9 o 
Journal of Agricultural Research 
Vol. VII, No. 3 
experiment much with nicotine and did not endeavor to ascertain what 
tissue is vitally affected by any particular insecticide, but he seems to 
infer that nicotine affects the cells chemically in the same way as do the 
other contact insecticides. Even if nicotine has no therapeutic use, it 
is classified as a poisonous drug; and for this reason the investigations in 
which it is used give the best results when it is considered from the 
standpoint of toxicology. 
PHYSIOLOGICAL EFFECTS OF NICOTINE 
At the outset it was decided to select one of the most specialized insects 
and to feed it nicotine so that the results might be compared to those 
previously obtained after administering nicotine to certain higher animals. 
Although nicotine as an insecticide is rarely used as a stomach poison, 
nevertheless the experimentation was begun with this phase of the work. 
Since pharmacologists have determined that, as a rule, nicotine, regard¬ 
less of how it is administered, has practically the same general effects, it 
seems logical that nicotine as an insecticide will also have practically the 
same effect, regardless of how it is applied. 
I.—NICOTINE AS A STOMACH POISON 
Since the writer, during the past four years, has made a special study 
of the behavior of the honeybee, and as the honeybee is one of the highest 
forms of insects, it was first selected for making a special study of the 
physiological effects of nicotine on this class of animals. 
(a) BEES FED PURE NICOTINE 
To avoid the complications which often arise when a drug composed 
of more than one constituent is administered, pure nicotine was fed to 
bees in the following manner: Honey and pure nicotine were thoroughly 
mixed in the proportion of i part of nicotine to 100 parts of honey. 
Ten c. c. of this mixture were poured into a small tin feeder covered with 
parallel pieces of wire; then the feeder and contents were placed inside a 
triangular observation case, previously described by the writer (17). 
Fifty bees (guards) were next introduced into this case. On account of 
the faint nicotine odor emitted from the mixture of honey and nicotine, 
the bees did not eat the food readily. To be certain that the bees had 
eaten some of this poisoned food before they died, the honey stomachs 
of several dead bees were examined. It was found that each stomach 
contained more or less honey, and this was certainly not eaten before the 
bees were put into the case, because the honey stomachs of guards never 
contain honey. Testing this supposedly poisoned honey for the presence 
of nicotine by using alkaloidal reagents, such as silicotungstic acid and 
phosphomolybdic acid without first attempting to isolate the alkaloid* 
means nothing, for these reagents also precipitate honey and many other 
