GREY MATTER. 39 



phenomena show themselves under proper 

 conditions ; (3) That mind phenomena 

 correspond with the quantity and quality 

 of the grey matter, and with the kind 

 and intensity of the stimulus ; (4) That 

 when the grey matter of corresponding 

 parts of both hemispheres of the brain 

 is damaged or diseased, mind in some of 

 its faculties is impaired or diseased, and 

 when the damage or disease is repaired 

 the mind is restored ; (5) That on tracing 

 the rise in the scale of intelligence, it is 

 found that with every increase in intelligence 

 there is a corresponding increase in the 

 quantity of grey matter. The greater 

 the quantity the larger the mind, and 

 the finer the quality the higher the quality 

 of the mind from an amoeba to a Newton. 

 Now, grey matter is present in many 

 parts of the body, but is especially abundant 

 in the brain and spinal cord. It is dis- 

 tributed throughout the whole body, 

 perhaps in single molecules, in the lowest 

 animals, the protozoa ; and must there 

 be of the lowest quality, perhaps differing 

 but little from the highest quality of not- 

 nervous protoplasm ; but with the rise 

 in the scale of intelligence it is collected 

 into masses, and finally into the form of 



