262 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



enemies are insects (ladybirds, &c.), and parasitic fungi. The latter 

 attack all three scales. — G. H. L. 



Lime-Sulphur Mixtures, Experiments with home-made con- 

 centrated. By P. J. Parrott and W. J. Schoene {U.S.A. Exp. Stn., 

 New York, Bull. 330; December 1910). — A nmnber of experiments 

 with home-made concentrated lime-sulphur spray mixtures were car- 

 ried out and the results are here reported. A new formula is suggested, 

 viz. 



Quick (unslaked) lime . . . . . . 36 lb. 



Sulphur . 80 1b. 



Water ......... 50 gals. 



The mixture may be stored and used diluted as required, the dilution 

 being such that the Beaum6 hydrometer gives a concentration of about 

 44°. 5 B. for a spray suitable for use against San Jose Scale, 3°. 5 B. for 

 use against pear leaf blister mite, and 1° B. for use as a summer spray 

 on apples against scab, &c. 



Success was attained in most cases when the wash was used against 

 these pests and growers appear to be well satisfied with it, apparently 

 preferring it to Bordeaux mixture. Several instances of burning of 

 foliage especially in pears were reported but these were soon obscured 

 by the rapid growth of the shoots and their results were discounted by 

 the superior crops secured through freedom from disease and insect 

 pests. Bordeaux mixture frequently causes russetting of the fruit, 

 but no such effect was produced upon the apples by use of the lime- 

 sulphur mixture. 



Various causes are suggested to account for this burning but it is 

 evident that the true reason has not yet been definitely settled. 



F. J. C. 



Lime-Sulphur Wash, Chemical Investig-ation of best condi- 

 tions for making. By L. L. van Slyke, A. W. Bosworth, and 0. 

 0. Hedges {U.S.A. Exp. Stn., New York, Bull. 329; December 1910). 

 — The object of the investigation carried out and here reported was to 

 ascertain under what conditions the compound made by boiling togeiher 

 sulphur and lime should contain the greatest quantity of calcium 

 pentasulphide (OaSg). 



The amount of sediment is least when the ratio of lime to sulphur is 

 about 1 : 2 and increases with the increase or decrease of the ratio of 

 lime to sulphur. The proportion of sulphur that goes into solution 

 is ^greatest when the amount of sulphur used is not more than 2'25 

 times the amount of lime used. 



The nature of the sulphides produced depends largely upon the pro- 

 portions in which the lime, sulphur, and water are used, and when the 

 ratio of sulphur to lime is largest and the ratio of lime and sulphur to 

 water is less than 3:1, then the largest proportion of pentasulphide is 

 produced. 



As a result of the investigation it is recommended that the standard 

 conceatrated lime-sulphur wash should be made by slaking 36 lb. of 



