Studies from the Rockefeller Institute for Medical Research Volume 37 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 edition. Excerpt: ...of KC1 = M/2,000) lowers the rate of diffusion of water into the solution considerably less. Fig. 7. Free osmosis. Depressing effect of the addition of KG, MgClj, and CaCli upon the attraction of water by M /256 Na2SO. Fig. 8 shows that the addition of KC1 and CaCl, to M/512 Na, SO has the same depressing effect on the rate of transport of liquid through the collodion membrane in the case of electrical endosmose. In this, as in the preceding experiments, on electrical endosmose, identical solutions were put into both sides of the collodion membrane. These solutions were M/512 Na2SO4 alone or with the addition of small quantities of KC1 or CaCl2. A P.d. of 15 volts was produced on the opposite sides of the membrane and the rate of transport of water (which took place to the cathode) was observed. The curves in Fig. 8 show the result. The quantity of transport of liquid was depressed both by the addition of KG and of CaG2 but more by CaG2 than by KC1. The addition of 0.1 cc. of M/4 CaG2 to 100 cc. of M/512 Na2SO4 (concentration of CaG2 = M/4,000) lowers the transport of water more than twice as much as the addition of 0.1 cc. of M/4 KG. The depressing influence of the addition of KG or CaG2 in the electrical transport of water through a collodion membrane can be demonstrated equally well with M/256 solutions of Na2SO4 as with M/512 solutions. u 40SD 3550 ISC0 500 230 125 Concentration of KQ and CaC Fig. 8. Electrical endosmose. Showing that a similar depressing effect as in Fig. 7 exists in the case of electrical endosmose. These experiments on electrical endosmose show that the density of negative charge on the membrane in contact with a M/256 or M/512 Na2SO4 solution is diminished by the addition of any electrolyte (whose anion does not..