132 CONTAGION. 
thefe fhould be termed infedtious, the latter contagious, 
and for this reaf'on the mode of prevention would be dif¬ 
ferent : in a country or town where the firft were rife, 
quitting'thofe places is abfolutely neceffary ; where the 
lafh, cautious refidence in the fame is fufficient, avoiding 
commerce with perfons fo contaminated, or touching 
any materials which are capable of retaining the conta¬ 
gious matter. 
Among the mod valuable of modern contrivances for 
preventing or deftroying febrile Contagion, is a very 
dimple chemical procefs lately adopted by Dr. Carmi¬ 
chael Smith, and ufed with luccefs in fome infected 
-hofpital (hips-belonging to the Britifh navy. The Union 
was an hofpital flu ip at Sheernefs, and the experiment 
on-board her was conducted by Meifrs. Menzies and 
Balfan, furgeons; and when it is confidered, that frefh 
contagion was daily pouring in from the Ruffian velfels, 
at that time lying in the Downs, and which had brought 
with them a fpecies of fever that might in every fenfe 
be termed epidemical, it will be allowed that the fuc- 
cefs of this procefs cannot be too generally known. The 
wards were extremely crowded, and the (ick of every 
defeription lay in cradles, promifeuoufly arranged, to 
the number of nearly two hundred ; o.f which about one 
hundred and fifty were in different (lages of the above 
malignant fever, which was extremeLy contagious, as 
appeared evident from its rapid progrefs and fatal ef¬ 
fects among the attendants on the lick and the /hip’s 
company. 
The utenfils and materials provided for the procefs 
were the following: A quantity of fine .land, about two 
dozen quart earthen pipkins, as many common tea-cups, 
fome long Hips of glafs to be ufed as l'patulas, a quantity 
of concentrated vitriolic (fulpluiric) acid, and a quantity 
of pure nitre, (nitrat of potaffi.) The procefs was con¬ 
ducted in the following manner: All the ports and Rut- 
ties v/ere flmt up ; the fand, which had been previoufiy 
heated in iron-pots, was then (cooped out into the pip¬ 
kins by means of an iron-ladle and, .in this heated land, 
in each pipkin, a lmall tea-cup was immerfed., contain¬ 
ing about half an ounce of the fulphuric acid, to which, 
after it had acquired a proper degree of heat, an equal 
quantity of nitrat of pot<dh in powder was gradually 
added, and the mixture ftirred with a glafs fpatula till 
the vapour arofe from it in confiderable quantity. The 
pipkins were then carried through the wards by the 
jiurfes and convalefcents, who kept walking about 
with them in their hands, occalionally putting them un¬ 
der the cradles of the fick, and in every corner where 
any foul air was fufpeded to lodge. In this manner 
they continued fumigating until the whole fpace between 
the decks was filled with the vapour, which appeared 
like a thick haze. The vapour at fuff excited a good 
deal of coughing, which gradually ceafed as it became 
more generally ditfufed through the wards ; part of this 
effeCt, however, was to be attributed to the inattention 
of thofe who carried the pipkins, in putting them too 
near the faces of the fick ; which caiiled them to inhale 
the ftrong vapour as it immediately iffued from the cups. 
The body-clothes and bed-clothes of the (ick were, as 
much as poffibie, expofed to the nitrous vapour during 
the fumigation ; and all the foul linen removed from 
them was immediately immerfed in a tub of cold water,, 
afterwards carried on deck, jrinfed out, and hung up till 
nearly dry, and. then fumigated before it was taken to 
the walh-houfe ; a precaution extremely neceffiry in 
every cafe of infeCiious diforder. Due attention was 
alfo paid to cleanlinefs and ventilation. It took about 
three hours to fumigate the (hip. In about an hour 
after, the vapour having entirely fublided, the ports and 
•i'cut-vles were thrown open for the admiffion of frelh air. 
