Page:Popular Science Monthly Volume 48.djvu/516

474 hundred and eighty pounds, the hard turpentine two hundred and forty pounds, and pitch, thirty-two gallons to the barrel. All spirits of turpentine are gauged by the inspectors of naval stores. Tar and turpentine barrels are marked and certified, and usually show the initials of the maker's name.

Very few people have any correct notion of the number of uses to which the products of turpentine have been put. Let us mention some of the different ways spirits of turpentine enters into the arts and manufactures. Many who read this article by gaslight will remember when they read their newspapers by the smoky light furnished by "camphene." This was before the introduction and use of petroleum. Camphene is prepared by mixing the rectified oil of turpentine with alcohol. Although kerosene is now so cheap, the rectified spirits of turpentine is still used for illuminating purposes in some backwood sections of the South.

Perhaps the most common uses of the spirits of turpentine are those in the arts, where it enters into the preparation of paints and varnishes, and especially in the manufacture of India-rubber goods. The paint and varnish industries take about five million gallons annually, while the rubber industry requires about three and a half million gallons a year.

But spirits of turpentine has other uses not so well known to most readers. How many would enjoy their salad oils and other vegetable oils, if they knew that they were adulterated with turpentine oil? How many invalids know that their medicines contain spirits of turpentine, or that the liniment or ointment which relieves their aches and pains is largely composed of turpentine?

Quite as varied and valuable are the products of rosin in the arts and manufactures. Do you know that the finest grades of rosin are used in the manufacture of paper? How many persons who look at the printer's ink on this paper would say that it contains rosin? How many, washing their face and hands, ever suspect that there is rosin in the scented soap? There is rosin in all these products, as there is in sealing wax, putty and sizing, and in varnishes.

Two kinds of rosin oil are obtained from rosin by the process of dry distillation. The light rosin oil is used principally in the fine varnishes. The heavy oil enters into the manufacture of axle grease, and machine and lubricating oils. It is one of the best and cheapest lubricants for metal bearings in machinery, the petroleum oils not excepted. The heavy rosin oils are largely used in the preparation of cheap paints, such as are used to cover metal, roofs, and so forth.

The product called "pitch" is the residue from the dry