REPORT OF THH ENTOMOLOGIST. 135. 
Confined it fifteen minutes. All of the leaves and about nine-tenths of the Iceryze 
were killed. 
(12) Took one-twelfth ounce brass turnings and one-third ounce pure nitric acid. 
Pees twenty-five minutes. All the leaves and four-fifths of the Iceryz were 
illed. 
The skins of the dead Iceryze in this and the preceding expertments soon became 
very dark colored and soft, readily breaking. 
(183) Took one-fifth ounce brass filings and one-half ounce pure nitric acid. Con- 
fined it twenty-five minutes. All the leaves were killed and all the Iceryz on the 
upper part of the tree, but scarcely one-half of those on the lower part were killed. 
Whenever the brass filings were used, the leaves showed the destructive effects 
of the gas much sooner than when the turnings were used. 
(14) Took one-sixth ounce pure zine and five-sixth ounce pure nitric acid. Con- 
fined it twenty-nine minutes. Residuecolorless. All of the leaves were killed and 
about one-half of the Iceryze on upper part of tree, but only one-fourth of those on 
the lower part were killed. 
(15) Dissolved one-half ounce of arsenic in 2 ounces of water in which one-half 
an ounce of caustic soda had been dissolved. Took 2} ounces of water and two- 
fifths of an ounce of the arsenic-soda solution. Confined it twenty minutes. Leaves 
uninjured; about one-third of the Iceryze were killed. 
(16) Took 24 ounces of water and 1 ounce of the arsenic-soda solution. Confined 
it twenty minutes. Leaves uninjured; very few of the Iceryz were killed. 
(17) Took 1 ounce of mercury and 1 ounce pure nitric acid. Confined it twenty 
minutes. One-tenth of the leaves and nearly all of the Iceryze were killed. Resi- 
due colorless, but becoming bluish upon adding water to it. 
I can not account for the good results obtained in this experiment. I have fre- 
quently tried to repeat it, but always without success. 
(18) Took one-half an ounce of mercury and 1} ounces pure nitric acid. Con- 
fined it twenty minutes. Leaves scarcely affected; about one-fourth of the Iceryz 
were killed. 
(19) Took one-eighth ounce pure tin in small pieces and 1 ounce pure nitric acid. 
Confined it twenty minutes. Residue nearly milk-white. Leaves uninjured; about 
one-fifth of the Iceryz were Inlled. 
(20) Took one-eighth ounce tin and 2 ounces nitric acid. Leaves uninjured; no 
Icerye killed. 
(21) Took one-half ounce of mercury and 13 ounces nitric acid. Confined it 
twenty minutes. No leaves nor Iceryz were killed. 
(22) Took three-fourths ounce mercury and two-thirds ounce nitric acid. Con- 
fined it twenty minutes. Nearly all the leaves but none of the Icerye were killed. 
(23) Took one-twelfth ounce pure copper in small pieces and 14 ounces nitric 
acid. Confined ittwenty minutes. Residuedeepblue. Allof the leaves and about 
one-sixth of the Icerye were killed. 
(24) Took 34 ounces of water and 1} ounces of the arsenic-soda solution of experi- 
ment 15. Confined it twenty minutes. Leaves scarcely injured; only a few of the 
Icerye were killed. : 
(25) Put 1 ounce of sal ammoniac in 3 ounces of water; all of the sal ammoniac 
had not dissolved after the lapse of several hours. Took 2 ounces of this solution 
and added it to three-fourths of an ounce of quicklime. Confined it twenty min- 
utes. All of the leaves but none of the Iceryze were killed. 
(26) Took an ounce of the sal ammoniac solution and added it to one-half an ounce 
of quicklime. Confined it twenty minutes. Ali of the leaves but none of the Icerye 
were killed. d 
(27) Took one-sixth of an ounce of naphthaline and 1} ounces nitric acid. Con- 
fined it twenty minutes. One-third of the leaves but none of the Iceryze were 
killed. 
(28) To residue of above was added half an ounce of quicklime. Confined it 
twenty minutes. One-tenth of the leaves and one-half of the Iceryze were killed. 
(29) Took half an ounce of mercuric chloride and 14 ounces nitric acid. Confined 
it twenty minutes. Leaves uninjured; about one-fourth of the Iceryee were killed. 
(30) To residue of above was added one-haif an ounce of quicklime. Confined it 
twenty minutes. One-third of the leaves and one-fourth of the Iceryz were killed. 
(31) Took one-sixth ounce mercuric chloride and 1 ounce of nitric acid; added 
one-half an ounce of quicklime. Confined it twenty minutes. One-fourth of the 
leaves were killed; Iceryze uninjured, 
(32) Took one-fourth ounce of mercurious ointment, composed of lard and mer- 
cury, and three-fourths ounce of nitric acid. Confinedittwenty minutes. Leaves 
uninjured; only a few Iceryz were killed. | 
(33) To above residue was added three-fourths of an ounce of quicklime. Con- 
fined it twenty minutes. No leaves and but few Iceryz were killed. 
