PARATHYROID GLANDS 79 



and unknown, that would fulfil the conditions ; it 

 will suffice to mention silver as an illustration. This, 

 if taken into the body, would withdraw so much of the 

 available iodine as inert silver iodide, that the thyroid 

 must enlarge to obtain the indispensable minimum. 



Major McCarrison, who has been observing endemic 

 goitre amongst the Gilgit highlands in North India, 

 has lately brought forward fresh arguments in favour 

 of a bacteriological theory of its causation. He has 

 induced a definite swelling of the thyroid both in 

 himself and in natives by drinking the muddy residue 

 on the filter ; the filtered water, in a short experi- 

 ment, did not give rise to goitre, nor did boiled water. 



No organism could be found in punctures of the 

 gland. Goats given water to drink contaminated by 

 the faeces of goitrous patients in some cases, though 

 not in others, developed a certain amount of swelhng 

 of the thyroid gland, and in man ten-grain doses of 

 thymol, used as an intestinal antiseptic, reduced the 

 size of a goitre in some patients. Hence, McCarrison 

 believes that the disease is due to an intestinal 

 organism. The evidence does not seem very conclu- 

 sive ; chemical substances permeating certain geo- 

 logical formations we are acquainted with, but 

 pathogenic bacteria having a special soil distribution 

 would be a novelty. According to Wilms, Bircher, 

 and others,* the water of goitre wells retains the 

 power of inducing thyroid enlargement in rats after 



* Bircher, Deut. mei. Wochensch., 1910, No. 37 ; Wilms, Deut 

 med. Wochensch., 1910, No. 13 ; Koll^ Konespond. f. schweiz., 

 Arzte, 1909, No. 17. 



