copper ; ni- 

 trates of copper, of magnesia, and of iron ; sulphates of tin 

 and of alumina, etc. 



PROCESS FOR COVERING COTTON WITH SILK. 



A patent for effecting this object has been granted to A. 

 Miiller, the details of which are stated as follows : He makes 



