PLANTS INSECTTCrDAL PROPERTIES. 11 
gants against two species of aphids, sabadilla, pyrethrum, derris, and 
" cube " were efficient, while hellebore was inefficient. 
Used as decoctions against Aphis spp. A and B, sabadilla, ami- 
anthium, and hellebore had practically no effect (Aphis sp. A omitted 
for these three powders) ; but pyrethrum, derris, and " cube " were 
efficient. Used as hot- water extracts (decoctions filtered) against 
the same species, pyrethrum had no effect; derris killed 60 per cent 
within 24 hours, while " cube " killed practically all within the 
same time. 
Used as an infusion against two other species of aphids, " cube " 
was quickly efficient. 
Alcoholic nnd benzene extracts of various powders. — Reference to 
Table 4 shows the following: 3 The alcoholic extracts+soap+water 
(2+4+100) of sabadilla, amianthium, and hellebore were inefficient 
against Aphis spp. A and B, while those of pyrethrum, derris, and 
" cube " were efficient. The alcoholic extracts (8+2+100) of the 
first three powders were also inefficient against Macrosiphum sp. A, 
while the benzene extracts (8+2+100) of the same powders seemed 
efficient, although the control mixture evidently killed 50 per cent 
of them. The nicotine sulphate (1/1,200) + soap+water (0.8+2+ 
100) was efficient, although it killed rather slowly. 
Alcoholic and benzene extracts and nicotine sulphate against 
Macrosiphum sp. A. — Reference to Table 5 shows the following 
comparative results obtained by spraying Macrosiphum sp. A : The 
alcoholic extracts+water (4+100) of " cube," derris, and pyrethrum 
were efficient within three days; " cube " is best and derris is slightly 
better than pyrethrum. 
The alcoholic extracts+soap+water (4+2+100) of " cube," der- 
ris, and pyrethrum and nicotine sulphate ( 1/400) + soap+water 
(2.5+2+100) are about equally toxic; the same extracts (2+2+100) 
and nicotine sulphate (2.5+2+100) are about equally toxic, but the 
extract of pyrethrum acts the most slowly; the alcoholic and ben- 
zene extracts (1+2+100) of "cube" and derris and nicotine sul- 
phate (2.5+2+100) are equally efficient, but the alcoholic and ben- 
zene extracts (1+2+100) of pyrethrum are inefficient; the alcoholic 
extract (3/4+2+100) and the alcoholic and benzene extracts (1/2+ 
2+100) of " cube," and nicotine sulphate (2.5+2+100) are about 
equallv toxic, while those of derris are less toxic and may be com- 
pared "with nicotine sulphate (1/800) or (1.25+2+100), and those 
of pvrethrum are far below efficiencv : the alcoholic and benzene 
extracts (1/3, 1/4, 1/5, and 1/6+2+100) of "cube " and nicotine sul- 
phate (1.25+2+100) compare favorably in toxicity, while those (1/3 
and 1/4+2+100) of derris are inefficient. 
Alcoholic extracts and nicotine sulphate against 11 species of 
aphids. — Reference to Table 6 shows the comparative results ob- 
tained by spraying 11 species of aphids with alcoholic extracts. In 
8 In Tables 4 to 8 the expression "alcoholic extract + soap + water (2 + 4 + 100)" 
means that the extract from li pounds of powder was mixed with 4 pounds or' fish-oil 
soap and 100 gallons of water. The expression " Control, alcohol + soap + water 
(2 + 4 + 100)" means the same amount of alcohol, soap, and water as used in the pre- 
ceding mixture; or, in other words, this mixture differs from the preceding only in that 
it does not contain the dry extract. The expression " 40 per cent nicotine sulphate 
(1/1,200) + soap + water (0.8 + 2 + 100)" means 1 part by volume or 0.8 pound 
of nicotine sulphate to 1,200 parts of soap solution (2 pounds to 100 gallons of water). 
The weight of the nicotine sulphate is merely given so that its cost can be compared with 
that of the various powders used. 
