OF THE NERVOUS SYSTEM IN GENERAL. 469 



paired continually by the arrival of arterial blood, are convey- 

 ed, according to him, from the brain, as from a centre, to all 

 parts of the body, and reciprocally; their flux from the brain 

 to the muscles causes motion, their reflux from the senses to 

 the brain produces sensation. This inadmissible explanation 

 should be separated from the sufficiently exact anatomical ob- 

 servation upon which it rests. 



Prochaska having examined with the microscope a laminae 

 of nervous substance sufficiently thin to be transparent, found 

 that it resembled a sort of pulp formed of innumerable glo- 

 bules or round particles; by the action of water, this pulp is 

 divided into little flocculi, and each flocculus is composed of a 

 certain number of globules; maceration, prolonged even dur- 

 ing three months, is insufficient to separate the globules from 

 each other. He concludes that the uniting medium is a deli- 

 cate cellular tissue, formed in part by sanguineous vessels, and 

 in part by prolongations of the envelope of the nervous sys- 

 tem: the globules appeared to him different in size in the same 

 part of the system; he estimates the size of those of the brain 

 and cerebellum at about one eighth part of that of the globules 

 of the blood; as to the structure of the globules themselves, 

 the most powerful microscopes teach us nothing on that sub- 

 ject. 



Barba has observed the globules, and has found no difference 

 in the substance which unites them, in the different parts of 

 the nervous system. 



The brothers Wenzell have added some observations to 

 these; they have found the nervous substance throughout form- 

 ed of globules which they regard as vesicles filled with medul- 

 lary or cineritious substance, according to the parts; the glo- 

 bules seem to touch each other or to adhere, and nothing is 

 perceptible between them. This globular appearance resists 

 desiccation, the action of alcohol, either pure or acidulated. 



Messrs. Home and Bauer have published two different re- 

 sults of microscopic observations: according to their first re- 

 searches, the fresh brain is composed of fibres formed by the 

 reunion of globules nearly equal in size to those of pus. Ac- 

 cording to their new observations, the nervous substance is 



