208 P A T II O L O G Y. 
of expofure, which different perfons have defcribed dif¬ 
ferently. Some have felt a (harp tafte in the mouth, as 
if blue vitriol were diifolving in it, but which nowafhing 
or gargling could remove. Others have compared the 
firft imprefiion to that of an earthy exhalation from a 
newly-opened grave, the fenfation extending down to the 
ftomach, fometimes exciting inftantaneous ficknefs and 
fflivering. Dr. Haygarth mentions that two of his pa¬ 
tients, who were phyficians, were infe&ed fuddenly by a 
fhort expofure. One of them thought that he caught 
the fever by creeping behind, in order to affift, his pa¬ 
tient; the other by infpefting morbid faeces. In both 
thefecales, the expofure was fuch as might probably af¬ 
ford a full dofe of the contagion. Dr. Lind is of opi¬ 
nion, that, in thefe difeafes, the dools, efpecially if very 
fcetid, are mod communicative of contagion; next to 
thefe, the breath; and, ladly, the effluvia from the 
body. 
The aftivity of contagion is not always proportionate 
to the appearances of malignancy in the difeafed. Some¬ 
times only one man in a fhip may be feized with the pete¬ 
chial or with the yellow fever, fays Dr. Lind, while all 
the red continue unaffefted. And on the contrary, fe¬ 
vers, of the milded defcription, fometimes fpread exten- 
fively. The period at which different fevers begin and 
ceafe to generate contagious effluvia is not abfolutely as¬ 
certained. It feems mod probable that in eruptive fevers 
there is no contagion till the eruption appears; and that 
contagion remains fo long as any fcab remains on the 
fkin. This is clearly the cafe in fmall-pox. 
When it is confidered, that contagion originates in ac¬ 
cumulated and confined animal effluvia, and is communi¬ 
cated either to thofe w’ho approach, or come in contaCl 
with the fick, or by means of fubdances impregnated 
with contagious matter, and in thefe ways only, the 
means of prevention are obvious. 
With refpeCt to the cafual origin of contagion, it is 
Scarcely neceffary to fay, that cleanlinefs and ventilation, 
as they preclude the confinement and accumulation of 
the animal effluvia and Secretions, will infallibly prevent 
the generation of the poifon. Where contagion exids, 
its farther communication may be prevented by avoiding 
contact or approach to the fick, and by confining the pa¬ 
tient to a Separate room, in which, if it be kept clean, 
and well ventilated, it has already been fliown that the 
contagion will be inert at a fhort didance from the fick ; 
and therefore that the neceffary attendants, and medical 
vifitors, will receive no injury from refpiring the air 
within it. In this way contagion has been prevented 
from Spreading in large Schools, and other places, where 
a number of people live together, as in workhoufes and 
liofpitals, of which Some examples have been already 
given. Dr. Haygarth’s rules for the prevention of in¬ 
fection, Seem to comprife all the requifite means to be 
adopted in houfes where contagious fever exids: they are 
the following. 
i. As fafety from danger entirely depends on cleanli¬ 
nefs and free air, the chamber-door of a patient, ill of 
an infectious fever, efpecially in the habitations of the 
poor, fhould never be fhut; a window in it ought to 
be generally open during the day, and frequently in the 
night. Such regulations would be highly ufeful both to 
the patient and nurfes; but are particularly important 
previous to the arrival of any vifitor. 
a. The bed-curtains fhould never be drawn clofe round 
the patient; but only on the fide next the light, fo as to 
fhade the face. 
3. Dirty clothes, utenfils, See. fhould be frequently 
changed, immediately immerfed in cold water, and waffled 
clean when taken out of it. 
4. All discharges from the patient fhould be indantly 
removed. The floor near the patient’s bed fhould be rubbed 
clean every day vPith a wet mop or cloth. 
5. The air in a fick room has, at the fame time, a more 
infectious quality in Some parts of it than in others. Vi¬ 
fitors and attendants fhould avoid the current of the pa¬ 
tient’s breath ; the air which afeends from his body, ef¬ 
pecially if the curtains be clofe ; and the vapour arifing 
from all evacuations. When medical or other duties re¬ 
quire a vifitor or nurfe to be placed in thefe fituations of 
danger, infection may be frequently prevented by a tem¬ 
porary fufpenfion of refpiration. 
