FOURTEENTH ANNUAL YEAR BOOK— PART X. 735 



ill the iucubator or under the hen for hatching, to remove any con- 

 tagion that might be on the shell; (3) hatching in an incubator, or at 

 least removing the eggs from under the hen a day or two before hatch- 

 ing would occur, wiping with alcohol, and finishing in an incubator, in 

 order to avoid exposing the poults to the hen; (4) placing the young 

 poults on ground at a distance from all other domesticated fowls and 

 which has not recently been occupied by other fowls; (5) excluding so 

 far as possible pigeons, other wild birds, and rats and mice from the 

 houses and runs occupied by the turkeys; (6) the frequent disinfec- 

 tion of the houses, feed troughs, drinking fountains, etc.; (7) the im- 

 mediate killing of diseased birds and the destruction of their bodies 

 by fire. 



These radical measures are necessary, and in sections of the country 

 which are not too intensely infected they will make it possible to carry 

 on the turkey industry successfully. However, it must be admitted that 

 up to the present blackhead has proved to be the most difficult of all 

 diseases to prevent or eradicate. 



The destruction of the contagion, after it has been introduced into a 

 poultry yard, has also been found difficult or impossible. Some have 

 proposed to dig up and burn the surface soil to a depth of several 

 inches, which might be done with small yards but is impossible with 

 large ones. In most cases the poultryman must be contented with the 

 application of a layer of freshly burned lime that has been carefully 

 slaked to a fine, dry powder. After a few weeks this ground should be 

 plowed and another layer of lime applied. The manure which has ac- 

 cumulated should be burned or mixed with lime and plowed into the 

 ground of some distant fields. The walls and floors of the buildings 

 should be covered with a good limewash containing 6 ounces of car- 

 bolic acid to the gallon. The fences should receive a coat of limewash. 

 The feeding troughs and drinking vessels should be put into a kettle of 

 boiling water for half an hour. Troughs too large for this should be 

 burned and replaced by new ones. After these measures are adopted, 

 the longer the premises are left vacant the more likely is the contagion 

 to be completely destroyed. The frezing and thawing of winter and 

 spring will be found of great assistance. In beginning with a new flock 

 the precautions already mentioned must be adopted to prevent the rein- 

 fection of the premises. 



TUBERCULOSIS. 



The tuberculosis of fowls is a chronic contagious disease, character- 

 ized by the development of nodules called tubercles in various organs 

 of the body, but most frequently in the liver, spleen, and intestines. 

 The disease is caused by a bacillus which differs somewhat in its man- 

 ner of growth in artificial cultures from the bacilli which cause the 

 tuberculosis of people and of cattle. The tuberculosis of fowls is readily 

 communicated to most species of birds and to several species of mam- 

 mals, but it is almost impossible to communicate the tuberculosis of 

 man and cattle to fowls. Parrots and the small cage birds are very 

 susceptible to human tuberculosis, however, and are often affected by it. 



Causation. — Tuberculosis is generally brought into the poultry yard 



