Page:Popular Science Monthly Volume 70.djvu/260

256 of one part by volume." The rest of the tests which must be applied and to which the denaturants must conform are not of general interest.

As the presence of denaturing agents prevents the use of the alcohol in numerous processes, other countries have long lists of substances used to partially denature alcohol destined for use in particular industries, partially protecting it, as it were, in transit from the factory in which it is made to that in which it is consumed. For instance, in France, alcohol intended for use in the manufacture of aniline dyes may be denatured by adding to 50 liters of the alcohol 50 liters of nitro-benzene or of nitro-toluene, and 10 grams of sodium hydroxide dissolved in 20 liters of alcohol. For varnishes, the product put on the market must contain 75 grams of resin per liter. There are in all about fifty different processes allowed for partial denaturing for as many special purposes. In Germany, for the manufacture of polish, alcohol may be denatured with one half of one per cent, of turpentine; for the manufacture of varnish, with 20 per cent, of a solution of one part shellac in two parts of alcohol; for the manufacture of the anesthetic, ethyl ether, and numerous other medicinal substances, with 10 per cent, of ethyl ether; for the manufacture of acetic acid, or vinegar, with 6 per cent, or 8 per cent, of acetic acid; for the manufacture of smokeless powders, 1 per cent, of camphor; and so on through a list as long as that in France.

Partially denatured alcohol never wholly leaves the watchful care of the guardians of the law. No list of partial denaturants permissible in this country has been determined upon. Interested parties are invited to make their suggestions and requests and these will be considered by the commissioner of internal revenue.

Every one knows from actual experience how clean and convenient spirit lamps are. There is never any soot nor smelly oil to be cleaned up, lamp chimneys remain clear and transparent and wicks require no trimming. The products of the combustion of ethyl alcohol are water and carbon dioxide, absolutely odorless and as harmless as any products of combustion can possibly be. It is much less inflammable than gasoline, and therefore safer. Water thrown on burning alcohol will immediately extinguish the fire, as alcohol is soluble in water in all proportions, while water thrown on burning oil or gasoline only makes matters worse. Oil and gasoline are lighter than water and are not soluble in it, so they float on top and continue to burn; throwing on water only spreads the fire.

Measured in terms of units of heat, calories, a given weight of ethyl alcohol is about twice as effective as an equal weight of petroleum. Its convenience, cleanliness, safety and adaptability to almost any sort of