180 Dr. Mitchell on the Physiological Actions of Spartine and Scoparine. 



powerful, two or three drops injected into tlie femoral vein of a dog killing 

 it in a conple of seconds. They are aU three narcotic poi-sons of con- 

 siderable power, acting upon the spinal cord, of which they appear to 

 exhaust the energy. They are, I think, the only three volatile natural 

 alkaloids with which we arc act^uainted, at least the only ones extracted 

 from plants employed in medicine. 



I have often felt inclined to believe that bodies similarly constituted, 

 chemically and physically, should exert similar influences on the animal 

 economy, and, as the reverse, that where similar effects are manifested, 

 similarly constituted principles should be found to exist. I know that 

 serious difficulties meet me on the threshold, but some of these are melt- 

 ing away under more accurate modes of investigation, and the new facts 

 which are from time to time being added to our stock, for the purposes 

 of generalization, are rather in favour of, than opposed to, such a view. 



In the datui-a stramonium, hyoscyamus niger, and atropa belladonna, 

 all belonging to the solanacese, three principles have been discovered, 

 atropine by Liebig, daturine and hyoscyamine by Brandes. And it has 

 been pointed out by Runge, that these thi-ee bodies have the same com- 

 position, Csi Ho.5 Oo N. Now between their physiological effects there 

 exists no difference in kind. They all produce " dilatation of the pupil, 

 insensibility of the iris to light, diminished feeling, giddiness, delirium 

 (extravagant) followed by stupor, a remarkable affection of the throat and 

 mouth." Between these results, however, and those from nicotine, 

 coneine, and spartiue, we have essential differences ; instead of dilata- 

 tion we have contraction of the pupil ; we have the absence of delirium 

 and the throat affection ; and, as somewhat characteristic, we have the 

 paralysing effect on the muscular system. But we have not only a 

 wide difference in their action on living beings, but a wide one also 

 between their chemical constitutions and general properties. And, as a 

 further illustration, it has been found, that wherever a plant has been 

 generally and extensively employed to yield a favourite and refreshing 

 beverage, some body has been detected in it, either the same as theine, 

 or closely allied to it. 



Most people admit, as a general rule, " that plants of the same family, 

 or, in other words, having the same botanical affinities, agree in the 

 nature of their medicinal operation," but we cannot, therefore, argue with 

 Dr. Lindley, in saying, " that a knowledge of one plant is a guide to the 

 practitioner, which enables him to substitute, ivith confidence, some other 

 plant which is closely allied to it," for to this statement there are many 

 remarkable exceptions, which, however, diminish, but do not destroy its 

 utility in practice. 



In what manner then does spartine produce the effects detailed? 

 The answer may be derived in part from what has been already stated. 

 Omitting altogether the question whither it acts by absorption or 

 by sympathy — a questio vexata on which no new light is thrown by 

 these researches — we are led to locate its primary action on the 



