582 
BIOCHEMISTRY: MACHT, HERMAN AND LEVY 
A QUANTITATIVE STUDY OF CUTANEOUS ANALGESIA 
PRODUCED BY VARIOUS OPIUM ALKALOIDS 
By David I. Macht, N. B. Herman, and Charles S. Levy 
PHARMACOLOGICAL LABORATORY. JOHNS HOPKINS UNIVERSITY 
Presented to the Academy, October 20. 1915 
The pharmacological and physiological literature contains but few 
quantitative and scientifically accurate comparisons of the narcotic or 
analgesic properties of the various opium alkaloids. This is chiefly 
due to a lack of an adequate method for studying the subject. The 
observations so far recorded are of a clinical character, and the conclu- 
sions drawn, even in the cases where alkaloids of reliable purity were 
used, show the greatest diversity of opinion. Thus, Claude Bernard^ 
regarded narcein, an inert substance according to the majority of in- 
vestigators, as a powerful narcotic; again Fronmiiller^ ranked narcotin 
in activity as next to morphin; while Baxt^ extolled the wonderful pain- 
reHeving virtues of papaverin. 
In the present investigations we have made use of a large Baltzer 
inductorium for producing quickly and conveniently finely graded pain 
stimuli. Having standardized our apparatus with the help of Dr. C. 
W. Hewlett of the Physical Laboratory of this University, we were able 
to express the values of these stimuli, quantitatively, in Henrys or 
C. G. S. units, and in this way compare the strengths of the stimuli re 
quired to produce pain under various conditions. 
The first step in the investigation was to determine whether a suffi- 
ciently constant pain threshold could be established. Martin^ and his 
coworkers have studied the threshold of electrocutaneous sensation 
with the induction current, by dipping a finger in a liquid electrode, 
and have found that a definite sensory threshold can be established, 
subject to physiological diurnal, nocturnal, and fatigue variations. 
Furthermore, Martin, Grace and McGuire^ in the only pharmacological 
study by this method, have found a definite lowering of the sensory 
threshold after administration of acetphenetidin by mouth. 
In our work we have made use of fine platinum electrodes, studying 
the effect of the induced current on individual pain points or groups of 
pain points in four different regions of the body. In this way our 
chances of error were lowered fourfold. The points most convenient 
for study employed by us were the skin on the back of the hand between 
thumb and forefinger, the tip of the nose, the tip of the tongue, and 
the lips. 
