826 
DE. SMITH ON THE ELIMINATION 
Table XLV. — Showing the effect of Water drunk during fasting over pulsation 
and respiration. 
Water. Water. Water. Water. 
Hour. 
9. 
10. 
11. 
12. 
2. 
3. 
4. 
5. 
6. 
n- 
10. I lOi. 
Pulsation ... 
Respiration... 
67 
14 
64 
64 
69 
121 
72 
13 
64 
60 
64 
13 
71 
70 
131 
73 
13i 
72 
I believe that this statement is true. 
2. That of Bidder and Schmidt, Frerichs, and Lehmann — that the excretion of urea 
results chiefly from excess of food, and represents “ luxus consumption,” and has no 
necessary relation to tissue action or tissue metamorphosis. This is based upon the fact 
that with excess of food, and with certain kinds of food, as gelatine, there is an almost 
immediate increase in the elimination of nitrogen ; and this is abundantly supported by 
the experiments of Lawes and Gilbert, and by those recorded in this paper. 
3. That of Ludwig and Fuhrer — that urea is due neither to the immediate changes 
from food nor to changes from tissue, but to the destruction of blood-cells. This view 
is, I think, of little value, since it simply indicates, in a general manner, that the urea 
is due to activity of the vital functions. 
The first view is in accord with Liebig’s theory of the use of nitrogen, and refers 
essentially to the formation of urea ; whilst the second view, regarding the close con- 
nexion of excess of food with urea, refers chiefly, or at least in great part, to the elimi- 
nation, and only by theoretical reasoning to the production of urea; and as the acts of 
production and elimination are not identical in nature or time, the two sets of views 
probably do not refer to parallel actions, and may both so far be true. 
It appears to me that there is much truth in both of these views, and that the 
difference is very much more one of terms than of things, as I will now endeavour to 
show. 
An idea which leads to divergence of opinion in reference to the first view is that 
connected with tissue-change, representing the tissue as something solid, and quite 
apart from the circulating mass. But a muscle, besides its tissue framework, and per- 
haps its fat, consists of fluids which are in the closest relation to the circulating fluid, 
for there is a perpetual interchange proceeding between them; and in reference to 
nutrition, the fluids in a tissue (and therefore nearly the whole of the soft tissues) are 
truly parts of the circulating fluid. 
Another idea, having a similar tendency and connected with the second \iew, is that 
which limits the changes proceeding in the blood from food, as if they were apart in 
space, and different in kind from the changes which proceed in the tissues ; but the per- 
petual circulation of the blood through every part of the body, which is completed every 
few minutes, makes this a distinction almost without a difference, for at every circula- 
tion of the blood it receives from and distributes to every tissue. 
