280 APPLIED BACTERIOLOGY 



in separating three and two well-defined albumoses respec- 

 tively from cultures of these two organisms. 



It has been pointed out elsewhere that Koch's 'tuber- 

 culin ' and ' mallein ' are the glycerine extracts of the 

 toxins of the tubercle and glanders bacilli respectively, as 

 has also their use as remedial and diagnostic agents in the 

 diseases of which these two organisms are the specific 

 cause. 



All these albumoses, or toxalbumens, give with Millon's 

 reagent* a white precipitate, which on warming becomes 

 brick-red in colour, thus indicating their proteid or albu- 

 min-like character. They are precipitated, however, by a 

 saturated solution of magnesium sulphate, which shows 

 they are not ordinary albumins. On the addition of a 

 drop of dilute sulphate of copper solution, followed by a 

 slight excess of potassium hydrate solution (the biuret 

 reaction), a rose-red, and not a violet, coloration is given, 

 thus indicating that they belong to the albumin rather 

 than the globulin group. 



' Intracellular ' Poisons. — Klein has recently shown f that, 

 by intraperitoneal and by subcutaneous injection of guinea- 

 pigs with small but definite doses of the protoplasm, living 

 or dead, of various species of bacteria, these animals can 

 be rendered tolerant of further injection in large amount 

 of the protoplasm, whether the protoplasm secondarily 

 injected be derived from the same or from some other 

 species of organism. He found that the spirillum of cholera 

 and of Finkler-Prior, the bacillus of typhoid, the colon 

 bacillus, the Proteus vulgaris and the Staph, pyogenes 

 aureus, when completely separated from their metabolic 



* Millon's Beagent. — Mercury is dissolved in its own weight of strong 

 nitric acid. The solution so obtained is diluted with twice its weight 

 of water. The decanted clear liquid is then known as Millon's reagent. 



f Local Government Board Report, 1893-94, p. 469. 



