The preventive measures directed against black-quarter and an investigation into the efficacy of setoning / by Stewart Stockman.

Date:
[1897]
Catalogue details

Licence: Public Domain Mark

Credit: The preventive measures directed against black-quarter and an investigation into the efficacy of setoning / by Stewart Stockman. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    We should regard that method rather as a barrier to stem the tide, while we are applying more radical measures which take a longer time to operate. Distribution of Black-quarter.—The disease in this country is con- fined to certain districts, and often in these districts to certain farms. Veterinarians in different parts of this country will point out to you black-quarter farms with neighbouring establishments which are practically free from the disease. In some parts it would be well worth an intending tenant’s while to inquire into the reputation of the farm in this respect. Strebel, in his valuable communication to the Sixth International Veterinary Congress, saj^s that the soils in black- quarter districts have a common character. They are of a clayey nature, hence impervious and damp. This, of course, simply means that filth, including disease germs, is not drained away from such a soil, and therefore the plague is kept up for a long time. It applies to the germs of other diseases as well as that of black-quarter. Hess, after inquiring into the distribution of the disease in various parts, could not admit that any one kind of soil was particularly favourable. We know, however, that one of the best preventive measures is to drain the land, but unfortunately that is not always practicable. It does not come within the scope of this paper to describe all the characters of the black-quarter bacillus, but I should like just to remind you here that it is a sporulating microbe, an obligatory anaerobe, and that its tendencies seem to be decidedly saprophytic. On the surface of the soil the bacilli, and probably for that matter the spores as well, do not remain active for any very long time. The combined effect of oxygen and sunlight is powerfully destructive. They sink into the ground, however, and there is evidence to show that the spores at least, if not the bacilli, may here remain active for years. With the earth taken from the damp parts of black-quarter pastures at a depth of I2 inches, Feser succeeded in inoculating sheep with black-quarter. The earth from the dry parts did not contain the pathogenic agent. Feser’s examinations seemed to show that the bacillus itself is present in the soil, but of this more evidence is required. There are two possible explanations of how these sub-soil germs are brought to the surface again. The one is that it is connected with the ri.se and fall of the ground water (so-called), the other is that, when the ground cracks, as it does in hot weather, the dry sub-surface earth gets blown or scraped to the top. These explanations savour somewhat of the hypothetical, but I think they are worthy of further investigation. Animals attacked.—The animals attacked by black-quarter are chiefly cattle and sheep. The goat is also susceptible, but the horse enjoys an almost complete immunity. Of the animals commonly used for experiment in the laboratory, the guinea-pig is the best reagent. The rabbit has a certain amount of immunity, but this can be overcome by injecting along with the virus such agents as lactic or acetic acids, certain other microbes, or the toxines of the black-quarter bacillus itself The micrococcus prodigiosus overcomes the immunity in the rabbit, but seems to strengthen the resistance of the guinea-pig. ^ Bruising of the tissues at the seat of inoculation seems also to intensify the action of the virus. These agencies are believed to act by taking up the