122 REPORT 186 J;. 



placed a pledget of bibulous paper an inch square, and saturated with nitrite, 

 on one of my arms, and covered the paper with thin metal. On the other 

 arm I placed a similar pledget saturated with chloroform, and covered it in 

 the same manner. The nitrite, retained on until it was quite dry, produced 

 only pale redness and slight irritation : the chloroform caused great pain, 

 so that I had some difficulty to keep it on, intense iujection and redness, and 

 some excoriation of skin. 



At the same time I may observe that the nitrite is undoubtedly absorbed 

 by the skin. To prove this, I applied it to the skin of a frog by immersiug 

 the hinder limbs of the animal in a solution of it. In a few minutes the 

 symptoms which markedly characterize the action of the substance, viz., 

 violent circulatory action followed by prostration, were developed. I also 

 applied some of the substance to my own skin, carefully retaining it in con- 

 tact over a six-inch surface : during the application the pulse rose, sensa- 

 tion of fullness in the head followed, and other signs which will be more 

 fully described in the sequel. 



Observations. — Series 5. Administered by the mouth the nitrite is com- 

 paratively slow in its action, but very decisive. Administered to rabbits in 

 doses of five, ten, fifteen and tweuty minims, and in more potent doses, its 

 effects are striking. It admits of being readily given in tincture diluted 

 with water. In five-minim doses it produces on these animals temporary 

 excitement. The circulation is quickened, the breathing is quickened, the 

 pupil is dilated, and the animal is restless ; the symptoms subside in from five 

 to ten mimites, and no harm seems to have been done. In doses of ten 

 minims the symptoms are the same, but more marked. In doses of twenty 

 minims, after the stage of excitement has passed away, depression follows, 

 and continues several minutes, and there may be feeble convulsive action, 

 but the animal recovers. There is no indication of vomiting. 



In drachm doses the nitrite is often fatal to dogs, cats, and rabbits. The 

 symptoms induced are violent action of the heart, rapid breathing, -v^-ide 

 dilatation of the pupil, con\'nlsions, not clonic but quick, and after an inter- 

 val of a few minutes rapid collapse and paralysis of motion. The heart falls 

 in its beats to a minimum, and the breathing may be reduced to one re- 

 spiration in two or even four minutes. To appearance, in fact, the animal is 

 nearly dead. It lies hke an animal profoimdly narcotized with chloroform, 

 but still it feels. When it is touched at any part or hghtly pinched, it Avinces 

 instantly if it has the power to move. The period of death is usually pro- 

 longed ; and often when the animal seems so nearly dead that recovery 

 appears hopeless, it continues still to breathe, it throws off the nitrite by the 

 lungs, and ultimately recovers. 



Observations. — Series 6. Administered by inhalation, the effects of the 

 nitrite are elicited with remarkable precision and quickness, and the pheno- 

 mena are amongst the most striking, perhaps are the most striking of any I 

 have seen in all my large physiological experience. If a piece of bibulous paper 

 be formed into a tube, and if an expanded end of the tube be made to absorb 

 two or at most three minims of the nitrite, a surface sufficiently charged for 

 inhalation even by the human subject is obtained. If the tube, charged as 

 directed, be held about two inches from the nose, and respiration be carried 

 on in the usual manner, the following symptoms rapidly show themselves. 

 The action of the heart is suddenly and greatly increased, so that in one 

 minute I have counted it rising eighty beats ; the breathing also becomes 

 quickened ; the face becomes deeply suffused with blood, the suffusion extend- 

 ing over the whole face, down the neck, and in persons who are bald, more or 





