137 
THE EPIDEMIC OF 1836. 
and I am convinced that, if they had considered this disease as 
one produced by a morbid state of the circulating current, they 
would have found a ready explanation of the different phenomena 
observed in its progress, and have discovered no mystery what- 
ever to unravel, and the “ mysterious energy and extreme sensibi- 
lity” would have been easily explained. 
In the years 1832 and 1833, I was particularly struck with 
the appearance of the blood drawn from some horses labouring 
under influenza. [ found it black in colour, thin in consistence, 
and it flowed in wiry streams from large orifices. Since that 
period I have been very particular ki my observations, and the 
result has led me to believe that the blood is actually diseased 
previous to the commencement of the attack. I briefly alluded 
to this subject at the time in the pages of The Veterina- 
rian on the “ External Causes of Disease*.” I then stated it as 
my opinion, that, in all diseases arising from aerial poison, the 
blood is injured in its vital properties: that the circulating cur- 
rent, to be preserved in a healthy state, requires a portion of pure 
atmospheric air , which it receives in the lungs, and this is diffused 
in the other material ingredients which enter the circulation 
through the medium of the thoracic duct; that it was by these 
grosser ingredients, air and vitality, that the blood is formed ; 
and that the vital principle which exists in the blood is as easily 
affected by noxious agents as the stomach is affected by improper 
food. Acting, then, on the supposition that the vital current 
was diseased in influenza, I soon became convinced that it was my 
duty not to lessen the quantity , but to endeavour to improve the 
quality of that fluid, the healthy condition of which is so essen- 
tial to life ; and to accomplish this I determined to try the effect 
of some of the neutral salts, as recommended by Dr. Stevens in 
his “ Observations on healthy and diseased Properties of the 
Blood.” But previous to this, I made some experiments on dif- 
ferent kinds of blood, and the result confirmed the opinions of 
Dr. Stevens, to whom much merit is due for his discoveries. I 
submitted some black blood that I took from the heart of a horse 
that died of influenza to the action of oxygen gas, and I found 
that it did not produce any change in its colour. I then added 
a small quantity of the solution of muriate of soda, and instantly 
the red colour was restored ; thus proving, in the first instance, 
that the blood which I submitted to the test of experiment was 
diseased, and, in the second place, the accuracy of the discoveries 
of Dr. Stevens, that the blood owes its red colour entirely to the 
presence of the saline matter which is invariably found to exist in 
* Vol. vii, page 214. 
T 
VOL. X. 
