OF UEEA Am) UEINAET WATEE. 
797 
by adopting a standard dietary for the whole period, for then the effect of season upon 
the requirement for food could not be determined; and hence the only practicable 
inquiry was to allow such food as the system requu’ed, and ascertain the absolute amount 
of urinary excretion during the whole period. 
The year 1860 was remarkable for the coldness of its summer, and for the long- 
continued frost during the winter, so that scarcely any opportunities were afforded of 
determining the effect of great heat over the elimination of the urinary secretion. 
The general effect of season was, however, well established by the results which were 
obtained, and it was shown that the urinary products increased in quantity as the summer 
advanced, and decreased in the winter season. 
Urea. 
Table III. shows that on the monthly averages the daily quantity of urea progressively 
increased from 462 grs. in March, through 489, 546, 541, and 505, to the maximum 
of 646 and 665 grs. per day in August and September, and thenceforward fell through 
518, 455, 451'6, 475, and 515 to 417 grs. in the last month of the inquiry. The 
progression in the rate of increase was well sustained through the spring and summer 
months, whilst the fall was rapid in autumn; and the rate continued much below 
the average of the year throughout the winter. The months of distinct increase were 
April, May, June, and July; the maximum months were August and September; the 
month of decrease was October, and the stationary minimum months were all those at 
the end of autumn and during the winter. [The monthly averages in 1861 and 1862 
differed somewhat from the above in actual quantities, but followed almost precisely 
the same course. Those recorded in September were much loAver than those of the 
corresponding month of 1860, because I was not then staying at the sea-side.] 
Thus the year may be conveniently divided into two seasons, one extending from May 
to October inclusive, and the other from November to April inclusive, — the former being 
the season of heat and of maximum production of urea, and the latter of cold and the 
minimum production of urea. The average elimination of urea in the former period 
was 570T grs., and in the latter 480-5 grs. daily [in 1861 and 1862 the quantities were 
530 grs. and 460 grs.], a difference so marked as to show a natural dirision of the year 
into the two seasons. In this arrangement the month of April would be that of a 
change towards increase, and October that towards decrease. 
Tlie increase from the daily rate of elimination in March to the maximum quantity 
was 36 per cent, of the former, and the decrease from the maximum to the rate in the 
following March was 29 per cent, of the maximum, whilst the extreme difference 
beween the minimum and maximum quantities on the monthly average was 46-1 per 
cent, of the former. 
Urinary water. 
The rate of excretion of urinary water followed the course just described in reference 
to urea, viz. increasing with the summer and decreasing in the winter, but with less 
5 p 2 
