Notices respecting New Books. 373 
in consideration, it materially lessens the expense in setting up, as 
well as in wear and tear, for it does not require the retort to be 
heated any thing near so hot. We must all agree with Mr. Par- 
ker, that the subject of these decompositions is worthy a strict 
examination, and which indeed they have had in their uncom- 
bined state by many of the first chemists of the day, but not in 
combination as in coal-gas. That the sulphuretted hydrogen 
may be decomposed by the mere matter of heat, and converted 
into carburetted hydrogen by passing it over ignited charcoal, is 
well known ; and that the carbonic acid is converted into carbo- 
nic oxide by giving a portion of its oxygen to the iron, one may 
suppose ; but how the ammoniacal gas, which, according to The- 
nard, is decomposed without the iron receiving any addition, or 
the volume of the gas being in the least altered, remains to be 
explained. Ina future Number of your Magazine, if you should 
think it worthy a place, I perhaps shall be able to send you an 
account of the same principle of purifving, still further simplified, 
as applicable to horizontal retorts; in which the tube containing 
the iron turnings, scraps of tin, charcoal, &c. is placed within the 
body of the retort. We are now setting one up, but it is not in 
sufficierit progress to describe. Pardon me the length of this hasty 
letter, and believe me Your well wisher, 
Derby, Noy. 14, 1818. G. LowE. 
LX. Notices respecting New Books. — 
Ty spring last Dr. Watt of Glasgow published a Prospectus, ac- 
companied with a specimen, of a work to be entitled “ Biblio- 
theca Britannica: or a General Index to the Literature of 
Great Britain and Ireland, ancient and modern, with such Fo- 
reign Works as have been translated into English, or printed in 
the British Dominions: including also a copious selection from 
the writings of the most celebrated authors of all ages and na- 
tions. In Two Parts. In the first, the authors are arranged al- 
phabetically, and of each, as far as possible, a short biographical 
notice is given; to which is subjoined a correct list of his works, 
their various editions, sizes, prices, &c., and in many instances 
the character of the work. In the second, the subjects are ar- 
ranged alphabetically ; and, under each, the works, and princi- 
pal parts of works, treating of that subject are arranged in chro- 
nological order. ‘This part also includes all the anonymous 
works which have appeared in this country, inserted according 
to their respective subjects and dates.” A first part of this work 
is now in the press, and will be published in February. This, 
consisting of 35 sheets, or 280 pages, is calculated to be about 
Aa 3s one 
