568 REPORT OF NATIONAL MUSEUM, 1887. 



H. G. Beyer — Continued. 



Particular attention is called to the necessity of investigating the action of drugs with uue 

 regard to the chemical constitution of the latter, and examples are cited showing, beyond doubt 

 the relation which exists betweeu chemical constitution and physiological action. 



A new outline classification of the whole science of pharmacology is included in this arti- 

 cle, with explanatory notes of each of the terms used in this classification, which is as follows: 

 ( Pharmaco-mineralogy.. 1 



( Descriptive.. <; Pharmaco-botany I 



[ Pharmaco-zoology 



Pharmacology . { ( Pharmaco-physics )> Pharmacotherapy. 



„ . , , Phaimaco-chemistry .. . 



I Experimental < „, . ,'. 



i Pharmaco-physiology .. 



I Pharmaco-pathology -. j 

 H. G. Beyer. The action of Tropin Hydrochlorate and Sodium Tropate on the 

 peripheral blood-vessels. 



American Journal of the Medical Sciences, 1887. 



By a careful experimental study of the influence of atropine on isolated organs we have 

 been able to furnish good pharmacological evidence in proof of the fact that this alkaloid ex- 

 erts a double action on those organs which are supplied by both motor and inhibitory sympa- 

 thetic-nerve structure. 



It has been shown that very small doses of the drug will stimulate the motor-nerve elements 

 and that larger doses of it will stimulate the inhibitory portion of the nerve-supply of these 

 organs. Thus, very small doses of atropine will give rise to contraction of the pupil, to ac- 

 celeration of the heart's action, to increased peristalsis of the intestine ; large doses, on the 

 contrary, produce dilatation of the pupil, arrest the heart in diastole, and stop the peristaltic 

 movements of the intestine. Furthermore, in view of the important researches of Ladenburg 

 on the chemical constitution of atropine, it seemed to me strongly advisable to try and ascer- 

 tain if this double action of atropine could possibly be explained by a careful study and com- 

 parison of the action of its two constituents, tropin and tropic acid. 



The pupil did not seem to me a sufficiently typical object for the determination of this all- 

 important point, and I therefore concluded to try the blood-vessels, more especially since it 

 is now looked upon generally as a well-settled question in physiology that the blood-vessels 

 are supplied by two kinds of nerve structures, namely, vaso-motor and vaso-inhibitory, or 

 dilator, the stimulation of the former causing vaso-constriction, that of the latter giving rise 

 to vasodilatation. 



Consequently, we might argue that tropic acid is that part of the molecule of atropine which 

 causes pupillary dilation, and if we have, furthermore, reasons to believe that tissues which 

 are identical, both in histological structure and physiological function, are al o similarly 

 affected by the same chemical stimuli, then it ought to follow that this same portion of the 

 molecule of atropine should give rise to vaso-dilatation. Atropine, however, producing also 

 vaso-constriction (in small dos.es at least), it would perhaps further follow that the remaining 

 portion of the molecule should give rise to vaso-constriction. 



In these experiments on the blood-vessels with sodium tropate and tropin hydrochlorate an 

 improved method was used. Instead of an artificial heart and lung to arterialize and pump the 

 blood through the blood-vessels, as had been used in the latest researches of this kind by Drs. 

 von Frey and Gruber, a natural heart and lung were interposed between the blood-reservoirs 

 and the blood-vessels. Hence this method is free from all those objections which still cling to 

 the old method, and, consequently, the result ought to be reliable. 



After making a number of experiments, it was found that tropin hydrochlorate produced 

 vaso-constriction, and that sodium tropate gave rise to vasodilatation. We have here, then, 

 an important and very decided illustration of the relation of chemical constitution to physio- 

 logical action, and, at the same time, a very striking explanation of the double action of the 

 alkaloid a tropin. 



H. G. Beyer. Report on the Section of Materia Medica in the U. S. National Mu- 

 seum, 1884. 



Report Smithsonian Institution, 1884 (1886) II, pp. 7C-77. 



William G. Binney. A second supplement to the fifth volume of the Terrestrial Air- 

 breathing Mollusks of the United States and adjacent Territories. 



Bull. Mug. Oomp. Zoology, Harvard College, xm, No. 2, Dec, 1886, pp. 23-48, PL I-III. 

 Contains a list of the locally introduced species, of the universally distributed species, and 

 the species of the Central and Pacific provinces, with notes and new facts regarding them. 

 The paper is partly based on material furnished by the Department of Mollusks, U. S. Na- 

 tional Museum. 



