892 AgriciHcurcd Gazette of N.S.W. [Dec. 2, 1920. 



With siome experience of it on my private property, and subsequently in 

 the Botanic Gardens and parks of Sydney, I drew particular attention to 

 the valuable Cape Colony experiments of Mr. A. C MacDonald with this 

 substance. See this Gazette, September, 1898, p. 983. Subsequently Mr. 

 Valder, then Principal of Hawkesbury Agricultural College (see this 

 Gazette, January, 1902), used it for the eradication of pear locally, and 

 other writers in the Gazette have also so used it or recommended it. 



In an article entitled " Destruction of Prickly Pear with arsenical spray," 

 in the Queensland Agricultural Journal, November, 1909, Mr. A. J. C. 

 Brunnieh writes : — 



Prepare a concentrate by mixing intimately, 10 lb. arsenic . . . . 34 II). 

 cau.stic so<la do per cent., the most economical form), and slovs-jy ami carefnily 

 add cold water to make 8 gallons of concentrate. The heat generated spontane- 

 ously by adding the water to the mixed dry chemicals is generally sufficient to 

 dissolve all the arsenic, Init should, after standing, some of the arsenic he foui^d 

 undissolved settled on the bottom of the drum, boiling of the concentrate for 

 a few minutes will be necessary. . . . 



The 8 gallons of concentrate will make 100 gallons of spraying solution, which 

 contains 1 oz. of arsenic in soluble form, by simply diluting with the necessary 

 amount of water. 



He also recommends the use of Stockholm tar, or coal tar or resin 

 to enable the liquid to adhere more closely to the glaucous leaves of 

 the pear. 



A circular issued by Mr. Brunnieh, under date 9th June, 1915, describes 

 a dry powder (chiefly composed of common salt and arsenic) for injection 

 into prickly pear, a concentrated solution of the same, also for injection, 

 and a diluted solution for spraying the pear. 



Both in New South Wales and Queensland men often carry a small 

 bottle of arsenical sheep dip with them in their pocket, and when they see a 

 small pear, they dismount from their horses, stick a pocket-knife in the 

 pear and pour in a little dip. Much killing of single pear plants in pad- 

 docks has been brought about in this way. 



In addition we have arsenical poison-mixtures in large numbers. It may 

 in some cases be better to buy your own arsenic and make your own prepara- 

 tion. It seems fair to say that the most effective toxic agent known, so 

 far as plant life is concerned, appears to be arsenic in one or other of its 

 forms. 



Other Poisons. 



Practically every cheap-selling poison available has also been tried in 

 addition. If a man desires to patfonise a proprietary he can easily make or 

 procure an analysis to see if it is worth his while to purchase the article. 

 There are differences of opinion in regard to many pear-poisons, and their 

 merits cannot be assessed without a judicial inquiry, but it may be said 

 that while " all poisons are good, some are better than others." Let not 

 poisoning be relaxed simply because other experiments are afoot, but let 

 it be borne in mind that, while any fool can kill pear, it takes a wise man 

 to show a good balance-sheet. 



