36 
a fufficient precaution, as being a power- 
ful de-mephitifator.” The moft infected 
Vans and fieves lofe their fmell when mixed 
with the whiting of fize of lime. Citizen 
Cadet de Vaux makes mention of having 
brought a putrified carcafe to fuch a ftate, 
as to be entirely free from cdour, which 
he had been formerly authorized by an ar- 
ret of parliament to exhume. ‘This me- 
phitifm, he fays, is fo inherent, that even 
time cannot diffipate t.; witnefs the Den- 
geon at Vincennes, when it ceafed to be a 
prifon. of ftate, under the miniftry of 
Malefherbes—the perfons who had’ been 
prifoners init, were, among a multitude of 
ethers, curious to fee it, and they found 
again the fame {cent which had ftruck them 
en frit entering it; the doors and windows 
however had been removed, and the eleva- 
tion of the Donjeon expofed it to the free 
ation of the air. Workshops, fattories, 
infirmaries, hofpitals, prilons, &c. have 
an atmofphere peculiar to. them—this at- 
mofphere is fatal, or often becomes the 
germ of epidemical, and fometimes peftilen- 
tial, diforders, fuch as ni€ticpy, the hofpital 
and prifon fever, &c.&c. Plants deprived of 
air Janguifh and fade, and by confequence 
much mote animals, whofe lungs confume 
fo large a mafsof it. Citizen Guyton 
Morveav has difcovered a method of 
purifying air, that contains in it the prin- 
ciple of epidemical or fatal diforders, by the 
help of muriatic gas, and efpecially of 
muriatic gas oxygenated. He purges thele 
atmo{pheres, and deprives them of their 
miafmata, which he confines or rather de- 
fivoys. But chis falutary means of puri- 
fying the air cannot act fo efficacioufly on 
walls which conceal deeply, in the porofity 
of the ftone, the miafmata with which they 
are infected ; but the aétive power of lime 
produces this effect. Citizen Cadet de 
Vaux fates the refult of one of his experi- 
ments ; beirg willing to try the effect of 
lime as a means of deméphitifation, he re- 
moved from a wall a thicknefs of nine 
lines (a French meafure containing the 
z2th part of an inch)* before he arrived 
‘at the coating or layer not yet affected. 
The other portion of the fame wall, re- 
ferved for an experiment of comparifon, . 
was completely demephitifed, in the fame 
thickne's, by three fucceffiveapplications of 
common white wafh clean water and quick 
a The author adds in a note, that in a glafs 
. bottle having expo'ed, to a maderate heat the 
duft removed from a wall, he can judge by 
the frell, whether it is or is net poluted. 
je has, he fays, feen itones more than a 
t and a haif thick tinged with mephitic 
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Literary and Philofophical Intelligence. 
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lime. But lime enters white-wathing, 
and may become the principal fubfanck of 
it, by fubfituting it for Spanifh white. 
‘Phis (ubititutionis more ceconomical, con- 
fidering the cheap price of lime : a toile of 
this white-wafhing, will only come to five 
cenlimes 5 as tothe workmanfhip, ‘hands 
wiil not be wanting in hdufes of fo large 
eftablifhments, where every thing ought 
to be for ceconomy. To deftroy the me- 
phitifm of walls in‘ afylums of indigence 
and misfortune, is fome confideration ; but 
to prevent the evil, not to have to remedy 
it, is'no Jefs an objet ; but white-wafhing 
with lime as the principal ingredient an- 
fwers this purpofe, by preventing: walls 
from being impregnated with infegtious 
miafmata. ‘To the objection for what pur- 
pole is the addition of the milk and the oil? 
the anfwer is, that lime has no adherence 
on walls, that no-body or fubftance can be 
given tothe Jayer ; ‘and laftly that the 
lighteft rubbing with a fimple pencil-bruth 
rubs it off, and leaves. the walk naked, 
whenceit happens that the contaét of walls 
fo whitened {tains the cloaths. “ ‘The 
cheefy part of the milk, the addition of 
otl, which makes a foapy body-with lime, 
form on the contrary, after the evapora- 
tion of the humidity, a denfe, coherent 
layer, fufceptible of 'a body; it is a fort 
of varnifhed plafter, “which overcomes 
the porofity of ffone, of plafter, of brick, 
and of wood, and the duft of which may 
be removed, without leaving the white- 
wafhed part naked. 
other advantage, namely, that of checking 
the mitrification of walls,-which the paint- 
ing of them in water-colours accélerates. 
In fact, glue is an animal fubftance, of 
which azote is one of the principal ingre- 
dients, but the decompofition of glue 
leaves the azote at liberty, which is like- 
wife one of the conftitucnt principles of 
nitric acid, and configns it to the oxygen 
with which it forms this acid. White- 
wathing forming no azote, there is one ali- 
ment Jefs in the nitrification ; it is not be- 
cafe the cheely part doesenot alfo contain 
azote, but as it 1s not decompofed, this 
principle is not at liberty to contract an- 
other union. Moreover, this wafh clofes 
up the pores of the ftone and is interpofed 
between the walls and ‘the nitrifying ac- 
tion. Citizen Cadet de Vaux concludes 
his letter by obierving, that he has fub- 
mitted his theéry and experiments to the 
t\vo principal French chymifts, Citizens 
particularly in the privy of the Hétel des Inva- 
lides, and des Celeftins, he has noticed the re« 
markable cixcumfance of the ftone which 
formed thé interiors being otally deftroyed. 
: oh 
This wath has an- | 
