TO READERS AND CORRESPONDENTS. 
* A Subscriber” is. informed, that a greater quantity of heat is 
generated, and consequently a greater quantity of steam raised in a 
given time, by the rapzd, than by the slow, combustion of a given quan- 
tity of fuel: hence the economy of a quick draught attained by a lofty 
chimney. 
We have been obliged to postpone an Antiquarian Communication 
from a Correspondent at Birmingham. 
A paper from Dawley in Shropshire we must decline inserting, and 
will therefore dispose of it as the author may choose to direct. 
If “ A Constant Reader” will take the trouble of referring to 
Glauber's Prosperity of Germany, he will find that we are right. 
It is necessary to inform some of our Correspondents, that if we 
receive no directions respecting communications which are not inserted, 
they are destroyed upon the publication of the number of the Journal 
next after the receipt of their papers. 
F.R.S. will observe that his request has been complied with. 
In the Foreign Science of our last number, most of our readers will 
probably have observed, that the word grains is misprinted for grammes. 
Those who have not already remarked the error, will please to correct it. 
Mr. Harvey's paper on the Formation of Mists we reserve for our 
next number. 
In reply to “ A Member of the Alfred,” and to M. R. I., we must 
again observe, that this Journal is scarcely a fit channel for the 
publication of their grievances. We cordially join them in repro- 
bating the disgraceful manner in which the parish of St. George, 
Hanover-square, is lighted, and we recommend our correspondents 
upon the subject, as well as others who feel its nuisance and danger, to 
draw up a petition to the Vestry, where we have little doubt that it will 
meet with attention ; for the neglect with which it has hitherto been 
treated, arises probably from ignorance of its extent, among those who 
have the power of remedying it. 
In Dr. Yeats’s paper (page 345,) the possibility of carbonate of 
lead being very slightly soluble in water impregnated with carbonic 
acid, is mentioned. We have, however, found that it is perfectly in- 
soluble under such circumstances ; hence, where it operates as a poison, 
it is diffused through the water, but often in so fine a state of division, 
and so small in quantity, as scarcely to render it perceptibly turbid, 
and to be a very long time in entirely subsiding. 
