336 CM.CCLU 



Experiments Small, for obvious reasons, and seldom increasing its aces* 

 tion°on'^^^ Cent properties (as ascertained by the usual tests) beyond 

 &c. what frequently occurs, in the urine of those who use 



acescent drinks, or are aillictcd with gout or gravel. A 

 standard quantity Avas always laid by for comparison; and 

 the temperature from sixty to seventy-five degrees, being 

 in autumn, 1799. And to begin with the vegetable acids. 



Exp. 1. To four ounces of the urine of an adult, was 

 added one draclun of common acetous acid, which (like 

 every other acid) caused no immediate change in it; but, in 

 a very short time, and before it cooled down to the tempe- 

 rature of the atmospliere, some extremely minute shining 

 spicula?, observable only by a lens, were seen floating iii 

 it : these gradually increased in number and size, began to 

 reflect the light, and, from being perfectly transparent, 

 soon became coloured, to settle upon the usual cloud, or 

 nubecula^ which now began to form, adhere to the sides 

 of the glass, and partly fail to the bottom, in the shape 

 of small bright red crystals, In the standard, after twelve 

 hours, nothing more observable, than the usual nubecula ; 

 nor was there any sign of crystalization, or separation of 

 uric acid, even after twenty-four. 



Exp. 2. To the same quantity of adult urine, were 

 added one drachm and half of acetous acid, which caused 

 a more copious separation and crystallization of this sub- 

 stance, with the foregoing appearances. None observable 

 m. the standard after twenty-four hours. 



E^p. 3. To four ounces of urine of a healthy child, 

 who never was observed to pass gravel, and of the usual 

 degree of acidity, was added one drachm of acetous acid, 

 -which soon caused an evident and copious separation of 

 '^crystallized uric acid. The crystals were, however, not 

 quite so coloured ; the urine of children not being so much 

 impregnated with the uree, or colouring matter. No such 

 appearance in the standard after twelve hours or more. 



Exp. 4. To four onncas of adult urine, rendered very 

 soon after a tea breakfast, and nearly in a state of urina 

 potus, was added one drachm of acetous acid. After three 

 hours, a crystallization of minute sandy particles took place. 

 None in the standard, even after three days. 



" ' Exp. 



I 



