. The complete poultry book. Poultry. 72 THE COSirirTr POT'LTnY BOOK. preciable inierval in the impregnation, the \vhole series will reproduce the atten- uated virulence of that which served as the starting point. Similarly, when the virulence is small, it produces no efi'; Professor Pasteur proceeds to show that this decrease of virulence in the disease-germ is due to continued exposure to the oxygen of the air, and that it may be continued to such a point as shall cause the vaccination of tlie fowl with it to produce more or less complete immunity from subsequent attacks, and yet ca
. The complete poultry book. Poultry. 72 THE COSirirTr POT'LTnY BOOK. preciable inierval in the impregnation, the \vhole series will reproduce the atten- uated virulence of that which served as the starting point. Similarly, when the virulence is small, it produces no efi'; Professor Pasteur proceeds to show that this decrease of virulence in the disease-germ is due to continued exposure to the oxygen of the air, and that it may be continued to such a point as shall cause the vaccination of tlie fowl with it to produce more or less complete immunity from subsequent attacks, and yet cause little or no inconvenience to the fowl itself. If the virus be very much weakened it may require several vaccinations to give complete immunity—tlirce or four being found necessary in some of Pasteur's experiments, and the ojiera- tion may require to be repeated at intervals of a year. This discovery is yet in its infancy, but it is worthy of extended and careful investigation. Prevention hy breeding from insnKreptilile foirh.—Dr. Salmon states tluit he lias found a considerable number of fowls that were cai)able of resisting repeated inoculations with very active virus, some sliowing only the mildest symptoms of. Fig. 27 the disease, and others remaining entirely free from any appreciable results, either in general health or at the point of inoculation, and Chauveau has shown that the Algerian sheep are, as a breed, insusceptible to the influence of charbon, hence they urge the importance of breeding from such animals, with the hope of producing strains that will possess this characteristic in a still greater degree. If there is reason to fear that the flock has been or is likely to be exposed to the coutagium of fowl cholera we should advise the use of hyposulphite of soda in their drinking water, at the rate of an ounce to the pailful of water. If tlie yellow coloration of the urates appear before a fowl shows other signs of disease the use of the homeopathic prepara
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectpoultry, bookyear1882
