30 POISONS : THEIR EFFECTS AND DETECTION. [§ 24 . 
power is strictly in the same order ; for, of the three, phenol is least and 
phloroglucin most poisonous. 
Replacing hydrogen by a halogen, especially by chlorine, in the fatty 
acids mostly produces substances of narcotic properties, as, for instance, 
monochloracetic acid. In the sulphur compounds, the entrance of 
chlorine modifies the physiological action and intensifies toxicity : thus 
ethyl sulphide (C 2 H 5 ) 2 S is a weak poison, monochlorethyl sulphide 
C 2 H 5 C 2 H 4 C1S a strong poison, and dichlorethyl sulphide C 4 H 8 C1 2 S 
a very strong poison : the vapour kills rabbits within a short time, and 
a trace of the oil applied to* the ear produces intense inflammation of 
both the eyes and the ear. 1 
The weight of the molecule has an influence in the alcohols and acids 
of the fatty series ; for instance, ethyl, propyl, butyl, and amyl alcohols 
show as they increase in carbon a regular increase in toxic power ; the 
narcotic actions of sodium propionate, butyrate, and valerianate also 
increase with the rising carbon. Nitrogen in the triad condition in 
the amines is far less poisonous than in the pentad condition. 
Bamberger 2 distinguishes two classes of hydrogenised bases derived 
from a and j8 naphthylamine, by the terms “ acylic ” and “ aromatic.” 
The acylic contains the four added hydrogens in the amidogen nucleus, 
the aromatic in the other nucleus, thus— 
CH CNH 2 
CH CH 
CH \/as/ CH 
CH CH 
a-Naphthylamine. 
Acylic tetrahydro- 
a-Naphthylamine. 
CH 
CH ^ CH 
CNH, 
CH 
c ch 2 
CH 
cnh 3 
ch 2 
CH v 
ch 2 
ch 2 
CH 
CH, 
CH M*/ CH 
CH CH 
/S-Naphthylamine. 
CH 2 CH 
\XcNZ 
CH 2 CH 
CNH c 
CH 
Aromatic tetrahydro- 
/TNaphthylamino. 
The acylic /btetrahydronaphthylamine, the /3-tetrahydroethylnaph- 
thylamine, and the jS tetrahydromethylnaphthylamine all cause dilata¬ 
tion of the pupil and produce symptoms of excitation of the cervical 
sympathetic nerve ; the other members of the group are inactive. 
§ 24. The result of replacing hydrogen by alkyls in aromatic bodies 
has been studied by Schmiedeberg and others ; replacing the hydrogen of 
the amidogen by ethyl or methyl, usually results in a body having a 
1 V. Moyer, Ber. d. chem. Ges., xx. 1725. 
2 Ber., xxii. 777-778. 
