Two years ago, at a meeting of this Association at Atlantic City, and before this Section, I had the privilege of describing some experiments made by some of my students and myself on intracellular toxins. I desire in this paper to make some additional statements on this subject.
By means of the large incubating tanks which I described in a paper read before the Association of American Physicians in 1901, and which are figured in the transactions of that society, I have been able to obtain both pathogenic and non-pathogenic bacteria in large amounts absolutely free from the constituents of the culture medium on which the germs have been grown. In this way I have studied the cell substance of the colon bacillus, the bacilli of diphtheria and anthrax, the Micrococcus prodigiosus, and the lemon and orange sarcines. I have found that the cell substance of all of these organisms