STATE POMOLOGICAL SOCIETY. 175 



The kerosene and soap mixture, especially when the latter is warmed , 

 iforms, upon very moderate agitation, an apparent union ; but the mix- 

 ture is not stable, and separates on standing or when cooled or diluted 

 by the addition of water. A proper emulsion of kerosene is obtained 

 onl}' upon violent agitation. It is formed, not gradually-, but suddenly : 

 in short, to use a familiar phrase, "it comes" like butter. The time 

 required in churning depends somewhat upon the violence of the 

 agitation, but still more upon the temperature, which, however, need 

 not be much above blood heat. 



"When obtained, an emulsion of kerosene and soap is known b}'^ the 

 perfect union of the ingredients, and the absence of oiliness, so that 

 the liquid clings to the surface of glass or metal. It resembles a 

 rich cream, more or less thickened according to the proportion of soap 

 in the mixture. 



PREVEN^TIVES AND REMEDIES FOR PEAR BLIGHT. 

 By Prof. J. C. Arthur. 



[From Report of the Mycological Section of U. S. Department of Agricultiu-e, 1886.] 



Whatever form Pear Blight assumes, it is started by germs gaining 

 access to the tree in one of the three ways described — through the 

 flowers, the growing shoots, or injuries of the bark. No method is 

 known or has yet suggested itself of rendering the tree insusceptible 

 to the disease, and a direct prevention must be sought in some means 

 of excluding the germs. There are three ways by which germicides 

 may be applied to trees — b}' fumigation, by spraying and by washing. 

 The first method offers a possibility of at least partial success, and 

 is done by sulphur mixed with lime and applied as a wash to the 

 trees. The odor remains upon the trees for weeks and is said to 

 ward off the disease. 



Spraying offers little more hope of success than fumigation. An 

 experiment tried during last season in spraying with a solution of 

 hyposulphite of soda, applied several times during the period of ex- 

 pansion of the buds, gave no evidence of beneficial effects. 



The application of washes cannot, of course, be made to the flowers 

 or growing shoots, but excellent results may reasonably be expected 

 when made to the trunks and larger branches. To decrease the 

 amount of cracking the boclj^ of the tree may be shielded from the 

 sun's fiercest rays by a low trimmed head, or by leaning the whole 

 tree toward the southwest, or by boards, matting, or other protection, 

 on the sunny side of the trunks. 



