PHYSIOLOGICAL ACTION OF ORGANIC CHEMICAL COMPOUNDS. 145 



Report on the Physiological Action of Organic Chemical Compounds. 

 By Benjamin Ward Richardson, M.A., M.D., F.R.S. 



The plan I have heretofore followed, of passing under review the practical 

 results of the labours chronicled in previous Reports, cannot be carried out 

 this year. The review itself would now become so comprehensive that it 

 would occupy all the time allowed for the reading of the Report to the ex- 

 clusion of the new matter to be brought forward. I shall therefore proceed 

 at once to the description of new research. 



Chloeal Hydrate. 



It is two years since the substance called chloral hydrate (the physio- 

 logical properties of which had been previously discovered by Liebreich) was 

 introduced into this country at the jN'orwich Meeting of this Association. 

 During the first year of tlie employment of chloral hydrate the enthusiasm 

 connected with the learning of its value prevented, in some degree, all fair 

 criticism as to its real values and dangers. The year immediately past 

 has afforded time for calmer and more judicial observation, greatty, as I think, 

 to the advantage of the public, since it has given to the professors of medical 

 art the opportunity of learning that the new agent placed in their hands, 

 blessing as it is to humanity, is not an unalloyed blessing, but one that haS 

 engendered a new and injurious habit of narcotic luxury, and has added 

 another cause to the preventible causes of the mortality of the nation. 



Recognizing these truths, I have felt it a duty to devote some part of the 

 labours of this Report to the elucidation of questions which have become of 

 public, not less than of scientific importance, and to these I would now ask 

 attention. 



1. I have endeavoured to ascertain what is a dangerous and what a fatal 

 dose of chloral hydrate. The conclusion at which I have been able first to 

 anive on this point is, that the maximum quantity of the hydrate that can 

 be borne, at one dose, bears some proportion to the weight of the animal 

 subjected to its influence. The rule, however, does not extend equally to 

 animals of any and every class. The proportion is practically the same in 

 the sam'e classes, but there is no actual universality of rule. A mouse weigh- 

 ing from three-quarters of an ounce to an ounce .will be put to sleep by one 

 quarter of a grain of the hydrate, and will be killed by a grain. A pigeon 

 weighing twelve ounces will be put to sleep by two grains of the hydrate, and 

 will be killed by five grains. A guineapig weighing sixteen ounces will be 

 put by two grains into deep sleep, and by five grains into fatal sleep. A 

 rabbit weighing eighty-eight ounces will be thrown by thirty grains into 

 deep sleep, and by sixty grains into fatal sleep. 



The human subject, weighing from one hundred and twenty to one hundred 

 and forty pounds, will be made by ninety grains to pass-into deep sleep, and 

 by one hundred and forty grains into a sleep that will be dangerous. 



Prom the eflfects produced on a man who had of his own accord taken a 

 hundred and twenty grains of the hydrate, and who seemed at one period to 

 be passing into death, I was led to infer that in the human subject one 

 hundred and forty grains should be accepted as dangerous, and one hundred 

 and eighty as a fatal dose. Evidence has, however, recently been brought 

 before me which leads me to think that, although eighty grains would 

 in most instances prove fatal, it could, under very favourable circumstances, 

 be recovered from. 



1871. 1 



