Book XIV.
Chap. 2.one that the parts of the chyle or lymph are more proper, by reason of their large surface, to be applied to, and to nourish, the fibres: the other, that they are less proper, because of their coarseness, to give a certain subtilty to the nervous juice. Those people have therefore large bodies and little vivacity.
The nerves that terminate from all parts in the cutis, form each a bundle of nerves; generally speaking, the whole nerve is not moved, but a very minute part. In warm climates where the cutis is relaxed, the ends of the nerves are opened and exposed to the smallest action of the weakest objeds. In cold countries the cutis is constringed, and the papillæ compressed; the miliary glands are in some measure paralytic; and the sensation does not reach the brain but when it is very strong and proceeds from the whole nerve at once. Now imagination, taste, sensibility, and vivacity, depend on an infinite number of small sensations.
I have observed the outermost part of a sheep's tongue, where to the naked eye it seems covered with papillæ. On these papillæ, I have discerned through a microscope, small hairs or a kind of down; between the papillæ were pyramids shaped towards the ends like pincers. Very likely these pyramids are the principal organ of taste.
I caused the half of this tongue to be frozen, and observing it with the naked eye I found the papillæ considerably diminished: even some rows of the papillæ were sunk into their sheath. I examined the outermost part with the microscope, and I perceived no pyramids. In proportions as the frost-went off, the papillæ seemed to the naked eye
