228 INFLUENCE OF FOOD PKESEEVATIVES ON HEALTH. 



the entire preservative period, namely, 107.8, show a slight decrease 

 from the fore period, and the decrease continues during the after 

 period. 



As has been the case with all the calculations, the individual data have 

 been carefully checked and found to be correct. If any error, there- 

 fore, has crept into the observations it has been in the imperfect col- 

 lection of samples, or other errors in analysis which could not now be 

 corrected. As the analytical data, however, were compiled by the 

 same experts throughout the entire course, it is hardly likely that they 

 would have been influenced by a systematic error running through the 

 whole series. It is true that four of the subjects experimented upon 

 during the fifth series had already passed through two periods of borax 

 administration previous to the beginning of the fifth series. They 

 were members of the first and third classes. It is hardly probable, 

 however, that there would have been any continued influence relating 

 to the excretion of phosphorus remaining from the experimental 

 work of the first and third series. It is, of course, a matter of regret 

 that data of this kind should show apparent contradictions, but prob- 

 ably it is unavoidable when the experiment is conducted, as in this 

 case, with so man} 7 individuals, extending over so long a period, and 

 without that absolute control which would be desirable if practicable. 



COMPARISON OF PERCENTAGES OF PHOSPHORIC ACID ELIMINATED. 



In order to bring together as a whole the results of the experimental 

 work, the mean data obtained are compared in the following tabular 

 statement: 



Per cent. 



Fore periods 97. 3 



Preservative periods .". 103. 1 



After periods 97. 



The above summary shows a marked influence exerted by the admin- 

 istration of borax upon the excretion of phosphoric acid. While it is 

 true that there are many contradictory data, yet it must be admitted 

 that when the whole work is compared the influence mentioned above 

 is clearl} T brought out. 



Another point to be considered is that this influence is manifested 

 even in the first periods of the administration of borax, when the quan- 

 tities are extremely small as compared with those subsequently given. 

 It is thus fair to conclude that even small quantities of borax have a 

 tendenc} 7 to influence in a marked degree the excretion of phosphorus. 

 The question of whether or not such an increase is useful or deleteri- 

 ous may be difficult to decide definitely. One point, however, is 

 brought out in a vivid light, namely, that as a whole the normal con- 

 ditions attending the digestion of ordinary food are decidedly dis- 

 turbed by the addition of this preservative. It is necessary, therefore, 



