( 1187 ) 
at the same pressure of the armlet. Von RECKLINGHAUSEN explains 
this by admitting purely theoretically, that the artery is not com- 
pressed long enough to be perfectly closed, if the pressure in the 
armlet is just a little more than the diastolic pressure; and that the 
following systolic pulse-wave comes already before the artery is 
perfectly closed. Consequently only at a higher pressure in the armlet 
the oscillations will obtain the maximal amplitude. 
It may however be asserted that if in the armlet a pressure prevails 
somewhat higher than diastolic pressure, the artery is only slightly 
pressed down on account of the resistance offered by the arterial 
wall, and that not until the pressure in the armlet has increased 
with the amount required to overcome that resistance, the artery is 
entirely pressed down during the diastole of the heart, and of course 
the oscillations have not reached the maximal amplitude before that 
moment. 
From this consideration it might follow that the difference of the 
{wo pressures corresponding to the greatest oscillations and the 
beginning of the great oscillations represents the resistance of the 
arterial wall. 
It may easily be granted that this is likewise a purely theoretical 
reasoning: yet it explains the gradual increase of the amplitude of 
the oscillations at an increase of the pressure in the armlet in a 
more plausible way than the reasoning of voN RECKLINGHAUSEN. 
Judging from the objection brought forward above there was great 
need of discovering a method which, besides enabling to make a reliable 
determination of Mp and mBp, permitted a valuation of the influence 
that the resistance of the arterial wall had on these determinations. 
Moreover it seemed desirable to make the method as objective as 
possible, free from all subjectivity both of the investigator and of 
the patient. And as graphical methods as a rule satisfy this condition 
of objectivity best, it was evident that, at least for projecting and 
elaborating the method, graphical registration should be used. 
After many researches we have at last come to the conclusion 
that we might publish the following method, expecting that by careful 
investigation, also by others, it will prove to answer the requirements 
mentioned above. 
Il. DESCRIPTION OF THE METHOD. 
After all this method is very simple. /¢ consists in neither observing 
palpatory, nor recording sphygmographically, nor overhearing stethos- 
18% 
