Note 31 — Chapter XIV · COCAINE AND ITS SALTS.

This forms a stable 10 per cent. solution, which for the use of oculists may be diluted to a 2 per cent. solution, and still remain free from tendency to develop fungoid growths. The salicylic acid remains as free acid in the mixture, as with perchloride of iron it gives a more permanent violet coloration than the so-called salicylate of cocaine. The official solution may be used as an application for producing local anæsthesia or for hypodermic injection, for which purpose it is found to be unirritating. A solution up to the strength of 50 per cent. may be prepared in salicylic acid solution of the above strength, which is nearly saturated.