REPEATED paracentesis has frequently been proposed as a treatment for ammonia burns of the eye.1 That such a treatment might be effective has been suggested by experimental and clinical indications that ammonia penetrates rapidly into the aqueous humor2 and that damage of the iris and lens may result.3 However, no substantial series of patients so treated has been presented, and the experimental evidence for the effectiveness of paracentesis appears to be limited to observations on three rabbit eyes which were reported to have benefited from this treatment in the hands of Siegrist1b in 1920. This evidence is quite inadequate in view of the relatively slight benefit reported and the considerable variations which are generally encountered in the responses of animals. Observations which have been made of the penetration and persistence of ammonia in the aqueous humor have been based principally on determinations of the ammonium ion