536 INDUCTION. 



permeates its membranes, and rapidly spreads through the 

 system. 3rd. Alcohol taken into the stomach passes into vapour 

 and spreads through the system with great rapidity ; (which, 

 combined with the high combustibility of alcohol, or in other 

 words its ready combination with oxygen, may perhaps help 

 to explain the bodily warmth immediately consequent on 

 drinking spirituous liquors.) 4th. In any state of the body in 

 which peculiar gases are formed within it, these will rapidly 

 exhale through all parts of the body ; and hence the rapidity 

 with which, in certain states of disease, the surrounding atmo- 

 sphere becomes tainted. 5th. The putrefaction of the interior 

 parts of a carcase will proceed as rapidly as that of the 

 exterior, from the ready passage outwards of the gaseous pro- 

 ducts. 6th. The exchange of oxygen and carbonic acid in the 

 lungs is not prevented, but rather promoted, by the inter- 

 vention of the membrane of the lungs and the coats of the 

 blood-vessels between the blood and the air. It is necessary, 

 however, that there should be a substance in the blood with 

 which the oxygen of the air may immediately combine ; 

 otherwise instead of passing into the blood, it would permeate 

 the whole organism : and it is necessary that the carbonic 

 acid, as it is formed in the capillaries, should also- find a sub- 

 stance in the blood with which it can combine ; otherwise it 

 would leave the body at all points, instead of being discharged 

 through the lungs. 



5. The following is a deduction which confirms, by 

 explaining, the old but not undisputed empirical generaliza- 

 tion, that soda powders weaken the human system. These 

 powders, consisting of a mixture of tartaric acid with bicar- 

 bonate of soda, from which the carbonic acid is set free, must 

 pass into the stomach as tartrate of soda. Now, neutral tar- 

 trates, citrates, and acetates of the alkalis are found, in their 

 passage through the system, to be changed into carbonates ; 

 and to convert a tartrate into a carbonate requires an addi- 

 tional quantity of oxygen, the abstraction of which must lessen 

 the oxygen destined for assimilation with the blood, on the 



