418 URINE. 



administration of these salts, is very various, and that in different 

 cases very different quantities of these salts are necessary to render 

 the urine alkaline. From the experiments of a young chemist, whose 

 urine constantly became alkaline even after the use of a few baked 

 plums, I was led to observe that in many persons who are living 

 on a mixed diet, the urine becomes alkaline in two or three 

 hours after swallowing half a scruple of acetate of soda, whilst in 

 others who are living on a purely vegetable diet, two drachms 

 of acetate of soda never succeeded in rendering the urine alkaline. 

 From numerous experiments on healthy persons, and observations 

 on patients who had taken alkaline acetates and tartrates, I could 

 only deduce the following certain conclusions ; when the salts in 

 question exert a purgative action, the urine does not readily be- 

 come alkaline ; in fact, it seldom becomes alkaline at all under 

 these circumstances : as might be expected, the urine of persons 

 living upon animal food does not so readily become alkaline as 

 that of persons living on vegetables and those on an antiphlogistic 

 diet : if, however, the febrile affection be accompanied by a very 

 acid urine, then it naturally follows that the urine is longer in be- 

 coming alkaline ; hence two febrile patients might be taking the 

 same doses of these salts, and the urine in one case might be 

 alkaline and in the other it might remain distinctly acid. In one 

 and the same person living on the same kind of food, the urine 

 may become alkaline after a dose of these salts, if he remain quiet ; 

 but may retain its acid reaction after an equal dose, if he take 

 strong bodily exercise. Hence we should be far from the truth if 

 we believed that these points were thus cleared up ; for a very 

 small amount of observation at the bedside would suffice to 

 convince us that we are far from being able to comprehend why, 

 in special cases, the urine remains acid, or why it becomes alka- 

 line. We must generally assume it as an undoubted fact, that 

 the metamorphosis proceeding in the blood during the conti- 

 nuance of the morbid process tends, in a greater or less degree, to 

 the formation of acid; and hence that in one of the cases, a smaller 

 quantity of the vegetable salt is necessary to saturate the free acid 

 of the urine than in the other case. The alkalinity of the urine 

 during the use of vegetable diet appears, however, to be by no 

 means solely dependent on the alkali contained in the organic salts 

 of the food : for I have seen my own urine, which usually has a 

 strong acid reaction, remain alkaline for eighteen hours after the 

 use of food altogether devoid of nitrogen and alkalies, as, for in- 