6. Vifitors Should not go into an infeCted chamber with 
an empty flomach ; and, in doubtful circumltances, on 
coming out, they fflouid blow from the nofe, and fpie 
from the mouth, any infectious poifon which may have 
been drawn in by the breath, and may adhere to thofe 
pafflages. 
Befides thefe precautions, we are advifed to endeavour 
by gafeous agents to deftroy the contagious pabulum. 
The vapours of vinegar, and thofe of the Sulphureous 
acid, have been long ufed with fome degree of fuccefs ; 
but thofe of the muriatic, and ftill more perhaps thofe 
of the nitrous, acid, appear to be the belt antidotes to 
accumulated contagion. The evidence of the efficacy 
of the nitrous-acid fume, in purifying infeCted places 
and fubftances, which was a few years ago laid before the 
Houfe of Commons by Dr. Carmichael Smyth, was fuch 
as to induce that houfe to vote a national donation of 
five thoufand pounds to him for the difeovery. This 
vapour is eafily obtained, by mixing with powdered nitre 
a little of the ftrong acid of vitriol or Sulphuric acid ; 
the latter combines with the potafs, the bafe of the nitre, 
expelling at the fame time the nitrous acid in fumes. 
(See Dr. C. Smyth’s treatife on the fubjeCt.) The va¬ 
pour of the muriatic acid may be obtained in a Similar 
manner, by ufing common fea or rock fait, inllead of 
nitre. Where contagion has been long pent up in clofe 
cells or rooms, it is apt even to adhere to the walls. In 
fuch cafes, white-walking, with hot or newly-flaked lime, 
is an efficacious aid of the acid fumigations. 
We are Sorry, however, after all, to be obliged to ad¬ 
mit the juftice of a remark of Dr. Clutterbuck’s; 
“that thefe modes of chemically neutralizing the conta¬ 
gious virus, while they lead to a falfe Security, are often 
quite ufelefs.” For this reafon, ventilation and cleanli¬ 
nefs are the chief means on which we fhould place our 
dependance in guarding againlt the diffufion of fever. 
Thefe are both meafures of fo much importance, that 
the profoundeft phyficians have not thought it derogatory 
to their dignity to enter into minute and particular di¬ 
rections for their perfect eftablifflment. The means re¬ 
quired are however obvious to the meaneft capacity. 
We fliall juft quote a fhort extraCt from Dr. Jackfon, be- 
caufe the fad it contains is not generally known. He 
fays, “ In cold, damp, and foggy, weather, the free 
admiffion of external air might probably be injurious; 
for air of that defcription is not calculated to abforb or 
diflipate the floating contagion. In this cafe, the ftrong 
heat of fire in open fire-ftoves, fo placed as to diffufe its 
influence into the lower layer of the atmofphere, has ap¬ 
peared to myfelf to be the only fubftitute for defeCt of 
common ventilation, and the only fure means of recti¬ 
fying the air that is vitiated by emanation from the bo¬ 
dies of living men. Heat, as aCting on the fkin, proba¬ 
bly operates favourably on the conditions of contagious 
fever; it evidently operates favourably, as exciting and 
maintaining circulation of air within the apartment. I 
here take leave to mention the circumftance that firft di¬ 
rected my attention to it. The wards in the barrack in 
Weftmoreland Fort, on Spike Ifland, which were allot¬ 
ted to the reception of the fick of the St. Domingo ex¬ 
pedition, and which were crowded to the molt extreme 
degree of crowding, were alfo in fome degree cooking- 
places ; that is, employed for the preparation of the 
lighter parts of diet. A large fire was neceffary : and a 
long grate, being filled with coals, threw out a great heat, 
fufficient to roaft a furloin of beef. This was the cafe 
in the larger wards, .where there were from forty to fifty 
perfons flowed on the floor as clofe as they could lie. 
Thofe who lay within a certain diftance of the fire gene¬ 
rally did well,though thefymptomsof thedifeafewereoften 
4 violentj 
