16 



THE AGRICULTURAL JOURNAL. 



ior to cyaniding for the destruction of 

 scale insects. The results of this n^ethod 

 of treatment have been very marked, trees 

 that were practically useless and even 

 dying from the attacks of scale insects of 

 various kinds having thereby recovered, 

 and subsequently made extra vigorous 

 growth and produced fruit of superior 

 quality. 



Few trees are subject to the attacks of 

 so many kinds of insect pests as citrus 

 trees — the orange, lemon, lime, and their 

 allies. They are injured by insects that 

 live by sucking the leaves, bark, or skin 

 of the fruit ; by insects that destroy the 

 leaves, skin of the fruit, and bark of 

 smaller twigs by actually devouring the 

 same ; by insects boring into and destroy- 

 ing the fruit ; and by insects boring into 

 and destroying the branches, trunks, and 

 roots of the trees. The first-named group 

 — the insects that live by suction— include 

 the scale insects, aphides, and sucking 

 bugs, and it is in the case of these that 

 the gas treatment, or fumigation, is found 

 specially effective. In the extensive 

 orange orchards of California it has prac- 

 tically taken the place of spraying for ihe 

 destruction of the red scale, the purple or 

 mussel scale, and all other armoured scales. 

 In Cape Colony it is now largely used for 

 destroying red scale, and is found to be 

 the cheapest and most effective means for 

 suppressing the attacks of this insect. 

 Extensive experiments have been made 

 by the Queensland Department of Agri- 

 culture to ascertain the efficacy of hydro- 

 cyanic acid gas as an agent for destroying 

 xed scale, circular black scale, mussel scale, 

 white scale. Glover scale, greedy scale, 

 pink wax scale, and San Jose scale, _ and 

 in every case success has been attained. 

 In order to apply the gas it is necessary to 

 envelop the tree to be treated with a gas- 

 tight covering, in the form of either bell- 

 tents or octagonal sheets. The former 

 can be made large enough to cover trees 

 up to 10ft. in diameter and 12ft. high, but 

 for trees exceeding this size sheets are 

 preferable, as bell tents would be too 

 heavy and unworkable. The tents and 

 sheets are made of the best Canadian duck, 

 tanned for the purpose of preservation 

 with a strong extract of iron-bark and 

 wattle-bark. For charging the tent with 

 gas it is necessary to calculate its cubic 

 contents, and to provide one ounce of 



cyanide of potassium, one fluid ounce of 

 sulphuric acid, and three fluid ounces of 

 water to every 300 cubic feet of space. 

 The water is put in an earthenware dish, 

 the acid is next poured in very slowly, 

 and the dish is placed under the tent, as 

 far from the canvas as possible. The 

 cyanide is now added to the solution, and 

 the operator promptly retires from the 

 tent, which he renders air-tight by every 

 means available. The reaction of the 

 sulphuric acid and the cyanide of potas- 

 sium results in the generation of hydro- 

 cyanicacid (that is,prussic acid) gas, which 

 is a poison that kills all scale and other 

 insects subjected to it. The trees remain 

 covered for 45 minutes. On account ot 

 the deadly nature of the insecticide many 

 precautions have necessarily to be ob- 

 served by the operator. Mr. Benson, who 

 took the diploma of the Royal Agricul- 

 tural College, Cirencester, 22 years ago, 

 has constructed a very useful table of 

 measurements of trees and quantities of 

 material for the use of " cyaniders." 



Not much progress has yet been made 

 in England with this new insecticid»l pro- 

 cess, though it is unquestionable that a 

 considerable degree of success has attended 

 its application in warmer countries. Scale 

 blight is not so troablesome here as in 

 hotter regions, but our fruit growers are 

 familiar enough with such a pest as, for 

 example, the mussel scale, Mytilaspis 

 pumorum. Of the closely-allied aphis 

 blight they have a much larger experience, 

 audit seems not unlikely that, for the 

 suppression of this trouble, the practice 

 of fumigation with hydrocyanic acid gas 

 will be more largely resorted to m the 

 future in this conntr j .— Daily Neivs. 



In July, 1898, a gelding named Newman, by 

 Newminster, was put up for sale at Brisbaneas 

 useless for racing, owing to unsoundness. Me 

 was bought for £9 and turned out for a rest, 

 with the result that he made a complete recovery, 

 stood training, and won races withui a year ot 

 his purchase. Another horse which was • given 

 away " by mistake was Mangere ; he was going 

 a-begging at £14, and a trainer named William- 

 son was asked to look at him. He did so, and 

 declined to taku the horse at any price. Mangere 

 was then inclut'cd in a batch of horses otiered to 

 a tramway company, and was weeded out by tue 

 buyer. He then found a buyer in a Mr. Faul 

 for a £10 note, and not long afterwards won the 

 Auckland Steeplechase. It was after this that 

 the trainer Wilbamson, who had had the chance 

 of buying him for £14 or less, ofEered £btX) tor 

 Mangere, and failed to get him. 



