628 ; RECEINT WORK ON INSULIN
throw lighllt on the interesting problemns -which arise fromn these
preliminary experiments.
I am indebted to 1\Iiss J. Ridout, 1I. A., for her efficient
assistance in connection with some of the experiments referred
to in this communication.
IIBLIOGRIIAPH Y
1. Banting, F. G., & Best, C. H.: J. Lab. & Clin. M. (St. Louis), 1921
7, 5.
2. Banting, F. G., & Best, C. H.: J. Lab. & Clin. M. (St. Louis), 1922,
S, 464-472; and Banting, F. G., Best, C. H., Collip, J. B., & Macleod,
J. J. R.: Tr. Roy. Soc. Can., 1922.
3. Doisy, E. A., Somogyi, M., & Shaffer, P. A.: J. Biol. Chem. (Balt.).
1923, 55, xxxi-xxxii (Proc. Am. Soc. Biol. Chem.).
4. Fisher, N. F.: Am. J. Physiol. (Balt.), 1923, 67, 57.
5. Dudley, H. W.: Biochem. J. (Liverp.). 1923, 17, 376.
6. Dudley, H. W., & Starling, W. WV.: Biochem. J. (Liverp.), 1924, 1S,
147.
7. Krogh, A.: Commun. to Insulin Committee.
8. Robertson, T. B., & Anderson, A. B.: Commun. to Insulin Committee.
9. Moloney, P. J., & Findlay, I). M.: J. ]3iol. Chem., 1924, 57. 359.
10. Clough, H. D., Allen, R. S., & Murlin, J. R.: Am. J. Physiol. (Balt.),
1924, 68, 213.
11. Dodds, E. C., & Dickens, F.: Lancet (Lond.), 1924, 1, 330.
12. I)odds, E. C., & Dickens, F.: Brit. J. Expelr. Pathol. (Lond.), 1924, 5.
115.
13. Best, C. H., & Scott, D. A.: J. Biol. Chem. (Balt.), 1923, 57, 709.
14. Somogyi, M., Doisy, E. A., & Shaffer, P. X.: Proc. Am. Soc. Biol.
Chem., 6, No. 2.
15. Fraser, D. T.: J. Lab. & Clin. M. (St. Louis), 1923, 8, 425.
16. Voegtlin, C., Dunn, E. R., & Thomnpsoin, J. WV.: Proc. Am. Soc. Biol.
Chem., 6, No. 2.
17. Allen, F. N.: Am. J. Physiol. (Balt.), 1924, 67, 275.
18. Dodds, E. C., & Dickens, F.: See (12).
19. Clough, H. D., Allen, R. S., & Murlin. J. R.: See (10).
20. Dudley, H. W., & Starling, W. W.: See (6).
21. Hédon and others: See Woodyatt (23).
22. Clark, A. H.: Johns Hopkins Hosp. Rep. (Bait.). 1917, 18, 229.
23. Raulston, B. O., & Woodyatt, B. T.: J. Am. MI. Ass. (Chicago), 1914.
R7, 13, 996.
24. Murlin et al: See (10) and previous communications.
25. McCarthy & Olmstead: Am. J. Physiol. (Balt.), 1923, 65, 252.
26. Best, C. 1., Scott, D. A., & Banting, F. G.: Tr. Roy. Soc., Sec. V, 81
27. Best, C. H., Smith, R. G., & Scott, D. A.: Ans. J. Physiol. (Balt.),
1924, 6S, 161.
98. Ashby, J. S.: Am. J. Physiol. (Balt.), 1923, 6, .
29. Vincent, S.: Lancet (Lond.), 1924, i, 947.
30. Oertel, H.: Lancet (Lond.), 1924, i, 695.
31. Vincent, S.: See (29).
32. See (27).
33. Macleod, J. J. R.: Physiol. Rev. (Balt.), 1924. 4. 21.
34. Banting, Best, Collip, Macleod & Noble: Tr. Roy. Soc. Can., 1922, 16,
35. Collip, J. B.: J. Biol. Chem. (Balt.), 1923, 58, 163.
(DISCUSSION OF PAPER OF DR. BEST)
Dr. John R. Murlin, Rochester, N. Y.: Dr. Best referred to our
experiments in extracting insulin by perfusion and percolation. He
said we obtained a greater yield by perfusion than by the other meth-
ods. That was true until we found an improved method of simple
extraction which we think is better, and which we reported in our last
article. We now obtain more insulin by the simple aqueous extrac-
tion, using hydrochloric acid and heat, than we do from the same
pancreas by either percolation or perfusion. The amount runs as
high as 5400 units per kg. of pancreas. However, our comparison
has been made only on the crude extracts. We have not given any
figures on the yield of insulin in the refined form. The reason for
this is that, as reported last winter in St. Louis, we have found a