PHYSIOLOGICAL ACTION OF ORGANIC CHEMICAL COMPOUNDS. 155 



•which the essence of cure lies in reestablishing a good capillary circulation. 

 It may be, therefore, that by administering the nitrite of amyl, or the other 

 organic nitrites, secundum artem, we may make them further agents in the 

 cure of disease, and thereby add another progress to physiological as distin- 

 guished from empirical mcchcine. 



Nitrate of Ethtl. 



^ In one of my previous Eeports I touched incidentally on certain of the 

 nitrates of the organic scries of compounds. These substances diflcr from 

 the nitrites simply in that they contain an additional equivalent of oxygen. 

 It is a very interesting study to follow the difference of physiological action 

 upon so simple a change of chemical constitution ; and this year I studied 

 once more this difference from two of the representatives of the nitrate 

 series, viz. from nitrate of ethyl and nitrate of amyl. 



_ Nitrate of ethyl, to which I first refer, is a fluid, almost colourless, and 

 yielding an agreeable odorous vapour. It has a specific gravity of 1-112, a 

 boiling-point of 85° C. (185° F.), and a vapoui-- density of 45. Its composi- 

 tion is C^ H. NO3. It is made by dropping 10 grms, of absolute alcohol into 

 20 grms. of colourless concentrate nitric acid in a platinum vessel surrounded 

 by a freezing-mixture. Mr. Ernest Chapman was kind enough to make me 

 a fine specimen of this nitrate, with which my experiments have been con- 

 ducted. 



Nitrate of ethyl was used in experiment, physiologically, in 1848, by the late 

 distinguished Professor of Midwifery in the University of Edinburgh, Sir 

 James Simpson. Sir James considered that it possessed some anaDsthetic 

 properties.^ It has for many years, I may say centuries, also been used in 

 medicine, in combination with alcohol, under the name of nitric ether, and 

 so employed- has been considered valuable for its diuretic properties. 



I find, on using it in the undiluted form, that it may be introduced into the 

 system either by inhalation, by hypodermic injection, or by the stomach, and 

 that the effects which follow its administration in large doses are closely analo- 

 gous to those induced by nitrite of amyl, i. e. it produces rapid action of the 

 heart, some pulsation of the vessels of the head, fliishing of the face, and 

 muscular prostration. In the strict sense of the word, it is not an anesthetic; 

 when administered in an extreme dose, there is no evidence of insensibility', 

 imtil death is imminent. In all cases the motor force is overcome com- 

 pletely long before the sensory organs are influenced. The paralysis of tho 

 vessels is slower than from nitrite of amyl; the danger of using the ao-ent is 

 consequently much less ; and as the eff'ects are more prolonged, the substance 

 becomes very manageable in medical practice. 



_ When the adniinistration of the nitrate is carried up to death, the con- 

 dition induced in all the vascular organs is an intense congestion. In 

 this congestion the lungs and the kidneys specially share ; and I think'there 

 is no doubt that the well known diuretic action of the substance is due 

 altogether to the paralysis of the renal vessels it produces. It alters much 

 less than the nitrites the colour of the blood, interferes in no way with the 

 process of coagulation, and is eliminated rapidly from the body both by the 

 lungs and the kidneys. Administered to tho production of complete prostra- 

 tion, it reduces the animal temperature in a definite degree. In pigeons the 

 temperature goes down five and even six degi-ees, in rabbits three degrees, 

 and in gnincapigs from two to three degrees. Like the nitrites, nitrate of 

 ethyl reduces the tetanic spasm of stiychnia ; and I would suggest that in 

 tetanus, and other acute diseases of spasmodic character, it might be used 



