160 REPORT 1870. 



that, when calmly and impartially compared with opium and the deri- 

 vatives of opium, it will rank as subordinate to its ancient and trusted 

 rival is probable ; and that it will be found less potent in relieving acute 

 physical pain than in calming the senses and in producing deep, but not 

 insensible sleep, is also probable. -But whatever modification of thought may 

 occur in regard to it, it is an established messenger between science and 

 disease, and must henceforth find a place in the pharmacopoeias of all civilized 

 peoples. 



PART II.— RESEAECH WITH NEW AGENTS. 



Passing from the review of the past I come to the work of the present, 

 adding it to the classified list of my last Report in the order in which its 

 parts naturally come. 



Hydrides. 



Two additional hydrides have been studied, viz. the hydride of caproyl or 

 hexyl, and the hydride of oenanthyl or heptyl. 



Hydride of Caproyl or Ile.vyl. — Of this hydride, known commonly as light 

 petroleum spirit, C,, H,3 H, a pure specimen is before us ; it has a fluid 

 density of -669, a vapour-density of 43, taking hydrogen as unity, and a 

 boiling-point of 154° F. It is insoluble in water. It is not an unpleasant 

 vapour to inhale, and it produces sleep when it is inhaled very much as 

 chloroform does. The second degree or stage of narcotism, stage of excite- 

 ment, is prolonged, and vomiting is not uncommon during this stage ; when 

 the third degree of narcotism is reached there is perfect insensibility. The 

 fourth degree is attended with great muscular prostration, but recovery 

 from the narcotism begins in from three to four minutes, and is usually 

 rapid, no injurious effects being left behind. The temperature of animals 

 (pigeons and rabbits) during the full influence of this ana3sthetic falls from 

 two and a half to three degrees Fahrenheit. When a warm-blooded animal, 

 narcotized with the hydride of hexyl, is allowed to sleep to death in the 

 vapour, the death, as from chloroform, is almost imperceptible, it is so 

 gentle ; the respiration ceases first, but the heart soon follows in cessation 

 of action. After death the lungs are found to be slightly blanched, but the 

 heart contains blood on both sides. The vapour in no way modifies the 

 coagulation of blood, but the colour of the venous blood is rendered darker 

 than is natural, and the arterial blood is also darkened. The corpuscles are 

 not visibly changed. 



I should consider the hydride of caprojd in the light of a narcotic which 

 acts by reducing the respiratory process of change of blood rather than by 

 direct influence of its own on the nervous centres. In the absence of chloro- 

 form it might be used as a substitute for it ; and had it been tried pUre in the 

 early days of anaesthetic research, it would possibly have obtained position 

 over ether. We ncfcd not, however, consider it at the present time any 

 further, as we have better agents at our command. 



Hydride of (Enanthyl or Hepiyl. — This hydride, which may be obtained 

 in a pure form by careful fractional distillation from some petroleum oils, is 

 composed of C^ H^, H. It has a specific gravity of -709 at 60° E., a vapour- 

 density of 50°, and a boUing-point of 201° E. It has a rather agreeable 

 odour, and is easily inhaled. Administered by inlialation, it produces a stupor 

 with some insensibility, much muscular tremor, and a reduction of tempera- 

 tiire, which in birds may be brought down to not less than five degrees. It also 

 reduces the action of the heart, while it quickens the respiration. It darkens 

 arterial blood, but does not interfere with the process of coagulation of blood. 



