238 . Mr. Donovan on the nature and combinations 
which when united to lead would not afford crystals. In the 
two latter 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 following properties. 
1. The acid, when separated from the juice, was of a crim- 
son 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. 
3. Its combinations with lime and lead possessed their 
proper characteristics. 
The acid of very young sour apples was combined with 
lead, and the compound treated with boiling water : the 
washings deposited much more crystals than mature apples 
would have done. 
The truth was now manifest. Beside the malic, there is 
another acid formation, which in different fruits is formed at 
different periods, and which has hitherto escaped observation : 
and I consider the preceding details b}^ no means redundant, 
inasmuch as they establish one decided difference between the 
two acids. Many others will shortly be stated. 
The first step towards confirming the difference, was to 
obtain the new acid in a state of purity : and after numerous 
attempts, I found that the only way to obtain it pure, was to 
separate it from the crystals. The process is indeed complex 
and difficult. 
The berries of the Sorbus Aucuparia are to be collected 
