Cheinistry. li 
_ rated in a mortar with its own weight of glassy boracic acid, and 
heated sufficiently in a glass flask, the meconic acid sublimes in 
the state of fine white scales or plates (see Annals of Philosophy, 
_ xiii, 229): This acid, according to Choulant, possesses the 
following properties : 
Taste, strongly acid, with an impression of bitterness. Soluble 
in water, alcohol, and ether. Reddens vegetable blues, and 
changes the solutions of iron to a cherry-red colour. When 
these solutions are heated, the iron is precipitated in the state of 
protoxide. From the experiments of Vogel, we learn that it is 
‘only on the persalts of iron that the meconic acid produces this 
colour.. This property then is common to the meconic and sulpho- 
chyazic acid. Meconic acid, it would appear from the experi- 
ments of Semmering, is not of a poisonous nature.—(Ibid. xii. 
POS) 40 
11. Malic Acid.—A very important set of experiments on the 
different substances, considered as containing malic acid, has 
been published by M. Braconnot. He examined the juice of 
apples, of the house-leek, &c. I consider these experiments to 
leave no doubt whatever that the malic acid of Scheele, when 
brought to a state of purity, is identical with the sorbic acid of 
Mr. Donovan: Of course there are not two distinct acids, as has 
been hitherto supposed, but merely one acid. It has been called 
malic acid when in a state of impurity, and sorbic acid when 
obtained in a sufficiently pure state. ‘To Mr. Donovan then we 
are indebted not for the discovery of anew acid, but for pointing 
out a method of obtaining an old acid ina state of purity, and of 
course in such a state that its characters can be recognized and 
established. Since this is the case, it seems but fair to return 
again to the original name given to this acid by Scheele, who 
was undoubtedly the original discoverer of it, though he did not 
succeed in procuring it in a state of complete purity. 
Malic acid then, when pure, is colourless, soluble in water, 
alcohol, and ether, and is capable of crystallizing. It is readily 
sublimed when heated, but the sublimed crystals possess charac- 
ters somewhat different from those of malic acid before it has 
been exposed to heat. The acid, thus altered, has been called 
pyro-malic acid. 
Malate of magnesia and malate of zinc crystallize readily ; but 
malates of potash and soda are incapable of crystallizing. 
Pure malic acid neither precipitates nitrate of lime, nor nitrate 
of silver, nor nitrate of mercury. With acetate of lead it forms 
a white precipitate soluble in distilled vinegar, and even in boil- 
ing water. It produces no sensible change when dropped into 
lime or barytes-water. Such readers as are interested in vege- 
table physiglogy should peruse the paper of Braconnot above 
alluded to. Itis to be found in the Ann. de Chim. et Phys. viii. 
149. A good deal of valuable information will be found likewise 
. in M. Braconnot’s paper on ae acid, and in that of M. Vau- 
2 
