648 , ON THE DISTEMPER AMONG CATTLE. 
ease itself ; so as to give it a more or less destructive character. 
We may easily conceive that an analogous modification may take 
place in the zymotic diseases from the malaria or morbid poison 
suffering some change during its progress ; and this we find to be 
the case, as was exemplified in the benign character assumed by 
the aphthous disease in cattle during the last spring. 
By alterations in the type of disease thus induced the remedial 
measures proper at one period are found to be insufficient or even 
injurious at another, and hence, in some measure, the discrepancies 
of authors respecting the virtues of many medicinal agents. 
Illustrative of this, I may state that, in this locality, in the sum- 
mer of 1840, many of the diseases of cattle were accompanied by 
an irritable condition of the mucous coat of the alimentary canal, 
which precluded the exhibition of tartarised antimony and several 
valuable therapeutics, in cases where such are usually our sheet- 
anchors. 
The veterinarian of extensive practice will find that a solitary case 
of any disease rarely occurs; but pneumonia, enteritis, and tetanus, 
will each reign predominant during a certain period, and leave the 
work of devastation to others in the list of our nosology. It is of 
great importance to detect any peculiarity that may attend the 
prevailing disease, so as to shape the treatment accordingly. 
A very instructive history of a disease that occurred among 
sheep in the environs of Pesth, in Hungary, is given by Raspail 
in the ninth volume of The Medical Times , page 158. The dis- 
ease attacked the flocks at pasture and set at nought the attempts 
of veterinary surgeons and learned commissions to discover its na- 
ture and to impede its progress, until at length it was found to be 
of mechanical origin. The spiculse of a plant that abounded in the 
locality penetrated the skin of the sheep and produced extensive 
and complicated constitutional derangement and death. 
These observations are intended to shew that we may have a 
certain disease very prevalent, and even assuming a peculiar type, 
without regard to malaria or contagion • but the history of veterinary 
medicine and our own experience inform us, that certain specific 
diseases occasionally invade our domestic animals — diseases that 
have been known as murrains, distempers, epizootics, &c. — varying 
much in their form, but supposed to originate in a morbid poison. 
These miasms or morbid poisons have been distinguished as ani- 
mal, or those that, under certain circumstances, are developed in 
the animal system, as glanders, rabies, &c. ; and terrestrial or 
marsh miasms, or those that proceed from the decay and decompo- 
sition of matter on the surface of the earth. Although the idea of 
noxious gases emanating from the interior of the earth during earth- 
quakes and other convulsions in nature, as developed by Syden- 
