UREA. 163 



of carnivorous animals is very rich in urea (Vauquelin*, Hieronymif, 

 Tiedemann and GmelinJ,) while the urine of graminivorous 

 animals is comparatively poor in this constituent (Boussingault). 



Notwithstanding the considerable influence which the nature of 

 the food exerts on the quantity of urea excreted by the kidneys, 

 there is as much urea in the urine after prolonged abstinence from 

 all food (after a rigid fast of 24 hours) as after the use of perfectly 

 non-nitrogenous food. 



Lassaigne|| found urea in the urine of a madman who had taken 

 no food for 14 days ; and we observe something similar almost 

 daily in patients with typhus fever and other diseases, who for 14 

 days or more have taken nothing but an oily emulsion or an emol- 

 lient decoction, and yet always pass urine containing urea, and 

 often rich in it. After living for three days on a perfectly non- 

 nitrogenous diet, I still found, in the morning urine, more than 1 g- 

 of urea. 



Strong exercise of the bodily powers causes an increased 

 excretion of urea. 



While, from numerous observations, I ascertained that, during 

 my ordinary habits of life, I discharged about 32 grammes in 24 

 hours, I found that after strong bodily exercise, I, on one occasion, 

 passed 36 grammes, and on another 37'4 grammes in 24 hours. 



The urine of women and children contains, according to 

 Becquerel,1f less urea than that of men. 



Becquerel found the ratio of urea excreted in 24 hours by 

 women, to that excreted by men=15'582 : 17*537. 



Like Becquerel, I have failed in establishing the fact that there 

 is an augmentation of urea in certain forms of disease, although 

 English physicians have shown an inclination to assume an urea- 

 diathesis. 



Although we are, a priori, prejudiced against all these diatheses 

 which English physicians have attempted to establish on certain 

 urinary analyses, (see p. 47 3 ) we must especially protest against such 

 an urea- diathesis ; for how does this indicate a morbid process ? The 

 nature of this or that disease does not depend on an increased 

 excretion of urea, which is only a consequence of another process. 



* Schweigg. Journ. Bd. 3, S. 175. 



f Journ. de Ch. et de Pharm. T. 3, p. 322. 



J Verdauung u. s. w. Bd. 2, S. 4. 



Ann. de Chim. et de Phys. 3 Ser. T. 15, pp. 97-1 U. 



|| Journ. de Chim. me'd. T. 1, p. 272. 



1f Seme'iotique des Urines &c. Paris, 1841, p. 34. 



M 2 



