VOL. XI.] PHILOSOPHICAL TRANSACTIONS. 3/1 



bubbles appeared at the top of the liquor, and made there a copious froth, many 

 of them being, by reason of the viscosity of the fluid, very large, and divers ot 

 them, because of the nature and texture of it and the thinness of the films, 

 exhibiting the colours of the rainbow. When this substance had resumed its 

 consistent form, there were intercepted between the upper and the lower sur- 

 faces of it, some large bubbles which had a considerable reflection. 



Water being so considerable a body here below, I thought it would be worth 

 while to endeavour to observe its surface when contiguous to other fluids than 

 air, and if possible, when surrounded by them. For though it is taken for 

 granted, that the falling drops of rain are spherical, yet their descent is so swift, 

 both by reason of their gravity in respect of the air, and the height from whence 

 they fall, that I fear men have rather supposed than observed that their figure is 

 spherical ; which will be the more questionable, if it be true, which is com- 

 monly thought, that hail is but rain frozen in its passage through the air. Now 

 the surface of water may have different figures, according as it is totally incom- 

 passed with heterogeneous fluids, or, as it is only in some places contiguous to 

 one or more of them. In the former case it is not easy to make an observation, 

 because there are not any two liquors that will not mingle either with one 

 another or with water. Having cautiously therefore conveyed into some oil of 

 cloves, some portions of common water of different sizes, taking care as far as 

 we could, that they might not touch one another; by which means, the oil be- 

 ing transparent, and yet a little coloured, it was easy to observe, that the smaller 

 portions of water were so near totally environed with the oil, that they were 

 reduced into almost perfect globes ; those portions that were somewhat larger, 

 as about twice the size of a pea, would be of a figure somewhat approaching to 

 that of an ellipsis ; and those portions that were yet somewhat larger, though 

 they seemed to be sunk almost totally beneath the oil, yet they held to it by a 

 small portion of themselves, and their surface was easily enough distinguishable 

 from that of the oil. These larger portions of immersed water, being almost 

 wholly environed with the other liquor, were by it reduced into a round figure, 

 which was commonly somewhat elliptical, but more depressed in the middle 

 than that figure requires. But all this is to be understood of those portions of 

 water, that touched only the oil and the air: for those that touched each other 

 without mingling, and much more those that adhered more or less to the sides 

 of the glass, had their surfaces too differingly and irregularly figured to be here 

 attempted to be described. 



Having put into a slender pipe a little oil of cloves, and upon this some oil of 

 turpentine, that so the water might both above and beneath be touched by hete- 

 rogeneous liquors, the oil of cloves was not manifestly tumid at the top, nor the 



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