Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/402

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
Dialogue. III.
375

he likewise granteth to mixt bodies compound motions by——

Sagr.Stay a little, Simplicius, & answer me to the questions I shall ask you.Aristole grants a compound motion to mixt bodies. You say that the Load-stone is no simple body, now I desire you to tell me what those simple bodies are, that mingle in composing the Load-stone.

Simpl.I know not how to tell you th'ingredients nor simples precisely, but it sufficeth that they are things elementary.

Salv.So much sufficeth me also. And of these simple elementary bodies, what are the natural motions?

Simpl.They are the two right and simple motions, sursum and deorsum.

Sagr.Tell me in the next place? Do you believe that the motion, that shall remain natural to that same mixed body, should be one that may result from the composition of the two simple natural motions of the simple bodies compounding, or that it may be a motion impossible to be composed of them.The motion of mixt bodies ought to be such as may result from the composition of the motions of the simple bodies compounding.

Simpl.I believe that it shall move with the motion resulting from the composition of the motions of the simple bodies compounding, and that with a motion impossible to be composed of these, it is impossible that it should move.

Sagr.But, Simplicius, with two right and simple motions, you shall never be able to compose a circular motion, such as are the two, or three circular motions that the magnet hath: you see then into what absurdities evil grounded Principles, or, to say better,With two right motions one cannot compose circular motions. the ill-inferred consequences of good Principles carry a man; for you are now forced to say, that the Magnet is a mixture compounded of substances elementary and cœlestial, if you will maintain that the straight motion is a peculiar to the Elements, and the circular to the cœlestial bodies. Therefore if you will more safely argue, you must say, that of the integral bodies of the Universe, those that are by nature moveable, do all move circularly, and that therefore the Magnet, as a part of the true primary,Philosophers are forced to confesse that the Magnet is compounded of cœlestial substances, and of elementary. and integral substance of our Globe, pertaketh of the same qualities with it. The errour of those who call the Magnet a mixt body, and the terrestrial Globe a simble body.And take notice of this your fallacy, in calling the Magnet a mixt body, and the Terrestrial Globe a simple body, which is sensibly perceived to be a thousand times more compound: for, besides that it containeth an hundred an hundred matters, exceeding different from one another, it containeth great abundance of this which you call mixt, I mean of the Load-stone. This seems to me just as if one should call bread a mixt body, and * Ogliopotrida a Spanish dish of many ingredients boild together. Pannada a simple body, in which there is put no small quantity of bread, besides many other things edible. This seemeth to me a very admirable thing, amongst others

of