120 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



best remedies tested was pine tar 2 parts, cottonseed oil 1 part. 

 Animals kept on infested premises after treatment usually became 

 reinfested within one or two months. The best results were obtained 

 from treatment administered during the late autumn or early winter. 



Cattle ticks. — Tests of a lime-sulphur-arsenic mixture in Okla- 

 homa and Texas showed that it was unsatisfactory as a remedy for 

 cattle ticks. 



The field test for arsenic employed by the bureau shows the amount 

 of unoxidized arsenic in a bath, but does not show the oxidized 

 arsenic. Owing to the tendency of arsenical baths to undergo oxida- 

 tion, replenishing a bath on the basis of the strength shown by the 

 field test ma}!' result in a dipping solution which contains a consider- 

 ably higher percentage of arsenic than the field test indicates, the 

 additional arsenic being present in the more highly oxidized form. 

 Further investigations of this question have confirmed earlier work 

 in showing that if the unoxidized arsenic (arsenite) in a dipping 

 bath is kept at a strength of about 0.2 per cent, additional arsenic 

 in the oxidized form (arsenate) may be present sufficient to give a 

 total arsenic content of 0.5 or even 0.6 per cent (in terms of arsenic 

 trioxid) without injuring cattle. So high a percentage of total arsenic 

 resulting from oxidation is not likely to occur under actual condi- 

 tions, consequently the fact that the field test shows only the arsenic 

 present in the unoxidized form is not of practical importance. 



Tests of a material, apparently of vegetable origin, received from 

 Guatemala, where it is said to be extensively used as a remedy for 

 cattle ticks, showed that it had no eifect when used in accordance 

 with the directions given, which specified that certain amounts be 

 injected intramuscularly several times at intervals of 24 hours. It 

 was also claimed that the same remedy was a cure for Texas fever, 

 but in view of its failure as a tick remedy it was not tested as a 

 remedy for Texas fever. Another alleged remedy, which has been 

 extensively advertised in some parts of the South, consisting essen- 

 tially of common salt and sulphur compressed into blocks, to be 

 placed in pastures for the cattle to lick, was tested in cooperation 

 with the Insecticide and Fungicide Board and found to be without 

 value as a tick remedy. 



Miscellaneous. — Experiments on hog mange and sarcoptic mange 

 of cattle have been continued. Tests of several proprietary articles 

 for which claims have been made as remedies for external parasites 

 have been carried out in cooperation with the Insecticide and Fungi- 

 cide Board. A Farmers' Bulletin (No. 798) on the sheep tick was 

 issued during the year. 



ANTHELMINTICS AND TREATxMENT FOR INTERNAL PARASITES. 



Various substances were tested with reference to their value as 

 anthelmintics, including iodoform, commercial gasoline, petroleum 

 benzin, copper sulphate, ether, santonin, turpentine, tobacco, thymol, 

 spigelia, latex of Ficus laurifolia^ oil of chenopodium, chloroform, 

 oleoresin of male fern, and pelletierin tannate. The animals which 

 were subjected to experimental treatment included sheep, hogs, dogs, 

 cats, and chickens, and the parasites which were involved included 

 various species of roundworms and tapeworms. 



