1863.] 441 



During a period of 163 days (100 days at sea, 63 days at Hong 

 Kong during the change of monsoon), Dr. Becher collected the 

 daily quantity of urine, and determined the amount of urea and 

 NaCl by the volumetric method (solutions of nitrate of mercury), 

 and registered meteorological observations as accurately as circum- 

 stances would permit, observing all the time as constant a mode of 

 living (with regard to food, exercise, &c.) as was practicable without 

 undue restriction. 



The whole of the observations, divided into the two periods indi- 

 cated, are fully detailed in Tables, and graphically represented in 

 Diagrams. 



The results show a most remarkable relation between air-tempera- 

 ture and daily quantity of urea and NaCl, viz. a constant increase 

 with the rising of temperature from 50-70, and an equally constant 

 falling off with the further rise of temperature from 70-90. 



The physiological limit of the tropical zone, as marked by the 

 sudden decrease in the quantity of urinary water, is constantly fixed 

 at 76. 



Appended is an extract from a manuscript of Dr. Forbes Watson, 

 containing a series of observations on the daily quantity of urine and 

 the amount of solids therein excreted by a number of healthy soldiers 

 in various temperatures during a voyage to India in 1850. 



These observations were made by Dr. Forbes Watson, who most 

 kindly consented to their being added here, as far as they serve to 

 illustrate the influence of temperature under otherwise constant 

 conditions. They are tabulated and graphically represented as much 

 as possible on the same plan as those of Dr. Becher, and in their 

 results show the most satisfactory harmony with the latter. 



