a i i ie 
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Arsenic not injurious to Larves of Flies. 169 
thoroughly injected with a solution of arsenic acid, havin bes 
mat yerionlly thrown aside and left unnoticed Le een days 
his matter is one of some importance ene occupied 
with judicial sari oaticnae who must not infer that a fly-blown 
organ can contain no arsenic; and is especially interesting from 
the fact that several authors have urged that the attention of 
which they found, from having observed that the flies which 
fed upon ei suspected organs soon perishe 
But the subject is also, as it seems to me, worthy the attention 
of this society, as affording another indication of the great dif- 
ferences which exist between animals in their several coitons 
of metamorphosis* and of the caution with whic expe 
ments upon the action of remedies or poisons on animals of any 
one species should be received when brought forward as indica- 
tions of what that action will be upon other animals, 
* IT cannot refrain, more ing attention to its obvio 
: over, from calling atter : vious bearing upot 
the important practical question of the destruction of insects hh ta to vegeta- 
: ; insects besides 
phor, for 
hes-moth, an d its” a is 
P ¢ clot 
doubtless aiplegeane' to, Pe ost k not Abeotataly doptriviive of, tat insect pee 
terfly sta 
in its but- 
te; but, as is well known, while it remains a worm it can feed with impu- 
__ hity upon woolen stuffs, no matter how thickly they may be strewn with — 
_ In like manner the larvze of Dermestes and Anthreni, a as prov ved by the experiments 
_ of Dr. Cabot (Proc. Bost. Soc. of Nat. ae vii, 5), can consume bird-skins which 
4 have been soaked in strong solutions of e or ina rope hot 
of arsenious acid, age they will not vouch «pete ehh On 
dipped in an alcoholic solu tion of strychnine. 
SECOND SERIES, Vor. XXVIII, No. £0,-SEPT; a 
22 oe Fi fee ore pe 
