WAVES OE HEAT AND WAVES OF DEATH. 187 
the clead-honse of Mount St. Bernard on the Alps have lost 
water by evaporation_, and are dined ; but they are not putrid : 
they are preserved by cold_, which means absence of heat. 
Hence we say that cold is an antiseptic as alcohol is_, and 
chloroform^ and ammonia_, and creasote^ and snlphm’ons acid^ 
and other similar substances. Cold is an antiseptic,, then^ but 
why ? Because it prevents^ as do the bodies named a moment 
ago^ the union of oxygen gas with combustible matter. The 
molecules of oxygen^ in order that they shall combine,, and in 
their combination evolve heat,, require to be distributed, and 
are distributed by the force or motion known as heat : deprive 
them of this force, and they come into communion with them- 
selves, are attracted to each other, and lose to the extent of 
this attraction their power of combining with the molecules of 
other bodies for which they have an affinity. In an analogous, 
but more obvious way, we may see the same effect of motion 
in the microscopic examination of blood. In the blood, while 
it is circulating briskly in its vessels, there are distributed 
through it, without contact with each other, millions of small 
round bodies, called blood corpuscles. In the circulation in 
the free channels of the body, the arteries and veins, it is 
motion that keeps these corpuscles apart : we draw a drop of 
blood and let it come to rest on the microscope glass, and 
as the motion ceases the separated corpuscles run together, 
and adhere so firmly that we cannot separate them by any 
force less than disintegration. If we were to drive them in 
this state round the body, through the vessels, they would not 
combine readily with the tissues ; they have, in fact, forfeited 
the condition necessary for combination. So with oxygen, 
when its invisible molecules are deprived of the force called 
heat, which is motion, they do not readily combine with new 
matter. But perfect combination of oxygen and carbon in 
the blood is essential to every act of life. In the constant clash 
and union of molecule of oxygen with molecule of carbon in the 
blood lies the mainspring of all animal motion ; the motion of 
the heart itself is secondary to that. Destroy that union, 
however slightly, and the balance is lost, and the organic body 
is, in a plain word, ill. 
Cold, or decreased temperature, below a given standard, 
which for sake of comparison we may take at a mean of 55° 
Fahrenheit, does destroy this combination of oxygen and 
carbon in blood. In the Lettsomian lectures of the Medical 
Society of London, delivered four years ago, I entered very 
fully into this subject, and illustrated points of it largely by 
experiment. Since then I have done more, and although I 
have not time here to state the details of these researches, I 
will epitomize the principal facts. I found then that, by 
