EXTRACTS FROM EXCHANGES. 
379 
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point that the principal part of the renal function belongs to 
the blood circulation through those organs ; but various opinions 
are expressed upon the relations which exist between the circula¬ 
tion on one side and the quantity of urine secreted on the other. 
With a special apparatus, Schwarz has succeeded in applying at 
will pressure on the renal vein, thus to reduce the rapidity of 
the circulation in the kidneys. In those experiments he ob¬ 
served not a reduction in the quantity of the secretion, but, on 
the contrary, an increase. When the circulation' was com¬ 
pletely shut up, urine still increased in quantity, varying be¬ 
tween 2 ^ to 50 times more. Ligature on the vein produced 
after two hours and fifteen minutes, a complete arrest of the 
secretion. Experimental arrest of the renal circulation, when 
made for a short time, produces no bad effects ; soon after the 
urine resumes its normal qualities. But, if the arrest is kept up 
for some time, the kidney swells, increases in weight, and in all 
its dimensions. The reduction in the renal secretion obtained 
by Hudenhain, is explained by Schwarz in admitting that the 
venous stasis, which occurs in these experiments, gives rise to 
blood coagulation in the tubes of Malpighi, and interferes with 
its permeability. Electric lighting of the superficial glands re¬ 
duces the secretion of urine. Irritation has no effect on them 
when they have received first an injection of atropine. Experi¬ 
ments made with diuretic substances has shown that not one 
acts through the intermediate of the blood circulation 011 the 
kidneys—it must be supposed that they have a direct action on 
the epithelium of the urinary canaliculi.—(. Archiv. Vet. Russ, 
and Prog. Vet.') 
Upon the Coagulation of Milk [A. Rosaz]. —The au¬ 
thor has directed his attention to the minute ehemico-bacteri- 
ologic study of the coagulation of milk. The determination of 
lactic acid in coagulated milk and the cultures on various 
medias were made with the methods of Gunther and Thier- 
feldel. The numerous experiments of the author show that in 
the coagulation of the milk, besides the lactic acid polarizing 
to the right, there is another lactic acid which is without optic 
effect. The formation of these acids depend on the temperature 
when the coagulation itself occurs. When it takes place at the 
temperature of the chamber dextogiric acid predominates ; 
when it takes place at 36°-39°, it is the other. Three different 
micro-organisms promote the coagulation, the bacillus acid, 
paralactici, the bacillus luerolactic Halensis, and the micrococ¬ 
cus acidi paralactici Halensis. The most important and most 
