ALLANTOIN AND UREA— ROBINSON 457 



quently in the foUdore and sometimes in essays and historical writings 

 references have been made to this practice. Such statements have 

 been traced through medieval times back to the writings of Cato, 

 175 B. C. Records have been found tending to show that even the 

 ancient Babylonians, about 800 B. C, indulged in the same practice. 

 Since the main constitutent of urine, next to water, is urea, in about 

 2 percent concentration, this ancient remedy for nonhealing wounds 

 now appears to be basically sound. 



The method of applying the urea treatment in our experimental 

 work was on gauze dressings thoroughly wetted with 2 percent solu- 

 tion, the same as in the allantoin treatment. Urea is a stable, bland, 

 and nontoxic substance, and no report of any ill effect from the treat- 

 ment has been received. It is very soluble in water and a concentra- 

 tion as high as 40 percent is possible. Many kinds of bacteria contain 

 an enzyme called urease, which breaks down urea and releases 

 ammonia. For that reason sterile water should be used if the solution 

 is to be kept for some time. 



A report published in the American Journal of Surgery, August 1936 

 (Robinson, 1936), on the remarkable healing properties of such a 

 common excretory substance as urea again interested many of the 

 newspapers and journals in the United States, and once more a con- 

 siderable amount of publicity was given to these experiments. The 

 result was a wide trial of urea by the medical profession and, happily, 

 with confirmation of our results. An article by Bogart (1937) on 

 his successful use of urea has alread}'- appeared in the medical press. 

 He refers to the outstanding healing effects he obtained when other 

 methods had failed, and concludes as follows: "It seems reasonable 

 to assume that a new and very potent factor in the healing of indolent 

 wounds has been added to the armamentarium of the surgeon." Still 

 more recently Lewy (1937) has reported beneficial results with 2 

 percent urea solution in the treatment of infected conditions of the 

 nose, ear, and throat. 



Nevertheless, a certain amount of skepticism naturally exists that 

 urea has such healing properties as described. Holder and MacKay 

 (1937) suggest that we are mistaken in attributing healing character- 

 istics to urea. They obtained good results \vith strong urea solutions 

 but believe it to be due solely to the solvent and bacteriostatic action 

 of strong urea. 



The tendency to doubt that urea has healing powers and the neg- 

 lect of this potent agent, despite the extensive background of usage 

 in urine, become still more pronounced when contrasted with the 

 general acceptance of its numerous and remarkable uses in industry 

 and pharmacy, as described by Berliner (1936). This skepticism and 

 neglect are no doubt due to the long association of urea with animal 

 excretions. Urea is, however, of common occurrence in plants, some 



31508—38 33 



