112 REPORT OF THE COMMISSIONER OF AGRICULTURE. 
peculiar feature of the test is that the stronger substance (London 
purple) is used in much smaller dilution than the wezker substance’ 
(Paris green), and it is a very strange result that the purple used in 
the proportion of 1 pound to 160 gallons water should badly injure 
the foliage in the case of the two varieties of pear experimented with, 
and slightly damage the apples, while in Michigan 1 pound to 100 
gallons is recommended as perfectly safe for apples. The California 
varieties may have been peculiarly susceptible, or the climatic con- 
ditions of moisture and evaporation such as to render the trees more 
liable to damage than in Michigan. We can not find that Professor 
Cook indicates the proper time of day for spraying, but we have 
found in Washington that spraying on a warm, dry, sunshiny day 
will be more apt to produce injurious results than the opposite, or, 
in other words, the more rapid the dehydration the greater the effect 
upon the foliage. Professor Riley has also shown (see Bulletin 10, 
Div. of Ent., p. 13) that after each rain the poison takes a new effect 
upon the foliage, and the inference is plain that in a climate where 
the dews at night are heavy and the days dry and warm the effect 
of the poison will be greater. Moreover, the foliage is more rapid 
of growth and consequently tenderer in California than in our North- 
eastern States. ; 
The white arsenic experiments recorded in the following tables 
are practically valueless on account of the small scale upon which 
they were tried. The inference is, as Mr. Wickson points out, i hat 
the worms were not on hand to be killed in the case where the 
stronger solution shows a percentage of loss while the weaker shows 
a percentage of gain. 
Paris green (1 pound to 160 gallons of water). 
| | | Worms in fruit 
| iar | and under 
| bands. 
Fruit. Variety. | Date of application. | Apparent effects. 
; On. |Onun- 
treated) treated 
| | tree. | tree 
} ' 
| _ 
Rea ises 88s | Nouveau Poiteau......| May 3 and 19......... Nonoicss coerce 10 | 23 
Pearerce 5.0 Wantais--2>-esssaous | le eD 19 and'once}...:do.......2.%.- 4 | 4 
| ater. | | } 
ADDO a. oh to suls\-t IReaiCanada =. 227-51 | Wha. 8, 19) and/Jtme dz |e do. sey eee | 4 35 
dete User orc CRE en tee ar or tt cdo.s oer kis scam snc Eielairaciaesia ees ck cuaaaleahene sees i 1§ 62 
Gamspercentie. 7.5). = cece eee ce Bopha era eS Saws 33 dan San WageesSoseese (eS Bak ear 
t 2 ee | 
Paris green (1 pound to 320 galions of water). 
| | 7 | 7 
Beare nent “cclacce | Duchesse Précoce ..... (ELE) ASTON Re ee aNe Ae jONOnG Sekine ge od 3 | 8 
REA ede aa: aaee DR REEGEES posse etc as Mitayecianed Opens ees le 8 GO. Sao cape neeeee 1} 27 
g 272° ee SS et a es Ghaptal Foes ca ceew ces | (May 3, t8"and Jane i); °Go 2.23.2. 2.256 6 1 
Apple tet sesecs a: Duchess Oldenburg....| May 3and19.........|.... GO lee seeee eee of | 1 
Applet Le i453 129 nitamMeUuseeesecc sete ace i Mawi3s0 0: and June 14), .04@O ns bese seeses § | 4 
| | peed ity, | 1. 
FRobaly. ss Oe acento OG ate Bees nacdceood arr | Serobiee Sb acaeceees 19 | 41 
Gain, pence POO EEC AS Se SES bie noe fic ols eee ote aea ote oe Bodteraseass ates ser 54 sete Ne 
Paris green (1 pound to 160 gallons of water, with 2 pounds of soap). 
' 5 a ar | 
Pear..... 2oeobed- | Beurre Gris d@’hiver....| May 3 and 19* ........ | Inform ons SSS NSae2 5 2 
pple ecco." Wells’ Sweet .......... Mesty 33s Some Who bs $i J don: Saparee Gal 3 | 3 
Ape |e J23s6- | Duchesse Mignonne ...| May 3and19.........|.... GOs serie cast ace 1} 13 
| | | | 
Fotallzccs: . [chet SAN, gD e A LE An bls WE RNR t ye 8 Pe eS re ieee a ie See 9 is 
Gain percent) Feet =o eerie ot = lees eRe tA 9 Ago Soe 2 fy ie Ae eee ea a Uhl eteoees 
* Considerable settling in can. 
