,9o8.] UPON HEALTH AND METABOLISM. 311 



general clearing house for all the surplus of saline matters, ingested 

 in the foods. 



The most interesting of the observations which were made dur- 

 ing the progress of the experiments was in the study of the direct 

 effect of boric acid and borax, when administered in food, upon 

 the health and digestion. When boric acid, or its equivalent in 

 borax, is taken into the food in small quantities, not exceeding half 

 a gram (yl grains) a day, no notable effects are immediately pro- 

 duced. The medical symptoms of the cases, in long-continued ex- 

 hibitions of small doses or in large doses extending over a shorter 

 period, show in many instances a manifest tendency to diminish the 

 appetite and to produce a feeling of fullness and uneasiness in the 

 stomach, which in some cases results in nausea, with a very general 

 tendency to produce a sense of fullness in the head, which is often 

 manifested as a dull and persistent headache. In addition to the 

 uneasiness produced in the region of the stomach there appear in 

 some instances sharp and well-located pains, which, however, are 

 not persistent. Although the depression in the weight of the body 

 and some of the other symptoms produced persist in the after 

 periods, there is a uniform tendency manifested after the with- 

 drawal of the preservative toward the removal of the unpleasant 

 sensations in the stomach and head above mentioned. 



The administration of boric acid to the amount of 4 or 5 grams 

 per day, or borax equivalent thereto continued for some time, results 

 in most cases in loss of appetite and inability to perform work of 

 any kind. In many cases the person becomes ill and unfit for dutv. 

 Four grams per day may be regarded, then, as the limit of exhibi- 

 tion beyond which the normal man may not go. The administration 

 of 3 grams per day produced the same symptoms in many cases, 

 altliDugh it appeared that a majority of the men under observa- 

 tion were able to take 3 grams a day for a somewhat protracted 

 period and still perform their duties. They commonly felt injurious 

 effects from the dose, however, and it is certain that the normal man 

 could not long continue to receive 3 grams per day. 



In many cases the same results, though less marked, follow the 

 administration of borax to the extent of 2 grams and even of i 

 gram per day, although the illness following the administration of 



