92 THE DISEASES OF THE THYROID GLAND 



tic digestion does not seem to alter the specific substances, as we are able 

 to bring about the complete action even on peroral administration. All 

 experiments point to the fact that the thyroid gland carries iodine in a specific 

 organic combination, perhaps iodthyroglobulin. 



The iodine-contents of pathological glands varies greatly. The purely 

 parenchymatous Basedow strumas contain almost no iodine; strumas 

 rich in colloid are also rich in iodine. Investigations by Oswald, A . Kocher. 

 and others have shown that the iodine-contents of strumas rich in colloid 

 is really not absolutely greater than in the normal thyroid-gland, but that 

 relatively, that is, taken in relation to the amount of thyroid-gland sub- 

 stance, it is less. On the contrary, the holding in thyroglobulin is abso- 

 lutely and relatively greater; in colloid goiters there is found, therefore, 

 either an iodthyroglobulin poor in iodine or less iodthyroglobulin and more 

 thyroglobulin. Probably in the Basedow struma the formed iodothyro- 

 globulin reaches the circulation immediately in consequence of the increased 

 permeation with blood. 



The function of the thyroid gland, if the organ is altered pathologically, 

 may be influenced by the administration of inorganic iodine. Individuals 

 with normal thyroid glands separate out again the excess of iodine rather 

 promptly, without any disturbance of the iodine equilibrium. Strumous 

 individuals, according to the investigations of A. Kocher, behave very 

 diversely; in strumas with abundantly functionating parenchyma more 

 iodine is excreted than is introduced, so that thyroid-gland tissue is melted 

 down and symptoms of thyroidism may appear. In strumas with relatively 

 iodine-poor colloid this is first iodized; there therefore occurs an iodine re- 

 tention, but on continued treatment with iodine there may come about 

 melting down of the colloid and thyroidism. Administration of the phos- 

 phates should favor the action of iodine and keep back the melting down of 

 tissues. This experiment renders intelligible the old experience that in 

 certain forms of struma the administration even of very small amounts of 

 iodine leads to manifestations of thyroidism. 



Kocher's investigations stand in the most intimate relation to the 

 older experience as to the so-called iodine Basedow's. Coindet, in Geneva, 

 introduced iodine into therapy in 1820. Shortly afterward it was reported 

 by Coindet himself and by Gautier, d'Espine, Relliet, and others that after the 

 administration of iodine there often occurs a series of symptoms that are 

 sharply distinguished from those of pure iodism (acne, catarrh of the mucous 

 membranes, etc.). These symptoms (tachycardia, tremor, emaciation, etc.) 

 could develop in strumous individuals after the administration of mimimal 

 amounts of iodine, and long outlast the medication. Already Lebert ad- 

 vocated the opinion that in such cases the administration of iodine led to 

 rapid absorption of thyroid glandular substance and the symptoms mentioned 

 could be referred to this. Breuer explained the contradiction that these 



