MUSTARD BEETLE. 97 



top is weak and does no good, and that at the bottom is too strong and 

 burns the leaves. 



In application of Paris-(freen spraijings, it must always be borne in 

 mind that, whatt'ver kind of eiujine or sprayinij machine is used, the )inxture 

 must be kept an even, strength throughout, and no sediment allowed to form 

 at the bottom, or damage to leafage is sure to happen. 



Unless (as ought to be the case) the sprayers have an automatic 

 arrangement for the purpose of keeping the fluid in motion, the Paris- 

 green should be kept well stirred ; and even then in the case of (say) 

 a barrel, this should be well washed out after it has been filled ten or 

 twelve times. 



The " Knapsack " sprayer * is a very convenient form, as it can be 

 easily carried by a man amongst the crops (where there is room for a 

 man to pass), and at the pleasure of the bearer he can direct the spray 

 where needed. But even with this form it is desirable between each 

 filling to well stir round at the bottom of the can, so as to disturb the 

 sediment. 



The spray should be thrown so finely as to reach all parts of the plants 

 and both sides of the leaves, and coat the leaves as with a fine dew, 

 but it should not be allowed to run down and drip. As soon as dripping 

 begins spraying should cease. 



It should on no account whatever be thrown so as to " swill " or 

 " souse " the plants, and run off the leaves in drops or streams ; this 

 is bad practice in every way. It uses a great deal more of the chemical 

 than is needed ; the leaves get little but pure water at their highest 

 part, and much too strong application where the fluid has settled at 

 the tips; and also a drip is caused on to the ground beneath, which 

 in spraying in orchards over grass, may possibly, if the arsenite has 

 been used in great excess, render it temporarily poisonous, f 



* The English agents for this sprayer are Messrs. Charles Clark & Co., Windsor 

 Chambers, Gt. Saint Helen's, London, E.G., price ;35/-, or possibly somewhat less. 



t Full directions, both as to method of application, and precautions in use of 

 Paris-green, are given in a short pamphlet arranged by myself, which I shall be 

 happy to forward gratuitously to any applicant. But although with the most 

 moderate care it may be used with perfect safety, yet as it is poisonous some 

 caution is requisite. I give appended the observations on this head from my 

 pamphlet : — 



" Paris-green " is an aceto-arsenite of copper, and of a poisonous nature, and there- 

 fore should be used with care in mixing, and should never be applied to fruit or to 

 vegetables that are used for food. But, as is shown above, the quantity to which, in 

 order to be beneficial, it is requisite to limit application in spraying is excessively small, 

 and our English experiences of the past season, as well as those on the Continent of 

 America where Paris-green has been used regularly in farm and orchard prevention 

 for many years, show that with proper care it may be used with perfect safety. 



The cautions to be observed in the use of Paris-green arc : — The bags should be 



