280 CRILE— THE KINETIC SYSTEM. [April 22, 



advantage either functionally or histologically, for there is as yet no 

 available test for thyroidism in the blood as there is for adrenalin, 

 and thyroid activity is not attended by striking histologic changes. 

 Therefore the only laboratory studies which have been satisfactory 

 thus far are those by which the iodin content of the thyroid has been 

 established. Iodin is stored in the colloid lacunje of the thyroid and 

 in combination with certain proteins is the active agent of the thyroid. 

 Beebe has shown that electrical stimulation of the nerve supply 

 of the thyroid diminishes the amount of iodin which it contains and 

 it is known that in the hyperactive thyroid in Graves' disease the 

 iodin content is diminished. The meagerness of laboratory studies, 

 however, is amply compensated by the observations which the sur- 

 geon has been able to make on a vast scale — observations which are 

 as definite as are the results of laboratory experiments. 



The Thyroid. 



The brain-cells and the suprarenal glands are securely concealed 

 from the eye of the clinician, hence the changes produced in them by 

 difTerent causes escape his notice, but the thyroid has always been 

 closely scrutinized by him. The clinician knows that every one of 

 the above mentioned causes of increased brain-cell, suprarenal, liver 

 and muscle activity may cause an increase in the activity of both the 

 normal or the enlarged thyroid ; and he knows only too well that in 

 a given case of exophthalmic goiter, the same stimuli which excite 

 the brain, the suprarenals, the liver, and the muscles to increased 

 activity will also aggravate this disease. 



The function of the thyroid in the kinetic chain is best evidenced, 

 however, by its role in the production of fever. Fever results from 

 the administration of thyroid extract alone in large doses. In the 

 hyper-activity of the thyroid in exophthalmic goiter, one sees a 

 marked tendency to fever ; in severe cases there is daily fever. In 

 fact, in Graves' disease we find displayed to an extraordinary degree 

 an exaggeration of the whole action of the kinetic mechanism. 



We have stated that in acute Graves' disease there is a tendency 

 to the production of spontaneous fever, and that there is a magnified 

 diurnal variation in temperature which is due to an increased output 

 of energy in even the normal reaction producing consciousness. In 



