3^0 PHILOSOPHICAL TRANSACTIONS. [anNO 1676'7. 



good remedies; and proposes what trades are proper to be advanced in the 

 several parts of England ; how to be there advanced ; and what the peculiar con- 

 veniences. 



Thus he runs through all the intrigues of trade, noting the secret abuses and 

 obstacles; and offering genuine remedies, confirmed by the experience of 

 foreign nations, large territories and principalities. 



^ Continuation of Mr. Boyle's Experiments published in the last Number of the 



Transactions. N° 132, p. 799- 



On pouring into a slender phial, more than half filled with common water, 

 that had been a little warmed, a little essential oil of aniseeds, its upper surface 

 became somewhat concave, as that of the water was; but the lower surface sur- 

 rounded by the water was very convex, appearing almost of the figure of a large 

 portion of a sphere. This being done, the phial was stopped, and suffered to rest 

 for some time in a cold place, by which means the water continuing fluid as be- 

 fore, the oil of aniseeds was found coagulated in a form approaching to that it 

 had whilst in a fluid state. 



And it was worth observing, how great a difference there was between the 

 dull reflection it made when it was coagulated, and the fine reflection it had 

 made whilst fluid. The latter of which reflections brought into my mind, how 

 vivid the reflective power of some fluids is, in comparison of that of the genera- 

 lity of solid bodies, of which there is scarcely any, if there be any at all, that is 

 observed to have a stronger reflection than clean quicksilver ; and yet I have 

 sometimes found, that even this may be increased by the addition of a liquor. 

 For having observed that quicksilver and rectified petre oleum are, the former 

 of them the heaviest, and the latter the lightest of all the visible fluids ; and 

 having also observed the latter of them to be considerably reflective, I had the 

 curiosity to try among other things that related to them, the following experi- 

 ment. Some distilled quicksilver being put into a small phial, and held in such 

 a posture, that the incident light was strongly reflected to my eye, I slowly put 

 to it some petroleum, which being well rectified was very clear ; and observed, 

 that as this liquor covered the quicksilver, there was at the imaginary plain 

 where they both met, a brisker reflection than the quicksilver alone had given 

 before. 



On putting a competent quantity of a resinous or gummy substance, that 

 looked like high coloured amber, but was easy to melt, into a deep round glass 

 with a wide mouth, and holding it by the fire in a moderate warmth, till it was 

 brought to a fluid state; we then transferred it into a pneumatical receiver, and 

 having caused the air to be pumped out by degrees, we found that store of 



