230 PHYSIC 



taminated atmosphere, through the exposed surfaces of 

 their bodies, or from the walls of the air passages, including 

 the nasal, oral, pharyngeal, laryngeal, tracheal, and pul- 

 monary. 



The entrance of the materies morbi having been effected, 

 and the period of incubation which is usually compara- 

 tively short having been passed, the series of phenomena 

 characterising the disease occur in rapid succession, and 

 terminate, in the mildest cases, in a few hours or days, and 

 in the more severe cases in as many weeks or months, or 

 it may be fatally, or in more or less permanent disablement. 



The phenomena or symptoms of the disease primarily 

 centre in the nervous system, being, it may be said, at 

 once, or soon, followed by rapid loss of strength without 

 any possible corresponding loss of body weight, and hence 

 are, and must be, the outcome of a more or less profound 

 disturbance of the machinery of the production, conserva- 

 tion, and distribution of nerve force or energy through 

 contact of that materies morbi microbes and toxins 

 with the central nerve elements. 



Taking for granted that this disease is truly zymotic, 

 it would appear that its rise, progress, and decline syn- 

 chronise with the stages of existence of its specific microbe 

 or bacillus, and that, in mild uncomplicated cases, spon- 

 taneous recovery is effected without the need of medical 

 intervention, it follows that the line of conduct to be 

 pursued, when dealing with such cases, must be founded 

 on a broad as well as minute study of its " natural history." 

 And here we might interpolate a few observations on the 

 subject of zymotic diseases generally, or on what we might 

 call zymosis as now taught. 



We remark, firstly, that these diseases are characterised 

 by very differing periods of incubation, very different 

 manners of attack, as well as very different degrees and 

 rates of progress, due to the particular "system," or part 

 of the body, implicated. The disease under consideration, 

 influenza, is, as has already been observed, very short in 

 its period of incubation, the materies morbi acting almost 

 at once on the nervous system. Typhoid fever, acquired, 

 it may be, through the lungs, alimentary canal, or cutane- 

 ous surface, incubates slowly, apparently in the systemic 



