of a newly-discovered vegetalle Acid. 437 



The raspberry was found by Scheele to contain the same 

 acids. I examined this fruit in a similar manner, but no crystals 

 were produced. 



Vauquelin detected malic acid in a variety of plants, but in 

 none so abundantly as the. Seynpervivum Tcctonim. In the juice 

 of this plant it is united to lime in the state of a supersalt*. 



Malate of lead was formed by pouring solution of acetate of 

 lead into the filtered juice of this plant. The precipitate, when 

 washed wiih boiling water, deposited on cooling the same sub- 

 tile powder as usual, but no crystals. Nor were any obtained 

 when the malate was partially decomposed Ijy sulphuric acid, in 

 the manner already described. 



Scheele found that the berries of the Samhucus nigra contain 

 the malic acid unmixed with any other. I therefore examined 

 their very mucilaginous juice, but could not ])roduce crystals. 



As in my experiments on apples I had obtained crystals, I 

 wished to try what effect the vinous fermentation might have on 

 their juice. The process v/as repeated with cyder ; but I was 

 surprised to find, that although a malate of lead was obtained, 

 the property of forming crvstals had l)een destroyed. 



From various conjectures it apjjeared possible that the berries 

 of the Sorbus, while very young, might perhaps contain a malic 

 acid that would furnish few or no crystals. In the beginning 

 of x\ugust (1812), the berries being still green, I made an in- 

 fusion of them, which after filtration aiforded a precipitate with 

 acetate of lead. Boiling water produced no crystals, nor did 

 the mass become hard as on former occasions. 



Seven varieties of malic acid had noiv been examined, which 

 when united to lead avouUI not afford crystals. In the two lat- 

 ter cases it was surprising that those acids which in other trials 

 afforded abundance, would now afford none. That the juice of 

 the green berries was real malic acid, was proved by the follow- 

 ing properties : 



1. The acid, when separated from the juice, was of a crimson 

 colour. 



2. When evaporated to dryness, it soon deliquesced. 



3. When rendered solid, and acted on by nitrous acid, some 

 crystals of oxalic acid appeared. 



4. The acid formed deliquescent salts with potash, soda, and 

 ammonia. 



5. Its combinations with lime and lead possessed their pro- 

 per characteristics. 



The acid of very young sour apples was combined with lead, 

 and the compound treated with boiling water: the washings 



• Attnahi de. Chimie, tome xxxiv. p. 12f. 



E e 3 deposited 



