INSECTIC1J)I:S, /•U/:V/:.\'77y/':s, AM) IMACII I .\' l:l< V. ,, ^,j 



rarely used alone ; but eonihined with any of t lie arsenites it is 

 niicd in the: orchard until dan!,Mi' from the (odlin^; moth is ovit, 

 and in potato fields is usc-d to hit both blij^ht and beellcs. 

 The formula for the Bordeaux inixluro is as follows: 



Siilpliati- of coi)i)c-r 6 ixmnils 



(Juiclvlinie 4 ixjuiuls 



Water 22 j^allons 



Dissolve the sulphate; of copi)er in one ci^allon of hot wal<i- and 

 slake the lime in another vessel with an ciinal (piantily ; icdiice 

 to a creamy milk of lime and add slowly to the ( ojipci- solution, 

 stirring ronstantly. i'inally add water to make up llie twenty- 

 two gallons, an<l this gives the old full slren^lli nnxture. It is 

 rare-ly used now at tiiis concentration, fifty gallons of water 

 rc'jjlaeing the twenty-two in gcncM'al practice ; but whether full, 

 half, or (|uarter strength, the lungicide counts a:, so mii< h water 

 for the pm'pose of measuring the amount of iIh- arsenite to be 

 used. TIk; excess of linu; in the Bordeaux is usually sufficient to 

 n(nitraliz(- the soluble arsenic in i'ai'is green, and in the arsenic 

 and lime combinations there is an actual addition from th(; insecti- 

 cide. None of the other fungicides have appiovecl t hcmselv(,'S SO 

 well for combined applications, and no olln 1 toiniiila, wf^-A be 

 given here, though in s|K;ciaI instances olheis may be usclul. 



Bichloride of mercury, or "corrosive sublimate," is an ex- 

 tremely violent poison of which s(jn)e us(.- has b<M'n made, but on 

 the wiiole with small satisfaction. The margin of safety between 

 effectiveness against insects and safety to plants is so small that 

 its use is not advised. 



It may l)e well to add that all the :io called slomac h poisons 

 are useful against chewing or mandibulale insects only ; as 

 against plant-lice and other sj^ecies that live by sucking plant 

 juices, none of the arsenit(;s ar<; in th<- least effectiv(^ 



Tobacco, white hellebore, and pyi'eihnmi are useful both as 

 stomach and contact insecticides, though as a lule used in the 

 latter form. 



Pyrelhrwn^ also known as Persian or Dalmatian ins('Ct i)owd(;r, 

 or " Huhach," is made from platits behjnging to the genus 

 Pyrethruni which bear aster-like- flowers. It is sf)ld in the form 

 of a fine, y(.'Ilf)wish powder with a pleasant and somewhat pun- 

 gent odor, wliich it loses rapidly on exjiosure tcj the air. It is a 