.It could plainly be perceived that the air of the hofpital 
was greatly fweetened even by this firft fumigation. The 
.procefs was repeated again next morning; and the people 
employed, being now better acquainted with it, were 
more expert, and fimfhed the whole in about an hour’s 
time. In an hour afterwards, the vapour having en¬ 
tirely fubfided, the frelh air was freely admitted as be¬ 
fore. Fewer pipkins were employed for the evening fu¬ 
migations than for thofe of the mornings, as the frelh air 
could not be admitted fo freely after the former as the 
latter. 
The pleafmg and immediate effeCt of the fumigation 
in deftroying the offenfive and difagreeable fmell, ariling 
from fo many (ick crowded together, was now very per¬ 
ceptible, even to the nurfes and attendants ; the confe- 
qiience of which was, that they began to place confidence 
in its efficacy, and approached the cradles of the infefted 
with lefs dread of being attacked with the diforder; fo 
that the fick were better attended, and the duty of the 
hofpital was more regularly and more cheerfully per¬ 
formed. In Ihort, a pleafmg gleam of hope feemed now 
to call its cheering influence over that general defpon- 
dency, which was before evidently pittured in every 
countenance, from the dread and horror each individual 
naturally entertained of being, perhaps, the next vittim 
to the malignant powers of a virulent contagion. 
It is a remarkable fadt, that, from the 26th of Novem¬ 
ber 1795, when the fumigation was firft reforted to, till 
the 2.5th of December, not a perfon on-board was at¬ 
tacked with the fever, though, in the three months pre¬ 
ceding, more than one-third of all the people in tire Ihip 
had been feized witlr the diftemper, and of thefe more 
than one in four were carried off by it; and the proba¬ 
bility is, that the ficknefs and mortality would have 
gone on, increafing in proportion to the dilfufion of the 
contagion, and to the increafing defpondency of the peo¬ 
ple, who confidered themfelves as fo many devoted vic¬ 
tims. The advantage of tire fumigation was not felt by 
the ffiip’s company and attendants alone, whom it pre- 
ferved from the baneful effects of the fever; the (ick 
and convalefcents derived alnroft an equal benefit from 
it. The fymptoms of the difeafe were meliorated, and 
loft much of their malignant appearance; and tie ad¬ 
vantage of a pure air, and free from ftench, to conva¬ 
lefcents, may be readily conceived. The fuccefs of the 
experiment was not confined to the Union alone ; the 
power of the nitrous vapour in deftroying contagion was 
equally, difplayed on-board the Ruffian (hips in which it 
was employed. The fafety, too, with which it may be 
ufed, in any fituation, without inconvenience or rifle of 
fire, is another great recommendation in its favour. 
From the defeription ff;at has been given of the pro¬ 
cefs, no perfon can be at any lofs'in reforting to the 
fame kind of fumigation. It is only neceffary to obferve, 
for the fake of thofe who may not be converfant in che¬ 
mical purfuits, that the ingredients ought to be pure, 
and that metal veffels or rods mull not be employed. 
Any kind of metal getting among the ingredients would 
caufe the vapour to be very noxious inftead of falutary. 
The fumes that rife fhould be .white ; if they are of a 
red colour, there is reafon to fufpefft the .purity of the 
ingredients. The importance of this difeovery need not 
be infifted on ; it is equally applicable to every fpecies 
of putrid contagion; even to the plague itfelf. It fhould 
therefore be ufed in all hofpitals and parifh workhoufes^ 
and fhould be conftantly reforted to by the proprietors 
of all large works, on the firft appearance of infetfious 
difeafe among the people employed in them : indeed it 
fhould be employed even as a preventive in all lltua- 
tions where a number of people, from the nature of their 
bufinefs, are obliged to be crowded together, or where, 
from local .circumftairces, there are reafons for (u(petting 
that the purity of the air is injured by noxious-exhala¬ 
tions, or other caufes. If there be any circumftances in 
which its utility may be called in queftion, it can only 
be in cafes of inflammatory difeafes ; for, in fuch, fnper- 
oxygenation has been found hurtful. For the principles 
on 
