THE AGRICULTUKAL NEWS. 



How Ticks are Killed 



When Cattle 

 Are Dipped or Sprayed 



CATTLE TICK 



FEMALR 



I 



^ 



3 



A knowledge ot Wow a dip i» absoftwd by Ticks when cattle are dipped or sprayed with an arsenical waih is of great assistance in elucidating the 

 prohlem of Tick destruction. Although this subject has given rise lo much conjecture. ver\- little definiie information is obtainable as a result of practical 

 experiment. Work directed by William Cooper and Nephews in South Africa haa, however, hirnished results from which feasible deductions have been 

 made, and these appear to throw some lighr on the subject. 



The theories advanced by different workers are : — 



t . That the Tick absorbs the poison through its own skin during the process of dipping or spraying. 



That the absorption of the poison through the sUn of the Tick takes place after the operation of dipping or sprajping is completed. 



That the poison is absorbed by the skin of the animal, and that the Tick sucks in the poison with the fluids extracted while feeding on 

 the animal. 



It follows from No. 1 theory, and it is asserted by those who faTour thi* theory, that the longer the period of immersion of the animal in the tick-killing 

 laid, the more certain is the destructive effect on the Ticks. For this reason the supporters of this theor>' advocate a dipping bath with a long swim. 



As a result of the work carried out under the direction of William Cooper and Nephews, it has been established that a brief, thorough immersion of 

 (be animal kills the Ticks as effectively as a long one. That is to say, com|dete immersion for a comparatively short time, ensured the death of the Ticks. 



If Ticks are taken off cattle soon after they have been dipped or sprayed with ao arsenical wash, and are thoroughly cleaned to remove any externally 

 adherent arsenic, their bodies are found to contain no traces of the poison, whilst Ticks similarly removed on each of the six days following dipping are 

 found to contain appreciable quantities of arsenic; thus proving that the arsenic is absorbed alter the operation of dipping or spraying is completed. 



With regard to theory No. 2, it is highly improbable that the arsenic is absorbed through the sldn of the Tick, for the fluid dries on the skin in less 

 than an hour after treatment, during which period, as was shown in the previous paragraph, no absorption takes place. 



There only remains then theory No. 3, viz., that the host animal absorbs the poiion into its sldn, and Ut«r. dtvTick imbibes the poison doling the 

 process of feeding. All experience with dips in the field goes to support this theoi;. 



Given dips which contain equal amounts of the poisonous agent, it kat been proved by actual experaotiitt that thoae which spread over and thoroughly 

 wet the whole surface of the skin of the animal possess the greatest killing power. Therefore^ as catentia) feature of a dip is that it should give complete 

 end uniform penetration over the whole skin inrfaoe of the animal. 



It is a proven fact that those dips vdudi saturate the skin in patttict kill only the Ticks v^iidi aiAen to Aoie patches. It u found, moreover, that if 

 a solution of arsenic is injected subcutaneoutly, the Ticks attached around the nte of the injection are poisoned, and although they have had no contact 

 with arsenic from the exterior, their remains are iimnd to cootain appreciiUe qnantities. Ttkis poisonous acdon it limited to an area of about 6 inches radius 

 Iroim the site of inocolatjon. 



Investigations have shown that arsenic applied to the tudamaged ikio of an anima] does not appear m appreciable quantities in the internal organs of 

 the body. This seems lo prove that the arsenic which Is absorbed by the sldn fails to reach the circulating blood which would carry the poison from the 

 surface lo the interior. The accumulated facts which have resulted from enquiries into the matter lend the greatest support to the theory that the linng 

 cells, which form the deeper layers of the skin, have an actual affinity for arsenic, and the poison is arrested and fixed in them and thus prevented from 

 reaching the circulating blood. If this theory is correct, then after dipping or spraying, the deeper layers of the sldn will become strongly impregnated 

 «nth arsenic, possibly in a state of combination with the organic bssues. It is then easy to suppose that while feeding on a beast which has been recently 

 dipped or sprayed, the tick takes in considerable quantities of the poison with the blood and lymph which have necessarily passed through these daepcf 

 layers of the skin, which are more or less ^atarated with arse 



COOPER'S CATTLE TICK DIP 



Mas received the official approval of the following Countries : 



Union of South Africa, Northern Rhudesia, Brazil, Basutoland, 



NYasaland, Swaziland, Southern Rhodesia, Madagascar, 



British East Africa, German East Africa, Portuguese East Africa, 



Portuguese West Africa Egypt, Argentine Republic, Queensland, 



United Stales of America, New South Wales, 



Northern Territory of Australia. 



Manufacturers :• WILLIAM COOPER & NEPHEWS, Berkhamsted, England. 



BRANCHES ; Toronto, Chicago, Sydney, Melbourne, Auckland, Buenos Aires, Monie V'deo, Punta Arenas, East London, Odessa. 



WEST INDIAN AGENTS : 



ST. Kl'lT.S; S. L. Horsforil it Co. 



ANTHtIA Beimett. Brvsoii & Co. 



.lAMAiCA ; L) Henderson iV: Co.. King.sU.n. 



(iRENADA ; Thomson. Hankey A Co. 



BARB.\D<»S ; Barlw.liw (.'o-ojd'nitivi- Cotton Co.. \.U\. 



BAHAMAS : W. N. Twvnaiii. Nassau. 



TRINIDAD : r. (i..,(Wes(ir:inl, I'mt-of-Spain. 



BRITISH <;l lANA : .Siti.dUacli. Parker* Co. 



ST. VINCKNT : Orea A Co.. Kingstovrn. 



NKVIS : .S. D. Malone. 



DANISH WEST INDIES: A. Sclnniegelow, St. Croix. 



MONTSERRAT: W. Llewellyn Wall. 



DriMINICA ; Hon. H. A. Frampton. 



-r. I.rciA : Barnard Sons .V Co., C.istries. 



