284 OF THE BLOOD: ITS VITAL PROPERTIES, 



which have what is called a "cumulative" tendency; this tendency being, 

 in fact, simply the result of their want of stimulating influence upon the ex- 

 ci'etory organs, whose functional activity is rather impeded than promoted 

 by them. This is pre-eminently the case in regard to lead, which is prob- 

 ably the most cumulative poison with which we are acquainted; its continual 

 introduction in doses of even extreme minuteness, being capable, if suffici- 

 ently prolonged, of causing the most serious disturbance in almost every func- 

 tion in the economy. Even here, it is rather in the tissues, than in the 

 blood, that it accumulates, as is indicated by a variety of facts, but more 

 especially by the difficulty with which it is eliminated from the system by 

 means that would be probably effectual in removing it from the circulating 

 current. 



221. There are some substances of this class which are, nevertheless, of a 

 nature and composition which render them peculiarly susceptible of change, 

 when subjected to the influences which they must encounter in the living 

 body, and more especially when exposed in a state of very fine division to 

 the agency of oxygen. We see exemplifications of this mode of elimination 

 of poisons in the transient operation of moderate doses of Alcohol, Ether, 

 Chloroform, Opium, Strychnia, Prussic Acid, Snake poison, 1 etc., in all of 

 which the question of life or death is one of time; for if the fatal result do 

 not speedily follow the absorption of the poison into the blood, the patient 

 gradually recovers from its effects ; and the most effectual treatment cou- 

 sisjs in the artificial maintenance of the respiratory movements, which the 

 influence of these poisons upon the nervous centres might otherwise suspend. 

 With regard to certain poisons of this unstable class, there is strong evidence 

 that whilst in moderate doses they are partially or completely destroyed 2 in 

 the system ; when taken in large doses they pass into the urine and are elimi- 

 nated, without undergoing any change that impairs their physiological ac- 

 tion ; this evidence being afforded in the effects of the reingestion of the 

 urine, either by the individuals themselves, or by others. A very curious 

 example of this kind is afforded by the intoxicating fungus Amanita mus- 

 caria, which is used by some of the inhabitants of the northeastern parts of 

 Asia, in the same manner as alcoholic liquors by other nations. Its effects, 

 like those of other excitants, have a limited duration ; for a man who is in- 

 toxicated by it one day, "sleeps himself sober" by the next. His restora- 

 tion is due, however, not to his repose, but to the elimination of the poison 

 which takes place during the interval ; for if he drink a cup of his urine 

 the next morning, he is yet more powerfully intoxicated than he was the 

 preceding day ; and this fluid has the same effect upon any other individual 

 into whose urine the active principle then passes; so that, according to the 

 testimony of travellers, the intoxicating agent may be transmitted in this 

 manner through five or six persons, a small stock at the commencement thus 

 serving to maintain a week's debauch. . Results of the same order have been 

 obtained by Dr. Lstheby, in regard to opium, belladonna, hemlock, aconite, 

 etc.; the passage of these substances into the urine being proved by the in- 

 duction of their characteristic effects, when that fluid was administered to 

 other animals. 



222. Between the substances which admittedly rank as poisons, and those 

 which are reckoned as materies morborum, no definite line of demarcation 



time become increased in size, and less liable to change under the influence of re- 

 ugents. 



1 See in particular the experiments of Brunton and Fayrer on the nature and 

 physiological action of the poison of Naja tripudians, etc., Proceed. Koy. Soc., 1873, 

 p. 358, and 1874, p. 08. 



' 2 Sue the researches of Anstie and Dupre on Alcohol, in the Practitioner. 



