URINE. 



1277 



in certain cases, they may be found in the 

 urine of these animals. If the nutriment of 

 these animals contains no soluble phosphates, 

 their urine cannot contain any ; whilst, if we 

 add a certain proportion of grain to their 

 food, the alkaline phosphates may be detected 

 in their urine. Thus it is obvious, likewise, 

 that the soluble phosphates in the urine of 

 man are merely accidental constituents, and 

 that by simply adding lime or magnesia to the 

 aliments, and thus assimilating the constitution 

 of these aliments to that of the food of herbi- 

 vorous animals, the urine must become altered 

 in its nature and properties. The knowledge 

 of the influence which alkalies, magnesia, and 

 lime, or acids, exercise upon the properties of 

 the urine, or, in other words, upon the secre- 

 tory process of the kidneys, in the healthy 

 organism, is of the highest importance for the 

 curing of diseases. 



" I believe that there is now required only 

 a small number of good and correct observa- 

 tions to establish a fixed rule for the remedies 

 necessary in various cases. Future properly- 

 directed experiments will prove whether san- 

 guification is absolutely dependent upon the 

 presence of alkaline phosphates or not ; we 

 shall be able to determine whether weak so- 

 lutions of alkaline phosphates are not the 

 best solvents for uric acid deposited in the 

 bladder ; and likewise what is the influence 

 which aliments rich in sulphur, such as mus- 

 tard, for instance, exercise upon the se- 

 paration of uric acid in the bladder, in con- 

 sequence of the formation of sulphuric 

 acid. At any rate, we may, by a judi- 

 ciously-selected diet, alter with positive cer- 

 tainty, and at pleasure, the nature of the 

 urine ; we may, without causing any injury to 

 health, keep it alkaline for a long time, by 

 adopting a vegetable diet ; and this is cer- 

 tain!}' the first condition necessary to insure 

 the entire prevention of the formation of uric 

 acid, as is the case with the herbivorous 

 animals. By its combination with an alkaline 

 base, uric acid must in the organism resolve 

 itself into its ultimate oxygen compounds 

 with the same facility as other organic acids, 

 if the physician prohibits all substances to be 

 taken as food which, like wine or fat, take 

 possession of the oxygen necessary for the 

 transformation of uric acid into carbonic acid 

 and urea. 



" The carbonated alkali in the urine of 

 herbivorous animals is separated from the 

 blood by the kidneys ; the urine derives it 

 1'rom the blood ; it is certain, therefore, if we 

 examine the blood one hour or a few hours 

 after the animal has partaken of food, we 

 must find in it this alkali in the same state as 

 it is found in the urine, and that at other 

 periods of the day the ashes of the blood may 

 not contain the least trace of free alkali. But 

 the free alkali does not co-operate in the vital 

 process in the animal organism ; or, if it is 

 necessary in this process, the part which it 

 has to perform may be undertaken with the 

 very same effect by the bibasic and tribasic 

 alkaline phosphates. 



" In like manner, when we are contemplat- 

 ing the presence of hydrochloric acid in the 

 gastric juice, we must remember that the alka- 

 line bases, soda, potass, lime, magnesia, are 

 present in the aliments whilst in their natural 

 state, invariably in the form of salts ; that is, 

 in combination with phosphoric acid, or with 

 organic acids. When, therefore, in the diges- 

 tive process, hydrochloric acid is supplied by 

 the gastric juice, the first action of this acid 

 is confined to the decomposition of these 

 salts ; the hydrochloric acid withdraws lime 

 from the phosphate of lime ; potass, or soda, 

 chloride of calcium, or chloride of sodium or 

 potassium, is formed on the one hand, and 

 acid phosphate of soda or potass, or acid 

 phosphate of lime, on the other ; or acetic 

 acid, paratartaric acid, or citric acid, are liber- 

 ated by the decomposition of the salts of 

 these vegetable acids contained in the ali- 

 ments. At a certain stage of digestion the 

 chyme will, according to the nature of the 

 food partaken of, contain acid phosphates 

 or free vegetable acids ; and it is only upon 

 the supply of gastric juice continuing, that 

 thus, upon the amount of the hydrochloric 

 acid increasing, we may detect, by analysis, 

 free hydrochloric acid in the chyme : the gas- 

 tric juice taken from an empty stomach con- 

 tains invariably free hydrochloric acid, or acid 

 phosphates." 



Lehmann has made some very interesting 

 observations, published in the " Journal f iir 

 Praktische Chemie," by which he has shown 

 the effects of diet on his own urine. He first 

 observed the results produced by his ordinary 

 diet during thirteen days, and found that the 

 urea amounted on an average to about 46 per 

 cent, of the whole of the solid matter excreted. 

 The average quantity of urea excreted during 

 the 24 hours amounted to about 500 grains. 



During six days, on an ordinary diet, the 

 uric acid excreted averaged about 1'089 parts 

 per 1000, and the amount excreted during the 

 24 hours was about 18 grains. 



On a purely animal diet, Lehmann found 

 the amount of solid matters discharged in the 

 urine during the 24 hours was much increased. 

 The urine became pale in colour and strongly 

 acid. On the addition of nitric acid, crystals 

 of nitrate of urea were immediately formed, 

 and uric acid was deposited in large crystals. 



By careful analysis, however, Lehmann de- 

 termined, that though a purely animal diet 

 increases the proportion of urea excreted 

 during the 24 hours, the amount of uric acid 

 is not by any means materially influenced. 



The earthy phosphates were discharged in 

 large quantities under a purely animal diet, 

 rising to about three and a quarter times as 

 much as when ordinary mixed diet was taken. 



With respect to the effects of a vegetable 

 diet, Lehmann observed the urine to become 

 of a darker colour than natural, and to remain 

 of an acid reaction much longer than ordinary 

 human urine. The following tables of com- 

 parison have been constructed by Franz Si- 

 mon from the results of Lehmann : they 

 possess a high physiological value. 



