Milk of the Cow- Tree. 239 



ters have any close resemblance to those of fibrin. It is not un- 

 likely that it was derived from the inner bark of the cow-tree. 



But by far the most abundant constituent of the cow-tree 

 milk is the substance which was dissolved in the hot alcohol. 

 When the alcoholic solution cools, it becomes white and opaque 

 like milk, and gradually deposits abundance of snow-white flakes. 

 If we pour the alcoholic solution upon a filter, these snow-white 

 flakes are retained, and the liquid passes through colourless-like 

 water. When the matter thus retained is exposed to a mode- 

 rate heat it melts, and on cooling assumes the form of a yellow- 

 ish-white, opaque, wax-like substance, which I shall distinguish 

 by the name ofgallactin. 



The alcohol thus freed from gallactin was put into a retort, 

 and drawn off at a low heat, till only a small quantity of fluid 

 remained. A transparent liquid substance gradually separated, 

 as the alcohol was drawn off. This liquid was at first of the con- 

 sistence of oil, and very adhesive. When left exposed to the air, 

 it became gradually more and more viscid, and at length assumed 

 the consistency of turpentine. A cuticle formed on its surface 

 by degrees, which was not in the least adhesive. But the liquid 

 below, when the cuticle was broken, continued as adhesive as 

 ever. Six weeks' exposure to the air produced no farther change ; 

 but when I spread it thin on a plate of glass, it gradually as- 

 sumed the appearance of a stiff, but soft transparent varnish. 



The substance to which I have given the name of gallactin, 

 has been described by MM. BOUSSINGAULT and MARIANO DE 

 RIVERO, under the name of wax, to which it certainly bears a 

 very striking resemblance ; but as it differs from wax in some of 

 its most remarkable properties, I have thought it better to dis- 

 tinguish it by a particular name, which I have borrowed from 

 the generic name assigned by HUMBOLDT to the Cow-tree. 



Gallactin, after it has been deposited from hot alcohol, and 

 melted into a cake, is a solid substance, having a light yellowish- 



