8i8 THE POPULAR SCIENCE MONTHLY. 



that some of these forms are highly poisonous. We see this hy 

 what happens to a man when he is drowned. A drowned man is in 

 reality a poisoned man. The waste which is going on everywhere 

 and at every moment in his tissues is producing a poison of so 

 deadly a character that when it can not be oxidized by receiving 

 oxygen from the blood (as it does under ordinary circumstances 

 by means of the two gallons (nearly) of air he breathes in a min- 

 ute) death ensues in a few minutes. In this case the poison pro- 

 duced all over the system has been no longer rendered harmless 

 by oxygen, and goes as poison to the brain. Now, this poisoning 

 does not appear to be primarily or necessarily due to an excess of 

 carbonic acid, which also accumulates in the blood when a man 

 is drowned. As Dr. Foster shows, even where carbonic acid is 

 got rid of and no oxygen available the same result follows. Thus 

 we have a pretty clear indication that the poisoning which re- 

 sults is the non-oxidization of certain active poisons. Other indi- 

 cations point to the same conclusion. When a man faints from 

 loss of blood he probably faints because the diminished stream 

 of blood does not carry a sufficient quantity of oxygen with it to 

 neutralize the poisons which reach the brain.* It is also notice- 

 able that in both these cases convulsions occur — that is, oxygen 

 being denied, the poisons (which retain all their virulence, from 

 being non-oxidized) act as a very powerful stimulant on a part of 

 the nervous center, which, in turn acting through the nerves, 

 throws one set of muscles after another (connected with the re- 

 spiratory system) into action, in order to obtain the oxygen that is 

 absent ; ending at last in that general violent movement which is 

 called convulsions. After a short time the poisons overpower the 

 nerve-centers and death ensues, f 



Both fevers and violent exercise seem also to illustrate the 

 same thing. In fever the tissue rapidly wastes, and great quan- 

 tities of waste poison are poured into the blood. These poisons 

 affect the nerves, and are the cause of quickened respiration, and 

 often of quickened circulation, % which are necessary in order to 



* One of the writers was informed by a friend in Africa that he was present when a 

 man cut himself badly with a bill-hook and was carried into a cabin. Each time the door 

 was closed the roan fainted ; each time the door was thrown open he came back to his 

 senses, indicating pretty clearly that the supply of oxygen, which was unduly diminished 

 by the loss of blood, was increased when the door was open, and was just sufficient to neu- 

 tralize the effect of the waste poisons and prevent unconsciousness. 



•)• It Is interesting to remark here that this reaction of the nerve-center under the 

 effect of the poison seems to be of that " protective character " which occurs so often, and 

 to which Prof. Foster more than once has referred — that is to say, that it produces a vio- 

 lent movement of the muscles in the effort to obtain air, which can alone neutralize the 

 mischief. 



\ In certain cases, however, the heart and circulation are slowed, not quickened. This 

 is the case, Dr. Foster says, in drowning after a slight quickening has taken place. May 



