20 PHILOSOPHICAL TRANSACTIONS. [aNNO 1665. 



that the author has doubted, whether the sense could discern a cold body, other- 

 wise then by immediate contact. Where several experiments are delivered for 

 the examining of this matter, together with a curious relation of the way used 

 in Persia, though a very hot climate, to furnish their conservatories with solid 

 pieces of ice of a considerable thickness : To which is added an observation, 

 how far in earth and water the frost will pierce downwards, and upon what 

 accounts the depth of the frost may vary. After which, the care is inculcated 

 that must be had in examining, whether cold may be diffused through all 

 mediums indefinitely, not to make the trials with mediums of too great thick- 

 ness : where it is made to appear, that cold is able to operate through metalline 

 vessels, which is confirmed by a very pretty experiment of making icy cups to 

 drink in ; the way of which is accurately set down. Then are related the trials, 

 whether, or how, cold will be diffused through a medium that some would 

 think a vacuum, and which to others would seem much less disposed to assist the 

 diffusion of cold than common air itself. After which follows a curious experi- 

 ment, shewing whether a cold body can operate through a medium actually hot, 

 and having its heat continually renewed by a fountain of heat. 



12. How to estimate the solidity of the body of ice, or how strong is the 

 mutual adhesion of its parts ; and whether differing degrees of cold may not vary 

 the degree of the compactness of ice. And our author having proceeded as far 

 as he was able towards the bringing tlie strength of ice to some estimate by 

 several experiments, he communicates the information he could get about this 

 matter, among the descriptions that are given us of cold regions : and then he 

 relates, out of seamen's journals, their observations touching the insipidness of 

 resolved ice made of sea-water ; and the prodigious magnitude of it, extending 

 even to the height of two hundred and forty feet above water, and the length of 

 above eight leagues. To which he adds some promiscuous, but very notable 

 observations, concerning ice, not so readily reducible to the foregoing heads : 

 viz. Of the blue colour of rocky pieces of ice ; and the horrid noise made by the 

 breaking of ice, like that of thunder and earthquakes, " together with a con- 

 sideration of the cause whence those loud ruptures may proceed. 



13. How ice and snow may be made to last long; and what liquor dissolves 

 ice sooner than others, and in what proportion of quickness the solutions in the 

 several liquors are made: where occasion is offered to the author to examine, 

 whether motion will impart a heat to ice ? After which, he relates an experiment 

 of heating a cold liquor with ice, made by himself in the presence of a great and 

 learned nobleman, and his lady, who found the glass, wherein the liquor was, so 

 hot that they could not endure to hold it in their hands. Next it is examined, 

 whether the effects of cold do continually depend upon the actual presence and 



