Disinfecting Powers of Increased Temperatures. 117 
The circumstances under which the experiments were conducted, 
render it, L think, demonstrable that the disinfecting agency belongs 
to heat alone; for the receptacle, in which the infected waistcoats 
were placed, having in every instance been closed, change of air 
could have had no share in the effect. The phenomena, then are 
reduced to their simplest form and the results put us in posses- 
sion, of a disinfecting agent, the most searching that nature af- 
fords ;—one that penetrates into the inmost recesses of matter in all 
its various states. As a disinfectant of ardcles which are capable of 
imbibing and retaining contagion, heat is greatly superior to the va- 
pours or gases used for the same purpose ; inasmuch as the trans- 
mission of the latter may be stopped by a few folds of compressed 
materials; while heat, if time enough be allowed, finds its way in 
spite of all obstacles. ‘To avoid being misunderstood, I must how- 
ever repeat, that it is to the destruction, by heat, of contagion exis- 
ting in substances technically called “susceptible,” that I limit the 
proposal ;—for instance, to infected clothing of every description ; 
to infected bedding and bed-furniture of every kind that would be 
spoiled by washing ; to trunks and other packages brought by travel- 
lers from infected places; and to merchandize, whenever it can be 
shown, or rendered highly probable, that such merchandize has 
been in the way of imbibing contagious matter.* 
This is not the fit occasion for obviating anticipated difficulties, 
arising out of the consideration of practical details. A few of these 
have been candidly stated to me, and have led to actual trials, chiefly 
as respects time and labor, the results of which have been satisfac- 
tory to the objectors themselves. ‘The remaining element of calcu- 
lation, the expense of apparatus and fuel, 1 am unable to supply ; 
but much observation of the use of steam, on a large scale, induces 
me to believe that the cost of producing and of applying it to this 
purpose would be far more than compensated, by the great and mani- 
* Afier taking great pains te obtain information, I have not been able to satisfy 
myself whether any, and what amount of danger exists from the presence of con- 
tagion in merchandize. There is one article, however, which is more likely than 
any other to be a vehicle of infection, viz. old rags, of which large cargoes are 
constanly imported into this country. 
Letters, which are often rendered almost illegible by fumigation, might be disin- 
fected in this way, if closed not with sealing-wax, but with wafers. Writing-paper 
I find by experiment, begins to turn brown a little under 300°; but it still retains 
its texture, and the ink is not materially changed. 
