1813.] 



<md some other Animals, 



335 



The same cLarcoal, exposed to heat a second time, burnt 

 with a slight flame of phosphorus ; but after a certain interval it 

 softened as before, and assumed the form of a paste. It was 

 washed a second time, and the water became acid, as before. 

 These proces es were repeated in the same manner till the wliole 

 of the charcoal was consumed. 



The water employed in washing the charcoal being evaporated, 

 yielded a white deposite, with a tint of blue, and a pasty con- 

 sistence. This deposite, being separated from the liquor by the 

 filter, melted very readily into a transparent glass. The same 

 deposite reduced to powder, and mixed with diluted sulphuric 

 acid, furnished sulphate of lime, but in a quantity v»?hich did 

 not correspond with that of the matter employed. 



Ammonia being mixed with a small portion of the liquid 

 from which the above-mentioned deposite had been separated, 

 occasioned only a very slight precipitation. Caustic potash, on 

 the contrary, occasioned a very plentiful one. This last preci- 

 pitate was chiefly magnesia, while the deposite formed sponta- 

 neously in the liquor was phosphate of lime. 



As every thing seemed to show that the acidity of the liquor 

 mentioned above was due to phosphoric acid^ lime-water was 

 mixed with it till no farther precipitation took place. This last 

 precipitate being washed, was dissolved in muriatic acid, and the 

 lime precipitated from it by means of oxalate of ammonia. The 

 liquor of this last experiment was treated with caustic potash f 

 *but no precipitate took place while it remained cold. A boiling 

 heat being employed, a flocky precipitate was obtained, which 

 "possessed the properties of magnesia. 



The liquor precipitated by lime-water, as mentioned above^ 

 %as evaporated in ao open vessel, that the excess of lime might 

 fall down. After filtration this liquid had a yellowish colour, a 

 caustic taste, and precipitated abundantly nmriate of platinum 

 yellow. This liquor, when concentrated, was left in the open 

 air, that it might crystallize, and that it might be seen whether 

 it contained soda : but a!' the experiments to which it was sub- 

 jected demonstrated thai it wasoniy potash partly saturated with 

 carbonic acid. 



These exT>erimerits on the combustion of the brain prove that 

 the salts contained in that organ are phosphates of lime, of 

 magnesia, and of potash. 



The matter of the brain, after having been repeatedly boiled 

 in alcohoi, being burnt in a platinum crucible, exhibited almost 

 the same phen<*mena as i! e brain in its natural state ; that is to 

 say, it decrepitated and flamed, but emitted less smoke ; and its 

 charcoal bejng calcined, did nut soften, and ^:ave no signs of 

 acidity. 1 his proves that the cuntjiltuents which produced this 



