TETANUS. 323 



' Kronecker and Stirling find that ten stimuli per second will cause 

 complete tetanus in the red muscles of the rabbit, whereas the pale 

 muscles require at least double that number. 



' When the stimuli are repeated more frequently than is required to 

 bring about a complete tetanus, the constituent contractions are still 

 proportionately increased in frequency. This is shown by the increased 

 j)itch of the muscular sound. 



' Kronecker and Stirling, by using a special instrument for rapid 

 interruption, the so-called tone inductorium, have been able to obtain in 

 all cases a complete tetanus with alternating induction shocks, even when 

 repeated, they believe, as frequently as 22,000 times a second ' (Foster). 



Thus it appears that the number of constituent contractions which 

 may coalesce to form a tetanus is very great indeed, and we can only 

 conclude from this that in the disease where so many muscles are in- 

 volved the expenditure of force entailed is enormous, even if we suppose 

 that the spasms are not of a very complex character, that is, are not 

 constituted by a large number of component contractions. 



Every time a muscle contracts there is manifestly an expenditure of 

 energy. Work is done ; force is supplied, directly or indirectly, by 

 means of the dissociation of highly complex organic compounds, of 

 whose nature little is known, and thus waste products are produced. — 

 From an article in the Veterinakian {Oct. 1882), hy Mr. J. B. 

 Gresswell. 



Varieties and Symptoms. — There are several varieties 

 of tetanus, which have received various names from the 

 particular muscles mainly involved. 



As a general term tetanus comprises all the varieties, 

 and involves a greater or less number of the voluntary 

 muscles, and probably also some sets of involuntary 

 muscles. 



When the muscles of mastication are alone or in chief 

 part affected, the condition is called trismus, or lock-jaw. 

 This is noticeable as being in most cases of tetanus a prelude 

 to the succeeding symptoms. 



When the superior cervical and dorsal muscles are 

 especially affected, producing elevation of the head, and 

 curving downwards of the spine, the affection is called 

 opisthotonos. 



When the muscles of one side are affected, the condi- 

 tion is called pleurosthotonos, or tetanus lateralis. 



When the inferior muscles are involved, the chin drawn 



21—2 



