34 CHEMICAL PBODUCTS OF BACTERIA. 



that the symptoms of each and every individual disease investigated 

 are due to the chemical products elaborated by the activity of the 

 germ, but these chemical products are not, in the majority of these 

 diseases, basic in character, and consequently they cannot be classed 

 among the ptomains. Brieger succeeded in isolating from pure 

 cultures of the tetanus bacillus as many as four ptomains, but the 

 poisonous effects induced by these substances are not comparable in 

 violence with those which follow injection of tetanus cultures from 

 which the bacillus has been removed by filtration. The fact that the 

 filtered culture is more poisonous than any or all of its basic contents 

 necessitates the conclusion that the culture contains some more active 

 constituent. 



What is the nature of the powerful poisons that are formed in 

 cultures of the bacteria of tetanus, diphtheria, tuberculosis, typhoid 

 fever, anthrax, and other infectious diseases, and which are also 

 formed in the bodies of animals infected with these microorganisms? 

 At present no positive and satisfactory answer can be made to this 

 question. At one time Roux and Yersin thought that it might be a 

 ferment, and Brieger and Fraenkel advanced the belief that the diph- 

 theria poison is an albuminous body; however, there are weighty 

 objections to each of these theories, and up to the present time all 

 attempts to isolate the specific toxins have proved unsuccessful. In 

 1891 Freer made an ultimate analysis of a toxin obtained by 

 Vaughan from a toxicogenic germ found in drinking water, and 

 obtained the following results : Carbon, 48.46 per cent. ; hydrogen, 

 7.69 per cent. ; nitrogen, 13.44 per cent. ; phosphorus, 0.69 per 

 cent. Sulphur was absent. The absence of sulphur and the very 

 small per cent, of phosphorus were supposed at that time to indicate 

 that the toxin was nearly pure. In 1893, Brieger and Cohn found 

 that the tetanus toxin, in the purest form in which they could obtain 

 it, contained no phosphorus, and only unweighable traces of sulphur, 

 and they attributed the presence of the latter element to contamina- 

 tion with ammonium sulphate, which was used in precipitation. 

 Later (1895), Brieger made an ultimate analysis of the tetanus toxin, 

 so far purified that 0.000,000,05 gram killed mice, with the following 

 results : Carbon, 52.8 per cent. ; hydrogen, 8.1 per cent. ; nitrogen, 

 15.71 per cent. This purified toxin is not precipitated by ammonium 

 sulphate, and it gives the biuret reaction so imperfectly that Brieger 

 felt justified in saying that the coloration is not due to the toxin, but 

 to proteid impurities. 



tlschinsky has made an important contribution to our knowledge 

 of the toxins, inasmuch as he has demonstrated that these substances 

 are not split products, formed by the action of bacteria on proteids 

 preexisting in the culture media, but are synthetical products, and 

 are formed when the germs are grown in culture media containing 

 no proteids. He succeeded in growing a number of pathogenic 



