"Take of amber in powder, and pure sand, equal parts; mix, and put them into a glass retort, of which they may fill one half. Having adapted a large receiver, distil from a sand-bath, with a gradually raised fire. A watery liquor with a little yellow oil will first distil over: then a yellow oil with an acid salt; and, lastly, a reddish and black oil. Pour the liquor out of the receiver, and let the oil be separated from the water. Press the acid salt, collected in the neck of the retort and on the sides of the receiver, between folds of bibulous paper, that it may be freed from the adhering oil; then purify it by solution in hot water, and crystallization."

Acidum succinicum et oleum succini, Dub. Succinic Acid.

"Take of amber coarsely powdered, and pure sand, each a pound. Distil, with a gradually increased heat, an acid liquor, an oil, and an acid under the form of crystals. Wrap up this salt in bibulous paper, and subject it to the press to separate the oil; then let it be again sublimed. The oil strained through the bibulous paper may be obtained separate from the acid liquor."

Syn Acide Succinique (F.), Bernsteinsaure (G.), Acido Succinico (I.).

The use of the sand in these processes is to prevent the amber, which swells very much, from passing over into the receiver. The heat which is necessary for the complete decomposition of the amber is very considerable; and therefore, by following exactly the formulae of the colleges, this is scarcely ever accomplished. The succinic acid is partly dissolved in the water which condenses in the receiver, but the greater part is sublimed in the neck of the retort, and is so much contaminated with the oil, that after repeated solution and crystallization, and even resublimation, it still retains a portion of it. According to Guyton Morveau2, it may be obtained perfectly pure by distilling from double its weight of nitric acid, with a heat not strong enough to sublime the succinic acid, but sufficient to evaporate the solution to dryness. The oil is decomposed, and the acid remains untouched. It is then to be well washed in a little water, and crystallized by dissolving it in boiling water and evaporating.

Qualities. - The crystals of succinic acid are minute quadrilateral prisms. When pure, they are white, translucent, and shining; have a slight, penetrating, sour taste; redden infusion of litmus; are unalterable in the air, volatile and inflammable, and burn away without leaving any odour. They are soluble in twenty-four parts of water at 60°, and two parts at 212°; the greater part, however, crystallizing as the water cools. They are also soluble in alcohol, and in sulphuric and nitric acid, without suffering decomposition. With the alkalies, earth, and metallic oxides, succinic acid combines and forms succinates. It is a triple compound of 47.600 parts of carbon, 4.512 of hydrogen, and 47.888 of oxygen1; or of 4 equivalents of carbon=24.48 + 3 of oxygen =24 + 2 of hydrogen =2 = 50.48.

1 Edin. Med. Journ. vol. xix. p. 198.

2 Annales de Chimie, xxix. 165.

This acid is often adulterated with tartaric acid, hydro-chlorate of ammonia, and sulphate of potassa. The first is detected by carbonate of potassa; the second by nitrate of silver; and the sulphate by barytic water. It is altogether discarded from practice.