On Muscular Motion and Animal Spirits 269 



tation of bile. While yet, on the contrary, in the 

 natural fermentation excited in the intestines, the 

 saline-sulphureous particles are brought to a just 

 volatility, as appears from the fetor of the dejections 

 and the inflammability of the flatus escaping from 

 the belly. Wherefore it is probable that the effer- 

 vescence produced when the bile and the pancreatic 

 juice are mixed together, arises from the working of 

 the nitro-aerial particles contained in that juice with 

 the saline-sulphureous particles of the bile, which 

 fermentation is fitted to exalt the saline-sulphureous 

 particles of the bile, as we show elsewhere. 



OF THE USE OF THE SPLEEN 



Let us now, lastly, draw from this hypothesis of ours 

 a conjecture also as to the use of the spleen. If we 

 consider the wonderful structure of the spleen and 

 its notable size, and further regard the numerous 

 branches of nerves devoted to it, and its immense 

 supply of blood, we shall certainly conclude that the 

 spleen (which is to be found in all animals) serves 

 some general purpose. But it is an astonishing thing 

 that animals can live although their spleen is com- 

 pletely extirpated, and indeed bear its loss without 

 any manifest inconvenience. Hence there has been 

 much discussion among anatomists as to the function 

 of the spleen ; so that it might seem that this 

 troublesome organ had been made to harass the 

 minds no less of the physician than of those suffering 

 from it. For, indeed, nature has covered the spleen 

 more than other parts with blackness and darkness, 

 as if she wished to hide it and keep it in the dark. 

 Some have assigned to it a use so frivolous and mean, 



