CHEMISTRY. 207 



yellow tint to wool, but does not in the least affect cotton, linen, 

 jute, or china-grass. In the examination of ribbons and some 

 other stiffened goods, it is often necessary to immerse them for a 

 few minutes in boiling water to dissolve out the starch or size 

 prior to applying the chlorhydric acid test ; for, by this simple 

 expedient, the results are rendered much more decisive. 



The mucilaginous solution of silk in chlorhydric acid cannot be 

 evaporated even over a water-bath, without becoming somewhat 

 carbonized. The brownish uncrystallizable residue left on evap- 

 oration reacts acid on test-paper, and has, when warm, an odor 

 suggestive of caramel. If to the residue which remains after 

 evaporating the silk solution under a bell-jar over slaked lime,, 

 ammonia be added in excess, a clear solution results, which may 

 find some application in photography; for, when this liquid is 

 evaporated, there is left, a brown saline mass of rough astringent 

 flavor, which, when mixed with an aqueous solution of nitrate of 

 silver, gives a peculiar flocculent form of chloride of silver, which 

 is no longer curdy, and which is much more rapidly affected by 

 light than the ordinary chloride. These properties enable the 

 silk compounds to be usefully employed in the production of 

 "matt-paper" prints, and direct solar-camera enlargements. 

 J. Spiller before British Association, 1870. 



Phcni/l Broivn, the so-called Plienicienne. MM. Bollcy and 

 Hummel. This substance, also called rotheine, is not to be con- 

 founded with the brown coloring matter made by Messrs. 

 Roberts, Dale, & Co., at Manchester. The phenyl brown of M. 

 Roth's invention is a substance which, without the use of any 

 mordant, yields, upon silk and woollen fabrics, fast colors. Since 

 it has been alleged that the brown dye alluded to is possessed of 

 explosive properties, the authors have investigated the manufac- 

 ture, and the reactions which take place during the process. 

 The authors find that, when a mixture of nitric and sulphuric 

 acids (1 part of the former of a sp. gr. of 1.35, and 2 of the latter, 

 concentrated) are made to act upon phenol, two different prod- 

 ucts are always produced, one of these a solid substance, 

 sometimes like thick tar, sometimes grainy; and a deep red- 

 colored liquid. When this latter is poured into cold water, a 

 pulverulent brown-colored substance is precipitated, which pos- 

 sesses all the characteristic properties of commercial phenicienne. 

 The result of the researches arrived at by the authors is, that 

 the phenicienue is a compound mixture of binitro-phenol, and a 

 peculiar amorphous substance, which has some likeness to the 

 ulinic and huniic substances, but the precise nature of which has 

 not been ascertained. Moniteur Scientifique. 



Naphthaline lied. This coloring matter is called in England 

 Magdala Bed, in honor of Lord Napier, the hero of Abyssinia, in 

 imitation of the French names of Magenta and Solferino for 

 aniline colors. It is prepared by the action of nitrous acid on 

 naphthylamine, and is manufactured in large quantities in France 

 and England. It is a dark brown powder soluble with deep red 

 color in boiling alcohol, only slightly soluble in cold water, but 

 largely in hot water ; not soluble in ether. The solution in alco- 



