506 Mr. Beetz on the Spontaneous Change of Fats. 



This composition is the same as that of stearine from mut- 

 ton tallow, according to the authority of Lecanu. I insert 

 here an analysis of stearine, made by Liebig and Pelouze, 

 and the result of their calculation, in order to compare them 

 with the analysis made by myself. 



Liebig and Pelouze. Calculated. 



146 C =76-14 76-21 



236 H= 12*30 12-18 



17 O = 11-56 11-61 



100-00 100-00 



The solubility of the substance is also the same as that of 

 stearine, and the difference of the temperatures at which the 

 two bodies melt is very small. The melting point of stearine 

 is 62°, that of the body under examination 59°, while that of 

 tallow is not more than 37° C. 



A portion of the body was saponified by soda. The soap 

 was solid and hard, and when dissolved in hot water it formed 

 on cooling a gelatinous mass, even when the quantity of soap 

 was very small. It was decomposed by hydrochloric acid, and 

 the fat acid obtained in this manner was also hard and brittle ; 

 its melting point was 60° C. 



On burning the acid with oxide of copper, the following 

 result was obtained : — 



0*3215 gr. of the substance gave 0*3715 gr. of water and 

 0-836 gr. of carbonic acid. 



This composition, calculated to the 100 parts and compared 

 with the analysis and the calculation of stearic acid made by 

 Berzelius, gives the following results: — 



Calculated. Berzelius. Found. 



70 Carbon =79-963 80-145 79-40 



134 Hydrogen =12-574 12-478 12-81 



5 Oxygen = 7*463 7*377 7*79 



It cannot be supposed that this fat came into the mine in 

 the form of stearine, but most probably it had been a miner's 

 candle, and had probably been changed into stearine by the 

 continuous action of water, for the composition of stearine 

 differs from that of tallow in its containing a greater percen- 

 tage of carbon. Tallow contains to 100 parts of carbon, 

 14*81 hydrogen and 11*76 oxygen. Stearine to the same 

 quantity of carbon, 16*02 hydrogen and 15*14 oxygen; so that 

 this change can be accounted for by supposing that the tallow 



