372 PHILOSOPHICAL TRANSACTIONS. [anNO 1676-7. 



lower surface of the oil of turpentine, for the upper was concave, very convex; 

 for somewhat convex it was downwards. And from this it will be easy to con- 

 clude the figure of the cylindrical portion of water intercepted between these 

 two oils. 



Having taken oil of aniseeds, thawed by a gentle warmth, and common water, 

 and having put them together in a conveniently shaped glass, they were suffered 

 to stand in a cold place till the oil was coagulated ; which done, it was parted 

 from the water, and by the roughness of its superficies, showed that when its 

 parts were no longer agitated, or whatever other agent or cause it were, to 

 which it owed its fluidity, then the contiguous water grew unable to inflect, or 

 otherwise place them after the manner requisite to constitute a smooth surface. 

 And what happened to that part of the oil's surface that was touched by the 

 water, happened also to that which was contiguous to the air; save that the as- 

 perity of the last surface was differing from the other. But I have often observed, 

 that the upper surface of the oil of aniseeds, when this liquor comes to be coa- 

 gulated by the cold air, was far from smooth, being variously asperated by many 

 fiaky particles, some of which lay with their broad, and others with their edged 

 parts upwards. 



An inequality and ruggedness of superficies I have also observed in water, on 

 covering it with chemical oil of juniper, and exposing it in very cold weather; 

 though the oil continued fluid, yet the water, being frozen, had no longer a 

 smooth superficies, as when in its liquid state it was contiguous to the oil. And 

 the like inequality, or rather a greater, we observed in the surface of water 

 frozen, which had chemical oil of turpentine swimming on it; yet a no less, if 

 not a much greater roughness, may be often observed in the surfaces of 

 divers liquors that abound with water, when those liquors being frozen, their 

 surfaces have an immediate contact with the air. I shall here add, that having 

 purposely caused a strong and blood red decoction of the soot of wood to be 

 exposed in a large glass, in a very cold night, I was more pleased than surprised, 

 to find in the morning a cake of ice, curiously figured, being full of large flakes, 

 shaped almost like the broad blades of daggers, but neatly fringed at the edges. 

 And these figures seemed to be as it were imbossed, being both to the eye and 

 the touch raised above the horizontal plain or level of the other ice. 



This may be observed in the best sort of what the chemists call regulus martis 

 stellatus, where the figure of a star, or a figure somewhat like that of the decoc- 

 tion of soot lately mentioned, will frequently appear embossed on the upper 

 superficies of the regulus ; and such a raised figure I have on a mass of regulus 

 made of antimony without mars. But if to those two bodies copper be also 

 skilfully added, the superficies will be often adorned with new figures according 



