288 Distribution of Iodine. 



Thus, then, we may class the relations which exist between 

 iodine, goitre, and cretinism, as follows : — 



First zone., normal^ that of Paris, — Goitre and cretinism are 

 unknown. We find that, in this zone, on an average, the 

 volume of air respired by man in twenty-four hours is from 

 (7000 to 8000 pints, litres, according to M. Dumas) : the 

 quantity of water drunk, and of food consumed, during the 

 same time, each include from p^o to -^^-^ of a milligramme 

 of iodine. 



Second zone, that of Soissonnais. — Goitre is more or less 

 rare, cretinism is unknown. It differs from the first zone 

 only in the waters being hard, and being deprived of iodine. 



Third zone, that of Lyons and Turin. — Goitre is more or 

 less frequent, cretinism is almost unknown. The proportion 

 of iodine has descended from ^^o^o to -^^^-^ of a milligramme. 



Fourth zone, that of the Alpine valleys. — Goitre and cre- 

 tinism are endemic. The proportion of iodine in the quantity 

 of air, water, and food, consumed in a day, is at most g^oVo ^^ 

 a milligramme. 



In the intermediate zones the goitre is subordinate to the 

 general influences ; in the fourth zone the deficiency of iodine 

 preponderates. 



We can do something to procure the iodine in the normal 

 proportion : in the second zone by collecting the rain water ; 

 in the intermediate zones by the same waters, by making a 

 choice of the springs, and by procuring food from those coun- 

 tries which are rich in iodine; in the fourth zone by the use 

 of the preceding aliments, and of sulpho-iodine waters, after 

 being deprived of sulphur, lavished by nature on the districts 

 most afflicted with goitre, as well as by the use of iodurated 

 salts, already advised by M. Boussingault and by M. Jules 

 Grange. Animal and vegetable productions became iodurated 

 by the use of saline waters, for drinking and in irrigations, 

 as well as by the warm solutions procured by alkaline water 

 from the most ferruginous soils and rocks. 





