810 
DE. SMITH ON THE ELIMINATION 
In order to ascertain how far the addition of alcohol, tea, and coffee may have 
modified these results, I have in the last column of the preceding Table separated 
the average returns before those substances were administered. The exceptional case. 
No. 1041, was regular up to that period, and on the whole average yielded a small 
increase on treadwheel days ; but the general results in the other cases were varied 
only so far as that the effect of the treadwheel was less on the short than on the long 
average. 
The average amount of urea excreted daily to each pound weight of the body is as 
follows ; and for comparison I have added the proportion in myself. 
Table XXXVI. 
No. of prisoner 
858. 
948. 
1040. 
1041. 
Average of 
the whole. 
Myself. 
Urea, grs. to each lb 
4-61 
4-74 
4-58 
4-39 
4*58 
2*73 
The foregoing facts prove that, whilst there is no average increase in the elimination 
of urea during the period of actual treadwheel labour without food, there is a small 
increase in the production on the whole day when ordinary food is taken ; but on some 
occasions this increase is not eliminated on the day of labour, but on the following one 
of rest. The proportion of urea to the weight of the body on the whole period of 
labour and rest combined, is 59 per cent, greater than is observed in myself with much 
greater weight, less food, and less labour. 
Eudolph found that dming fasting there was an increase in the solids in the urine 
emitted, on the increasing weights of the men ; but Beneke and others have shown that, 
whilst there may be this general relation, there is much diversity in the results. More- 
over, since in one person the bones, and in another the fat, may be relatively heavier 
than the muscle in a third, and since in relation to body weight the amount of food 
and the activity of the vital functions vary much, it is impossible that there should be 
any strict relation. In the case of these prisoners there was but little fat, and the 
bones were not unusually large, and the muscular system was over worked and under 
fed. They did not lose weight during this inquiry ; but they had been long imprisoned, 
and the weight with which the final weighing was compared was not that on their 
entrance into the prison, but the reduced one at the period of this inquiry. It is pro- 
bable that the knowledge of the relation of urea to body weight is of very little value. 
Urinary Water. 
The excretion of urinary water was greater on treadwheel days than on days of com- 
parative rest. On the whole cases combined the daily quantity was 69‘6 oz. on the 
former and 6 4’ 6 oz. on the latter days, or an increase of nearly 8 per cent, on the days 
of severe labour. The relative amounts evolved during the first ten days, before any 
variation of the food occurred, were 74*7 and 67 ’7 oz., giving an increase with labour of 
10 '4 per cent. 
The rule thus established was not maintained without variation ; but on every short 
