Sulphocyanates

Sulphocyanates, or SULPHOCYANIDES, are prepared by fusing cyanides with sulphur. These salts do not possess the poisonous character of the cyanides. Sulphocyanide of potassium, KCNS, is anhydrous, but very deliquescent, and occurs in long streaked colourless prisms, somewhat resembling nitre both in appearance and taste; it is extremely soluble in water, and fuses on the application of a gentle heat. The sulphocyanide of mercury is a white powder which possesses the property of swelling or growing in size to an almost incredible degree when moderately heated. The resulting mass often assumes a most fantastic shape, and is sufficiently coherent to retain its form; it is of a yellow colour externally, but black within. It is this sulphocyanide which is the ingredient of the toy known as 'Pharaoh's serpents.' Each serpent consists of a little cone of tinfoil, resembling a pastille in shape, and filled with the above-named compound. On lighting the cone at the apex, there begins to issue from it a thick serpent-like coil, which continues twisting and increasing in length to an extraordinary degree, the serpent-like shape resulting from the salt being burned in the tinfoil cone.