THE WEIGHT OF THE BRAIN AND SPINAL CORD. 85 



total of over 13,000 observations. For the most part 

 these have been made in England and in Germany, and 

 and to a lesser extent in France, Italy, Russia, and 

 Austria. 



Investigators who have weighed the brain and its 

 parts have had before them several objects. The facts 

 were primarily of importance to the medical profession 

 from the anatomical and anthropological point of view, 

 while pathologists sought to associate different forms of 

 mental disease with variations in the brain-weight and 

 form. At the same time the search for a correlation 

 between the size and form of the brain and the degree 

 of the intelligence has interested all who have worked 

 on this organ, and although it might be designated as 

 the psychologist's standpoint, it has, from the very first, 

 been in some measure before the minds of all. To a 

 statement of the observations on the physical characters 

 of the central nervous system we therefore turn. 



Experiment and clinical observation have very clearly 

 shown that disturbances of the encephalon are capable 

 of causing disturbances of intelligence, and the study of 

 the evidence justifies us in claiming the brain as the 

 organ of the mind. Yet the brain is not entirely 

 made up of nervous tissues, but contains other elements 

 as well. It is surrounded by membranes, the pia 

 and dura, supported inside and out by a framework of 

 supporting tissues, and penetrated in all directions by 

 nutrient channels, the blood-vessels and the lymphatics. 

 This mass, consisting of nervous tissues, supporting 

 tissues, and nutrient vessels in various degrees of disten- 

 sion, sometimes with the pia, sometimes without it, is 

 the structure, the weight of which has been determined 

 and recorded as that of the brain. Within the ence- 

 phalon are cavities, the ventricles, and in these ventricles 

 are to be found under different conditions varying quan- 



