D. CHEMISTKY AND METALLURGY. 95 



principal constituent of chlorophyl, which owes its color to a 

 mixture of these two substances. 6. Dead leaves of a brown 

 color contain, with very little of chlorophyl remaining unaf- 

 fected, a great excess of the yellow matter of Filhol. 1 E, 

 part vi., 1871, 114. 



RED COLOR OF APHIS. 



Mr. Sorby has lately described a red coloring matter found 

 in some species of Aphis (or plant louse), named by \\\vnAph- 

 ideine. This resembles cochineal in some of its characters, 

 but in others the red coloring matter of the blood of verte- 

 brate animals, though entirely distinct from either. It can 

 exist in an oxidized and in a deoxidized state, and thus may 

 perhaps serve to convey loosely combined oxygen from the 

 respiratory organs to other parts of the body. One of its 

 most remarkable peculiarities is that it rapidly passes into 

 a series of fluorescent products, giving remarkable spectra, 

 which, unlike the original substance, are not dissolved in wa- 

 ter, but are soluble in bisulphide of carbon, and thus are like 

 the coloring matters of wax and oils, which they also resem- 

 ble in their general consistence, when left dry on evapora- 

 tion. This change is so rapid that it occurs in the course of 

 a few minutes, when the living insects are crushed and ex- 

 posed to the air ; and special care was therefore required to 

 prove that none of these fluorescent substances exist during 

 life, and that the fatty matter then found is similar to that 

 met with in other insects. 13-4, October 15, 1871, 481. 



CRYSTALLIZED INDIGOTINE, 



it is reported, may be made by solution in hot phenol, which 

 takes up the indigotine and redeposits most of it on cooling 

 in a crystalline form, retaining enough to color the acid deep 

 blue. To prevent a solidification of the phenol during re- 

 frigeration, alcohol, camphor, or benzine may be added. Five 

 hundred grains of phenol will serve for the preparation of 

 two grains of pure indigotine. 21 A, March, 1872, 250. 



INDOPIIAN, A NEW COLORING MATERIAL 



similar to indigo, is obtained as an accessory product when 

 dinitronaphthal is acted upon by potassium cyanide, being 

 converted thereby into naphthyl-purpuric acid. When pure 



