1S6 PHILOSOPHICAL TRANSACTIONS. [anNO 1745. 



trine. Their doctrine is, that equal springs, equally bent, will, by unbending 

 themselves, give equal moving forces to the bodies they act on, whatever those 

 bodies are. We agree to this, not generally indeed, but in the case before us, 

 where the bodies are of equal masses or weights, we agree to it. 



Let us therefore imagine the bent spring, which is pjaced between the two 

 bodies, to be divided transversely into two equal parts. In this case it is plain, 

 that the two halves of the spring may be considered as two entire springs, equal, 

 and equally bent, each of which rests at one end in equilibrio against the other 

 spring, and at the opposite end presses against the body it is to move. Conse- 

 quently, by the Leibnitian doctrine, to which, in this particular case, where the 

 bodies are equal, we also agree, the two springs will give equal moving forces to 

 the two bodies. 



But the moving force received by the hindmost body from the hinder spring, 

 was undoubtedly the moving force 1 : for by that force given it in the direction 

 backward, the moving force 1 , which it had before from the motion of the plane 

 in the direction forward, is exactly balanced and destroyed, the body remaining, 

 as was observed before, in absolute rest. Therefore the moving force received by 

 the foremost body, from the foremost spring, was also the moving force 1 . And 

 this, added to the other moving force 1 , which it had before from the motion of 

 the plane, makes the moving force 2, and not the moving force 4, as the Leib- 

 nitian philosophers pretend. 



Consequently, that body, which had before the velocity 1, and the moving 

 force 1, and now has the velocity 2, has also the moving force 2: that is, the 

 moving forces are proportional to the velocities. 



Observations on Luminous Emanations from Human Bodies, and from Brutes', 



with some Remarks on Electricity. By the Rev. Henry Miles, D.D. and F.R.S. 



N°476, p. 441. 



In the late edition of the works of Mr. Boyle, vol. 5, p. 646, is a letter from 

 Mr. Clayton, dated June 23, l684, at James city in Virginia; in which he gives. 

 Mr. Boyle an account of a strange accident, as he calls it, and adds, that he had 

 inclosed the very paper Colonel Digges gave him of it, under his own hand and 

 name, to attest the truth ; and that the same was also asserted to him by Madam 

 DiggevS, his lady, sister to the wife of Major Sewall, and daughter of the 

 Lord Baltimore, to whom this accident happened. This paper came not to 

 hand till after Mr. Boyle's works were printed, and therefore could not be inserted 

 with Mr. Clayton's letter, but having since met with it, the following copy of it 

 is here inserted. 



" There happened in Maryland, about the month of November l683, to one 

 Mrs. Susanna Sewall, wife to Major Nic. Sewall, of the province aforesaid, n 



