1284 PHYSIOLOGY 



The difference between the two salts can be made still more 

 striking if the process of resorption be augmented by increasing the 

 pressure within the tubules by partial obstruction of one ureter. 

 Thus in one experiment, where diuresis was produced by the injection 

 of 30 c.c. of a solution containing 5-85 per cent. NaCl -f 14-2 per cent. 

 Na 2 S0 4 , the right ureter was partially clamped so as to make the 



15 30 45 60 75 30 105 l0 135 



FIG. 534. Curves showing excretion of urine (thick line), of sulphate mole- 

 cules (~Q^ thin line), and of Cl molecules (oF7k dotted line), after 



injection of 50 c.c. of a solution containing T775 grin. Cl and 4-8 grm 

 S0 4 per 100 c.c. The black line along the base marks the duration 

 of the injection. (CusHNY.) 



right kidney secrete against a pressure of 30 mm. Hg. The following 

 results were obtained : 



We must conclude that the tubular epithelium possesses the 

 power of modifying the glomerular transudate not only by the absorp- 

 tion of water but also by the absorption of dissolved constituents, 

 and that the relative permeability of the cells to the constituents 



