346 CHEM1C0-PHYS 10 LOGICAL CONSIDERATIONS ON 
Water is essentially a diuretic. Every thing absorbed in drinks, 
and which passes into the circulating fluid, is in a great measure 
ejected by the kidneys ; that which is retained serving to preserve 
the just proportions of the serous parts of the blood, and to furnish 
the vehicle required for the materials of the other secretions or 
exhalations. 
The action of water on the urinary organs is so rapid, so prompt, 
that many physicians have no desire for any other diuretic, or at 
least have attributed to this liquid the greatest share in the action 
of medicines directing their operation on the urinary apparatus. 
And although there is much exaggeration in such views, it is never- 
theless not the less certain that the liquid form renders the action of 
most diuretic medicines more prompt and more certain. 
Through what mechanism does water cause diuresis 1 This ad- 
mits of several interpretations - 
First, the urinary apparatus being the regulator for the com- 
position of nutritive fluids, it would eject out of the system such 
of the water taken in by drink as was not required for nutrition : 
hence the reason why one passes in urine, after every repast, the 
largest portion of the fluid ingesta. {urina potus). 
On the other hand, water is in some measure the necessary 
vehicle for the excretion of useless matters out of the system, be 
they organic or inorganic. In the same manner as the expired air 
carries with it out of the lungs carbonic acid and aqueous vapour, 
the products of hematosis, so the water taken in as drink, having 
reached the blood, dissolves and carries with it through its organic 
passages the suroxyde products furnished by nutrition; such as 
urea, uric or hippuric acid, the saline principles of organs and 
liquids ( Urina decoctus.) The experiments of M. Becquerel 
have shewn in the clearest manner the diuretic and spoliative 
effects of water. This fluid does not pass out pure of the system 
after having passed through the kidneys. It always becomes im- 
bued with saline principles, as well as the products of transforma- 
tion of organs; so that, according to the quantity of water drunk, 
will the proportion of solid matters in the urine be excreted within 
any given time. A litre* of water causing the evacuation of 
33 grammes*, 85 centigrammes* of solid matters ; 2 litres pro- 
voking the expulsion of 43 grammes, 88 centigrammes of the 
same matters. Consequently, in the diuretic effect of water, the 
kidneys do not limit their action to the elimination of the aqueous 
excess, but are equally solicited to secrete other matters susceptible 
of elimination along with it through the same passage!. 
* A French litre is a little more than If pint English; a gramme is lo*4 
grains Troy; a centigramme , *154 Troy grains. 
f Becquerel. Semeiotique des urines. Paris. 1841. 
