Page:Scientific Memoirs, Vol. 1 (1837).djvu/167

 however, is only a sign for a certain expression, and thus considered it is perfectly indifferent what name may be chosen for any substance.

The fluid oil of the blossoms of the Spiræa Ulmaria is hydrospiroilic acid. This may be obtained by distilling the flowers with water; about as much water is to be distilled off as was originally employed.

The product of the distillation is however subjected to a redistillation till about ⅕th is come over in the receiver. A concentrated aqueous solution of the oil is thus obtained, and the oil itself, though only in very minute quantities. The oil is heavier than water, is of a light yellow colour, and possesses the odour of the blossoms in a very great degree. It mixes in all proportions with alcohol and æther, and is slightly soluble in water. It causes a burning sensation on the tongue. The fumes which come over during the distillation of the oil first render litmus-paper green, and then bleach it. The aqueous solution of the oil first of all slightly reddens tincture of litmus, and then deprives it of its colour excepting a greenish shade. It is inflammable, and burns with a shining smoky flame. If the oil be passed through a red-hot tube containing pieces of iron, neither ammonia nor prussic acid is obtained nor can the formation of any sulphuret of iron be detected. The oil does not experience any change either in dry or moist oxygen gas; it volatilizes unchanged. It solidifies at a temperature of – 20° *. Its boiling-point is about + 85°*, when it evaporates entirely without leaving any residue.

With the bases of salts, namely, with the alkalies and alkaline earths, it easily combines, forming insoluble or difficultly soluble compounds.

Concentrated sulphuric acid converts the oil into a black carbonaceous mass. Chlorine and bromine decompose it instantaneously, hydrochloric or hydrobromic acid and chloride or bromide of spiroil being formed. Nitric acid, if not too concentrated, immediately forms spiroilic acid; if however the acid be very concentrated and fuming, it immediately changes it into a yellow, very volatile, bitter-tasting compound, having the appearance of butter.

The experiments on the composition of the anhydrous oil, as well as the other compounds, were made in the usual manner with oxide of copper.

according to which 290 parts of the oil contain

Probably Centigrade.—.