On the General Distribution of Iodine. 315 



larval condition of worms. And since I have ascertained 

 that the Vorticellse are true Bryozoa, and botanists claim 

 the Anentera as Algse, there is not a single type of these mi- 

 croscopic beings left, which hereafter can be considered as 

 a class by itself in the animal kingdom. Under whatever 

 name and whatever circumscription, it has appeared or may 

 be retained to this day, the Class of Infusoria is now entirely 

 dissolved, and of Ehrenberg's remarkable investigations, the 

 descriptive details alone can be available in future: the 

 whole systematic arrangement is gone. , q l & \ m ^ 



This result has another interesting bearing ; for it shews 

 the correctness of Blanchard's view respecting the Planariw, 

 their close relation to the intestinal worms under the name 

 of Trematoda. Indeed, they belong to one and the same 

 natural group. 



Is it not remarkable that the two types of the animal king- 

 dom long considered as the fundamental supporters of the 

 theory of spontaneous generation should have finally been 

 brought into so close connection ; and that one of them — the 

 Infusoria — should in the end turn out to be the earliest lar- 

 val condition of the other, — the intestinal worms being the 

 parents of the Infusoria.* 



.siggAaA loagaloi*! oi \> 



~ r ax f xiae.B;gA sjm e 9mii 'to trusw ioi ngworfilA 



Vmiowkmtgotnino i ^Q 



On the General Distribution of Iodine. By Mr Stevenson 



Macadam, Teacher of Chemistry, Philosophical Institu- 

 tion, Edinburgh. Communicated by the Author. 



The present investigation owes its origin to some observations 

 lately made by M. Chatin of Paris, and communicated by him to the 

 French Academy of Sciences. 



Chatin is of opinion that in the atmosphere, in rain water, and 

 in soils, there is an appreciable amount of iodine ; that the quantity 

 of this element present in one district, differs from that in another ; 

 and that the relative amount of iodine in any one locality, determines 

 to a great extent, the presence or absence of certain diseases. For 

 instance, in the district of country which he classifies under the 

 general title of the Paris zone, the quantity of iodine present in 



*j 1 1 1 : 



* Vide Silliraan's Journal, May 1852. 



