234 Afr. Donovan cw the nature and combinations 
. ceptionable method appeared to be the transmission of sul- 
phuretted hydrogen through the clear liquor. This was 
accordingly done, after having heated the acid liquor so as to 
redissolve the crystals and sediment. The resulting sul- 
phuret of lead was filtered off, and the clear fluid was boiled 
for a length of time, to expel the superfluous gas. 
Supposing now that I had obtained the pure acid, I began 
to form various conjectures as to its nature ; in the midst of 
which I discovered, that the berries of the Sorbus Aucuparia 
had already occupied the attention of Scheele, and that he had 
pronounced their acid to be the malic. There was indeed a 
great coincidence of properties between the two acids : malic 
acid is red, when evaporated to dryness it deliquesces, its 
combinations with potash, soda, and ammonia are deliquescent ; 
such were also the properties of the acid under consideration. 
Yet I had never understood that malate of lead could be made 
to afford crystals : an experiment on this head, therefore, be- 
came necessary. 
The juice of nearly ripe apples was saturated with potash, 
and the solution when filtered, was mixed with solution of 
acetate of lead : the precipitate was collected on a filter. 
This after being edulcorated was washed with boiling water, 
as before. In sixteen hours, crystals, precisely the same as the 
berries had afforded, were deposited, although less in quantity. 
The production of crystals in both these cases, seemed to 
show that the acid of both fruits was the same : yet there 
was one difference. The precipitate remaining on the filter, 
after the action of boiling water, was, in that produced from 
apples, soft and pasty; but that obtained from the Sorbus 
berries was hard and dense. It became therefore necessary. 
