363 POISONS, CONTAGIONS, MIASMS. 



It is impossible to mistake the modus operandi of this poiaon, 

 for Colin has clearly proved that muscle, urine, cheese, cerebral 

 substance, and other matters, in a state of putrefaction, commu- 

 nicate their own state of decomposition to substances much 

 less prone to change of composition than the blood. When 

 placed in contact with a solution of sugar, they cause its putre- 

 faction, or the transposition of its elements into carbonic acid and 

 alcohol. 



When putrefying muscle or pus is placed upon a fresh wound 

 it occasions disease and death. It is obvious that these substances 

 communicate their own state of putrefaction to the sound blood 

 from which they were produced, exactly in the same manner 

 as gluten in a state of decay or putrefaction causes a similar 

 transformation in a solution of sugar. 



Poisons of this kind are even generated by the body itself in 

 particular diseases. In small-pox, plague, and syphilis, substances 

 of a peculiar nature are formed from the constituents of the 

 blood. These matters are capable of inducing in the blood of a 

 healthy individual a decomposition similar to that of which they 

 themselves are the subjects ; in other words, they produce the 

 same disease. The morbid virus appears to reproduce itself just 

 as seeds appear to reproduce seeds. 



The mode of action of a morbid virus exhibits such a strong 

 similarity to the action of yeast upon liquids containing sugar, 

 and gluten, that the two processes have been long since compared 

 to one another, although merely for the purpose of illustration. 

 But when the phenomena attending the action of each respective- 

 ly are considered more closely, it will in reality be seen that 

 their influence depends upon the same cause. 



In dry air, and in the absence of moisture, all these poisons 

 remain for a long time unchanged ; but when exposed to the air 

 in the moist condition, they lose very rapidly their peculiar pro- 

 perties. In the former case, those conditions \re afforded which 



rubbed into the skin, afforded relief; but this was only temporary, and 

 there was no improvement observed on continuing this treatment. 



Chlorine diluted with water, and used externally and internally, produced 

 no improvement : on the contrary, the tension and dryness were increased 

 so that it soon became necessary to relinquish this treatment. 



