276 M. Chevreul on Fatty Bodies, a>fd [OcT. 



treated with its weight of potash in the digester, and the opera- 

 tion was repeated eight times : a flexible saponaceous mass wa* 

 obtained, which produced a fat that was treated with water 

 of barytes. The soap then produced was acted upon by alcohol,, 

 and yielded 



Acid fat, soluble at 116-5° 0-82 parts 



Fat, which was not acid, soluble at 123-5°. 2*62 



3-44 



By adding together the different products, we have the pro-> 

 portion of acid matter 59-9, and of matter which is not acid 

 401, a result which proves that when cetine is dissolved by the 

 alkaline margarate of potash, the cetine does not undergo all the 

 change which might be produced in it by pure potash. 



M. Chevreul thought it desirable to repeat the preceding train 

 of experiments with a margaric acid which was procured from 

 some other substance besides cetine, because if it was found that 

 the two margaric acids acted in the same manner, it would indi- 

 cate a new point of resemblance between the substances. He 

 accordingly added together 1 1 parts of the margaric acid from 

 the ox, which was fusible at 134-5° ; seven parts of the sperma- 

 ceti of the shops, fusible at 111° ; and 16 parts of water holding 

 in solution 18 parts of potash ; they were digested for some time 

 with 500 parts of water, and after being heated to 158°, a ther- 

 mometer was plunged into the mixture. The fluid was now 

 perfectly opaque and milky ; at 147° it began to grow clear, at 

 140° it was semi-transparent, and at 138° perfectly transparent ; 

 at 131° it was again partially opaque, at 129° the pearly matter 

 began to be visible, at 127-5° it was no longer transparent, at 

 120° there was a great quantity of the pearly matter suspended 

 in it, and the fluid was considerably viscid : the opacity conti- 

 nued to increase as the temperature was lowered. 



The saponaceous mass was then decomposed by muriatic 

 acid ; 17*9 parts of a fatty matter were procured, which was 

 fusible at 117°; this was treated with water of barytes, and 

 the following substances were afterwards obtained: 1. 13-19 

 parts of an acid fat, fusible at 126°, which was formed from the 

 part of the soap that was insoluble in alcohol. 2. 0-423 parts of 

 an acid fat, fusible at 110°; this proceeded from the soap of 

 barytes which had been dissolved by boiling alcohol, and which 

 was deposited from it by cooling. 3. 4-287 parts of a fat which 

 was not acid, fusible at 111°. This last product was treated with 

 potash, and the saponaceous mass which was formed was 

 decomposed by an acid ; a fatty matter was thus obtained, 

 which was boiled with water of barytes, and then subjected 

 to the action of alcohol; the results were ; 1. 1-192 parts of an 

 acid fat, fusible at 71*5° ; 2. 3-095 parts of a fat which was not 



