438 Journal of the Department of Agriculture. 



Co., 7U!J-71T Sixth Anciiuc, ^'ew Yoik City, and the firm now (/Iters 

 it ill lOO-lh. and 200-11). eases at a price that compares favourahly 

 with the i)ri(.-c that ha.s to be paid lor other cyanide in South Africa. 

 It is prefeiable because made in rounded lumps weighing about 

 one ounce each, the convenient size for fiimigation. Ordinary cyanide 

 is in irregular chunks that may weigh a pound or more 

 and which, therefore, requires much breaking to piepare it for 

 fumigation doses. The pieces for fumigating had be.^t be from the 

 size of loaf sugar to that of turkey eggs, ac-cording to tlie weight of 

 the dose for the tree. In breaking a lump, it siiould be tapped smartly 

 with a hammer so as to detach i)ieces of the size wanted with the 

 least possible formation of ptnvder and small chips, very small pieces 

 being undesirable because of the rapidity with which acid acts on 

 them and the consequent great liability of splashing acid on to the 

 cloth. It follow's that a dose should not contain a high proportion of 

 small pieces. Sodium cyanide may be bought by fumigators from 

 most wholesale chemists. Lennon Ltd. has long made a specialty 

 of supplying it in lots of 7 lb. and upwards, while a considerable 

 saving can sometimes be made by purchasing it in bulk from the 

 Johannesburg merchants who import it in huge quantities for the 

 mines. For the mines it comes in 2-cwt. zinc-lined cases and Ifrgely 

 via Delagoa Bay. Before the war it cost only about Is, a pound in 

 Johannesburg, but in recent years it has generally cost Is. Gd. or 

 more. 



The exceedingly poisonous nature of the cyanide should never be 

 forgotten, and the precaution to put a " poison " label on every 

 receptacle in which any of it is put away should invariably be taken. 

 If left exposed to the air, especially damp air. cyanide deteriorates 

 rapidly; and it is unwise, as a rule, to purchase more at a time than 

 will be used in the same season. It should always be stored in dry, 

 air-tight vessels; and lever-top tins, such as some grocery supplies 

 come packed in. answer admirably for preserving it if kept tightly 

 closed. 



Acid ]>ctinls. — Sulphuric acid is used in large quantities for 

 various commercial purposes, and may generally be procured without 

 difficulty and at a fair i)rice from wholesale chemists. " Commercial 

 sulphuric acid should be asked for. The New Transvaal Chemical 

 Co., Deimas, Transvaal Province, the B.S.A. Ivxplosives Co., Modder- 

 fontein, Transvaal Province, and the Cape Explosives Works, 

 Somerset AVest, Cape Province, all manufacture the acid and will 

 sell it in bulk to fumigators. Fumigators who need large quantities 

 are likely to save much by buying direct from these or other manu- 

 facturers. The acid costs least when half a ton or more is bought in 

 a steel drum, but the makers can generally supply it in cases holding 

 four 2-gallon jars. The two gallons weigh 27 lb. The cost of small 

 lots at a chemist's is generally at least 6d. a i)ound, even when two 

 gallons are taken. Great care should be exercised to prevent any of 

 the acid being spilled on to the skin or clothes, as it is extremely 

 corrosive. One pound measures only about nine fluid ounces, and 

 about two and one-quarter pounds by weight are required for use 

 with a pound of sodium cyanide. Receptacles containing it should 

 be labelled " ]ioison," and should be kept closely stoppered to prevent 

 the acid from absorbing moisture and therebv becoming weakened. 



