ABSOIJITIOX— CL\MULAT1VE ACTION. 2^3 



tion so slow that tlierc lias not been sufficient time for the 

 removal of any considerable quantity from the blood. On this 

 account we must diminish the dose of a medicine in order to 

 obtain the same effect, according to the rapidity of absorption 

 from the place to which we apply it. Absorption is qnicikest 

 from a serous membrane, then from intercellular tissue, and 

 lastly, from mucous membrane. The vascularity and rate of 

 absorption from intercellular tissue is greater on the temples, 

 breast, and inner side of the arms and legs than on their outer 

 surfaces or on the back.* It should not be forgotten that any 

 drucp introduced into the stomach but not absorbed into the blood 

 is as nnich outside the body as if it were in the hand, for any 

 effect it will have on the system, provided always it have no 

 local effect on the gastric walls. For if it act directly on the 

 walls of the stomach, it may have an effect which it would not 

 have when held in the hand or applied to the skin. Thus 

 mustard, which would produce redness and burning of the skin, 

 will cause vomiting when swallowed ; but opium, which does 

 not act on the stomach itself, produces no effect until after it 

 has been absorbed. 



By the difference between absorption and excretion under 

 diflerent circumstances or in different individuals,! the cumula- 

 tive action of drugs, the effect of idiosyncrasy, habit, climate, 

 condition of body, as fasting, etc., disease, and form of adminis- 

 tration, can to a great extent, though not entirely, be explained; 

 but experiments on some of these points are deficient, and the 

 explanations now given are to some extent theoreticah 



Cumulative Action. — If a substance be naturally so slov/ly 

 excreted from the body that the whole of the dose in ordinary 

 use is not excreted before another is given, the amount present 

 in the body will gradually increase, just like the curare in 

 Hermann's experiment, and will produce an increasing or cumu- 

 lative effect. Examples of this are to be found in metallic pre- 

 parations, such as those of mercury or lead, which are excreted 

 very slowly ; or in some of the organic alkaloids, if given in 



* Eulenburg, Hiipodermatische TnjecHon der Arzneimittel, Srd edition, p. 65, 

 + Children absorb more quickly than adults, so opium is more dangerous to 

 them. Marx, Lehre von den Gift en, vol. ii, p. 117. 



