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product of three or four days continuous running of the factory. One other batch made in an entirely different manner deteriorated from 10 units to 5 units per c.c., and is probably going lower. The lots are now being divided up into smaller batches again and so far as we can judge up to the present most of these smaller batches appear to be holding up perfectly satisfactorily.

We are inclined to think that a poor grade denatured alcohol or a recovered denatured alcohol may have something to do with this difficulty even when used in the final precipitation stage. We have not thus far noted any PH range relations such as you observed, but are making a lot of tests with a view to checking this deterioration as well as eliminating the factor causing it. If you learn anything more about the matter please notify us immediately by wire, if necessary, and we will do the same for you. There is no need for nay uneasiness as regards the quotas being supplied to Toronto and other investigators, as in spite of this very heavy loss there is every prospect of our being able to handle the situation alright.

We are sending out between eighteen and twenty thousand units this week, of which four thousand units are going direct to Toronto and about two thousand to the cases sent home by Banting and Graham. I wish that Banting and Graham would both give us the minimum dosage as [?] the optimum dose on which a case could be kept going, as it is very extravagant to sent out such very large quotas to cases from which we get little or no satisfactory data at a time when every possible unit should be employed to secure accurate clinical information.

Please urge this strongly.

Yours sincerely,
G. H. A. Clowes
Director of Research.

GHAC:FC