II. On a special action of the serum of highly immunised animals, and its use for diagnostic and other purposes

The following conclusions are the outcome of an enquiry into the nature and value of “Pfeiffer’s reaction,” which was made at the suggestion and under the guidance of Professor Max Gruber, of Vienna, to whom my best thanks are due. The present communication deals with the effects produced upon microbesin vitro by the serums of highly immunised animals, even when extremely dilute.