70 TSE COMPLETE POULTRY BOOK. 



escapes being wet. It is impossible to thoroughly disinfect if the manure is not 

 removed from the roosting places. 



" Sulphuric acid is very cheap, costing at retail not more than^twentyrfiye cents 

 a pound, and at wholesale but five or six cents. The barrel of disinfecting so- 

 lution can therefore be made for less than a dollar, and should be thoroughly 

 applied. It must be remembered, too,- that sulphuric acid is a dangerous drug : 

 to handle, as when undiluted it destroys clothing and cauterizes the flesh 

 wherever it touches. The safest way is, therefore, to take a five-gallon r keg 

 nearly full of water to the druggist and have him place the strong acid inUtas; 

 the contents of the keg may then be safely transported and added to the barrel 

 of water. 



" 6. Eumigation.— In those cases where the disease has been raging fora consid- 

 erable time the feathers become saturated with the contagion, and it is neces- 

 sary, before placing the fowls on the disinfected run, to put them in a -close 

 building and thoroughly fumigate them with sulphur. For this purpose a pan 

 of burning coals is taken and flowers of sulphur thrown upon them as long as 

 the air can be breathed without danger of suffocation. When the disease, is rec- 

 ognized at the outset this is not necessary. 



"By a careful observance of these rules the fowl cholera may be excluded 

 indefinitely, and may be exterminated when it has made its appearance. ,The 

 writer ias had a very virulent form of the disease among experimental, fowls^or 

 nearly eight months, and though his home flock is but a short distance from 

 them, but a few of these have sickened; and the disease has been ' checked wiito 

 the loss of a single bird in each instance. It is believed that the birds which 

 thus contracted the disease were infected by flies, which would gorge tbem- 

 selves with virulent blood in the laboratory, where dissections were made,, and 

 then fall victims to the poultry which yrere running about outside. No, cases 

 have occurred in this manner since the cold weather has destroyed these is- 

 sects. " 



PremenMon by vaccmaPion.-^The researches of M. Pasteur have shown that the 

 virus of this disease may be so modified by cultivation as to commmiieKte the 

 disease in a much less virulent form, bearing the same relation to the genuine 

 chicken cholera that varioloid does to small-pox; and as one attack- of the dis- 

 ease gives immunity from it thereafter it is hoped that this discovery may lead 

 to practical results. Pasteur has already demonstrated its practical utility in the 

 kindred disease among sheep, called charbon in France, or splenicifever in-Eng<. 

 land, and which is said to cause an annual loss in France of four millions of 

 dollars.' Fifty sheep were placed at his disposal, of which twenty-five were vac- 

 cinated with cultivated virus of the charbon disease. A fortnight aiter ward .-the 

 fifty sheep were inoculated with uncultivated or virulent virus. The twenty-five 

 vaccinated sheep resisted the infection; the twenty-five unvaccinated died within 

 fifty hours. This experiment so awakened the farmers of the environs of Paris 

 that in the space of fifteen days Pasteur was called upon t» vaccinate more than 

 twenty thousand sheep, and a large number of cattle and horsesi 



The process by which this modified virus was obtained is thus described by 

 Pasteur in an address delivered at the International Medical Congress in Lon- 

 don, August 8, 1881 : 



