503 



Sorbus aucuparia, or, as it is commonly called in Ireland, the 

 mountain-ash tree. He also stated that malic acid can be 

 formed artificially by the action of nitric acid on sugar in a 

 certain ratio. 



" In this state Scheele's discovery remained for thirty 

 years, viz., until 1815 ; and about that period I made expe- 

 riments on the juice of the berries of the Sorbus aucuparia. 

 In the course of this investigation, so many facts presented 

 themselves, which disagreed with the statements of Scheele, 

 that I began to doubt the existence of malic acid in these 

 berries ; and at length came to the conclusion that the acid 

 contained in them is essentially difi'erent. I contrived a pro- 

 cess for preparing the new acid, which, from its source, I 

 named sorbic, and formed many combinations with it which 

 difiiered altogether in their properties from the analagous com- 

 pounds prepared with Scheele's malic acid. 



" I found that the same acid is contained in apples and some 

 other fruits ; and as in all these Scheele had ascertained the 

 presence of malic acid, I inferred that two acids exist in these 

 fruits, the sorbic being a distinct and peculiar one which had 

 escaped his observation. 1 was strengthened in this conviction 

 by finding that the malic acid, furnished by the plant Sem- 

 pervivum tectorum or houseleek, which Vauquelin proved to 

 contain malate of lime, evinced, when combined with bases, 

 habitudes quite difi'erent from those of the new acid. My con- 

 clusion was still further confirmed by observing that the acid 

 produced by the action of nitric acid on sugar, which Scheele 

 pronounced to be malic, could not by any means be made to 

 furnish combinations similar to those of sorbic acid; that it 

 was in fact totally difi'erent, as has since been proved by the 

 researches of chemists. I therefore presented to the Royal 

 Society of London a paper ' On the Nature and Combinations 

 of a newly discovered Vegetable Acid,' &c., which was pub- 

 lished in the Philosophical Transactions for 1815 : the sorbic 



VOL. IV. 2 p 



