50 INORGANIC PROXIMATE PRINCIPLES. 



FLUIDS WITH AN ALKALINE REACTION. FLUIDS WITH AN ACID REACTION. 



1. Blood-plasma. 1. Gastric juice. 



2. Lymph. 2. Perspiration. 



3. Aqueous humor. 3. Mucus of the vagina. 



4. Cephalo-rachidian fluid. 4. Urine. 



5. Pericardial fluid. 



6. Synovia. 



7. Fluids of the living muscular 



tissue. 



8. Mucus in general. 



9. Milk. 



10. Spermatic fluid. 



11. Tears. 



12. Saliva. 



13. Pancreatic juice. 



14. Intestinal juice. 



If we take into account the carbonic acid exhaled with the breath, 

 we see therefore that, while in general an alkaline condition is charac- 

 teristic of the internal fluids, the products of excretion, on the contrary, 

 present universally an acid reaction. 



Of all the internal fluids the most essential is the plasma of the blood, 

 since it affords the materials of nutrition to the entire system ; and its 

 alkaline reaction, which is distinctly marked, has been found to be in- 

 variably present, not only in the human subject, but also in every species 

 of animal in which it has been examined. This reaction of the blood is 

 moreover necessary to life, since Bernard has shown 1 that if an injection 

 of dilute acetic or lactic acid be made into the veins of the living animal 

 death always results before the point of neutralization has been reached. 



The alkaline reaction of the blood-plasma gives to this fluid its extra- 

 ordinary capacity for dissolving carbonic acid. According to Liebig, 

 water which holds in solution one per cent, of sodium phosphate is 

 enabled to absorb and retain twice its usual proportion of carbonic acid; 

 and the other alkaline salts, as is well known, have a similar dissolving 

 action upon this gas. Consequently the blood as it circulates among 

 the tissues rapidly absorbs from them the carbonic acid which has been 

 formed in their substance, and incessantly carries it away to be elimi- 

 nated by the lungs. This important property of the circulating fluid 

 depends upon its alkaline reaction. 



The alkalescence of the blood is due in great measure to the alkaline 

 phosphates, which are present in human blood in the proportion of 0.6 T 

 per thousand parts. A peculiar relation, however, exists in this respect, 

 for different classes of animals, between the alkaline phosphates and the 

 alkaline carbonates, which are to be mentioned hereafter. Both these 

 groups of salts have, when in solution, an alkaline reaction ; and both 

 contribute to the alkalescence of the blood in man and animals. But in 

 the carnivorous animals it is the phosphates which preponderate, while 



1 Liquides de 1'Organisme. Paris, 1859, tome i. p. 412. 



