BLANE MARSHALL HALL. 337 



The properties of different bodies in relation to each 

 other appeared to him to be the only proper subjects 

 of experimental reasoning. If, then, we can show 

 how, under the action of various forces, the parts 

 of the brain concerned in thought act in relation 

 to each other, we may obtain some knowledge as to 

 what forces bring about that relationship, although 

 we cannot affirm the connection of thought with 

 the corresponding changes in the corporeal organs. 

 We do not know much about heat, light, and 

 electricity, except as to their display in corporeal 

 subjects. 



Blane then proceeds to describe certain means 

 of expression of the emotions by motor signs. He 

 considered that no sharp line could be drawn 

 between instinctive and voluntary actions; he 

 thought instinctive movements to be comparable 

 with movements seen in the tendrils of plants. 



Marshall Hall * said, " The particular circum- 

 stances embraced in an examination of the morbid 

 states of the countenance are the changes induced 

 in the cuticular surface, the cutaneous circulation, 

 the cellular substance, the muscular system, some 

 particular features, and the general expression" 



" 61. The state of emaciation, so important to 

 observe and trace in chronic diseases, depends on 

 the loss of cellular and muscular substance, and 

 must be always distinguished from mere vascular 

 shrinking. 



" 62. The muscular system is principally affected 

 by diseases attended with pain, languor, or paralysis." 



* " The Principles of Diagnosis," vol. i. p. 31, par. 58. 



Z 



