DIP MATERIAL, 651 



minutes in 20 gallons of water, when the sulphide and 

 hyposulphite of calcium form. The resulting orange- 

 coloured liquid is finally mixed with sufficient cold water 

 to make it up to 100 gallons. The chief drawback to 

 this dip is the difficulty of preparing it in sufficient 

 quantity to dip large numbers of sheep say 25,000 to 

 100,000 in a short space of time. The authorities in the 

 Orange River Colony have (1904) emphasised another 

 possible objection by prohibiting its use, on account of the 

 serious damage done by lime to the wool when the material 

 is not properly made. 



Tobacco is the most valuable of the effective dip materials 

 for which may fairly be claimed the property of being non- 

 poisonous to sheep. Although not so immediate in its action 

 in killing living parasites as arsenic or carbolic, it is so dis- 

 tasteful to them that it is the best of all the dipping materials 

 used for preventing living acari from gaining access to the 

 fleece, and there re-establishing themselves, from " rubs " or 

 from the ground on which scabbed sheep have been resting. 

 The existing Customs restrictions on the importation of 

 certain useful forms of tobacco for dipping purposes are so 

 unnecessary and so troublesome that the matter requires 

 reconsideration. Before leaf-tobacco for dipping purposes 

 can be manufactured in a bonded warehouse under, practi- 

 cally, almost impossible conditions, it has to be mixed with 

 impurities which render it unsuitable for other uses for 

 every 100 Ibs. of dry leaf-tobacco, 10 Ibs. of blue vitriol, 

 15 Ibs. of common salt, and 2 Ibs. of oil of turpentine. 

 Ground tobacco, which can be bought in America at very 

 moderate prices, is not admitted into this country a 

 grievance of which farmers have just cause to complain. 

 The quality of the manufactured products of tobacco, in 

 the form of paste and juice, is not to be always relied 

 upon. 



Carbolic acid 1 is effective in killing living parasites 

 1 For the benefit of the ordinary reader we have retained the familiar 

 and;industrially more common name carbolic acid (phenol), although the 

 cheaper and for the purpose more suitable, nearly allied phenolic sub- 

 stance cresol or cresylic acid (95 to 97 per cent, purity) is preferred to 

 crude carbolic acid by the best so-called non-poisonous (carbolic) dip- 

 makers. Cresol is liquid at ordinary temperatures, while carbolic acid is 

 solid, although more soluble in cold water in the proportion of 1 1 to 29. 



