HYDE, ETC.: REFLEXES MODIFIED BY ALCOHOL. 231 
means, and also from control experiments on unalcoholized 
frogs with 8 per cent acetic acid, it was proved that under the 
conditions of experimentation fatigue of the peripheral nerve 
ending due to the stimulus played a subordinate part in the 
results. 
Fixed doses of pure alcohol, varying from 10 to 95 per cent, 
were experimented with. The dose determined upon for the 
different investigations consisted of a definite number of cubic 
centimeters of the desired per cent of alcohol for 10 grams 
frog. 
The alcohol was given per stomach, either in gelatine cap- 
sules or through a pipette, or by subcutaneous injections into 
the lateral lymph sack. The last method proved most satis- 
factory, because this manner of administration annoyed the 
frog less, and it was essential to avoid unnecessary excitement 
or stimulation, in order to keep the conditions uniform 
throughout. The alcohol has its depressing effect about five 
minutes earlier when given per stomach, being absorbed more 
readily than when given subcutaneously. 
The method of experimentation required that the reflex 
time of each one of the sensory pigment spots of a series be 
first secured from an unalcoholized frog. The frog that was 
to be experimented on, moreover, must have shown from re- 
peated tests that the responses were constant for long periods 
of time. The reflex time for each spot having been secured, 
the desired dose of the alcohol was given, and at once every 
spot of the series was tested. This procedure was repeated 
every ten minutes for about two hours of experimentation, and 
again six or twenty-four hours later, allowing an interval of 
ten minutes rest between each test. The turn-over, compensa- 
tory and swimming reflexes were also tested. Table I il- 
lustrates the method of recording the observations. While one 
of us recorded the reaction time, the other applied the acid to 
the spots and swabbed it off immediately after the frog re- 
acted. If it did not react, the acid was washed off after one 
minute. 
It was of interest to find the weakest dose of alcohol that 
produced a change in the reflex time of the cutaneous sensory 
spots, and whether such a dose had any apparent effect on 
other reflex actions, such as turn-over, compensatory and 
swimming, or upon the general behavior of the frog; also to 
