Often to all these causes of infection are added myriads of grasshoppers, which cover the ground, where they die, aggravating the mass of pestiferous vapour which fills the atmosphere. Finally, the water which slakes the thirst of the herds of cattle is corrupted; the plants on which they feed distil poisons; the air, the water, and the plants, carry within them a principle of venom and death. After this, how can we be surprised if this flood of putrid emanations is transformed into a contagious typhic virus, whose subtle and pestilential effluvia are conveyed by the ox to considerable distances?
In fine, let us recapitulate in our minds all the causes of destruction to which these passive creatures are exposed, and we shall acknowledge that there is no necessity to attribute to them a peculiar organization in order to understand the development of the typhus, which, at a given moment, cuts them all off; and that in the deltas of the different countries, as well in Asia, Africa, and America, as in Europe, are to be found those conditions of infectious disease which we have described. In these causes, and only in these causes, or in those which resemble them, will rational men seek for the principle of the contagious typhus in the bovine race.
Moreover, who is there who does not understand that what is true with regard to cholera is likewise applicable to this contagious typhus? The cholera, for causes analogous to these, subject to the particular state of the soil, is generated, not exclusively, it is true, but most frequently, on the banks of the Ganges, in the same manner as the contagious typhus is developed in certain countries where its natural focus is found.
The race of animals which exists on this deadly and destructive soil is an instrument of incubation for typhus, not in consequence of their peculiar structure, but because the conditions under which they live condemn them to this fate.
III
Now the breeding of cattle, and the feeding and fattening of them for the market, constitute a branch of industry – a great interest. They all have to be removed, conveyed to various distances, and sold; so that this traffic becomes a new cause to be added to all those which foster, develop and propagate the distemper.
In prosperous times, when the seasons, conformably with our wishes, have pursued a course which we call regular (for we are fain to believe that the planets turn on their axes on our account), and when the cattle find the ground covered with rich pastures, and limpid streams – conditions which are eminently favourable in themselves, though in Hungary it is necessary to add gum, salt, mineral water, and arsenic acid, before the health of these animals is satisfactory, – then the cattle breeders make their sordid calculations, and select the heads of cattle intended for sale.