The extensive use of nitrous oxid as an anesthetic in dental surgery and, more recently, in general surgery, and the possibilities of its containing dangerous impurities, owing to careless manufacture or lack of control, warranted a thorough investigation by the Bureau of Chemistry of the quality of this gas available on American markets.
It has been supposed that the odor of the gas is a good criterion of its purity, and experienced anesthetists have depended on the odor as a guide to its purity. The safety of such a procedure, however, is doubtful.
The seriousness of the presence of even small quantities of impurities in nitrous oxid,1 particularly the higher oxids of nitrogen, is hardly appreciated by the average user, and the detection of these small but dangerous amounts by odor is unlikely.
Lehmann and Hasegawa,2 in a study on the toxicity of several oxids of nitrogen, have