“Anticalcium” is a more recent preparation introduced as a bate by the same firm.[12] It is a solution of mixed sulphonic acids derived from cresols, and has considerable disinfectant powers. It removes lime very effectively, but from its acid character somewhat swells the skin. It is used very successfully as a drench for thin skins ([p. 163]).
[12] Gerber, 1895, p. 133.
“C.T.” (coal-tar) bate is a grey crystalline pasty mass, with a tarry smell, and is chemically very similar to anticalcium if not identical with it.
Naphthalene sulphonic acid has strong antiseptic properties. Its use in bating has been patented by Burns and Cross. (See [p. 163].)
Naphthols, C10H7(OH).—These bodies, which have the same relation to naphthalene as the phenols to benzene, are powerful antiseptics; and naphthalene itself appears to have antiseptic power, and is occasionally used for denaturising salt. There are two naphthols, varying in the position of the OH group in the molecule, and denominated α and β, of which α naphthol is the more powerful antiseptic and the less poisonous, though β, being cheaper, is the common commercial article. It is said that quantities so small as 0·1-0·4 grams of α naphthol per liter are sufficient to prevent the development of microbes, while of β naphthol about ten times that quantity is required.
Naphthols are not very expensive, but their value is diminished by the fact that they are insoluble in water. They are soluble in alkaline solutions, but their compounds with bases are of much lower antiseptic value, and the same is true of their alcoholic solutions; when an alcoholic solution is added to water the naphthol is precipitated, but if an addition of soap or camphor be made to the alcoholic solution, the naphthol remains in a very finely divided condition, if not dissolved.
Adopting Eitner’s suggestion with regard to oxynaphthoic acid (see [below]), hides may no doubt be sterilised by treatment first with an alkaline naphthol solution, and then with a very dilute acid to set the naphthol free.
“Hydronaphthol,” β tetra-hydro-naphthol, C10H12O, is obtained by the reduction of β naphthol by sodium (Rideal). It seems to be an excellent disinfectant.
Oxynaphthoic acid, α hydroxynaphthoic acid, C10H6(OH)COOH, which bears the same relation to naphthol as salicylic acid does to phenol, is cheaper than salicylic acid, and said to be a more powerful antiseptic. Its salts have no antiseptic power. In its commercial form it is a reddish crystalline powder, inodorous, but with a burning taste, and its dust causes violent sneezing. It is scarcely soluble in water, and is said to undergo some change on keeping which lessens its germicide power; it is readily soluble in alcohol, and the solution produces a milky fluid on mixture with water. Such a solution containing 15 grams of the acid in 4 liters of water, will sterilise a hide. Eitner recommends[13] that it should be dissolved in dilute soda solution, and the hides, after soaking in it, passed through water slightly acidified with hydrochloric acid, as has been suggested in the case of naphthol; the method is also applicable to creosotinic acid, the hides being permanently sterilised so that they cannot be unhaired by sweating, though they will lime in the usual manner.
[13] Gerber, 1888, p. 101; 1889, pp. 99 et seq. See also [p. 163].