458 ANNUAL REPORT SAIITHSONIAN INSTITUTION, 1937 



of which are used as food. Fourcroy and Vaiiqiielin (1798), who 

 discovered urea, found it first in urine and unfortunately called it 

 "ur6e." The stigma attached to urea could possibly be removed 

 through a fuller knowledge of its chemistry and its remarkable posi- 

 tion in phj'siology and industry. 



Urea was the first organic substance ever to be produced artificially. 

 This historic achievement by Wohler (1828), over a century ago, was 

 a discover}' of far-reaching unportance. It opened the way to the 

 preparation of other organic substances the number of which has now 

 grown to an enormous extent. It also shattered the belief commonly 

 held at that time that organic substances are the result of a mysteri- 

 ous vitol force which could not be duplicated in the laboratory. 

 Werner (1923) said that if the amount of study devoted to the chem- 

 istry of a subject is any indication of its importance, then urea must 

 take a high place in that regard. 



Under the present circumstances, since urea is now being used 

 clinically, it might be well to remember that the urea of commerce 

 and pharmacy is a manufactured product made by combining 

 two synthetic gases, ammonia and carbon dioxide, to form urea, 

 CO (NIT2)o, a pure crystalline product. Chemically pure urea made by 

 this process is now being produced commercially in the United States, 

 and thousands of tons are used annually. Its cheapness is greatly in 

 its favor for extensive cUnical use. It can be purchased at this time 

 in 1-pound bottles at 50 cents and in 20-pound containers at 18 cents 

 a pound. In 100-pound moisture-proof sacks the price is reduced to 

 the extremely low figure of 5 cents a pound. In concentrations of 2 

 to 10 percent the cost of daily applications to each patient is, there- 

 fore, so slight as to be almost negUgible. Bogart (1937) has used it 

 in strong solution, and even in crystalline form in some very resistant 

 cases, with good results. Even m these concentrations the cost of 

 daily treatments is exceedingly slight. 



Owing to the low price of commercial urea, it appears to be practi- 

 cal to make up a dilute solution of it in a bathtub (Robinson, 1936) 

 for treatment of cases of extensive secondary infections of the skin 

 following an injury by poisonous plants, insect attack, heat burns, or 

 sunburn. Extensive applications of this sort have already been made 

 on a small scale with good results in the treatment of certain general- 

 ized skin conditions. As there is a wide range in the concentration of 

 urea that can be used effectively, no exact amount appears to be 

 necessary when making up a solution in a tub. Two double handfuls 

 of the crystals have been found to make a satisfactory concentration. 

 It should be remembered that when urea is added to water the tem- 

 perature is lowered somewhat. 



Urea in amounts up to 10 or 15 percent can be incorporated with 

 ointment or jelly bases with great ease. It is merely added to the 



