THEIR MODE OF ACTION. 375 



ges, which has an acid reaction, retains all its frightful properties 

 under the same circumstances. 



In the former of these cases, the free acid present in the 

 stomach destroys the action of the poison, the chemical properties 

 of which are opposed to it ; whilst in the latter it strengthens, or 

 at all events does not offer any impediment to poisonous action. 



Microscopical examination has detected peculiar bodies resem- 

 bling the globules of the blood in malignant putrefying pus, in 

 the matter of vaccine, &c. The presence of these bodies has 

 given weight to the opinion, that contagion proceeds from the 

 development of a diseased organic life ; and these formations 

 have been regarded as the living seeds of disease. 



This view, which does not admit of discussion, has led those 

 philosophers who are accustomed to search for explanations of 

 phenomena in forms, to consider the yeast produced by the fer- 

 mentation of beer as possessed of life. They have imagined it 

 to be composed of animals or plants, which nourish themselves 

 from the sugar in which they are placed, and at the same time 

 yield alcohol and carbonic acid as excrementitious matters.* 



It would perhaps appear wonderful if bodies, possessing a 

 crystalline structure and geometrical figure, were formed during 

 the processes of fermentation and putrefaction from the organic 

 substances and tissues of organs. We know, on the contrary, 

 that the complete dissolution into organic compounds is preceded 

 by a series of transformations, in which the organic structures 

 gradually resign their forms. 



Blood, in a state of decomposition, may appear to the eye un- 

 changed ; and when we recognise the globules of blood in a 

 liquid contagious matter, the utmost that we can thence infer is, 

 that those globules have taken no part in the process of decom- 

 position. All the phosphate of lime may be removed from bones, 

 leaving them transparent and flexible like leather, without the 

 form of the bones being in the smallest degree lost. Again : 

 bones may be burned until they be quite white, and consist 

 merely of a skeleton of phosphate of lime, but they will still 

 possess their original form. In the same way processes of de» 



* Annalen der Pharmacie, Band xxix., S. 93 und 100. 



