CONTRIBUTIONS TO ZOOLOGICAL PATHOLOGY. 411 
therefore, become diminished in the depth of its colour, and should 
the intensity of smell which heretofore accompanied it become 
less, then there is the greatest possibility that the conditions of the 
former morbid actions have been changed, a more healthy set have 
been substituted, and, therefore, the disease is now progressing to 
a favourable termination. 
Along with these remedies, and for the purpose of protecting 
the diseased parts from the influence of external injury by the 
continued rubbing of the head of the animal against the ground, 
or any other hard surface, there should be applied a head-cap or 
hood, made rather full, over the affected ear, and such as are used 
by shepherds in their treatment of scald-head in sheep during the 
summer season. This hood I have seen of much benefit in con- 
fining a quantity of cotton wadding, saturated with the lotion, in 
the hollow of the cartilage of the ear, and it also prevents the dis- 
eased parts from being constantly exposed to sources of external 
irritation. 
In the second variety of polypus of the meatus, the chondro- 
matous, the treatment must depend much on the concomitant cir- 
cumstances. If the tumour is seated close to the membrana 
tympani, and has a broad and sessile base, then it cannot be 
excised or noosed with any degree of success. It must, therefore, 
be treated by the daily application of the solid nitrate of silver, 
applied exactly to its surface, and in the intervals of application 
the use of any of the abovementioned collyria may be had recourse 
to. If the substance of the growth be firm and solid, and pos- 
sesses little sensibility, then a very speedy mode of getting rid of 
it is to divide its substance with the point of a small knife ; and 
afterwards applying to the cut surfaces the solid nitrate of silver, the 
surface of the tumour is more easily destroyed and sloughed away. 
In many instances, however, of this form of polypus, the tumour 
is so deeply seated, and possesses so little vitality, that, after the 
removal of the concomitant ulceration of the meatus, it remains as 
a kind of exostosis within the tube ; and having been situated so 
near the membrana tympani, a corresponding morbid action will 
have been excited in the tissue of this membrane, and which, by 
the hypertrophy and thickening that have been induced, a greater 
or less degree of deafness and stupidity will be the permanent 
result. 
I might have here introduced the description of several cases of 
the above forms of disease in the ears of the dog, to shew the 
speedy effects of the methods of treatment that I have recom- 
mended in removing what had been viewed as incurable cases of 
canker ; but as this would have taken up too much of your space* 
