THE CONQUEST OF DISEASE 



the symptoms following removal of the thyroid 

 by inplanting in the abdomen of the animal a 

 piece of thyroid taken from another animal; 

 but the cure was not permanent, as the trans- 

 planted gland atrophied and the symptoms 

 recurred. Horsley had seen some cases of 

 myxedema in man, and he at once associated it 

 with the condition which he had produced in 

 monkeys. Could it be possible that these peo- 

 ple with myxedema were suffering from some 

 disease that had destroyed their thyroid 

 glands? Their symptoms surely resembled 

 some of the symptoms displayed by the mon- 

 keys whose thyroid glands he had removed. 

 He tried an experiment. He transplanted 

 the thyroid gland of a sheep under the skin 

 of a patient suffering with myxedema. To his 

 great satisfaction the patient at once improved. 

 The same operation was done upon other 

 patients and they all improved. The improve- 

 ment was but temporary because the trans- 

 planted tissue did not thrive well. Schiff and 

 others injected the extract of thyroid into ani- 

 mals with good results. Now patients with 

 myxedema are simply given the dried extract 

 of thyroid gland by the mouth ; and so long as 

 they take it they keep well. These glands are 



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