536 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



cined, suddenly cooled in water, and triturated with 5- 1 parts 

 of calcined bones and 3 of quartz. The dried article is finally 

 heated in a muffle, in a furnace similar to a porcelain furnace, 

 when both coatings fuse and mix, thus forming the enamel. 

 5 C, 1874, xxi., 166. 



SOLUBLE SESQUIOXIDE OF IRON IN DYEING SILK. 



The injurious effect of the usually very acid mordants upon 

 the durability of silk may be avoided by employing the aque- 

 ous solution of peroxide of iron, which remains in a dialyser, 

 supplied with a bottom of animal membrane or parchment 

 paper, and filled with a solution of chloride of iron, and float- 

 ed for some time in a vessel of water, the larger part of the 

 hydrochloric acid passing into the water. This solution is 

 also much more effective than the usual iron mordant, since 

 the affinity of the iron for the silk is not weakened by an 

 acid. In fact, mordanting by iron salts seems itself to rest 

 upon a dialytic process. 32 C, May 16, 1874, 240. 



DYEING WITH ANILINE BLACK. 



According to a process patented in France, the articles are 

 first stooped for two hours in a solution of 6 pounds of iron 

 in 20 pounds of hydrochloric acid and 2|- gallons of water, 

 after addition of enough water to bring it to 12 Baurne. 

 They are then exposed to the air for twelve hours, and are 

 finally dyed by heating them in a water-bath, in a closed 

 cylindrical vessel capable of turning on an axis, first to 86, 

 and then gradually up to 122 at the close of the operation, 

 in an aniline-salt solution prepared, for 66 pounds of stuff, of 

 6.6 pounds of aniline and 11 pounds of hydrochloric acid, to 

 which a solution of 4.6 pounds of chlorate of potash in 8 gal- 

 lons of water has been added. The development of the color 

 requires three to five hours, and it is fixed with bichromate 

 of potash, and the goods are finally drawn through an oil- 

 bath. 32 (7, May 16, 1874, 238. 



EGYPTIAN BLUE. 



Specimens of the so-called Egyptian blue, taken from Ro- 

 man ruins at Autun and a Gallic castle at Beuvray, were ex- 

 amined by Fontenay. They consisted of small round pieces 

 about the size of a marble, and afforded a beautiful turquoise- 



