By alkaline we mean "soap-like" or flat, like soda, lye, lime, and soaps of all sorts.

If you pour an acid and an alkali together--like vinegar and soda--they will "fizz" or effervesce, and at the same time _neutralize_ or "kill" each other.
The Use of the Saliva.

As the chief purpose of digestion is to prepare the food so that it will dissolve in water, and then be taken up by the cells lining the food-tube, the saliva, like the rest of the body juices, consists chiefly of water.

Nothing is more disagreeable than to try to chew some dry food--like a large, crisp soda cracker, for instance--which takes more moisture than the salivary glands are able to pour out on such short notice.

You soon begin to feel as if you would choke unless you could get a drink of water.