890 Agricultural Gazette of N.S.W. [Dec. 2, 1920. 



by the iucreasiug value of laud, the proprietors have got rid of the pest whole- 

 sale, and large agricultural areas are now under the plough and carryius 

 crops which had for tifty years been iniitenetrable thickets of the prickly pear. 

 Then, again, in what is terme^l the Perseverance Valley, between Port 

 Elizabeth and Uitenhage, whole plots on farms have been cleared, and the 

 profits conseiiuently accruing are such as to make it pretty certain that the 

 pest, once driven out. will never be allowed to return. Thus one might go 

 on particularising place after place, but I hardly think this is necessary. The 

 traveller by rail through tlie midlands can see for himself in every direction 

 piles of the extirpated pear heape<l up to rot and dry off, after liaving been 

 killed by the exterminator; and for miles where the land used to be so thick 

 with this plague that it could not carry stock, there is absolutely not a living 

 prickly pear to be seen. — Cape A(/ric. Joiinial, October, 1S99. 



The free carriage on the railways of proprietary poisons for fighting 

 the pest has been Queensland policy for a number of years. Arsenic (white 

 arsenic or arsenic acid) is carried free on the railways to settlers if supplied 

 by business i>eople. The State also supplies arsenic from its own mines at 

 £10 per ton, but this is not carried free on the railways because of its 

 reduced price, and a statutory declaration is required that the supply is for 

 treatment of pear-infested lands. 



Free exterminator (poison) was supplied to owners of pear-infested land 

 by the Cape Government for a number of years. Under the entirely excep- 

 tional nature of the problem, perhaiJs this might be considered in New 

 South Wales. 



In Xew South Wales caustic soda and arsenic declared to be for use in 

 the destruction of prickly pear will be charged by the Railway Commis- 

 sioners at " A " class rate, subject to a minimum of 10 cwt., on production 

 of a certificate from the Under Secretary, Department of Lands. 



In the Cape Agricultural Journal for November, 1906, will be found a 

 brief history of the pest in South Africa, with incidental notes on Australian 

 experience by Dr. Erie H. Nobbs. There is another paper by Dr. Nobbs in 

 the same journal, December, 1907, entitled " Experiments upon the destruc- 

 tion of prickly pear, 1907. Final report." The experiments were with 

 various preparations — the well-known arsenite of soda, together with other 

 substances of ascertained composition, and a number of proprietary articles. 

 Details of these experiinents are given, and the comparative cost of materials 

 for treating a specified area of pear is worked out. The following are 

 extracts from the report : — 



The arsenite of soda (Governnionl exterminator) has in all three instances 

 upheld its name as unquestionably efhcacious. and may without further com- 

 ment b(> written (Town as thoroughly successful. Satisfactory as it is to have 

 this jtroof and assurance that in the i)ast we have l)een working along right 

 lines, yet it is to be regi-etttnl that none of the proju-ietary exterminators used 

 have liroved themselves sui)erior to arsenite of soda, for at best it has to be 

 admitted that the use of the Government exterminator in this manner is 

 laborious, slow, and exjiensive. So nnicli is this the case, indeed, that it can 

 seldom pi-ove innneiliately prolilable, except on land intended for cro])s where 

 the removal of the I'oots is in any event a necessary proceeding. Only excep- 

 tionally can this method prove feasible in the case of grazing land. Yet all 

 the other methods tried, successful or not, were very much more costly than 

 that wifli arsenite of soda. . . . 



It would have been very pleasing had these comi>reheusive trials discovered 

 an exterminator superior to the arsenite of soda in general use. Such, how- 

 ever, is not the case. The value of this material when useil in methods addi- 

 tional to the customary way of spraying heaps has, however, been established, 



