THE SUPRARENAL SYSTEM 1 99 



some Ringer's solution, which is kept at the temperature of the 

 body and through which oxygen is allowed to circulate ; the altera- 

 tions in the length of the specimen are recorded graphically by 

 means of a lever. The walls of the large arteries of cattle become 

 appreciably shortened by the addition of adrenalin, and the degree 

 of the contraction is, up to a certain point, proportionate to the 

 amount of adrenalin added. The concentration necessary to pro- 

 duce an effect was found to be .000015 mg. to 15 c.cm. Ringer's 

 solution (i nooo million); by increasing the concentration, the 

 amount of contraction was increased; and maximal results were 

 obtained with a concentration of i 150,000. 



Owing to its sensitiveness, this reaction is a reliable biological 

 test both for the presence and the quantity of adrenalin. 



Meyer proved the presence of adrenalin in defibrinated bul- 

 lock's blood or serum by this method. We shall consider later 

 the extent to which Meyer's method may be employed as a test 

 for the presence of adrenalin in the heterogeneous blood serum. 

 I have proved the sensitiveness of the reaction in numerous experi- 

 ments. I was able, by this means, to detect adrenalin in the 

 ganglia of the ventral nerve-cord of leeches; and I found that an 

 extract, obtained from the fresh ganglion chains of ten leeches 

 in 2 c.cm. of normal saline solution, produces a vascular con- 

 traction equal to that obtained with io- 8 to io- 7 adrenalin con- 

 centration. In this instance, the ferric chloride reaction was un- 

 certain. Fraenkel's adrenalin test with the uterus taken from a 

 living rabbit (to be described later) gave results almost identical 

 with those which I obtained with portions of arteries.* 



Meyer proved by his method that, not only does adrenalin 

 act upon the customary preparations from the carotid and the 

 subclavian arteries of bullocks, but that it also reduces the length 

 of sections taken from the pulmonary artery and of longitudinal 

 strips from the jugular vein. He also found by this method that 

 there is an antagonism between the effects of adrenalin and those 

 of atropin, curarin, and cocaine, and he assumes, therefore, that 

 adrenalin affects the nerve terminals. As further proofs in sup- 

 port of his theory, he adduces the following : (i) That adrenalin 

 is active in low concentration and within certain temperature limits 

 only ; (2) that it ceases to affect preparations which are a few days 

 old, at a stage when they are still sensitive to muscular electric 

 stimulus; and (3) that adrenalin stimulates the vascular muscles, 

 while it inhibits the contraction of intestinal muscles which have 

 been removed from the living body. 



O. Langendorff obtained conclusive proof, by Meyer's method, 



* The statement which appears in a monograph by v. Neusser and 

 Wiesel, to the effect that " according to Wiesel " the physiological activity 

 of the ganglia of the ventral cord of invertebrates exactly coincides with 

 that of the chromaffine tissue of vertebrates, is the result, Wiesel informs 

 me, of a mistake in the name of the author. 



