40 INFLUENCE OF FOOD PRESERVATIVES ON HEALTH. 



nis on a hot day. Before the game he had carefully bathed and put 

 on a clean suit of flannels. As a result no boric acid could be detected. 



Two further trials were made for a longer period of time. The men 

 undertaking them bathed, put on clean suits of flannels, and wore them 

 for a period of twenty-four hours. During this time they played 

 tennis for several hours, and rode their bicycles for about an hour. 

 The temperature was quite high and prespiration was profuse. The 

 water used in bathing and in extracting the flannels was mixed, evap- 

 orated to dimness, and tested for boric acid. A very strong reaction 

 for boric acid was obtained, but the amount present was not sufficient 

 to permit its quantitative determination with certainty. 



In each case 3 grams of boric acid were administered at the begin- 

 ning of the experiment. It would appear that in the first experiment 

 the time allowed was not sufficient for the elimination of a sufficient 

 amount of boric acid to give a test. In the case of the second and 

 third, where a positive result was obtained, it can not be expected that 

 the result was as high as would have been the case if the subject had 

 been receiving the preservative for a number of days. As is stated 

 above, about eight days are required for the complete elimination of 

 the boric acid, and the amount eliminated in the first twenty-four hours 

 amounts only to from 30 to 60 per cent of the amount administered. 

 Owing to the small amount of preservative employed, the large amount 

 of water necessary to secure it, and the inevitable inaccuracies due to 

 the incomplete extraction, the amount of boric acid indicated by such 

 an experiment must be incomplete. Probably the greater part of the 

 23 per cent of the boric acid not accounted for in the urine escapes 

 through the pores of the skin. 



Attempts were also made to determine whether any of the boric acid 

 assumed a volatile state in the system and escaped in the respiration. 

 The well-known tendency of boric acid to pass off in certain cases in 

 boiling water led to the supposition that it might be reduced in the 

 system to a form in which it would be volatilized in the respiration. 

 One of the members of the table, who had been taking 3 grams of 

 borax a day for four days, breathed as continuously as practicable for 

 three hours through a solution of limewater. The limewater was then 

 tested for boric acid with a negative result. Confirmatory tests were 

 made with the same result. 



