348 MR. youatt’s veterinary lectures. 
be materially diminished. It has an unpleasant taste—it quickly 
becomes sour—it spoils that with which it is mixed. The butter 
made from it is ill-flavoured ; the cheese will not acquire the 
• proper consistence. Some have said that the milk is of a bluer 
colour, and that it has abundantly more serum in its composition 
than ordinary and healthy milk. Some of the puzzling disap¬ 
pointments of the dairyman may be accounted for by the deteri¬ 
oration of the milk from a cow labouring under phthisis. 
Post-mortem Appearances .—The first remarkable difference 
between the lesions presented in the lungs of the ox and the 
horse after death is the more frequent and complete adhesions, 
farther illustrative of the fact, that, in the ox, inflammations of 
the chest are in the great majority of cases those of the pleurae, 
and in the horse those of the substance of the lungs. The sub¬ 
stance of the lungs, however, is soon affected in the ox, as is 
the investing membrane in the horse; for there is nearly the 
same tubercular appearance, but generally less induration or 
hepatization: if there is any difference, it is that the tubercles 
in their state of hardness are more concrete than in the horse, 
and sometimes can scarcely be cut through. The tubercles 
here, however, are not confined to the substance of the lungs, 
but they are scattered over the pleura, both costal and diaphrag¬ 
matic, and are even found within the duplicatures of the medias¬ 
tinum. This is still farther illustrative of the difference in the 
origin of the disease in the two animals. Hydatids are also 
usually found about the lining membrane of the chest, or nume¬ 
rously and deeply embedded in the substance of the lungs. 
Causes. Hereditary Predisposition .—Of one and a very fre¬ 
quent cause of consumption in the cow, I can speak with con¬ 
fidence, for I have had opportunities of observing and tracing 
it; I mean hereditary predisposition. 1 have rarely known the 
offspring of a consumptive cow that was not also consumptive. 
I recollect two dairies that were almost destroyed by this heredi¬ 
tary taint. If it is a heifer-calf, she may possibly live a little 
after her first calving, but then she usually sickens, and the 
disease proceeds with a rapidity unknown in the mother. This 
will be a very powerful reason for our having as little to do with 
these cases as we can, lest we entail a kind of pest upon our 
employers. The cow that exhibits the slightest symptom 
of consumption should be sent to the butcher immediately, if 
she is in tolerable condition, or got into condition as quickly as 
possible, and sold. 
Ppideynic .—It is often epidemic; or, although the cow may 
have previously had the seeds of the disease within her, there 
are certain seasons when they are more rapidly and fatally 
