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A Summary of further Researches on the Etiology of Endemic 



Goitre. 



By Robert McCarrison, M.B., B.Ch., Captain, Indian Medical Service. 



(Communicated by Major Ronald Ross, C.B., F.R.S. Received October 24, — 

 Read November 26, 1908.) 



The object of the research was to determine by experiment on man 

 whether goitre was caused by matter held in suspension in goitre-producing 

 waters ; and to ascertain, as far as possible, the nature of the suspended 

 ingredient which had been surmised to be responsible for the production of 

 the disease. 



Thirteen individuals, including myself, were given suspended matter, which 

 had been removed by filtration from goitre-producing water, every morning 

 before the first meal of the day. I and three others developed enlargements 

 of the thyroid gland. The experiment was repeated in the case of eight 

 individuals who were given the same suspended matter, which had previously 

 been boiled for 10 minutes ; in no case did any enlargement of the thyroid 

 gland occur. 



It is concluded from these results that goitre is due to a living organism 

 of disease present in the water. The incubation period of experimentally- 

 produced goitre was 13 to 15 days. 



It is thought probable that the organism of goitre exists as an intestinal 

 parasite in goitrous individuals, since an intestinal antiseptic appeared to have 

 a marked curative effect. 



Experiments were made on monkeys to test the possibility of the spread of 

 the disease by the faeces of infected individuals, with negative results. 



Plentiful amoebic infection of the intestine was found in the majority 

 of cases of goitre examined. It is not known, however, whether amoebae 

 have any relationship to the disease. 



The research was carried out in Gilgit (Kashmir), and the results obtained 

 refer only to goitre as it occurs there. 



