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nerves of the orbit of the eye. 
pipes for its conveyance. In every age the brain has been 
considered a common sensorium, and all the nerves to be ca- 
pable of conveying sensation, unless when they had ganglia. 
If ganglia intervened, then the nerves were said to be cut 
off from the brain ; and those so distinguished were called 
vital nerves, neither serving the purpose of governing the 
muscles, nor of conveying sensation. With all this apparent 
simplicity of doctrine, there never has been presented such a 
crude heap of errors, in the history of any department of 
science. 
These notions were obviously founded on the mistake, that 
the same nerve served different purposes, and that a fluid 
moved in the same tube outwards to stimulate the muscles, 
and inwards to convey sensation of external impressions. So 
inconsistent are those opinions with the structure of the frame, 
that the simplest dissection proves them false. 
So far is it from being true that ganglia cut off sensation, 
that I have ascertained, and proved by experiment, that all 
the nerves, without a single exception, which bestow sensi- 
bility from the top of the head to the toe, have ganglia on 
their roots ; and those which have no ganglia are not nerves 
of sensation, but are for the purpose of ordering the muscular 
frame. 
The hypothesis, that the nervous fluid streams out from 
the great officina along the nerves, has had an unfortunate 
influence in directing the labours of the experimentalists. 
During the last age it kept the pupils of Haller engaged in 
inquiries regarding the influence of the nerves : de nutritione 
imprimis nervosa : and de nervorum in arterias imperio ; and the 
interest of this question has not subsided, but, on the contrary, 
has encreased among us. 
