These generalities, likewise, explain the various diseases--viz., those in which the animals blend together the typhous and exanthematic diseases. The measles and the scarlet fever, affecting the external or internal membranes, are like the first steps of these maladies; they are generally slight, and we have but to watch over the progress of the symptoms, and to assist nature, which, with few exceptions, brings all things to a favourable issue.
These disorders, which are relatively slight and do not provoke in the economy any of those changes which in some sort transform the constitution, are not absolutely proof against relapse. They lead us rationally and by degrees to the more infectious and contagious diseases, to the common typhus; therefore it is unnecessary to apply the preventive treatment to them, that being exclusively reserved for the latter.
Let it then be well understood, that the typhus of the ox, the study of which we are about to enter upon, may vary in its symptoms and post-mortem appearances, without losing thereby the characteristic mark which renders it a thoroughly distinct, and, in the present day, a thoroughly well known distemper.
Now that the reader possesses these general notions of the Contagious Typhus, we shall be able to speak to him in a language which he will understand, and give a definition which he will be able to judge and appreciate.
The typhus of the ox, then, is a _virulent, contagious, febrile, and non-recurring disease, with stupor and derangement of the nervous, respiratory, and digestive functions; leaving various changes in the respective organs of these functions, and chiefly in the intestines_.
This new definition seems to us to be more faithful and just than those hitherto given; and this, if needed, we could demonstrate.
I do not disguise from myself that some of the opinions expressed in these generalities may, at first sight, appear strange and liable to objection. Thus, it may be argued that inoculation as a preventive treatment of typhous maladies is far from being a general law, applicable to every case; since in Russia, for instance, where this inoculation is practised every day, it completely fails in certain foreign herds, and they die of the consequences of the operation; and that this, therefore, might happen in England.