26 REPORT — 1841. 



Report on Poisons. By G. L. Roupell, M.D., F.R.S. 



The complexity of the functions of the animal body, and their liability to 

 disturbance from a number of causes, must be apparent to the most super- 

 ficial observer. To those who endeavour to explain what takes place during 

 the disturbed performance of the vital actions, many difficulties jjresent them- 

 selves ; opposite causes occasion one common and similar result, and the 

 same agent will produce very different effects under circumstances apparently 

 analogous. Whilst, however, there may be thus many conflicting processes 

 exhibited to us, we are satisfied that there are leading principles and general 

 laws in operation which it is our great aim to seek for and discover. We 

 cannot avoid allowing the proposition, " That under actually corresponding 

 circumstances similar effects must ensue." Should then differences exist in 

 the effects of any substance upon the system, as a poison for example, we 

 naturally refer them to modifying influences ; at the same time that we explain 

 the production of similar effects from opposite causes, by the agency of funda- 

 mental principles, proving simplicity in the laws which regulate our frames. 



The object of my former communications has been to illustrate the effects 

 of those poisons which induce an alteration in the vascularity of the different 

 tissues with which they may come in contact, and to portray the appear- 

 ances exhibited by dissection : on the present occasion some views will be 

 stated concerning the operation of an agent which is constantly eliminated 

 from the system, the effects of which, although not indicated by obvious local 

 changes or capable of elucidation by drawings, appear nevertheless to be 

 highly deserving of consideration and study. Carbonic acid is the agent 

 alluded to ; one highly interesting, first, from its producing very marked and 

 injurious consequences if applied in any way to the human body, either in- 

 ternally or externally ; secondly, from its immediate connection with one 

 highly important function of our system ; thirdly, from the analogy of its 

 effects with some most serious maladies ; and fourthly, from the causes which 

 influence its secretion. 



It cannot here be requisite to insist upon the necessity for the rejection of 

 all effete matter from the body, or to show the importance of the changes per- 

 petually going on in the circulating fluids. These points will readily be con- 

 ceded to me ; nor will the mischief be questioned arising from the presence 

 of certain principles in the blood, such as bile or urea ; but, while these sub- 

 stances have deservedly occupied much attention of late, we are neglectful of 

 an agent far more injurious. The ducts of the liver may be partially, if not 

 entirely closed, for months ; the kidneys may be removed, or the secretion of 

 urine may be suspended for more than a week, yet life during that time may 

 be preserved ; but should the elimination of carbonic acid from the lungs be 

 prevented for a few minutes, nay, only for a few seconds, life will be placed 

 in imminent peril, if not irrevocably destroyed. 



We are well aware that carbonic acid is generated by various processes, 

 for example, by decomposition, both of animal and vegetable bodies, by com- 

 bustion, by fermentation, as well as by the respiratory apparatus. We are 

 also aware that plants yield it by night ; that it is exhaled from tlie earth in 

 certain situations, and that it is disengaged by chemical action, from com- 

 pounds of which it forms an ingredient. We are certainly ready to admit 

 that air charged with this gas, from whatever source it may be produced, is 

 positively and highly detrimental. Sir Humphry Davy deemed it not beneath 

 his notice to investigate the condition of the atmosphere rendered impure 

 by persons crowding together in large or public assemblies, and showed that 

 carbonic acid was present in excess in the vitiated air of such meetings. The 



