Now, this is evidently a very interesting case, and all physicians who wish to understand the “whys” and “wherefores” would like to have some additional light thrown upon this occult subject. In this instance, there is no intimation that the father had been previously rendered “immune” to the peculiar ptomain which, in this case, is supposed to have been derived from a can of condensed milk. How, then, could this blood-serum have exerted a favorable change in the metabolism of the infant which was but ten weeks old? Our bacteriological friends will tell us that the benefits were due to the “_natural antiseptic properties_” of normal blood-serum; but the clinician and intelligent and conscientious physician will want to know from whence this peculiar property is derived. The blood is an alkaline fluid, and we are taught that antiseptic solutions, to be effective, must be acid. How does it happen, therefore, that blood-serum obtained from normal blood, which is alkaline, possesses antiseptic properties? This question has already taken up so much space in the journal that, aside from our prospective subscribers, it would not be advisable to take further time for its elucidation. It will be sufficient, however, to say that it involves a principle first developed from a scientific standpoint by Professor VAUGHAN, who has shown conclusively that the antiseptic property of blood-serum is due to the fact that the nucleus of the white corpuscles secretes an actively antiseptic substance, a substance having all the characteristic of a proteid, which he has denominated “_nuclein_.” At the risk of becoming monotonous in furthering this measure, we repeat that nuclein solutions may be obtained from yeast-cells, from the yelk of the egg, from the thyroid gland, from the spleen and from other organs of the body, and when properly prepared, they are as powerful in modifying the multiplication of microorganisms as is corrosive sublimate or any other recognized bactericide. The principle underlying the subcutaneous use of blood-serum is, therefore, demonstrable, and is strictly within the confines of scientific medicine. How long it will require to educate the medical profession in this knowledge remains to be seen; but if it was merely an empirical claim or chimerical fancy, and backed by sufficient capital or government patronage, the period would be short indeed. _EDITORIAL NOTES._ The contents of this issue of the AMERICAN THERAPIST are as usual varied, practical, interesting, original—carefully arranged to make the reading harmonious as well as profitable. We say this for the benefit of those casual readers of this issue who are not yet—but ought to be—subscribers and regular readers. * * * * *