Hemiptera s. Rhynchota. 



985 



3% creolin, lysol, cresol or bacillol solutions has a good effect 

 in every variety of animal but must be repeated several times. 

 Gross recommends for horses a 6%, others a 10 to 15% creolin 

 emulsion, while Schindelka always had good results with a 0.2% 

 creolin solution, which made the employ- 

 ment of other measures superflous. Two 

 per cent solutions probably answer best, 

 but must be employed repeatedly. Gray 

 mercury ointment, which is not particular- 

 ly reliable, may also be employed in mild 

 cases ; a piece about the size of a hazelnut 

 may, in the case of horses, be placed on 

 the inner surface of the harness, in cattle 

 between the horns, in dogs half the quan- 

 tity on the inner surface of the collar, but 

 in all animals it is most properly rulDbed 

 on the diseased parts of the skin. On ac- 

 count of the danger of mercury poisoning 

 the employment of mercurial ointment 

 must be avoided if several animals in a 

 stable, particularly young ones, must be 

 treated. Widespread louse infection is not 

 removed by partial applications of mer- 

 cury ointment. Frohner obtained very 

 rapid results by cautious washing with a 

 1% corrosive sublimate solution. With 

 tobacco decoction (1:20-25) which is also 

 effective, the body should be washed only in 



sections where there is general disease in horses and cattle, in 

 order not to run any danger from nicotine poisoning. In dairy 

 barns where preparations containing tar or cresol cannot be 

 used, because their smell is taken up by the milk, Schindelka rec- 

 ommends washing with decoction of wormwood or of chrysan- 

 themum inodorum; decoction of stavesacre (sem. staphisagriae 

 5:100) may also be employed, but according to Biihler the effect 

 of this drug is not very reliable. The same is true for the Per- 

 sian insect powder (flores pyrethri) and other insect powders 

 which exert a parasiticidal effect only after previous moisten- 

 ing of the animals or if applied in form of a paste; they are 

 applicable chiefly in small sucking animals and birds. Petro- 

 leum with linseed or rape oil also kills the parasites, but in fine- 

 skinned animals it sometimes causes dermatitis. Good effects 

 are also produced by ethereal oils (1:10 alcohol or water), 

 and by benzene w^ater. Fatty oils or fats have been used suc- 

 cessfully. 



The socalled vinegar of arsenic (arsenic and potash of each 15 parts, vinegar 

 and water of each 1500 parts) suggested by Viborg and Schleg exerts a prompt 

 effect but is dangerous, especially in extensive disease, and therefore is to be 

 avoided. 



Fig. 161. Trichodectes 



scalaris (on a hair). 



Magnif. about 25. (After 



Kitt.) 



