Amorphous sulphur, Brown s.; Sulphur amorphum, S. fuscum, S. informe, S. rubrum, L. Prepared from sublimed sulphur, by melting it, increasing the heat to from 320° to 350° Fahr., and continuing it at that temperature for about half an hour, or until it becomes brown and viscid, and then pouring it into water. In this state it is ductile, like wax, may be easily moulded in any form, is much heavier than usual, and when it has cooled does not again become fluid until heated to above 600° Fahr. The same effect is produced more rapidly by at once raising the temperature of the melted mass to from 430° to 480° Fahr.
Precipitated sulphur, Hydrate of sulphur, Milk of s.; Sulphuris hydras, Lac sulphuris, Sulphur præcipitatum (Ph. L.). Prep. 1. From sublimed sulphur, 1 part; dry and recently slaked lime, 2 parts; water, 25 parts, or q. s.; boil for 2 or 3 hours, dilute with 25 parts more of water, filter, and precipitate with dilute hydrochloric acid; drain, and well wash the precipitate, and dry it by a gentle heat. Resembles sublimed sulphur in its general properties, but is much paler, and in a finer state of division.
2. (B. Ph.) Sublimed sulphur, 5 oz.; slaked lime, 3 oz.; hydrochloric acid, 3 fl. oz., or q. s.; distilled water, q. s. Heat the sulphur and lime, previously well mixed, in 1 pint of water, stirring diligently with a wooden spatula, boil for 15 minutes and filter. Boil the residue again in 1⁄2 pint of water and filter. Let the united filtrates cool, dilute with 2 pints of water, and in an open place, or under a chimney, add in successive quantities the hydrochloric acid previously diluted with 1 pint of water until effervescence ceases, and the mixture acquires an acid reaction. Allow the precipitate to settle, decant off the supernatant liquid, pour on fresh distilled water, and continue the purification by affusion of distilled water and subsidence, until the fluid ceases to have an acid reaction, and to precipitate with oxalate of ammonia. Collect the precipitated sulphur on a calico filter, wash it once with distilled water, and dry it at a temperature not exceeding 120° Fahr.
Prop. A greyish-yellow powder free from grittiness, and with no smell of sulphuretted hydrogen.
Obs. Many pharmacists regard Lac sulphuris and Sulphur precipitatum as distinct substances, and assume that by milk of sulphur is intended a preparation made by an old pharmacopœial process, in which sulphuric acid being employed, the sulphur so precipitated contains from 50 to 75 per cent. of sulphate of lime. Pareira, Royle, Atfield, and some other authorities, hold that Lac sulphuris and Sulphur precipitatum are synonymous; whilst others, including Professor Redwood (one of the compilers of the B. P.) entertain a contrary opinion.
Roll sulphur, Cane s., Stick s.; Sulphur in bacculis, S. in rotulis, S. rotundum, L. This is crude sulphur, purified by melting and skimming it, and then pouring it into moulds. That obtained during the roasting of copper pyrites, and which forms the common roll sulphur of England, frequently contains from 3 to 7% of yellow arsenic.
Sublimed sulphur, Flowers of sulphur; Flores sulphuris, Sulphur (Ph. L.), Sulphur sublimatum (B. P., Ph. E. & D.), L. Prepared by subliming sulphur in iron vessels. For medical purposes, it is ordered to be well washed with water, and dried by a gentle heat. “A slightly gritty powder, of a fine
greenish-yellow colour, without taste and without odour till heated.” (B. P.)
Sulphur vivum, Black sulphur, Crude s., Horse brimstone; Sulphur nigrum, S. caballinum, S. Griseum, L. This is crude native sulphur. It is a grey or mouse-coloured powder. The residuum in the subliming pots from the preparation of flowers of sulphur is now commonly substituted for it. It generally contains much arsenic, and is consequently very poisonous.
Pur. The sublimed sulphur of the shops is now, in general, of respectable quality, but the precipitated sulphur frequently contains about 2⁄3 of its weight of sulphate of lime (plaster of Paris), owing to the substitution of sulphuric acid for hydrochloric acid in its manufacture.[211] This is readily detected by strongly heating a little of the suspected sample in an iron spoon or shovel, when the sulphur is burnt or volatilised, and leaves behind the sulphate of lime as a white ash; this, when mixed with water, and gently dried, gives the amount of the adulteration. A still simpler plan is to dissolve out the sulphur in the sample with a little hot oil of turpentine or liquor of potassa; the undissolved portion is foreign matter.