rnVSIOLOGICAL ACTION OF THE METHYL AND ALLIED SERIES. 409 



very hard and quick pulse) inhaled the nitrite, I "noticed, during the time 

 when the face was suffused, that the pulse, which previously had been beating 

 at 80 per minute, did not rise to more than 86 beats, but became much 

 relaxed and even feeble, regaining its tone within a few seconds after the 

 agent was withdrawn. For practical purposes, the nitrite of butyl presents 

 to me no advantages over the nitrite of amyl, and it has the disadvantage that 

 it is more easily decomposed. 



Geneeal Review of the Nitrites in eesaed to Physiological Actios". 



With these observations on nitrite of butyl we may, I think, consider that the 

 physiological properties of the nitrites is, in an elementary sense at least, 

 understood. They all present a beautiful unity of action, varied only in in- 

 creasing force and persistency of action as the weight of each rejiresentative 

 in the series increases with and from increase of carbon. The summary of 

 their action is briefly as follows : they act instantaneously on the nervous 

 system of organic life, reducing the power or force of that system, and re- 

 ducing, as a result, the vascular tension ; thus they cause relaxation of 

 extreme vessels, and that suffusion of blood which is the most prominent 

 visible sign of their effect ; thus they cause intense action of the heart, 

 followed by quickened respiration, due to the liberation of the heart from 

 the tension to which it is normally subject ; thus, administered internally, 

 they cause (and this is specially the case with niti"ite of ethyl or nitric 

 ether) free secretion of organs, such as the kidneys, which are under the 

 control of the organic nervous centres. 



Acting in the manner thus stated on the vascular tension, they produce an 

 action on the voluntary muscles and on the brain, leading to paralysis of 

 muscular and mental power, when carried to extremity. But this paralysis 

 is in every sense a secondary action of the nitrites ; they produce no anaes- 

 thesia showing primary action in the cerebral organs ; they cause no con- 

 vulsion of the voluntary muscles showing primary action on the cerebrum, 

 cerebellum, or spinal cord. Unconsciousness and muscular prostration, when 

 they follow, are due to destruction of organic nervous control over the vessels 

 which supply the great nervous centres witli blood ; and the fiual general 

 prostration is syncope, syncope as pure as that emotional syncope which 

 awaits fear or intense anger, or the equivalent of these, sudden loss or re- 

 moval of blood from the centres of volitional power. 



I hope I do not seem to press these facts unduly ; for in reality, when the 

 whole question is seen by the experimental physiologist, it cannot be too 

 strongly urged. In the organic nitrites we hold in our hands a series of che- 

 mical agents Avhich exert an influence over a specific set of organs in animal 

 bodies, and over those organs in one specific way. Further, these agents, 

 against our wills, act through precisely the same means and in precisely the 

 same manner as do the more obscure, because more refined, inlluences which 

 excite daily in us what we call emotions. An act which shall call forth a 

 blush, an act which shall call forth the pallor of terror, an act which shall 

 produce involuntary secretion, an act which shall make the heart beat with 

 an intensity that is painfully felt, — all and any of these acts, which would be 

 called psychical, have their precise physical analogues in the actions of the 

 organic nitrites. In this study the physiologist meets the psychologist on 

 common ground ; his facts as to effects from the physical ca\;se are as sure 

 as are facts from the effects of mental causes ; but how either the phj'sical or 

 the psychical impression is made remains yet to be discovered. It may in either 

 case be an immediate impression conveyed by the nervous expanses of the 



1869. 2 E 



