l886.] NEW-YORK MICROSCOPICAL SOCIETY. 13 



and rises to the top of the alcohol extract, which is now of a 

 light yellow green color. 



Krauss calls the former xanthophyll, and the latter kyano- 

 phyll, and held with others that the two represent chlorophyll, 

 and both are components of the same green substance. 



According to the investigations of Pringsheim and Weisner it 

 appears that the kyanophyll of Krauss, is relatively pure 

 chlorophyll, but the xanthophyll of Krauss consists of yellow 

 modifications of chlorophyll whose relations to crude chloro- 

 phyll are not fully established. They considered that xanthophyll 

 is a mixtue of three yellows, namely, etiolin, xanthophyll and 

 anthoxanthin. Etiolin is the coloring matter which is formed by 

 etiolated growths breathing in the darkness. 



A NEW HIGH-REFRACTIVE MOUNTING MEDIUM. 



BY PROF. H. L. SMITH. 

 {Read Dec. i%th, 1885.) 

 Since the publication of the formula for a new mounting 

 medium composed of stannous chloride and glycerine jelly,^ I 

 have made what appears to be a very great improvement, by sub- 

 stituting bromide of antimony for the stannous chloride, and 

 boro-glyceride for the glycerine j elly. The boro-glyceride has been 

 prepared for me by Mr, C, F. Booth (Tarrant & Co., Manufac- 

 turing Chemists, N. Y. City), and was first brought to my notice 

 by this gentleman. I use a ^o per cent, solution of this, and it ap- 

 pears, so far, to answer admirably as a substitute for the gelatine, 

 and it possesses the advantage of making a much more solid mount. 

 Antimony bromide is somewhat more expensive than stannous 

 chloride, but it works very kindly in making mounts ; the com- 

 pound can be readily made by any one, and as only a moderate 

 heat is required it can be made in the bottle in which the 

 medium is to be kept. As the moisture of the air will affect 

 this medium, it will be better to prepare it, or at least to keep it, 

 in glass-stoppered bottles. Rubber corks, or indeed the ordinary 

 corks, do not appear to be much affected by it, still a suitable 

 glass-stoppered bottle is to be preferred. 



^American Monthly Microscopical Journal, Vol. VI., No. 9, Sept., 1885. 



