PHRENOLOGY. 217 



We have added this long extract from one of the high- 

 est physiological authorities of the age, to that of Dr. 

 Roget, for the purpose of showing those into whose 

 hands this volume may happen to fall, that there is still a 

 doubt among the most competent judges in Europe, not 

 only whether Phrenology is likely to be of any practical 

 utility to man, but even whether it has any founda- 

 tion in nature. At the same time, as it is acknowledged 

 by the advocates of its doctrines themselves, that it must 

 stand or fall on the facts which can be adduced for, or 

 against it, we can see no objection to their accumulation, 

 provided in the mean time, the public curiosity can be so 

 suspended as to prevent the waste of too much time in 

 studying it, or the adoption of a system, which does not 

 at present appear to be of any great practical use to the 

 rising generation, whatever it may ultimately become. 



Double Organs of the Mammalia. In man, as well as 

 in all the other vertebrated animals, every organ sub- 

 servient to the sensorial functions, and most of those 

 concerned in voluntary action, are double ; that is, there 

 is a symmetrical organ on each side, whose powers and 

 functions are exactly alike. Thus we have two eyes, 

 two ears, two arms, two legs, &c. The same law 

 holds with respect to the brain, this part, as we have 

 shown, being divided into two equal parts, called the 

 right and left hemispheres ; so that in fact, we have two 

 brains, and a double set of nerves, as well as double eyes 

 and ears. 



In the sensorial functions these two parts constitute, 

 in action, only a single organ of sensation ; thus the ac- 

 tion of the two eyes convey to the mind only a single im- 

 pression, and of the two ears only a single sound. This 

 effect is produced by a free communication which exists 

 between the two divisions of the brain, by means of me- 

 dullary substances, called tha commissures of the brain, 

 and which pass directly from one hemisphere to the oth- 

 er. The principal commissure is the corpus callosum, 

 shown at g, Fig. 120. In the functions of most of the 



What is said of the double organs of the sensorial, and muscular pow- 

 ers ? In sensorial action is the effect double or single 1 



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