Sulphur or brimstone is a well-known yellow substance largely used in the manufacture of matches, gunpowder and sulphuric acid. Aside from these uses, which are of interest only to large manufacturers, sulphur is employed for bleaching, disinfecting, making moulds for plaster casts, and as a cement for fastening iron bars in stone sockets.
Sulphur, when burned, produces sulphurous acid, a gas which destroys most vegetable colors and the germs of most diseases. As a bleaching agent it is sometimes to be preferred to chlorine, as it does not injure the fabrics so much. The method of using it is to hang the articles to be bleached in a large box or closet in which the sulphur is afterwards burned. The easiest way to burn the sulphur is to dip heavy brown paper in melted sulphur, and burn the matches thus produced. In this way the sulphur is exposed to the air sufficiently to cause it to continue to burn when once ignited. Another very good plan is to place the sulphur on a block of iron or brick which has been previously heated to above the melting point of sulphur. The sulphur, if then ignited, will continue to burn freely, but it is almost impossible to get a cold mass of sulphur to burn freely.
The same method answers for disinfecting rooms, and sulphurous acid vapors are the least injurious and most easily procured of all our disinfectants. The National Board of Health, in their recent "Instructions for Disinfection," say that " fumigation with sulphur is the only practicable method for disinfecting the house. For this purpose the rooms to be disinfected must be vacated. Heavy clothing, blankets, bedding, etc., should be opened and exposed during the fumigation. Close the rooms as tightly as possible, ignite the sulphur, and allow the room to remain closed for twenty-four hours. For a room about ten feet square at least two pounds of sulphur should be used; for larger rooms, proportionally increased quantities." Of course in making arrangements for burning the sulphur great care must be exercised so as not to set the floor on fire. Safety is best secured by placing the burning sulphur over a tub of water or a considerable heap of sand or soil.
In making moulds for taking plaster casts, the sulphur must be rendered plastic. This is an extraordinary property possessed by this material, and one known only to chemists and experts. When sulphur is melted and poured into water, instead of becoming hard it remains quite soft like dough, and in this state it may be pressed into the most minute crevices of a medal or other object, so as to take a perfect mould of it. From this mould plaster casts or electrotypes may be taken. After a short time the sulphur returns to its original hard, yellow, brittle condition.
As a cement for fastening iron rods in the holes sunk in stones, as in the gratings of windows and the iron work of fences, sulphur is now extensively used instead of lead. To pure sulphur, however, there is this very strong objection that it is exceedingly brittle and is readily fractured, and even reduced to coarse powder by sudden changes of temperature. We have seen a huge roll of sulphur broken simply by the heat of the hand. This may be avoided, in a measure, by mixing the melted sulphur with some inert powder like sand. Iron filings have also been mixed with it for the purpose.