On the Composition of an Acid Oxide of Iron. 217 



Journal of Science, vol. xxxv. p. 223) " the great storm of 

 November 29, 1836, appeared in the north of Germany after it 

 left the shores of England, and other British storms have also 

 exhibited an easterly progress." J. P. Espy has also traced 

 British storms which have moved towards south of east. 



But it will also follow that those regions which are visited 

 by storms, which have arisen within the tropics and have 

 moved from them into high latitudes, will have storms of two 

 characters ; the one progressing, as those which are the sub- 

 jects of this paper, towards north-east, and the other, those 

 originating within themselves, which move towards south of 

 east. Such a region is America and the portion of the At- 

 lantic adjacent to its coast ; and this seems to have given rise 

 to one part of the discordance between the observations of 

 Espy and those of Redfield; thus the former (page 188) in 

 quoting Redfield's language regarding the north-east progress 

 of the storms of the United States, says, " Perhaps they some- 

 times move towards east or even south-east." Now as tropi- 

 cal storms occur only in summer, those of winter must have 

 their origin in extra tropical latitudes, and therefore will be 

 those moving towards south of east ; and accordingly a decided 

 instance of this kind given in Espy's volume (page 283), is that 

 of a storm which occurred in December, and which was traced 

 by Professor Loomis in a direction towards south of east. 

 [To be continued.] 



XX VIII. On the Composition of an Acid Oxide of Iron {Ferric 



Acid). By J. Denham Smith, Esq.* 

 TN the autumn of the year before last, whilst pursuing some 

 *■ investigations respecting the alleged conversion of carbon 

 into silicon, I remarked that when the residuum of the cal- 

 cination in close vessels of ferrocyanide of potassium (carbu- 

 ret of iron) was fused with carbonate and nitrate of potash, 

 and the resulting compound treated with water, a solution of 

 a deep amethystine red colour was produced; this rapidly de- 

 composed, evolving oxygen gas, and depositing sesquioxide of 

 iron, until the decomposition being completely effected, it be- 

 came quite colourless ; no manganese could be detected in 

 the solution, nor in the deposit, although the colour of the 

 former was precisely similar to the permanganate of potash in 

 solutionf. 



Remembering that the combination of an oxide of iron 

 with potash was already on record, but unable to recall to 



* Communicated by the Chemical Society; having been read May 16, 

 1843. 

 f [See Phil. Mag., S. 3, vol. xix. p. 302.] 



