584 



The standard mixture is obtained by adding 1 lb. paste to a number of 

 gallons of water equal to the percentage of arsenic oxide. 



Lime solutions should only contain lime, sulphur and water. The 

 solution must be free from suspended matter, have a specific gravity 

 of not less than 1 -3 at 15° C. [59° F.] and remain clear at all dilutions. 



The exact requirements with regard to nicotine are still under dis- 

 cussion. The term is sometimes used for combinations of nicotine 

 with an acid — e.g., nicotine sulphate, which, although an excellent 

 insecticide, depends for its action on the nicotine it yields, which must 

 be released by an admixture of an alkali or a sufficiently alkaline 

 spraying soap. This solution can, therefore, only be valued by the 

 percentage of free nicotine it yields, a statement of which should be 

 given by the manufacturer. 



Copper sulphate should contain not less than 98 per cent, of 

 cr3^stalUsed sulphate of copper (Cu SO4 SHg 0). 



Soft or potash soap should be labelled with the separate percentages 

 of the fatty acids and resinous acids that it contains, and at least 

 95 per cent, of the total alkali should consist of potash. 



Liver of sulphur should consist of a mixture of salts of potassium, 

 chiefly sulphides, and should conform to the characters and tests 

 given in the British Pharmacopoeia 1914 for sulphurated potash, and 

 should contain at least 42 per cent, but not more than 45 per cent, of 

 sulphur as detennined by the process there described. This recom- 

 mendation should not in any way discourage the use of the sulphides 

 of sodium, as the action of either potassium or sodium sulphide depends 

 on the sulphur. 



Sodium cyanide when treated with an acid should evolve at least 

 56 per cent, of its weight as hydrocyanic acid and potassiimi cyanide 

 at least 43-7 per cent. Sodium cyanide is the cheaper of the two, 

 and weight for weight gives off more gas. 



WooDvvoRTH (H. E.). A Host Index of Insects injurious to Philippine 



Crops. — Philippine Agric, Los Bailos, x, no. 1, August 1921, 

 pp. 9-35. 



In this list the insects injurious to crops in the Phihppines are 

 arranged under the scientific name of the food-plant. It is not com- 

 plete, and is only intended as a basis for further records. The popular 

 names of the food-plants, as well as of many of the insects, are given. 

 Many of the insects are recorded for the first time as injurious to crops 

 in the Philippines. 



Parker (J. R.), Strand (A. L.) & Seamans (H. L.). Our Present 

 Knowledge of the Pale Western Cutworm. — Montana Agric. 

 Expt. Sta., Bozcman, Circ. 94, December 1920, 8 pp., 2 figs. 

 [Received 10th October 1921.] 



Porosagrotis orthogonia, Morr. (pale western cutworm) is gradually 

 extending its range in Montana and becoming more injurious. In 

 many instances crops have been destroyed for three successive years. 

 A special fund has been set aside by the Experiment Station for the 

 study of this moth and its possible control. Farmers are urged to 

 report all occurrences of P. orthogonia. Experiments with a view to 

 ascertaining the practical value of light-traps are still in progress. 

 Cultivation methods appear so far to be the most reliable means of 

 reducing injury [7^. A.E., A, ix, 541]. 



