of the ducts. Stensen indeed, who had discovered the sub-maxillary duct, seems to have had a foreshadowing of the vaso-motor influence on secretion.
The subject of digestion need not detain me, the problems with which it is concerned are so essentially chemical in nature, that although in the latter part of Harvey's period and within a few years after, the existence of the digestive juices as secretions of the various glands was known, their composition and mode of action on the food stuffs were not a matter of anatomical enquiry and depended for their satisfactory investigation upon a knowledge of chemistry that was developed altogether outside the study of the living body.
Of all the functions of the body, none it would be at once admitted is more difficult of study or more obscure in the investigation than that of the nervous system. None also has been the subject of cruder description or wilder explanations. That this is so would seem natural, clearly associated as nervous phenomena are with the more recondite phenomena of life, and subject as their study has ever been to the influences of metaphysical speculation. At the same time, however, one, and as I conceive the most, important circumstance that has retarded the rational development of Neurology has been the extreme
