sECT.vi.] SUBSTITUTION OF BRAIN FOR VENTRICLES. 377 



For example, it was shown by anatomy, that all the nerves are 

 not of involuntary motion which arise from the cerebellum, as the 

 fifth pair of cerebral nerves is wholly derived from the medulla 

 of the cerebellum, the pons varolii. Ruysch, in opposition to 

 Malpighi, earnestly endeavours to prove, by his injections, that 

 the cortex of the brain is not glandular, but consists of parallel 

 vessels : however, Albinus clearly showed, that it was not alto- 

 gether vascular. Mayow attempted to show, that the animal 

 spirits consist of nitro-aerial particles ; Boerhaave, that they 

 consist of a very refined aqueous fluid, having also a nutrient 

 property, which was disputed afterwards by Haller. Some 

 thought they are aether, some electron ; Vieussens placed the 

 seat of imagination in his centrum ovale ; Lancisi and Peyronie 

 maintained, that all sensation is felt and motion excited in the 

 corpus callosum. Meyer placed the seat of memory in the 

 cortical matter, sensation at the origin of the nerves, and 

 abstract ideas in the cerebellum ; many, however, acknowledged 

 that it was not possible to determine the seat of the mental 

 faculties with any accuracy, although there could be no doubt 

 that nature had not formed so many and so various divisions of 

 the cerebrum and cerebellum without an object. Haller thought 

 that the only prospect of attaining to any knowledge of the 

 uses of these portions (if it were possible) was in diligently 

 availing ourselves of every opportunity for dissecting fatuous, 

 oblivious, or maniacal persons, or in accurately comparing the 

 cerebra of animals whose faculties are well known with the 

 human brain, &c.^ Meckel, Gasser, and others agreed with 

 WilHs in affirming, that the consentience of the nerves is 

 effected by the communicating branches; Whytt, Kaauw, 

 Astruc, objected to this doctrine, and maintained that con- 

 sentience takes place in the sensorium commune only, and 

 Haller adopted this opinion. Haller, and some of his dis- 

 ciples, amongst whom the celebrated Meckel, also conjectured 

 that the nervous loops had the function attributed to them by 

 Willis, but Haller subsequently retracted this opinion, being 

 taught by his own experiments, that nerves when torn or 

 irritated do not contract in the least. Vieussens, Ridley, Nuck, 

 and others, following Willis (and this indeed was the opinion of 

 Galen) classed the pineal gland with the lymphatic glands. 



' Elem. Phys., torn, v, p. 529. 



