ACTION OF POTASH UPON CHOLESTERINE. 265 



that the air in the interior arrived at 248° Fah. a change began 

 to take place in the mixture, and at 266° Fah. it was of a dark- 

 brown color. 



This was now treated with cold ether, which dissolved the 

 unaltered cholesterine, and also a matter of a resinous character, 

 which when dissolved in alcohol, and the alcohol allowed to 

 evaporate spontaneously, is deposited in the form of little round 

 concretions entirely devoid of crystalline structure. It is not 

 soluble in any of the alkalies. What remains after the treat- 

 ment by ether is of a brown color and completely soluble in 

 water. If hydrochloric acid be added to this solution it is 

 decomposed, and a yellowish substance arises to the surface. 

 This substance is soluble in ether, alcohol, potash, soda, and 

 ammonia, as well as their carbonates. It does not crystallize. 

 Its alcoholic solution reacts slightly acid upon litmus-paper. 

 In fact it is an acid of a resinous character. Its combinations 

 with alkalies have the character of soaps. Its silver-salt is of a 

 yellow color, but soon becomes black by exposure to the light. 



From the small quantity of cholesterine that was at my 

 disposal I have not been able to obtain sufficient of the acid 

 to examine its composition, but I have no doubt that it is a 

 new one. 



If the mixture when heated be not well exposed to the air, 

 very little of this acid is formed, even if we elevate the tem- 

 perature as high as 300° Fah. ; but, on the contrary, a consid- 

 erable quantity of the resin before mentioned (soluble in ether), 

 is formed. This though is capable of being converted into the 

 acid by the action of potash, a high temperature, and free 

 access of air. Thus then it will be seen that the action of 

 potash, instead of being a means of showing that spermaceti 

 and cholesterine are two substances of entirely different natures, 

 affords strong evidence of their being similar bodies. Further, 

 the action of potash upon spermaceti is to produce athalic acid 

 and athal, the former capable of forming soaps with the alkalies, 

 and the latter of being converted into the former by an alkali 

 and a high temperature. 



The action upon cholesterine is to form an acid (which it is 

 impossible for me as yet to name) and a basic resin. The 

 former forms soaps With alkalies, and the latter by the action 

 of potash at a high temperature is converted into the former. 



