352 On Shea Butter and Chinese Vegetable Tallow. 

 and the atomic weight of the anhydrous salt is — 



Acid .... 33*97 

 Oxide of silver . 14<'50 



48-47 



or leaving out the two last determinations, we shall have as a 

 mean for the three higher results the atomic weight of the acid 

 equal to 33-82. To determine the composition of the anhy- 

 drous acid, the three following analyses were made by means 

 of oxide of copper and chlorate of potash. : — 



I. 2-85 grs. of silver salt gave HO=2-30 grs. and C02=5-73 grs. 

 11. 3-91 ... ... =3-39 ... =7-87 ... 



III. 3-667 =3-058 ... =7-334 ... 



The following table gives the composition of the above salt 

 in 100 parts : — 



C 



H 

 O 

 Ago 



From the facts which have been stated in reference to the 

 acid contained in the shea butter, it is obvious it is margaric 

 acid, the same substance which is found in the human fat 

 and in butter. There is little doubt that on examination this 

 acid will be found extensively distributed in the vegetable 

 kingdom : its presence in the shea butter may assist in ex- 

 plaining the statement of Park, that this substance when fresh 

 is equal in taste to butter. 



Ckitiese Vegetable Tallow. — This is a solid oil, long known 

 to those who are acquainted with China, where it is exten- 

 sively used for making candles. It is derived from the seeds 

 of Siillingia sebi/era, which, according to Fortune ( Wander- 

 ings in China, p. 65), are pulled in November and December. 

 They are placed in a wooden cylinder with a perforated bottom 

 over an iron vessel filled with water, which is boiled and the 

 seeds well-steamed to soften the tallow; in ten minutes they 

 are thrown into a large stone mortar, and beat with stone 

 mallets to separate the tallow from the other parts of the seed : 

 the tallow is thrown on a sieve heated over the fire and sifted, 

 and is then squeezed out by a peculiar pro«:':oS. As imported 

 it is a hard, white, solid oil, with a green shade. It fuses at 

 about 80°. The oil was saponified, and the acid separated 

 and purified according to the method already noticed. A soda 

 salt was formed, and from this a silver salt was precipitated. 

 14-38 grains of this salt when burned left 4*03 grains of me- 



