226 Corrections in the last Number of the Annals. [Sept. 



To prepare the liquid containing its own volume of chlorine, 

 instead of the 3*98 grammes, &c. p. 221, we must take 92-127 

 grains of well crystallized oxide of manganese, and receive the 

 chlorine in 100 cubic inches of milk of lime ; and in the pro- 

 cess of assaying the chlorides, (p. 223) we must employ 125 

 grains of the mixed salts, and decant the solutions into the 50 

 cubic inch jar D. J. G. C. 



Article XIII. 



Corrections in the last Number of the Annals. 

 (To the Editors of the Annals of Philosophy .) 



GENTLEMEN, Jug. 18, 1824. 



Permit a constant reader to point out a few oversights that 

 occur among the Scientific Notices in the last number of the 

 Annals of Philosophy, viz. for August. 



Your candour, added to your wish to render the journal as free 

 from error as possible, will find an excuse for the liberty now 

 taken. 



1. In Article 4, p. 140, where the table exhibiting the quan- 

 tity of each chalybeate preparation containing 1 grain of 

 oxide of iron is given, the numbers that ought to have been 

 attached to Petri Subcarbonas and to Ferrum Ammoniatum are 

 transposed, and thus absurdly erroneous quantities are set down 

 for these substances. 



2. The title of Article 5, p. 140, is erroneous, " On the Use 

 of Nitrous Oxide in Eudiometry." It ought to be Nitric Oxide. 



3. ArticleS, p. 151, "Inflammation of Sulphuretted Hydrogen 

 by Nitric Acid." In this title, as well as in the description of 

 the experiment, I apprehend that you have substituted nitric for 

 nitrous acid. 



The experiment is not a new one, and it is not due to Berze- 

 lius. I remember well having seen it above twelve years ago in 

 the lectures on chemistry in the University of Edinburgh, and 

 I am certain that Dr. Hope made use of strong fuming nitrous 

 acid. It may be mentioned by the way that the exhibition is 

 remarkably striking and brilliant when made on a large scale. 



To the best of my recollection, the Professor, instead of using 

 a flask containing four or five cubical inches of gas, as recom- 

 mended by Berzelius, employed a large wide-mouthed receiver 

 of nearly 200 cubical inches capacity, and poured into it about 

 half an ounce of the strongest fuming nitrous acid, covering the 

 orifice slightly with a piece of paper. 



The explosion is not violent, but the flame in the interior of 

 the vessel is beautiful. 



I remain, Gentlemen, your obedient servant,. A. B. 



We thank our friend A. B. for his good opinion of our can- 



