58 PHILOSOPHICAL TRANSACTIONS. [aNNO 1673. 



it not iinfrequently happens that learned men, proceeding in their researches on 

 solid principles, though they reside in places far distant from one another, and 

 without any mutual communication or knowledge of their respective studies, 

 yet happen to light upon and discover the same things and truths ; as may 

 easily be made out by undeniable proofs in the matter of curve lines found equal 

 to straight ones; in the doctrine of motion; in the anatomy of plants, &c. And 

 having said thus much, if M. Sinclair still persists in the good opinion he has of 

 himself, we shall leave him still to enjoy it; though we think it may be much 

 sunk by this time. — In the 4th tract our author endeavours experimentally to 

 show, that, though not only the peripatetic schools, but the generality of phi- 

 losophers both ancient and modern, as well as the vulgar, ascribe the ascension 

 of lighter bodies in water to an internal principle, by them called positive levity ; 

 yet we need not admit any such thing for the true and adequate cause of the 

 emersion of wood and such lighter bodies, put under water. — In the 5th he adds 

 to the proofs, already given of the power of the spring of the air, some of the 

 operations he has discovered it to have on bodies placed under water. In doing 

 which he employs two sorts of trials, showing, that a small quantity of inclosed 

 air may by its pressure have a considerable operation on bodies covered with 

 water, notwithstanding the interposition of the liquor ; which pressure may be 

 manifested, both by what it directly and positively operates upon bodies under 

 water ; and by the things that regularly ensue upon the removal of the inclosed 

 air, or the weakening of its spring. — In the 6th and last, the author consider- 

 ing that it has proved a great impediment to men's freely acquiescing in the 

 doctrine founded on the phaenomena of his physico-mechanical experiments, 

 that if the atmosphere could really exercise so great a pressure, as he ascribes to 

 it, it would unavoidably oppress and crush all the bodies exposed to it : he 

 therefore employs in this tract divers weighty considerations and remarkable 

 experiments, to remove the force of that plausible objection. 



II. Esperienze intorno a diverse cose naturali, et particolarmente d quelle che 

 ci son portate dall' Indie; fatte da Francesco Redi. In Fir. 1671, in 4to. 



This learned author, desirous of examining many traditions about natural 

 things, begins with certain snake-stones, described by various authors, found in 

 the head of some serpents in the East Indies, and believed to be a sure antidote 

 against the biting or stinging of venomous animals, when applied to the wound, 

 to which it is said they will stick very fast, till they have imbibed the poison ; 

 which done, they will fall off: all which is invalidated by the author upon 

 many trials. 



He next takes notice of several things that produce real effects, but not 

 always, by reason of some impediments intervening. Ex. gr. That aqua-vitae 



