797 



the test solutions, and thus the degree of acidity or alkalescence was 

 determined. 



Diurnal variations in the acidity of the urine were observed. The 

 acidity of the urine was found to ebb and flow ; it was greatest a 

 short time before food was taken, and Avas least about three hours 

 after breakfast, and five or six hours after dinner, when it reached 

 the minimum point ; after which it again increased, and attained the 

 maximum point previous to food being again taken. 



If no food was taken, the acidity varied but slightly for twelve 

 hours. 



By comparing the effect of vegetable food with animal food, it 

 appeared that the food which irritated the stomach most and caused 

 most secretion of acid in the stomach, caused the greatest oscillatioDs 

 in the urine. 



Dilute sulphuric acid taken in large doses produced but little 

 effect on the variations of the acidity of the urine ; but it was pro\ ed 

 to increase the aaidity of the urine. 



Part II. On the sim idfaneous variations of the amount of Uric Acid 

 and the Acidity of the Urine in a healthy state. 



The result of these experiments is, that there is no relation be- 

 tween the acidity of the urine and the amount of uric acid in it. 

 The urine that was most acid contained least uric acid ; that which 

 contained most uric acid was not most acid. All food causes an in- 

 crease in the amount of uric acid in the urine ; and there is no de- 

 cided difference between vegetable and animal food, either as to the 

 increase or diminution of the amount of uric acid in the urine- 

 Part III. Variations of the Suljjhates in the Urine in the healthy 

 state, and on tJ-e influence of Suljjhuric Acid, Sulphur and the Sul- 

 phates, on the Sulphates in the Urine. 



The result of these experiments is, that the sulphates in the urine 

 are much increased by food, whether it be vegetable or animal. Ex- 

 ercise does not produce a marked increase in the sulphates. Sul- 

 phuric acid, when taken in large quantity, increases the sulphates in 

 the urine. In small quantity, even when long-continued, no effect 

 on the amount of sulphates is manifest. 



Sulphur taken as a medicine increases the sulphates in the urine. 

 Sulphate of soda and sulphate of magnesia produce the most marked 

 increase in the sulphates in the urine. 



February 8, 1849. 

 The EARL OF ROSSE, President, in the Chair. 



A paper was read, entitled " On the application of the Theorv of 

 Elliptic Functions to the Rotation of a Rigid Bodv round a Fixed 

 Point." By James Booth, L.L.D.,F.R.S. 



In the introduction to his investigation, the author, after noticino- 

 the investigations of D'Alembert and Euler, and the solution of this 



