SYSTEMATIC SYNTHESIS OF TISSUES, 197 



SECTION X. 



Gases. 



232. THE BLOOD HAS A CAPACITY of taking into it- 

 self a certain amount of gas of, so to speak, dissolving it. 

 Now it does not drink all the air, but makes a choice, 

 taking the oxygen and leaving the nitrogen. This it 

 does in the lungs and in the stomach, when air is swal- 

 lowed in the saliva, as it is especially while speaking. 



233. THE OXYGEN OF THE BLOOD MAY BE OF USE in 

 two ways : it may combine with some of the constituents 

 of the Blood in its circuit and produce heat, or it may 

 seize upon some of the decomposing elements in the tis- 

 sues and assist in bringing them into the Blood. It is 

 certainly of great use, and should be plentifully received : 

 the capacity of the Blood to receive it should be con- 

 stantly satisfied. 



234. CARBONIC ACID is a gas that is constantly form- 

 ing in the different parts of the Body, both by the de- 

 composing tissues and the calorific food. Any surplus 

 quantity must be speedily removed, for it is very deadly, 

 and at times accumulates very fast. 



235. OTHER GASES ARE PRODUCED by disease, indi- 

 gestion, etc., but their number is not definite nor uniform, 

 nor is their quantity. 



Practical JReview. 



236. A REVIEW OF WHAT HAS BEEN SAID Upon Tis- 



sues, Liquids, and Gases, and their constituents, will 

 convince any one that they are topics of the utmost im- 

 portance in reference to the Laws of Hygiene. 



237. IN THE FIRST PLACE, IT HAS BEEN DEMON- 

 STRATED that certain substances must be selected for 

 food, since the Body is composed of only a few. 



232. For what ? 233. How ? 234. What ? 235. How ? 286. The 

 effect ? 23T. What ? 



