n6 
Journal of Agricultural Research 
Vol. VII, No. 3 
The successive stages of nicotine poisoning in the frog are briefly sum¬ 
marized by Langley and Dickinson (14) as follows: (1) Stage of excita¬ 
tion; (2) stage of spasms; (3) stage of quiescence; (4) stage of flacddity; 
(5) stage of paralysis of the central nervous system; (6) stage of paralysis 
of the motor-nerve endings. 
Blyth (3, p. 273) says, “Birds.also show tetanic convulsions, followed 
by paralysis and speedy death,” and Sollmann (23, p. 262) asserts that— 
Nicotine is one of the most fatal and rapid of poisons; the vapor arising from a glass 
rod moistened with it and brought near the beak of a small bird causes it to drop dead 
at once, and two drops placed on the gums of a dog may cause a similar result. 
According to Langley and Dickinson (14), the symptoms of nicotine 
poisoning in rabbits, cats, and dogs are in a general way similar, and may 
be briefly described as follows: There is a preliminary excitement; clonic 
spasms; twitchings of the muscles in various parts of the body; stimula¬ 
tion of the central nervous system; paralysis of the motor-nerve endings 
in the skeletal muscles; quickening and deepening of the respiration, 
followed by slowing and cessation; dilation of the pupils; paralysis of 
the cervical sympathetic system; rise and fall of the blood pressure; rise 
of temperature; constriction of intestines, followed by dilation, and slight 
vomiting in cats and dogs. If the doses are sufficiently large, the cerebro¬ 
spinal system is totally paralyzed. 
According to Blyth (3), the symptoms witnessed in mammals poisoned 
by nicotine are quite similar. With large doses, there is a cry, one or two 
shuddering convulsions, and death; with smaller doses, there is trembling 
of the limbs, excretion of feces and urine, stupor, a staggering gait, and 
then the animal falls on one side. One or two drops of pure nicotine may 
kill a rabbit, cat, or dog within five minutes. Vas (24) found that the 
substance resulting after washing tobacco smoke affects the health of 
rabbits; they lose weight, the number of blood corpuscles is decreased, 
and the hemoglobin of the blood is diminished. According to Blyth, 
nicotine also affects horses similarly to the smaller domestic animals. 
Blyth says that Dragendorff ascertained that nicotine is absorbed into 
the blood and is excreted unchanged, in part by the kidneys and in part 
by the salivary glands. 
Krocker (13) was among the first investigators to determine the phar¬ 
macological effects of nicotine on man. He found that it paralyzes the 
nervous system and that death is caused by the rapid benumbing and 
paralysis of the respiratory center, but not from heart paralysis, although 
nicotine powerfully influences the action of the heart. 
Holland (11) states that two or three drops of the alkaloid is fatally 
poisonous to man when taken into the stomach, and that death is caused 
by heart failure. In this latter statement other authorities do not agree 
with him, for they say that death is due to asphyxia, on account of the 
paralysis of the respiratory center. In the lower vertebrates the heart 
still beats some time after life is extinct. 
