LATENCY. 97 



should, I hope, induce my auditors to advance into the 

 subject of the present lecture with, at least, some par- 

 tiality for the new doctrine. 



No one has yet attempted to explain satisfactorily the 

 cause of the latency of the malarious poison. " The 

 latent residence of narcotic marsh poison in the system, 7 ' 

 says Stevens, "is incredible." Lind says, that a man 

 may be attacked by fever almost immediately after ex- 

 posure to its causes, or after a day or two, or even after 

 weeks. Usually the attack occurs within a few days of 

 the time of exposure, and often on the following day. It 

 is not easy to comprehend this, unless we suppose that the 

 poison received into the system, is organic and vital, and 

 that the phenomena of disease depend on its modification, 

 and reactions in the body. In this way we can also under- 

 stand how such a poison may remain dormant, like some 

 of the animal poisons, and that its absorbed germs may 

 be stimulated not only by time but season, following laws 

 which we are just beginning to study. 



This study is, necessarily, very limited as yet, for we 

 are denied a direct examination, and trust often to ana- 

 logies, feeble sometimes, and at others scarcely perceptible. 

 On this part of the subject, as in one already discussed, 

 we can only examine the effects of visible fungi, when 

 swallowed, and trust to the light thus imperfectly obtained 

 for a farther progress. It is, however, a very curious 

 fact, that, of all the known poisons, that of the fungi lies 

 dormant in the system for the longest time. 



One of the greatest peculiarities (Christison) of fun- 

 gous poison is, the interval before attack, and the difference 

 in that interval. He endeavors to explain both these 

 phenomena by ascribing them to the difficult solubility of 

 the poisonous matter, surrounded as it is by vegetable 

 9 



