20

ON COMPOUND BODIES.

more particularly examine those that are the mostessential.

This class of bodies was formerly divided intomineral, vegetable, and animal acids, according tothe substances from which they were commonlyobtained. •

CAROLINE.

That I should think must have been an excellentarrangement; why was it altered ?

mbs. n.

Because in many cases it produced confusion,In which class, for instance, would you place car-bonic acid ?

CAROLINE.

Now I sec the difficulty. I should be at a lostwhere to place it, as you have told us that it existsin the animal, vegetable, and mineral kingdoms.

EMILV.

There would be the same objection with respectto phosphoric acid, which, though obtained chieflyfrom bones, can also, you said, lie found in smallquantities in stones, and likewise in some plants.

MRS. B.

You see, therefore, the propriety of changing thismode of classification. These objections do notexist in the present nomenclature; for the compo-