256 THE HUMAN SPECIES 



contact of a cold object with certain parts of the skin (abdomen 

 and back), or by shrill sounds. 



The feeling of nausea is excited by the sight of loathsome 

 objects, by foul odours, or by taking evil-smelling or tasting 

 things into the mouth or stomach. 



Hunger and thirst are experienced after abstention for a 

 sufficient length of time from food or drink. 



All these organic and general sensations exist in animals ; 

 we can conclude from observing certain signs that these feelings 

 exist, but we have no accurate knowledge on the subject. 



2. Psychology. 



The physiology of the senses, although still full of dark 

 places, has during the last fifty years been slowly divulging its 

 secrets : from the work of Weber and Fechner we have learnt 

 to know for each several sense the maximum capacity for stimu- 

 lation, and the percentage by which the stimulus must be in- 

 creased in order to produce an appreciable increase in sensa- 

 tion. In this province no one denies to physiology the right to 

 scientific explanation. It is therefore all the more astonishing 

 that psychology, which after all merely forms one branch of 

 physiology, is strenuously claimed by the advocates of trans- 

 cendentalism as their original domain. 



Where is the abode of the mind ? What is its real nature ? 



These two questions have, in all the ages, been met with 

 the most diverse replies. The natural philosophers of ancient 

 Greece were all at variance. Empedocles (like the Jews of 

 old) placed the mind in the blood, Diogenes in the heart cavities, 

 Parmenides (like van Helmont in later times) in the stomach, 

 Strato between the eyebrows. Then Stookes looked for it in 

 the heart, but the majority of later observers inclined to some 

 region in the brain, Descartes in the pineal gland, Boerhaave 

 in the spinal cord, Sommering in the vapour in the cerebral 

 ventricles, Lancisi and Bonnet in the medullary substance, 

 Haller and Wrisberg in the pons, Digby the septum lucidum, 

 Willis the corpus striatum, and Platner the corpora quadrige- 

 mina. In more material fashion Jager (v.s., p. 201) maintained 

 that he had discovered the mind in the specific odour, or exhala- 



