a76 PHILOSOPHICAL TRANSACTIONS. [aNNO 1705. 



glaze, on the outside of a glass, adds any thing to the light ; having produced 

 the same by a glass much worn by often using. 



I have repeated the same experiment about noon in a clear day ; and the 

 success was, that the light produced in vacuo was then as sensible to sight, as 

 a piece of red hot glass of the same size, at the same time, would have appeared 

 in the open air. But though the appearance is such, it is> no longer so than 

 the motion is continued. Hence it is to be observed, that though it seems to 

 be of the colour of red hot or melted glass, yet it is not really so ; for if it 

 were, it must of necessity some small time outlive the motion ; which in the 

 darkest night I could never yet discover. 



£xP£R. V. On the Production of Light by the Attrition of Glass on Glass 

 under Water. — This experiment was nothing more than a repetition of the last ; 

 saving only, that the included apparatus was entirely covered with water ; from 

 the surface of which, when the air came to be withdrawn, and the great wheel 

 turned as usual, it was easy to discover a pretty smart light, on the first motion 

 of the included glass globe against the tubes, illuminating the whole body of 

 the water. The parts of the tubes, where the friction was made by the globe, 

 were distinguishably red; but soon lessened in their appearance, and in a little 

 time extinguished ; the water, by the continuance of the motion, approaching. 

 nearer and nearer to the colour of whey ; and at last became so thick, by the 

 grit or powder produced by the attrition of the glasses, that the light could 

 then be but just discovered through the body of it, and that not constantly, 

 but like faint flashes at a distance. This experiment I have made, when it has 

 succeeded so as to appear more luminous than at this trial. I have observed the 

 dust, produced from the glasses by their attrition, through a good microscope, 

 but could not discover, by the greatest attention, that the parts were any ways 

 melted; only they appeared of a long and slender figure. 



Of a Puppy in the Matrix that received no Nourishment by the Mouth. By 

 Mr. Samuel Brady. N*' 304, p. 21 76. 



In a conversation held about the nourishment of the foetus in the womb, in 

 which we seemed to agree that it was performed by the umbilical vessels only, 

 without the assistance of the mouth, I mentioned a puppy at its full growth, 

 which could never have received any nourishment this latter way. It had no 

 appearance of a mouth at all, and lived some time after it was whelped ; pulling 

 the skin off its head, there was not the least passage through it; the head was one 

 solid bone, without sutures, somewhat round like a man's skull, with a little 

 prominence on the fore-part, resembling the os nasi of a man, but without any 

 aperture. It had no place for eyes, nor meatus for ears, only the outward re- 



