Another light is thrown upon the waste poisons of the tissues by the statement that they exhaust the power of muscle to contract. Muscle taken from a freshly killed animal, if fed with arterial blood, or blood supplied with oxygen, may retain for some time its power of contraction. But if venous blood (blood that has lost its oxygen and is charged with waste poisons) be injected into it, the power of contraction is lost quicker than if no blood be supplied to it. In the same way the power of the muscle is soon exhausted if a solution containing substances which can be extracted from muscle (such as kreatin, lactic acid, etc.) be injected into it (M. Foster, page 150). These facts help us to see the local mischief which must often arise from these poisons, as well as their effects on the nerve-centers. Many an ache and pain are probably due to local effects of the waste poisons, whether they are the normal waste poisons of the system, which under unhealthy conditions of life we are not properly getting rid of, or the special waste poisons of skin and lungs that we have rebreathed into the system.[1]
- ↑ Where Nature does not get fair play, where, for example, the blood is vitiated by our constantly rebreathing poisons that have been already got rid of, other dangers probably exist. In the delicate chemical translations which take place when tissue is being changed into harmless waste, it may happen that the process goes wrong, and an abnormal poison is formed. Thus, under certain circumstances, instead of urea, uric acid is formed; thus in uræmia, or retention of urea in the system, various secondary compounds are formed (Carpenter, p. 448), which act on brain or spinal cord as narcotic poisons; thus, in acute yellow atrophy, where liver-cells lose a part of their activity, a substance called leucin is manufactured to a considerable extent instead of urea (M. Foster, p. 755); thus gall-stones are formed instead of gall, and certain changes take place in the bile, by which some of its constituents cease to be dissolved in it (M. Foster, p. 431); thus the ptomaines—a class of mysterious poisons—are formed in the system (Quain, Ptomaine, p. 1816) after various illnesses. [In connection with these ptomaines a dispute arose during an Italian trial as to whether a poison detected in a body was strychnine, or this naturally formed ptomaine.] Thus, too, Blythe (Poisons, A. W. Blythe, pp. 468-470) describes cases in which narcotic poisons have been formed by synthesis of substances in the tissue or in the blood. So also we might quote the interesting speculation of Dr. Carpenter (p. 368), that a cancer is an excretory organ, formed to get rid of poisons in the system, illustrating once more "the protective nature" even of that which brings pain and death; and the case of certain pathogenic organisms, which, as Dr. Klein suggests (p. 248), may not affect healthy living
work excreting. At every breath we give off a small quantity of poison, whether we are breathing in pure or bad air. The quantity given off is extremely (extraordinarily) small—so small that it can only be approximately measured by the amount of carbonic acid in the air. These bacteria are present whether we live in foul air or pure air. Their existence there means that they can thrive, and if they thrive they must feed, and if they feed, they must excrete, or something analogous to it. Personally, I am inclined to think they (these special lung and skin poisons) come from the blood, because ptomaines can be formed by the action of various chemical agents (such as acids) upon protoplasmic or albuminous material and as blood (serum) is albuminous, and as it contains various substances derived from tissue waste—e. g., lactic acid, uric acid probably, etc.—it may be that the two react upon one another, producing these ptomaine-like poisons. I think, however, that it is just possible that they may be formed on the surface.
