]^g4 EXPERIMENT STATION RECORD. [VoL 35 



The authors have found carbolineum far more effective than kerosene oil, 

 zenoleum, or carbolic acid in ridding the hen house of these mites, and it is 

 recommended for use where a comparatively small quantity is required, but 

 where large quantities are needed one of the coal-tar mixtures bought by 

 the barrel at a lower rate is preferable. A diagram is given of a roost con- 

 structed in a manner to reduce the breeding places of the mites. 



The scaly leg mite burrows under the skin and causes large irregular scales 

 and gray masses on the feet of hens. This mite may be killed by any oil 

 preparation which has a penetrating power when applied after the scales have 

 been loosened by soaking and scrubbing the legs with a brush in warm soapy 

 water. The authors have found nothing better than caraway oil mixed with 



lard 1 : 4. 



The importance of sanitation in the poultry house and on the range is em- 

 phasized, and the care of sitting hens, dusting and the use of dust baths, and 

 the use of sulphur on chickens are briefly discussed. 



Bacillary white diarrhea of young chicks: Its eradication by the elimina- 

 tion of infected breeding^ stock, L. F. Rettger, W. P. Kiekpateick, and R. E. 

 Jones (Connecticut Storrs Sta. Bui. 85 (1915), pp. 151-161, figs. 2).— In this 

 fifth report on studies of white diarrhea of young chicks (E. S. R., 31, p. 

 484) the authors report upon the eradication of the disease through elimi- 

 nating the reacting fowls from the breeding stock by means of the agglutination 



test. 



A summary of the work and the conclusions drawn therefrom are as follows: 

 "During the first year of the present campaign against bacillary white 

 diarrhea in this State 14,617 individual fowls and 107 flocks were tested by 

 the macroscopic agglutination test. The number of reacting (infected) fowls 

 was 1,440, or 9.85 per cent of the total number. Of 13,833 hens 1,417, or 10.24 

 per cent, were positive, and of the 786 males tested 23, or 2.9 per cent, reacted. 

 The testes of two of the males hurbored Bacterium pullorum in large numbers. 

 In four of the reacting males pericarditis and infection of the heart sac with 

 the same organism was observed. 



" The retesting of flocks which on the first examination by this method con- 

 tained bacillus carriers, and from which the reactors had been removed, gave 

 widely different results. In four flocks out of a total of 13 no reactors were 

 found at the time of the second test. In the other nine the percentage of 

 infection varied from 0.6 to 25.7 per cent, the number in each instance being 

 decidedly less than in the first test. The breeding records obtained from the 

 owners were most encouraging, and with a few exceptions showed a high de- 

 gree of success as compared with previous years. 



" The greatest value of the agglutination test is in its doLermination of 

 Infected and uninfected flocks. On the basis of 100 per cent of negative tests 

 in a flock the most successful campaign may be waged against bacillary white 

 diarrluja. Only such flocks should be employed as future breeders, and all 

 eucourauenient should be given to the owners to find a ready market for eggs 

 for hatching and for day -old chicks. On the other hand, where there is no 

 certainty that ovarian infection does not exist the fowls should not be used 

 as breeders until they are known to be free from all taint of the disease." 



RURAL ENGINEERING. 



How engineering may help fann life, B. B. McCormick (U. S. Dept. Agr. 

 Yearbook 1915, pp. 101-112, fig. i).— In a brief discussion of the application of 

 engineering efliciency to farm life and operations, it is pointed out 'that the 

 engineer can be of special assistance to the farmer iu the "economical and 



