ACTION OF TOXINS 407 



and a specific effect, as the two following illustrations will make 

 evident : — 



(1) They have a local action, as, for example, in the formation 

 of an abscess. The presence of the causal bacteria in the tissue 

 brings about very marked changes. There is a multiplication of 

 connective tissue corpiiscles, an emigration of leucocytic cells, a 

 congestion of blood corpuscles. These elements contribute towards 

 creating a swelling and redness, and pain results owing to the 

 subsequent pressure upon the nerve endings. "We have, in short, 

 a state of inflammation. It is then that the toxin commences 

 its local action. The oldest cells in the mass of congestion will 

 break down, and necrosis' or death will rapidly set in. The con- 

 nective tissue cells, leucocytes, blood corpuscles, etc., will thus 

 lose their form and function, and become pus. The local breaking 

 down of these gatherings of cells into fluid matter is believed 

 to be the work, not of the bacteria themselves, but of their 

 toxins. 



(2) Toxins may be absorbed and distributed generally throughout 

 the body. When this occurs they produce degenerative changes in 

 muscles, in organs, and in the blood itself. Of such a change 

 diphtheria is an example. The bacillus occurs in a false membrane 

 in the throat, and occasionally other parts. It first causes the 

 inflammatory condition giving rise to the membrane, and then it 

 breaks it down. In the body of the membrane the bacillus appears 

 to secrete a ferment which by its action and interaction with the 

 body cells and proteids, chiefly those of the spleen, produces alhumoses 

 and an organic acid (Martin). These latter bodies are the toxins. 

 They are absorbed, and pass throughout the body. As a result, we 

 get the frequent pulse and high temperature of fever: the toxins 

 irritate the mucous membrane of the intestine, and cause various 

 fermentative changes in the contents of the intestines, therefore we 

 get the symptoms of diarrhoea : they penetrate the liver, spleen, and 

 kidney, setting up fatty degeneration and its results in these organs : 

 they finally affect many of the motor and sensory nerves, breaking 

 up their axis cylinders into globules, and producing the characteristic 

 paralysis. Loss of weight naturally follows many of these degenera- 

 tive or wasting changes. Thus, then, we have some of the chief 

 changes set up by the toxins, and these changes constitute the leading 

 symptoms in the disease as it is known clinically. In addition to 

 the presence of the specific bacillus in the membrane, we also have 

 a number of other organisms, like the B. coli, Streptococcus pyogenes, 

 and various staphylococci, diplocoeoi, etc. Each of these' produces, 

 or endeavours in the midst of keen competition and strife to produce, 

 its own specific effect. Thus we obtain the complications of 

 diphtheria, such as various suppurative and septic conditions. The 



