172 RELATIONS OF BACTERIA TO DISEASE. 



cultures, nitrogen-containing bodies, which he called ptomaines. 

 Similar bodies occurring in the ordinary metabolic processes of 

 the body had previously been described and called leucomaines. 

 Ptomaines isolated from pathogenic bacteria in no case, except 

 perhaps in tetanus, reproduced the symptoms of the disease. 

 The methods by which they were isolated were faulty, and they 

 have therefore only a historic interest. 



The introduction of the principle of rendering fluid cultures 

 bacteria-free by filtration through unglazed porcelain, and its 

 application by Roux and Yersin to obtain, in the case of the B. 

 diphtherias, a solution containing a toxin which reproduced the 

 symptoms of this disease {vide Chapter XVI.), encouraged the 

 further inquiry as to the nature of this toxin. The products of 

 the B. diphtherias were investigated again by Brieger, now in 

 conjunction with C. Fraenkel. The method employed was pre- 

 cipitation by alcohol, and the material obtained gave certain 

 reactions of the parent fluids. This substance, if it did not con- 

 sist entirely of the diphtheria toxin, certainly contained the latter, 

 and from resemblances observed in it to serum albumin, was 

 called by its discoverers a toxalbumin. Similar toxic bodies 

 were obtained from the bacteria of tetanus, typhoid, and cholera, 

 and also from the staphylococcus aureus, but with these, though 

 death occurred from their injection, no characteristic symptoms 

 or pathological effects were observed. They probably consisted 

 largely of albumoses,^ and contained the toxic bodies in mixture 

 with other substances. 



The Occurrence of Bacterial Toxins. — The following may be 

 regarded as the chief facts regarding bacterial toxins which have 



1 In the digestion of albumins by the gastric and pancreatic juices the albumoses 

 are a group of bodies formed preliminarily to the elaboration of peptone. Like the 

 latter they differ from the albumins in their not being coagulated by heat, and in 

 being slightly dialysable. They differ from the peptones in being precipitated by 

 dilute acetic acid in presence of much sodium chloride, and also by neutral saturated 

 sulphate of ammonia. Both are precipitated by alcohol. The first albumoses formed 

 in digestion are proto-albumose and hetero-albumose, which differ in the insolubility 

 of the latter in hot and cold water (insolubility and coagulability are quite different 

 properties). They have been called the primary albumoses. By further digestion 

 both pass into the secondary albumose, deutero-albumose, which differs slightly in 

 chemical reactions from the parent bodies, e.g. it cannot be precipitated from watery 

 solutions by saturated sodium chloride unless a trace of acetic acid be present. Dys- 

 albumose is probably merely a temporary modification of hetero-albumose. Further 

 digestion of deutero-albumose results in the formation of peptone. 



