642 
ON THE ACTION OF DIURETICS. 
urinary apparatus ; the deficiency of one is made up by the re- 
dundance of the other, and vice versa. So that it is quite clear 
that the explanation of M. Trousseau, which is in part adopted by 
every physiologist, is well founded. 
But, independently of this functional dependence between the 
skin and the kidneys, the organs are mutually connected by sym- 
pathies. So that the moment the skin, even but for a short time, 
feels cold, there arises in the kidneys a secretory sur-excitation as 
the consequence of the nervous refrigeration, which the skin trans- 
mits to all organs, driving the blood from the circumference to the 
centre. This particular action, sympathetic between the skin and 
the kidneys, and which has not been sufficiently considered, ap- 
pears to us to have a large share in the diuretic operation of these 
medicines. And we would account for it after this manner : — 
All narcotic and counter-stimulant medicines, among which we 
may rank sedative diuretics, first excite the nervous centres, like 
all foreign substances accidentally introduced into the blood ; but 
soon they diminish its activity, its nervous influence, as well in the 
organs of animal life as in those of organic life ; whence result at 
once a diminution in their proper sensibility and in their organic 
activity. 
The skin, as the organ of the sense of touch, loses much of its 
sensibility and vital energy under the influence of such medicines, 
which shews it to be immediately dependent upon the nervous 
centres. Moreover, the central organs of organic life, the heart 
principally, having lost some of their functional activity, send no 
longer but a small quantity of blood to the surface of the body : 
likewise the skin, already weakened by deficient innervation, 
loses little by little its natural heat, and, under the direct influence 
of the air, becomes more and more cold and inactive. 
So that diminution of the secretion and transpiratory exhalation 
of the skin, of its general and tactile sensibility, with palpable abate- 
ment of its temperature, are the physiological effects produced upon 
this membrane by all sedatives, and especially by those now en- 
gaging our attention. The two former effects, and especially the 
diminution of the secretory functions, having been sufficiently ex- 
amined in their relations with the urinary secretion, there remains 
the third, the refrigerant effect, which, perhaps, we have not suffi- 
ciently noticed, from not having considered it apart from the two 
others. 
Let coldness of the skin proceed from what cause it may, diuresis 
invariably follows, as may be observed during the use of cooling 
and acidulated drinks, in the action of cold, &c. : this fact is 
evident enough. But is this effect owing to the suppression or 
diminution of the secretions or exhalations of the skin, or to that 
