TOXINS 39 



extremely poisonous and may occur in decomposing 

 flesh. Some of the ptomines produced by putrefaction 

 are very similar to certain vegetable alkaloids and are 

 thus of considerable medico-legal importance. The 

 ptomines are not specific like the true toxins, and toxic 

 ones may be produced by non-pathogenic bacteria. 



(2) Toxins. These are the soluble poisons elaborated 

 by the bacteria and excreted by the cells into the sur- 

 rounding medium. They are regarded by Martin and 

 others as being allied to the proteoses. Roux and Yersin 

 suggested that the diphtheria poison might be an enzyme, 

 while Brieger and Frankel regard it as albuminous. The 

 toxins are non-basic substances closely related to the 

 proteins and hence have been named tox-albumins, and 

 are considered to be the specific toxic poisons of the 

 pathogenic bacteria. It is difficult or impossible to prepare 

 them in a state of purity and their chemical constitution 

 is therefore unknown, and they are characterised by 

 extreme specificity. Such are the poisons of the diphtheria 

 and tetanus bacilli. 



(3) Endotoxins. -These are toxic substances elaborated 

 by the bacteria which do not to any extent escape from 

 the cells. They are as specific as the toxins and possess 

 analogous properties (see below). 



(4) Bacterial proteins.- These are toxic constituents of 

 the bacterial cells which do not diffuse from the cells, are 

 not specific, and which probably usually play little part 

 in the production of the disease symptoms. 



LITERATURE 



On Nitrification, see Warington, Journ. Chem. Soc., 1886, et seq. ; 

 Frankland, Cantor Lectures, 1892 ; Nature, 1890, et seq. ; Lohnis, 

 Handbuch der landwirtschaftlichen Bakteriologie (Borntraeger, Berlin, 

 1910, full bibliography). On Bacterial Products, see Cellular Toxins, 

 by Vaughan and Novy, 1902 (Bibliog.), Ueber Ptomaine, by Brieger, 

 1885 ; Macfadyen, The Cell as the Unit of Life (Churchill, 1908) ; 



