270 PHILOSOPHICAL TRANSACTIONS. [aNNO 1705. 



tions another like particle sprouts, and out of the second several others, but all 

 of them very short. To conceive this, I have represented a small particle of 

 sponge as it appeared through a microscope, in fig. 6, which I pared off a 

 sponge, as thin and as small as possible; where the parts of the sponge are 

 shown coming one out of the other, and then united together again; and 

 though we cannot conceive how the sponge grows larger, yet we may see that 

 this is the manner of its increasing. 



For suppose that the parts broken off, at kl or mn, grows out so far that 

 they come to touch one another, and to join, new parts will grow out of them, 

 and unite themselves again, as we may see in the dissection of this small parti- 

 cle of sponge, which is wholly formed after this manner. 



Concerning a large Ball voided by Stool. By Mr. Ra, Thoresbi/, F.R.S. 



N° 304, p. 2164. 



Madame C — ly voided a ball, after such severe pains that her life was in 

 danger, but she is not willing to have it cut, and the bulk of it is much short 

 of what I can now give you an account of from another hand; but this may 

 serve as a further instance of the danger of swallowing the stones of fruit, for 

 immediately after, she voided several plum-stones, though she had not for a 

 twelve month before eaten any of that fruit. Captain West told me he had 

 once seen two stones voided by a neighbour, larger than any of those three 

 formerly mentioned in N° 281 and 282: he has since procured them for me, 

 and the lesser of them somewhat exceeds the largest of the others ; the form 

 of it is not much unlike the echinus shell, or helmet stone, flat on one side, 

 and roundish on the other; it is above 6 inches one way, and 7 the other, in 

 circumference. They weighed 9 ounces when first evacuated, and were voided 

 by diet drink with an alkali powder, and a magistral stomach-plaster. The 

 person died 7 years after, of one that was too large to be voided; for on 

 griping it, between the hypochondria and share-bone, it felt to be as large 

 as a goose's egg. 



Experiments on the Attrition of Bodies in Vacuo \ made at Gresham College. 

 By Mr. Fr. Hauksbee, F.R.S. N° 304, p. 21 65. 



A description of the machine for giving a swift motion to bodies in vacuo, 

 without admitting the external air, represented in fig. 22, pi. 8. — aa is a step- 

 ladder, such as is commonly used in houses; bb a bar of iron passing through 

 the middle of the upper step, and is fastened to the back board of the ladder 

 by 2 nuts and screws, through both the board and iron ; c c the jaws of the 



