436 THE LAWS OF ORGANIC . 



still further a few other points of this important 

 subject, before we enforce the application of any 

 part to practice. As nausea has the tendency to 

 bring the blood from every part of the body to 

 the chest and abdomen, it seems reasonable to 

 suppose that this effect ought to be induced in 

 cases of apoplexy or cerebral congestions, in order 

 to relieve the head. But if we reflect that the de- 

 teriorated quality of the blood is equally as de- 

 trimental to the brain as a simple accumulation, 

 we shall perhaps think otherwise. 



D XXXIV. In the condition of the lungs 

 during nausea, the blood is certainly distributed 

 in less quantity, and with diminished force, to 

 the brain ; but, as this is not perfectly arterializ- 

 ed, it will increase the lethargic symptoms which 

 are present, as these arise, in part, from the dete- 

 riorated fluid, and will, most probably, at length 

 contribute to engorge the brain, by preventing 

 the free return of the blood. 



DXXXV. The division of the effects of eme- 

 tics into those that nauseate, and into those that 

 occasion vomiting, has long guided physicians in 

 the selection and employment of such medicines ; 

 but it has long appeared to me that this division 

 is insufficient to regulate our practice, and there- 

 fore the following is introduced as more definite 

 in its application. Emetics are found beneficial 

 in a variety of diseases that have few symptoms 

 in common with each other ; and from reflecting 



