256

ELEMENTS OF MATERIA MEDICA.

Naples , is celebrated for its native sul-phur, which is collected in considerablequantities for the purposes of commerce(Sir W. Hamilton, (Jampi Phlegrtei, 1776).Sulphur is also found in the mineral king-dom in a state of combination. Thussulphurous acid gas rushes out from vol-canoes. Sulphuric acid is found nativeboth in the free and combined states: hy-drosulphuric acid gas is evolved from thepure sulphurous or hepatic waters, andfrom the soil in some parts of Italy andother places: lastly, sulphur is found incombination with sulph ur. Dr. Thomson [Outlines of Mineralogy , &c.vol.i.p. 76) mentions fourteen native sulphurets and seventeen sulphur salts.

[b.) In the organized kingdom. —Sulphur is found in Liliaceee (as in gar-lic) ; in Crucifer a (as in mustard): in Umbelliferce (as in asafoetida), andin many other orders of plants. The alkaline and earthy sulphates arefrequently met with in vegetables. Sulphur is also a constituent of someanimal substances (thus it is found in eggs, urine, &c.); sulphates arefound in the urine.

Preparation. —Sulphur is procured in two ways; by the purificationof native sulphur, or by the decomposition of the native sulphurets. Thesulphur of British commerce is almost exclusively obtained in the firstway. It is brought principally from Italy and Sicily . During the year1830 no less than 236,338 cwts. of rough brimstone were imported fromItaly and the Italian islands ( Parham. Ret. 367, ordered to be printed,April 1832).

[a.) Purification of native sulphur. —In Sicily , from whence most ofthis substance is procured, the native sulphur is submitted to a rude pro-cess of fusion : it is collected in heaps, which are set fire to on the sur-face : the heat developed by the combusion of one portion fuses another(Daubeny, Description of Volcanoes, p. 197).

Another mode of purifying native sulphur is to distil it in earthen pots.These are arranged in two rows in a large oblong furnace (fig. 48, 1,1),

the top of each pot, which serves for the in-troduction of the sulphur and for the removalof the residuum, being kept closed during theoperation. The upper and lateral part ofeach pot communicates with an inclined tubeof about two inches diameter and fourteenlong. When the fire is lighted in the fur-nace, the sulphur fuses and sublimes, andDistillation of native sulphur. p asses through this tube into another pot (2),placed on the outside of the furnace, and perforated near its bottom toallow the melted sulphur to flow into a pail (3) containing water, whereit congeals, and forms the rough or crude sulphur [sulphur crudum ).(Dumas, Traite de Chimie, t. l er . p. 121).

Crude sulphur is purified in this country. The process formerlyadopted was to submit it to fusion in an iron cauldron: the earthy impu-rities subside, and the liquid sulphur is ladled out and cast in moulds.

Fig. 48.

Warm Spring of Solfatara.

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