292 EXPERIMENT STATION RECORD. 



the last, with the exception of sulpho-naphthol, gave but poor results in 

 the strengths employed and in the time for which the mite was exposed. 

 The Fort Collins lime and sulphur dip (lime 11 lbs., sulphur 33 lbs., 

 water 100 gal.) seems to have given fair results. The California dip 

 (sulphur 100 lbs., lime 25 lbs., water to make 100 gal.) proved equally 

 good, as did also the potassium sulphid dip (sulphur 60 lbs., sal soda 9 

 lbs., boiled together and diluted to make 200 gal). Cooper's dip is less 

 favorably reported. The black leaf dip, used in the strength of 1 to 

 GOO, is similarly reported, but used in strengths of 1 to 200 it seemed 

 to give good results. Experiments were also made with the eggs and 

 with the mites to determine the effect of exposure. As a result, it was 

 found that both readily succumbed to low temperatures, from which it 

 follows that infection can not be carried over winter by the mites or eggs 

 in the ground or buildings and that it is improbable that either mites 

 or eggs will live at any time of the year for more than a very few weeks 

 unless upon some animal which may serve as food. 



Experiments on the effect of dipping on the growth of the sheep 

 showed that there was a loss of about three-fourths of a pound per 

 sheep during the week following the dipping; but this loss will depend 

 largely upon the degree of cold and the manner in which the sheep are 

 subsequently handled. It must be taken into account in calculating 

 the cost of dipping if made shortly before the animals are sold. 



The author thinks the claims made that certain patent dips have 

 some beneficial tonic effect are not to be trusted. Under the head of 

 general directions for preventing and curing the scab, it is recommended 

 that newly purchased lambs or sheep coming from a locality where the 

 scab is known to be present ought to be dipped at least once, or better, 

 twice. There is no certainty of killing all the insects with even the best 

 dip after 2 dippings 14 days apart, especially if put back into the old 

 yards. Further, those employing the lime and sulphur dips are warned 

 not to use more than 1 lb. of lime to 1 lbs. of sulphur, as it is the excess- 

 ive lime which injures the wool. 



Abortion in domesticated animals, C. F. Dawson {Reprint from 

 Jour. Corny. Med. 1897, Feb., Mar., and Apr., pp. 15 ).— The author briefly 

 passes somewhat critically over the literature on the subject of abor- 

 tion, bringing out the fact that it teems with contradictory statements 

 both from members of the veterinary profession and from laymen. ISTo 

 data proving that abortion occurs through sympathy is found, though it 

 seems possible that the nervous system might receive such a shock as 

 to produce it. 



Abortion resulting from kicks, blows, disgusting sights, odors, etc., 

 is classed as due to external causes, and it is stated that there may be 

 sporadic abortion from internal or systematic causes. Thus a severe 1 ung 

 disease, limiting the respiratory area, causes an imperfect oxygenation 

 of the blood. A badly ventilated stable, containing many animals, 

 might, by reason of the accumulation of carbon dioxid and other poison- 

 ous exhalations, be the cause of abortion. Other causes are noted, and 



