GENERAL PRACTICE. ENEMIES. 2*5 



Hour is placed on u funnel with a win? sieve in it, and through the meshes of which the 

 Hour is washed by pouring water on to it; the London-purple is then added in the same 

 way. This mixture is then syringed on to the leaves in the form of a tine spray." 



The dose in the foregoing is only usable in America on matured foliage ; the quantity 

 of London-purple employed on tender foliage in the United States is 1 pound to 200 

 gallons of water. It is safer to begin with weaker mixtures in this country, remember- 

 ing that the effects on foliage are in proportion to its texture, and in our moist climate 

 the foliage is more susceptible to injury than that of trees in the drier atmosphere of the 

 Continent and America. Paris-green has been found more reliable than London-purple 

 for the treatment of orchard moth caterpillars in this country ; but London-liuid(a liquid 

 preparation of London-purple) in the proportion of 1 to 20 parts of water effectively dis- 

 poses of caterpillars, whilst not injuring the foliage. London-purple is an arsenite of lime 

 consisting of the subjoined percentages : rose aniline, 12*46 ; arsenic acid, 43*65 ; lime, 

 21-82; insoluble residue, 14-57; iron oxide, 1-16; water, 2*27; loss, 4 -07 = -100. 

 Its cost is 7d. per pound, that of Paris-green lOd. per pound. These substances, used 

 in the proportions advised, kill caterpillars without injury to the foliage and fruit. 

 Where damage has been inflicted it invariably arose from an overdose. 



Though Paris-green and London-purple are specifics for caterpillars and grubs eating 

 the leaves and fruit, their efficacy for the destruction of aphides, chermes, and other 

 insects feeding on the juices of trees by pushing their suckers into the soft tissues, is not 

 so pronounced. This entails spraying with another mixture or solution, doubling the 

 labour. A compound, therefore, that would destroy the whole race of animal and vege- 

 table parasites at the same time would be a boon to growers. It is, however, difficult to 

 ompound and combine a fungicide with an insecticide strong enough to destroy fruit- 

 tree pests without injury to foliage and fruit under every condition of growth. 



Dr. J. C. Neal, entomologist to the State Agricultural College, Florida, U.S.A., gives, 

 along with other valuable recipes for the destruction of insects, the annexed formula for 

 the preparation of a universal mixture in The Gardeners' Chronicle, vol. ix., third series, 

 p. 269. " Eesin compound. Caustic soda, 1 pound ; resin, 8 pounds; to make 32 gal- 

 lons. Dissolve the soda in 1 gallon of boiling water, take out half; add the resin slowly to 

 the remainder, and boil, stirring rapidly; when dissolved, add slowly the part taken out. 

 Dilute till it will pass readily through a thin cloth, which should be always done. 

 Dilute before using to 32 gallons. This alone is very valuable against most scales (also 

 cherry and plum aphides); but the addition of 2 ounces of London-purple makes assu- 



