AMONG CATTLK IN I III. LAND IN 184 * 2 . 
579 
ordinary degree in some parts, and much softened in others. In 
many instances, I have remarked that the tendency to effusion of 
lymph did not confine itself to the organs of respiration, but also 
extended to the surface of the animal, forming large tumours on 
the sides, and tumefaction of such magnitude about the neck, as 
alone, from the pressure on the throat, would be a sufficient cause 
of death. Indeed, it would seem that the most prominent feature 
in the pathology of the present distemper is an effusion of lymph. 
Although the pustular affection which preceded the present 
epizootic was highly contagious, the latter, I believe, from much 
observation, not to be at all so. Neither, therefore, is it infec- 
tious. 
The terms “ infectious” and “ contagious” are frequently syno- 
nymously applied, but in point of meaning they are widely differ- 
ent. By “ infection” is understood the power a disease possesses 
of being propagated from one animal to another, through the 
medium of the air alone. A disease being “ contagious” implies 
the necessity of the healthy animal coming in actual contact with 
the sick one, or at least some of the secretions of the disease, before 
he can become affected, or receive the diseasing principle. There 
is no infectious disease which is not necessarily a contagious one; 
but there are many highly contagious diseases that are not at all 
infectious. Of the contagious, but at the same time non-infec- 
tious class of diseases, syphilis and gonorrhoea in the human 
subject are well known, and with some, perhaps, too familiar 
examples. They are both contagious in the extreme, yet neither 
of them is capable of being propagated, excepting through the 
medium of actual contact with the diseased part or its discharge. 
Rabies, or canine madness, offers another example. A man 
might be for any length of time in the same chamber with a mad 
dog without being affected ; but let him be inoculated, by being 
bitten, or even in an indirect way with the saliva of the rabid 
animal, and, unless precaution be used, he will most probably in 
a short time become a victim to hydrophobia. It is curious that 
madness can only be propagated by the secretion of the animal’s 
mouth. Inoculation with the blood, the fluid from which the 
secretion of the mouth is elaborated, will produce no effect. The 
present distemper of cattle, we may safely conclude, is neither 
infectious nor contagious, although the animal decidedly becomes 
diseased from atmospheric influence. 
Peculiarity of Locality , Breed , Age, fyc . — Locality seems to 
have some influence in rendering animals predisposed to the 
present distemper. The cattle kept on low bottom-land are 
decidedly more liable to become attacked than those on upland 
pasture. In all situations exposed much to the inclemency 
