Q.'jQ PHILOSOPHICAL TRANSACTIONS. [aNNO I676. 



the objections of this learned author against some explications of new experi- 

 ments made by the said Mr. Boyle; which was printed in 1672, among some 

 other tracts, viz. new experiments touching the relation betwixt flame and air; 

 of the positive or relative levity of bodies under water; of the air's spring on 

 bodies under water, &c. The latter, in a discourse of gravity and gravitation, 

 grounded on experimental observations, presented to the Royal Society, printed 

 1675. These pieces being well considered, and the doctrine of hydrostatics 

 well understood and applied^ will make it easy to judge of the whole contro- 

 versy here treated of. 



END OP VOLUME TEN OF THE ORIGINAL. 



A Particular Anstver of Mr. Isaac Newton to M. Linus' s Objections to his Expe- 

 riment with the Prism, printed in N° 121, in a Letter from Cambridge, Feb, 

 29, 1675-6. N° 123, p. 556. Fol. XL 



Sir, — By reading Mr. Linus's letter, which you showed me at London, I re- 

 tained only a general remembrance, that Mr. Linus denied what I affirmed, and 

 so could lately say nothing in particular to it ; but having the opportunity to 

 read it again in N° 121 of the Transactions, I perceive he wished to persuade 

 you that the information you gave him about the experiment is as inconsistent 

 with my printed letters as with experience; and therefore, lest any who has 

 not read those letters should take my silence in this point as an acknowledgment, 

 I thought it not amiss to send you something in answer to this also. 



He tells you that, " Whereas you assure him, first, that the experiment 

 was made in clear days; secondly, that the prism was placed close to the hole, 

 so that the light had no room to diverge; and thirdly, that the image was not 

 parallel but transverse to the axis of the prism ; if these assertions be compared 

 with my relation of the experiment in N^ 80, it will evidently appear they can- 

 not be admitted, as being directly contrary to what is there delivered." His 

 reasons are these : 



First, that I said, " the ends of the long image seemed semicircular, which, 

 says he, never happens in any of the three cases abovesaid." But this is not 

 to set me at odds with myself, but with the experiment: for it is there describe 

 to happen in them all; and I still say, it does happen in them. Let others try 

 the experiment, and judge. 



Further he says, that " the prism is placed at a distance from the hole in 

 the scheme of the experiment in N° 84." But, what if it were so there ? for, 

 that is the scheme of a demonstration, not of the experiment, and would have 



