A little further experience teaches the young animal to suck by absorption, as well as by compression; that is, to open the chest as in the beginning of respiration, and thus to rarefy the air in the mouth, that the pressure of the denser external atmosphere may contribute to force out the milk.

The chick yet in the shell has learnt to drink by swallowing a part of the white of the egg for its food; but not having experienced how to take up and swallow solid seeds, or grains, is either taught by the felicitous industry of its mother; or by many repeated attempts is enabled at length to distinguish and to swallow this kind of nutriment.

And puppies, though they know how to suck like other animals from their previous experience in swallowing, and in respiration; yet are they long in acquiring the art of lapping with their tongues, which from the flaccidity of their cheeks, and length of their mouths, is afterwards a more convenient way for them to take in water.

V. The senses of smell and taste in many other animals greatly excel those of mankind, for in civilized society, as our victuals are generally prepared by others, and are adulterated with salt, spice, oil, and empyreuma, we do not hesitate about eating whatever is set before us, and neglect to cultivate these senses:  whereas other animals try every morsel by the smell, before they take it into their mouths, and by the taste before they swallow it:  and are led not only each to his proper nourishment by this organ of sense, but it also at a maturer age directs them in the gratification of their appetite of love.  Which may be further understood by considering the sympathies of these parts described in Class IV. 2. 1. 7.  While the human animal is directed to the object of his love by his sense of beauty, as mentioned in No.  VI. of this Section.  Thus Virgil.  Georg.  III. 250.

  Nonne vides, ut tota tremor pertentat equorum
  Corpora, si tantum notas odor attulit auras? 
  Nonne canis nidum veneris nasutus odore
  Quaerit, et erranti trahitur sublambere lingua? 
  Respuit at gustum cupidus, labiisque retractis
  Elevat os, trepidansque novis impellitur aestris
  Inserit et vivum felici vomere semen.—­
  Quam tenui filo caecos adnectit amores
  Docta Venus, vitaeque monet renovare favillam!—­ANON.

The following curious experiment is related by Galen.  “On dissecting a goat great with young I found a brisk embryon, and having detached it from the matrix, and snatching it away before it saw its dam, I brought it into a certain room, where there were many vessels, some filled with wine, others with oil, some with honey, others with milk, or some other liquor; and in others were grains and fruits; we first observed the young animal get upon its feet, and walk; then it shook itself, and afterwards scratched its side with one of its feet:  then we saw it smelling to every one of these things, that were set in the room; and when it had smelt to them all, it drank up the milk.”  L. 6. de locis. cap. 6.