404 PHILOSOPHICAL TRANSACTIONS. [annOISQ^. 



to make the saliva; but, that there are only two different juices that constitute 

 it. I think one of these to be an acid juice, the other an oleaginous liquor, 

 something like oil of turpentine. For among the many experiments I have 

 made, there was no one that gave me so much satisfaction as that which I made 

 with oil of turpentine and oil of vitriol, though I tried several other things that 

 will produce a fermentation on their mixture. And it was for this reason that I 

 made the experiment with oil of turpentine and the other oil. 



I took a piece of raw flesh, and having cut it into pieces, but much larger 

 than what our more solid food is reduced to by due mastication, and mixed 

 some crums of bread with it, I then poured in the oil of turpentine to them, 

 and upon that the oil of vitriol, and having shaken them together, I digested 

 them about four hours in balneo mariae, and then shaking them again in the 

 glass, I found the meat dissolved, and they all became a thickish pulp. I could 

 not but take notice, that oil of camphire, though it does not otherwise seem 

 very different in its nature from oil of turpentine, and oil of vitriol, being mixed 

 together, produce an effervescence as well as the oil of turpentine and oil of 

 vitriol, yet did not touch the meat upon which I poured them, so as in the 

 least to dissolve it. I cannot deny but that an acid and a solution of salt 

 of tartar dissolved some part of the flesh- meat which I mixed them with, but 

 yet neither so soon nor so perfectly as the two forementioned oils. And I 

 rather think one of those juices which constitute the saliva to be of the nature 

 of oil of turpentine, than of a fixed salt, because it will correct and temper 

 even oil of vitriol, so as to render it more tolerable to the fibres of the stomach. 



I conceive that four of the eight salivary glands, or two pair of the four, 

 supply one of these juices, and the other four glands the other. And this 

 seems to be a very good reason why they are so planted and the orifice of their 

 ducts so ordered, that the juice which is supplied by one gland is discharged 

 into the mouth, very near to the orifice by which the juice of a different na- 

 ture is transmitted from another, so that they must necessarily meet and mix 

 together. Thus the glandulae nuckianse and the parotides throw in two differ- 

 ent juices, by orifices which open into the mouth very near each other; and the 

 glandulae maxillares internae and sublinguals below supply the same kind of 

 juices by orifices that open so near to each other as to secure the mixture of 

 the two different juices. These glands then between them afford two sorts of 

 liquors, of such a nature as are apt to ferment on their first mixture, but per- 

 haps more considerably when they come to be digested by the heat of the sto- 

 mach. So that the colluctation or fermentation which attenuates and concocts 

 the food in the stomach does not commonly arise between the aliment and the 

 saliva, but between the several parts of the saliva itself. And indeed if the 



