C ^43 J 
Juice, if it were fo corrofive as Oil of Vitriol,^ would 
certainly be injurious and painful to the falivatory Dudfs, 
which convey it to the Mouth before it is mix'd with 
the oleaginous Liquor. But I only fay it is an Acid, 
and in fome degree approaches to the Nature of that 
Oil. And Nature, which can much better adapt feveral 
Caufes for the Produdion of fuch an Effed than Art. 
may attain her End by a more temperate Acid Tho' 
at the fame time we may be able to make fome proba- 
ble and true Conjectures about the Nature of thofe Cau- 
fes from Experiments. 
It being moft reafonable to fuppofe, that there are 
but two iorts of Juices, of a different Quality , that 
make the Saliva, I do conceive, that four of the eight 
falivatory Glands, or two pair of the four, do fupply 
one of thele Juices, and the other four Glands the other. 
And this Teems to be a very good Reafon, why they are 
fo planted, and the Orifice of their Dufts fo order'd, 
that the Juice, which is fupply'd by one Gland, is dil- 
charg'd into the Mouth, very near to the Orifice, by 
which the Juice of a different Nature is tranfmitted 
from another, fo that they muft neceflarily meet and 
mix together. Thus the Glam/ula Nuckia^a^ and the 
Faretides, throw in two different Juices by Orifices, 
which open into the Mouth very near to one another ; 
and the GlanduU Maxillares interna^ and Sublinguales^ 
do below fupply the fame kind of Juices by Orifices, 
that open fo near to one another as to fecure the Mix- 
ture of the two different Juices. 
Thefe Glands, I fay, do between them afford two 
diverfe forts of Liquors, of fuch a Nature as are apt to 
ferment upon their firfl Mixture, but perhaps more con- 
fiderably when they come to be digefled by the Heat of 
the Stomack. So that the Collu<aation, or Fermenta- 
tion, which attenuates and concods the Food in the 
N n X Stomackj 
