The aqueous solution of spiroilate of soda gives with acetate of lead a yellow, and with salts of copper a green, precipitate.
Sesquichromate of iron is not precipitated by spiroilate of soda, but is coloured deep cherry-red by it, as well as by the spiroilide.
If the salts of spiroilic acid are heated in contact with the air, they detonate briskly, leaving behind either a pure or carbonated base, and a soft powdery carbon.
If spiroilic acid be mixed with an easily inflammable substance, as sulphur, the mixture detonates when heated.
Fuming nitric acid acts very violently upon spiroilic acid; fumes of nitrous acid are immediately evolved, whilst a yellow semifluid mass is formed, which solidifies only after several days. This yellow substance has an intensely bitter taste, and colours the saliva, skin, and nails, &c. deep yellow; it is fusible and may be distilled, and possesses in a striking degree the smell of fresh butter; no oxalic acid is formed. Submitted to distillation with water, it distils over undecomposed with the water, partially dissolved and partly as a yellow powder.
If the residue of the aqueous solution after the yellow body has gone over be slowly evaporated, transparent colourless prismatic crystals are obtained, the nature of which requires further investigation.
An analysis of this substance, which appeared to possess acid properties, was several times commenced; but even by the most careful application of heat, the oxide of copper was always projected into the tube containing the chloride of calcium, whilst part of the substance was often conducted undecomposed into the potash apparatus. Nevertheless the determination of the carbonic acid has several times been accomplished: from the data thus obtained, this yellow substance must be very rich in oxygen.
Chloride of Spiroil.
Chloride of spiroil may be obtained by decomposing hydrospiroilic acid by means of chlorine. In a suitable apparatus and without the application of heat, dry chlorine gas was passed over the anhydrous acid; evolution of muriatic acid immediately commenced: if the chlorine be evolved but slowly, only a slight elevation of temperature takes place. Chlorine is to be passed through this solution so long as fumes of muriatic acid are evolved: the hydrospiroilic acid is entirely converted into a white crystalline mass.
If however the oil is become solid, the chlorine apparatus must be moved, and the chloride of spiroil which has been formed must be sublimed by the lowest possible heat.
The most beautiful crystalline plates of a dazzling whiteness are obtained, which melt at a very low heat, and, as has been before remarked, may easily be sublimed.
