SPECIFIC BACTERIAL PRODUCTS 443 



that class. Toxins are formed during the growth of bacteria 

 in media containing no proteid, but more abundantly when it 

 is present. Toxins are divided into two classes, namely, extra- 

 cellular and intracellular. The toxins produced by certain 

 bacteria such as the tetanus and diphtheria organisms during 

 their multiplication either in the tissues of the body or in 

 culture media are largely given up to the medium in which 

 they are growing while the toxins of the bacteria of tubercu- 

 losis, glanders, and the colon group and many other species are 

 largely retained in the bodies of the organisms. 



Extracellular toxins. The extracellular toxins are, so 

 far as known, uncrystallizable. They are soluble in water and 

 they are dialyzable ; they are precipitated along with proteids 

 by alcohol, and also by ammonium sulphate; if they are pro- 

 teids they are either albumoses or allied to the albumoses. 

 They are relatively unstable. The degree of heat and the 

 resistance to chemical manipulation varies much with the 

 toxins from different species. Among the precipitants em- 

 ployed to procure them in a pure state ammonium sulphate 

 seems to have the least harmful effect. The most important 

 of the extracellular toxins are those produced by the diphtheria 

 and tetanus bacteria. These bacteria may produce several 

 entirely distinct toxins ; thus, according to Madsen and Ehrlich, 

 the specific tetanus poison consists of two toxins, tetanospasmin 

 and tetanolysin. To the first of these the tetanic convulsions 

 are due, while the second has a hemolytic action. 



In case of several of the pathogenic bacteria, if it is not 

 true of them all, there are several toxins produced: the specific 

 or perhaps most characteristic product or toxin and other 

 products or toxines. Thus in case of the soluble products of 

 Bacterium diphtheriae there is the toxin or the only poison 

 capable of causing acute death 4 and the toxone which causes 

 the late manifestation or paralysis. The toxin is modified by 

 various influences such as light, heat, moisture, etc., and is 

 thereby converted into a toxoid. 



4 Rosenau. Bulletin No. 21, Hygienic Laboratory, Washington, 

 D. C. 



