138 Journal of the Asiatic Society of Bengal. [N.S8., XVIII, 
that the reverse current produces a volume of urine five to 
eight times as great as that produced by the direct current, and 
the facts. I venture to prophesy that when this experiment 
is repeated on the living animal, i.e. with blood as the medium, 
identical results will be obtained. 
' (3) The ee of the Urine is dependent on Fluid Pressure. 
e experiments recorded in Appendix G (Part IT]) 
afford ates proof of the statement that i increase of fluid pressure 
versa—a statement which is also confirmed by the results of 
many other experiments. Now supporters of the neo-Ludwig 
view explain the nitrogen-weakness and chloride- strength of 
the urine obtained by increase of blood pressure in the aorta 
(hence weaker nitrogen) and chloride (hence stronger chloride), 
despite the fact that increase of aortic blood pressure implies 
a correspondingly increased blood flow through the intertubular 
aie supplying the tubules. If we adopt this explanation! 
r the excess of urine produced by aortic pressure, when pres- 
sure in the intertubular plexus is relatively low, and the glo- 
post-caval vein, when pressure in the intertubular plosae is 
relatively high* and the glomerular filtrate scanty, ? should, 
according to the line of argument assumed in this explanation, 
be characterized by great strength of nitrogen and paucity in 
chloride. But the experimental results recorded in Exp. Ser. 
the case—the urine of the post-caval pressure experiments is 
qualitatively identical with that of the aortic pressure experi- 
ments, being like it weak in nitrogen and none in fie ‘ 
1 The present writer of course surplalite the nitrogen deficit (and chlo- 
ride excess) of the urine of this pressure diuresis as being due the 
excessive excretion of whee’ bar salt) by the kidney tubules, cust aa as the 
2 The cuit illaries being eg swollen, i.e. in the same — 
as _ ne “ yrs illi when intestinal a absorption is a = ctive 
