32 POISONS : THEIR EFFECTS AND DETECTION. [§ 24 . 
substituting various alkyls for the hydrogen of the hydroxyl group in 
para-aceto-amido-phenol. 
Para-aceto-amido-phenol when given to dogs in doses of 0-5 grm. for 
every kilogramme of body weight causes slight narcotic symptoms, with 
slight paralysis; there is cyanosis and in the blood much methsemoglobin. 
In men, doses of half a gramme (7*7 grains) act as an antipyretic, 
relieve neuralgia, and have weak narcotic effects. 
The following is the result of substituting certain alkyls for H in 
the HO group. 
1. Methyl .—The narcotic action is strengthened and the antipyretic 
action unaffected. The methhemoglobin in the blood is somewhat less. 
2. Ethyl .—Action very similar, but much less methsemoglobin is 
produced. 
3. Propyl. —Antipyretic action a little weaker. Methsemoglobin 
in the blood smaller than in para-aceto-amido-phenol, but more than 
when the methyl or ethyl compound is administered. 
4. Amyl. —Antipyretic action decreased. 
The smallest amount of toxicity is in the ethyl substitution ; while 
the maximum antipyretic and antineuralgic action belongs to the methyl 
substitution. 
Next substitution was tried in the Imid group. It was found that sub¬ 
stituting ethyl for H in the imid group annihilated the narcotic and anti¬ 
pyretic properties. No methsemoglobin could be recognised in the blood. 
Lastly, simultaneous substitution of the H of the HO group by ethyl 
and the substitution of an alkyl for the H in the NH group gave the 
following results :— 
Methyl .—In dogs the narcotic action was strengthened, the inethsemo- 
globin in the blood diminished. In men the narcotic action was also more 
marked as well as the antineural action. The stomach and kidneys 
were also stimulated. 
Ethyl .—In dogs the narcotic action was much strengthened, while 
the methsemoglobin was diminished. In men the antipyretic and anti¬ 
neural actions were unaffected. 
Propyl. —In dogs the narcotic action was feebler than with methyl 
or ethyl, and in men there was diminished antipyretic action. 
Amyl. —In dogs the narcotic action was much smaller. 
From this latter series the conclusion is drawn that the maximum 
of narcotic action is obtained by the introduction of methyl, and the 
maximum antipyretic action by the introduction of methyl or ethyl. 
The ethyl substitution is, as before, the less toxic. 1 
The effect of the entrance of an alkyl into the molecule of a substance 
is not constant ; sometimes the action of the poison is weakened, some- 
1 “ Ueber die physiologiseho Wirkung des p-amido-phenol u. einiger Dorivate 
desselben,” 0. Hinsberg u. G. Treupel, Archiv /. exp. Pathol, u. Pharm., xxxiii. 216. 
