82 INTERNAL SECRETION 



from the disease. Conclusive experiments were conducted on a 

 large scale at Bozel in the Tarantaise and at Rupperswil in 

 Aargau, to which localities a fresh water supply was brought from 

 goitre-free soil. In both districts goitre and cretinism were 

 formerly rife, but since the institution of the new water supply 

 these conditions have, in the space of twenty years, entirely dis- 

 appeared. Further observation, and especially the discovery that 

 goitre may be prevented by boiling and filtering the water, seems 

 to point to the conclusion that the diseases are originated by one 

 or more living agents. The chemical composition of the water 

 and the presence or absence of certain substances, such as iodine, 

 phosphates, lime or magnesium salts, can hardly be taken into 

 account. 



Though it seems highly probable that goitre and cretinism 

 are chronic infective diseases, the originator of which is to be 

 found in the drinking water, there is as yet no entirely satisfactory 

 proof of this. Moreover, we have no conclusive proof that the 

 diseases are due to a living agent. Kolle, who employed the 

 most perfect of modern methods, was unable to prove the presence 

 of a specific originator in either the intestinal flora, the goitrous 

 thyroid gland, or in blood taken from goitrous subjects. He also 

 endeavoured to prove the presence of specific substances by means 

 of immunization and immunity reactions, as well as by anaphylac- 

 tic reactions, but without success. Attempts to transmit goitre 

 by surgical means were also negative in their result. 



Animals in goitre districts frequently develop goitre, and 

 though certain experiments have been undertaken with the object 

 of producing the condition artificially, the material at our dis- 

 posal is very scanty. Lustig and Carle found that they were able 

 to produce a slow progressive enlargement of the thyroid in a 

 horse and a young dog (the only one out of 13) by means of 

 goitre water from the Val d'Aosta. The enlargement disappeared 

 when the animals were given filtered water. 



Grassi and Munaron found that the results of their 

 experiments varied considerably. In certain dogs brought from 

 goitre-free localities to localities where goitre was endemic, goitre 

 developed even after the food and drinking-water were boiled; 

 while others, which were given goitre-water and the sediment 

 obtained by filtering such water, remained free from goitre. But 

 dogs which were kept in enclosures in which there was a 

 quantity of damp earth and rotting material obtained from districts 

 where goitre was endemic, developed unmistakable goitre. Grassi 

 and Munaron conclude from this that goitre and cretinism result 

 from toxins produced by a specific microbe, which does not inhabit 

 the organism, but lives free in the outer world, always in damp 

 material and preferably in the soil. These toxins enter the 

 organism by way of the alimentary canal, to which they are 

 conveyed in different media, of which the drinking-water is 

 probably one. 



