554 PHILOSOPHICAL TRANSACTIONS. [aNNO I67I', 



least body may move the greatest body ? Whether the force of percussion be a 

 certain action of compression in the impellent body? What are the laws of two 

 projected bodies ; equal or unequal ; of equal or unequal velocity ? Whether 

 the times of the vibrations of different pendulums are in a subduplicate pro- 

 portion of their lengths ? Whether a body impelled, being reflected by a 

 springy and compressed body, restoring itself, be moved and carried back with 

 that impetus only which it received from the same ? Whether a body hori- 

 zontally projected will at the same time come to the ground, as if it had of 

 itself fallen down perpendicularly ? Why JDricks are broken by the percussions 

 of a hammer, though they remain whole under the weight of a vast and bulky 

 body ? And why a hatchet cleaves wood, whereas a very heavy weight laid 

 on a hatchet fixed in wood, does not ? What is the principle of the motion of 

 restitution ? and many more. Against the third he writes, about the ascent of 

 liquors in slender tubes ; to wit, whether that rising proceeds from the gravi- 

 tation of the air, or from its compression only, prescinded from its weight ? 

 Whether liquors do rise equally high, in longer and shorter tubes, but of 

 equal bore ? &c. 



V. Antonii Molinetti, Phil, et Med. Veneti, &c. Dissertationes Anatomicae 

 et Pathologicse de Sensibus et eorum Organis. Patavii, 1669, in 4to. 



Upon the subjects treated of in this work there is nothing sufficiently inte- 

 resting to be extracted. 



Extract of a Letter from Mr. John Ray, Jan. 13, I67O, concerning 

 some uncommon Observations and Experiments made ivith an Acid 

 Juice found in Jnts.* N' 68, p. 2063. 



What I now send you concerning the juice of ants, I received not long since 

 from Dr. Hulse and Mr. Samuel Fisher. The observations by Mr. Hulse 



• From the experiments of Neumann and others, it appears that the acid of ants has a great ana- 

 logy with that of vinegar, though in some respects it is different. It dissolves with great effervescence 

 coral, chalk, and quicklime, and concretes with them all into crystals, which do not deliquate in the 

 air. It does not precipitate silver, lead, or mercury, from the nitrous acid, nor quicklime from the 

 marine} hence it appears to have no analogy with the marine or vitriolic acids, the first of which con- 

 stantly precipitates the metallic solutions, and the otlier the earthy. It does not act upon filings of 

 silver, but, like vegetable acids, it totally dissolves, by the assistance of heat, the calx of silver pre- 

 cipitated from aquafortis by salt of tartar. It does not dissolve calces of mercury, as vegetable acids 

 do, but revives tliem into running quicksilver. It acts very weakly on filings of copper, but perfectly 

 dissolves copper that has been calcined} the solution yields beautiful compact green crystals. It dis- 

 solves iron filings with violence} the solution, duly evaporated, shoots into crystals more readily than 

 that made in distilled vinegar. It scarcely acts at all upon filings of tin. It does not, according to 

 Margraaf, corrode filings of lead, but dissolves, by the assistance of heat, the red calx of lead. It 



