354 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Uses. — Same as above. 



Arsenates are preferred to arsenites now. 



General Notes on Arsenical Washes. — Of the five mentioned there is 

 no doubt that Arsenate of Lead is best to use, because it is more easily 

 mixed and holds in suspension longer than Paris Green, &c, and the 

 burning of the foliage is almost entirely absent if properly mixed ; it has 

 also more adhesive properties. The paste form known as Swift's Paste has 

 been found satisfactory in many parts of the world, and is best to use, 

 unless great care is taken in making the home-made wash. Fruit trees 

 should not be sprayed with the arsenical washes when in flower, as the 

 bees are so readily poisoned, and they should not be sprayed for at least 

 four weeks before the fruit is gathered. This is a point to be remembered 

 when gooseberries and currants are growing beneath apple and plum. 



These arsenical washes should be put on in as fine a spray as possible. 



Animals may be kept in the grass orchards when the trees are sprayed 

 as long as they cannot get at the actual wash. All receptacles in which 

 the spray has been mixed should be cleaned and kept away from stock. 



We must remember that these washes, especially when concentrated, 

 are deadly poisons. 



Arsenate of Lead is usually used in conjunction with Bordeaux mixture, 

 and it also emulsifies paraffin, so that we can combine a fungicide and an 

 insecticide for mandibulate and haustellate insects in one. 



PARAFFIN SOAP EMULSIONS, OR CONTACT WASHES, FOR 

 HAUSTELLATE INSECTS. 



Paeaffin Emulsions. 



For winter application these washes may be used very strong, but for 

 summer use they must be much diluted. 



Except in bad attacks of scale insects they cannot be recommended as 

 summer washes, nor can paraffin in any form. In spring paraffin emulsion 

 may be used for red spider on gooseberries in the form given under 

 Paraffin Jelly, but paraffin is always best applied before the leaves are 

 showing, as even the finest oils do harm to vegetation. 



Through the work of Mr. Spencer Pickering we now know more of 

 these matters, and growers will do well to use the oil recommended by 

 him known as Solar Distillate. 



The usual form of paraffin emulsion is soap emulsion, but Mr. Pickering 

 has recently shown that metal emulsions are superior as emulsions. 

 Probably for scale insects the metal emulsions will soon supersede the 

 soap emulsions, but for aphides they are not likely to do so, as the soap is 

 the most active killing agent and is alone sufficient to destroy them. 



Soap Emulsions. 

 The emulsions I have used have been the following : — 



For Winter Use only. 



Formula : 



(1) Paraffin (Tea Rose) 10 gallons. 



Soft soap 15 lb. 



Water 100 gallons. 



