June 2 2, 18 76 J 



NATURE 



171 



or physiological, could, I found, be rendered insensible by 

 this agent safely and inexpensively. I invented a room 

 or chamber in which animals could be placed so as to 

 be exposed to the anassthetic, and I introduced the use 

 of this method of anaesthesia. From time to time 

 during the past twenty- five years, many necessary sur- 

 gical operations have been painlessly performed on 

 domestic animals under this anaesthesia, and almost all 

 my own physiological experiments which would have been 

 painful have been conducted under it without pain. Some 

 other physiologists have followed me in this procedure, and 

 have introduced the puff-ball narcotising box into their 

 laboratories in order to save pain from experiment. In 

 these v/ays the simple experimental research derived from 

 the observation on the bees has proved doubly useful. 



While these researches were first being pursued a friend 

 of mine came to me in great distress because his splendid 

 and favourite retriever dog had been bitten by a rabid 

 dog and was now stricken with rabies. He asked me to 

 destroy his dog in the kennel, as nobody dared to remove 

 the animal. I carried out the request at once by simply 

 closing the door of the kennel, covering it with a horse- 

 cloth, and letting the clarified and condensed fumes 

 from the burning lycoperdon pass into the kennel. The 

 animal lapsed quickly into sleep and died without a 

 struggle. I believe this was the first time in the history 

 of science in which anaesthesia had been employed inten- 

 tionally and systematically for the painless extinction of the 

 life of the inferior animals. I shall show in a future note 

 the singular importance of this application. 



Research with Carbonic Oxide. 

 The observation that the smoke of the burning lyco- 

 perdon would produce ansesthesia in the higher animals 

 led naturally to an inquiry after the agent that was at 

 work in creating the insensibility. I commenced to 

 make an analysis of the smoke in order to determine 

 the question, but was forestalled in discovery by two other 

 experimenters, ihe late Dr. John Snow, — so well known 

 for his researches in anaesthetics, and as the author of 

 the water theory of cholera, — and by the late Thornton 

 Herepath, one of our most promising young chemists. 

 These two gentlemen almost simultaneously discovered 

 that the gas called carbonic oxide is present in the smoke 

 of the lycoperdon. This was a new light, and led me to 

 study the action of carbonic oxide on animal life. I 

 found that this agent, a colourless and inodorous gas, 

 produced insensibility in precisely the same way as the 

 purified smoke of the puff-ball. I found that when the 

 combustion of the puff-ball was made so perfect that no 

 carbonic oxide was formed, there was no anaesthesia in- 

 duced by the purified fumes, and so the fact was rendered 

 clear that the special anjesthetic in the smoke is the gas 

 in question. I estimated also the proportions of carbonic 

 oxide that could be breathed in the atmosphere, and the 

 effects ol the gas in larger and smaller proportions on the 

 lower animals and on myself. 



Experintentation in Relation to Diabetes from Breathing 

 Carbonic Oxide. 

 In conducting iht observations on the action of carbonic 

 oxide on living bodies, I was led to examine the animal 

 secretions, and to my surprise I found that the renal secre- 

 tion of an animal subjected to the gas yielded evidence 

 of glucose or grape sugar. The faci was of such import- 

 ance I was compelled to follow it up until I had quite 

 established it, and had proved that by the inhaling ot this 

 active gas, a temporary attack of the disease known 

 commonly as diabetes, which in the human subject is 

 often fatal, could always be artificially induced in the 

 dog. In a further experiment I found that the inhalation 

 of common ccal-gas diluted with air would produce the 

 same condition, an effect caused by the carbonic oxide 

 which is always present in coal-gas. The same has sub- 

 sequently been observed in a human subject accidentally 



exposed to the gas. The ultimate value of these obser- 

 vations has yet to be proved. When I first published, in 

 the Medical limes and Gazette, on March 22, 1862, the 

 fact of the artificial production of diabetes by carbonic 

 oxide, nine years after I had first observed it, it was 

 looked upon rather as a curious than a practical demon- 

 stration. I have always felt that though it did not seem 

 to offer any immediate practical result, it must some day 

 be useful in throwing light on the origin, or at least on 

 one origin of a fatal malady. Quite recently Dr. Pavy 

 has published some valuable details on the production of 

 diabetes by the same means, that is to say, by making 

 animals inhale carbonic oxide, and he has been able to 

 arrive at some clear ideas on the question of the chemical 

 changes that are involved in the process. We may fully 

 expect to receive from him further valuable information. 



I wait a moment at this point to observe that the history 

 of experimental research given in the last note illus- 

 trates forcibly the value of what may be called the acci- 

 dental observations that are picked up in the course of 

 experiment. Who ever would have dreamed that from 

 a practice cf stupefying bees in order to rob them of their 

 honey, a practice which has been carried on by the vulgar 

 for many centuries, would come the discovery that the 

 higher animals, and even man himself, can be made to 

 produce glucose, and that they may become afflicted with 

 the symptoms which characterise a destructive disease 

 from a simple perversion in the animal chemistry induced 

 by the smoke of the burning puff-ball ? 



Experimentation with Oxygen Gas. 



The experiments with carbonic oxide led me to a series ot 

 experiments with oxygen gas. The late Sir Benjamin Brodie 

 and Mr. Broughton, in their experiments on this same sub- 

 ject, had observed that when animals are placed in pure 

 oxygen they die,with symptoms of sleep, as if they were 

 narcotized, although the products of respiration are re- 

 moved. Hence for many years oxygen gas, on which we 

 depend for life, was believed to be a narcotic or sedative 

 poison. In my experiments many new facts came out 

 which modified this view. In the first place I found that 

 some animals, such as frogs, will live in oxygen as readily 

 as in common air ; that herbivorous animals will live in it 

 if it be kept supplied to them in fresh current, but the 

 carnivorous animals will not live in the pure gas for a 

 long time without becoming drowsy and insensible and 

 without undergoing changes of their blood, which are 

 fatal to life owing to separation of the fibrine within the 

 vessels. The most important observation, however, which 

 I made on the subject of the effects of oxygen, is the 

 following : — I found that a narcotic action of the oxygen 

 is produced, however pure from the products of respira- 

 tion the oxygen is maintained, whenever it is breathed 

 over and over again by being passed backwards and for- 

 wards through the chamber in which the animals breathe 

 it. Subjected three times to this passage through the 

 chamber, though it be purified so fully from carbonic acid 

 that it contains less ol this gas than the common air, it 

 fails to support the active life of all common animals 

 excepting frogs. In a word, the oxygen assumes a negative 

 condition in which it will not support living function. In 

 a report on these researches, made to the British Associa- 

 tion for the Advancement of Science, at the Oxford 

 meeting in i860, I defined this state as one in which no 

 new poison was produced, but in which the oxygen lost 

 some principle or property by which in its fresh state it 

 sustained the animal life. 



The lessons taught by these observations extend to the 

 human family. They show that if the oxygen of the great 

 atmospheric sea in which we all breathe should from any 

 cause assume this negative condition, it will fail to sustain 

 the active life. They explain the depressing effect of 

 breathing over again the same air in close and badly 

 ventilated rooms. They throw a distinct light on that 

 " epidemic condition " of' the atmosphere, which, since 



