[162] Ueber die Bereitung des Malleins und seine Bestandtheile. Abstract in Jahresbericht f. Thierchemie, Band 22, p. 634. [163] Journal of Physiology, vol. 12, p. 9. Koch[164] has made a special study of the albumose which he considers as the specific toxic agent of the so-called tuberculin. This albumose was found by Brieger and Proskauer[165] to have a somewhat peculiar composition, inasmuch as it contains forty-seven to forty-eight per cent. of carbon and only 14.73 per cent. of nitrogen, agreeing, however, in this respect very closely with the peptone formed from egg-albumin by the action of bromelin.[166] Still more recently, Kühne[167] has made a thorough study of this albumose, as well as of the other products elaborated by the growth of the tubercle-bacillus. He designates all of the peculiar albumoses formed by these bacilli as _acrooalbumoses_. They are endowed with marked chemical and physiological properties, causing a rise of temperature when injected into the blood, as well as other phenomena more or less pronounced. It is thus evident there is ample ground for the statement that all nutritive media in which pathogenic bacteria have been planted are liable to contain, sooner or later, toxic substances, many of which at least are closely related to, if not identical with, the albumoses. It is not my purpose, however, to consider these points in detail, nor to quote the many results obtained by other workers in this direction. [164] Deutsche med. Wochenschrift, 1891, p. 1180. [165] _Ibid._ [166] Chittenden: On the Proteolytic Action of Bromelin, the Ferment of Pineapple Juice. Journal of Physiology, vol. 13, p. 303. [167] Weitere Untersuchungen über die Proteine des Tuberculins. Zeitschr. f. Biol., Band 30, p. 221. I wish merely to call attention to the fact that the proteoses, and likewise the peptones formed by pepsin-proteolysis, are more or less toxic when introduced directly into the blood, and that they share this property with the proteoses formed by bacterial organisms, or by the enzymes which they give rise to. In other words, these primary cleavage or alteration products of the proteid molecule, however produced, are more or less poisonous, and if introduced into the blood-current without undergoing previous change may show marked physiological action. It is, of course, not to be understood that these bodies are all alike. They are surely closely related and possess many points in common, especially so far as their chemical properties are concerned, but their chemical constitution and their physiological action must vary more or less with their mode of origin.