French National tnstllute. 15i 



The juice of onions presented a sharp, volatile and odori- 

 ferous oil, sulphur, plenty of saccharine matter and of mu- 

 cilasre, a vegeto-animal matter coagulable by heat, phos- 

 phoric and acetic acid, calcareous phosphate and citrate, 

 which last had not been previously discovered in vegetables. 

 It is this oil which gives onions their sharp taste previous to 

 their being dressed, and which irritates the eyes ; and it is 

 the sulphur they contain which blackens silver articles, and 

 contributes to the smell which onions give out when in a 

 slate of putrefaction. 



The free phosphoric acid being capable of dissolving the 

 phosphate of lime, would perhaps be useful as a remedy 

 against calculi of the bladder : and this has given rise to an 

 opinion that onion juice is an excellent medicine for the stone. 

 Calculi of uric acid and of oxalate of lime are unfortunately, 

 however, unattackable by it. The acetous fermentation of 

 onion juice develops a kind of manna, differing from the 

 saccharine matter from which it is separated, in so far as 

 the proportion of hydrogen and carbon is more considerable. 

 The milt of fresh-water fishes presented to these in- 

 defatigable chemists an important fact, and one entirely new 

 in the aimals of science. The above substance contains native 

 phosphorus, which is so intimately combined with it that it 

 remains united to its carbon after a total decomposition, 

 forming a true carburet of azoted phosphorus. Human 

 bones of the eleventh century, dug up from the old church 

 of St. Genevieve, and analysed by the same chemists, were 

 found dyed of a fine purple colour and covered with an 

 efilorescence of phosphoric acid and acid phosphate of lime. 

 Messrs. Fourcroy and Vauquelin are of opinion, from this 

 observation, that the exhibition of the phosphoric acid might 

 rather be one of the methods employed by nature for de- 

 composing the bones and restoring them completely to the 

 earth. 



[The report next details Mr. Davy's discoveries, which 

 have l)een already submitted to our readers.] 



M. de Morveau has attempted to apply Galvanism to cer- 

 tain interesting and obscure phaenomena in the mineral 

 kingdom; and particularly to the transition of a sulphuret 

 to the state of oxide, without any alteration of its primitive 

 form : some subterraneous production of electricity seemed 

 to him to explain the facts ; and on subjecting some sulphu- 

 rcts lo the action of the pile, they exhibited the same meta- 

 morphose. 



We know that of all the phjenomena of the mineral king- 

 dom the most perplexing perhaps is thai of btonos falling 

 K 4 from 



