366 POISONS, CONTAGIONS, MIASMS. 



subject, to certain parts of the organism, without 

 themselves being reproduced in their peculiar form 

 and nature during the progress of the decompo- 

 sition. 



The disease in this case is not contagious. 



Now when yeast is introduced into a mixed 

 liquid containing both sugar and gluten, such as 

 wort, the act of decomposition of the sugar effects 

 a change in the form and nature of the gluten, 

 which is, in consequence, also subjected to trans- 

 formation. As long as some of the fermenting sugar 

 remains, gluten continues to be separated as yeast, 

 and this new matter in its turn excites fermenta- 

 tion in a fresh solution of sugar or wort. If the 

 sugar, however, should be first decomposed, the 

 gluten which remains in solution is not converted 

 into yeast. We see, therefore, that the reproduc- 

 tion of the exciting body here depends 



1. Upon the presence of that substance from 

 which it was originally formed. 



2. Upon the presence of a compound which is 

 capable of being decomposed by contact with the 

 exciting body. 



If we express in the same terms the reproduction 

 of contagious matter in contagious diseases, since 

 it is quite certain that they must have their origin 

 in the blood, we must admit that the blood of a 

 healthy individual contains substances, by the de- 

 composition of which the exciting body or conta- 

 gion can be produced. It must further be admitted, 



