228 THE ENZYME TREATMENT OF CANCER
to warrant the conclusion that all the ampoules of amylopsin at that time sent out as “free from trypsin” did, in fact, contain much trypsin. As a fact—so I am informed—the amylopsin injections now on sale cannot be freed with certainty of all traces of trypsin.
In March, 1910, in the course of a correspondence with Mr. P. W. Squire, of Messrs. Squire and Sons, chemists on the establishment of the King, certain facts transpired which, by the kindness of Mr. Squire, I am permitted to publish in his own words. he wrote “ With regard to mentioning my name in your paper, I have no objection to this, providing you confine yourself to a question of actual fact, simply stating that my experiments confirm in this particular a theory you have formed; but it must be mentioned only as a question of fact, and you must not commit me to any theoretical view of the subject. The facts as I have them are as follows Sterilettes amylopsin (Squire) were being prepared, and a batch of the liquid was examined for its tryptic and amylolytic values, which were respectively found to be—trypsin = 500; amylopsin= 2,400. This was on July 28, 1909. On January 30, 1910, the liquid was again examined; the tryptic value then equalled 1,250, and the amylolytic value 1,200.” It may be added that Mr. Squire’s figures relate to the units of tryptic and amylolytic activity set up by the late Sir William Roberts.
I regard these facts as a scientific proof of the truth of my conclusion of January, 1907, that “amylopsin is a. modification of trypsin.” The facts recorded seem to indicate a decomposition of some portion of the amylopsin of July, 1909, into trypsin by January 30, 1910. Any mistake in the assays does not appear possible. The find also throws the needed light upon the discovery by Dr. Hald of trypsin in two different amylopsin prepara-