438 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



tity of absolute alcohol be gradually added, a beautiful blue 

 color is developed, as if by magic, by means of which silk can 

 be dyed without the use of any mordant. 8 C, xxvu., July 

 C, 215. 



NEW COLORING MATTERS. 



Professor Baeyer has lately brought to the notice of the 

 Chemical Society of Berlin a new class of coloring matters. 

 Thus, if pyrogallic acid be melted with naphthalic acid and 

 some other substances, a new coloring material is obtained, 

 named by him gallein, which appeal's in the form of either a 

 brownish-red powder, or of small metallic green crystals. If 

 this be boiled with a good deal of water, with addition of 

 zinc and dilute sulphuric acid, the dark color of the liquid is 

 transformed, after a certain time, into a light reddish-yellow. 

 Some resinous matter will be separated from this by filtering, 

 and the liquid becomes clear, but, on cooling, is clouded again 

 by the separation of some oil-drops, which, after a time, be- 

 come crystallized. Ultimately large brownish-red crystals 

 are obtained, which consist of gallin mixed with a little gal- 

 lein. 



If gallin be heated with twenty parts of concentrated sul- 

 phuric acid to 200 C, the reddish-brown color of the solution 

 changes after a time to a greenish-brown. After the reaction 

 is completed, the mass is to be boiled in a large amount of 

 water, and the very voluminous deposit washed with hot wa- 

 ter. This consists of ccerulein, a substance readily soluble in 

 hot aniline, with the production of a beautiful indigo-blue 

 color. Other substances referred to in Professor Baeyer's 

 paper are ccerulin, reforcin, fluorescein, etc., the latter of which 

 will impart a beautiful yellow color to silk and wool without 

 any mordant. 



Attention is called to the similarity of gallein, gallin, cceru- 

 lein, and ccerulin to the coloring matter of wood. The rela- 

 tionship is particularly striking between gallein and the col- 

 oring matter of logwood, and between ccerulein and the lokao 

 of the Chinese. 25 (7, xxvu., July 16, 222. 



MATERIAL FOR BLEACHING WOOL. 



According to a patent lately taken out in Melbourne by 

 Lande, one sixteenth part of soap and one part of cyanide of 



