June 9, 1922] 



SCIENCE 



607 



of my own teachers in the middle sixties, dis- 

 covered that the liver had a second function 

 totally unsuspected until then. Practically all 

 the blood from the intestines goes through the 

 liver on its way back to the heart. Bernard 

 opened the abdomen of a fasting animal, drew 

 some of the blood before it entered the liver, 

 and also some of the blood after it had gone 

 through the liver. He found .that the blood, 

 before it entered the liver, was sugar free, but 

 after it emerged from the liver, it always con- 

 tained sugar. This was the first step in the 

 scientific study of diabetes, in which there is 

 an excess of sugar which is excreted through 

 the kidneys. 



But the liver has no second duct or tube for 

 the discharge of this sugar into the blood cur- 

 rent. Being in solution, it soaks through the 

 thin walls of the blood vessels into the blood 

 current as it passes through the liver. 



roUowing this, came later the discovery of 

 the now numerous "ductless glands" of which 

 we have learned so much chiefly by animal 

 experimentation in the last few years. Some 

 of them, though only as large as a pea, are 

 essential to life itself. 



V. Let me now say a few words about one 

 of the most important of these ductless glands 

 — ithe thyi-oid gland in the neck. When it be- 

 comes enlarged it is familiar to us as a "goiter." 

 From this gland, as in the ease of the liver, 

 there soaks into the blood stream a secretion of 

 great importance to life. If the gland is rudi- 

 mentary, either in substance or in function, it 

 results in that form of idiocy known as cre- 

 tinism. As a remedy we have learned to ad- 

 minister an extract from the thyroid glands of 

 animals. The remedy is usually remarkably 

 successful. 



In certain conditions, goiter is very prevalent 

 in the thyroid gland of broolc trout. It has 

 even threatened to destroy the culture of these 

 food fishes.* By the administration of iodin, 

 this disease has been prevented in the trout. 

 As a result of this success, the same method has 

 been found efficient in preventing goiter in 

 human beings. 



Here, again, you perceive the solidarity of 



4 Kimball: American Journal of the Medical 

 Sciences, May, 1922, p. 634. 



the animal kingdom in such identity of func- 

 tion that the thyroid gland of animals, when 

 given as a remedy to man, performs precisely 

 the same function as the human thyroid. More- 

 over, it is not the thyroid gland from the 

 anthropoid apes that is used as a remedy, but 

 that from the more lowly sheep. 



VI. The Sympathetic Nerve and its won- 

 derful phenomena. When I was a student of 

 medicine, one of our text books was Dalton's 

 Physiology. In connection with the sympa- 

 thetic nerve, there was a picture of a cat, of 

 which the Chessy cat of Alice in Wonderland 

 reminded me, for in both only the face was 

 pictured. 



The sympathetic nerve is a slender cord 

 about as thick as a fairly stout needle. It runs 

 vertically in the neck, alongside of the carotid 

 artery and the jugular vein, and so close to 

 them that a dagger, a knife or a bayonet thrust, 

 or a bullet which would cut the nerve, would 

 almost surely cut the great artery and the vein. 

 The patient then would bleed to death in a few 

 minutes and never reach a hospital. Hence, 

 no one had ever had a chance to observe the 

 effects following division of this nerve in man. 

 Before Brown- Sequard's experiment in ani- 

 mals, in 1852, its function, therefore, was en- 

 tirely unknown. By a small incision he ex- 

 posed the nerve in the neck of a cat, rabbit and 

 other animals, divided the nerve, and observed 

 what happened. The small wound healed 

 quickly. 



These results were as follows: 1. The pupil 

 of the eye on the same side as the cut nerve 

 diminished from the normal large sized pupil 

 in the cat to almost the size of a pin hole. 

 2. The corresponding ear became very red 

 from a greatly increased flow of blood, i. e., 

 the blood vessels were greatly dilated. 3. On 

 that side there was increased sweating, that is, 

 the sweat glands became very active as a result 

 of the increase in the blood supply. 4. The 

 temperature increased to a marked degree; in 

 rabbits, by seven to over eleven degrees Fahren- 

 heit. 



Dalton's picture of the eat could not be for- 

 gotten Ijeeause the two pupils differed so 

 greatly in size. 



In 1863, during the Civil War, when I was 

 assistant executive officer of a military hospi- 



