YOL. XIV.] PHILOSOPHICAL TRANSACTIONS. 5 



stamina, and in others, the several steps and progresses toward a perfect figura- 

 tion, which seems to me an unanswerable argument, for their never having been 

 the spoils of animals. Some of these appeared in the inner side white, and it 

 came off on the fingers like chalk, and seemed as if a depression had been first 

 made in the bed, of the shape of a valve, and then the convex side rubbed with 

 chalk or painted white. 



The shelly matter having been decomposed and obliterated, nothing remained 

 but the casts or hardened matter with which the shells had been filled. 



The imperfect as well as the complete formation of some of the bivalvular 

 kind (the valves being only found single, and both sorts in a ground never 

 heretofore disturbed) are no light argument for their being stones. But by 

 what means they receive this likeness to shells, is hard to determine. There 

 can be no convincing argument given, why the salts of plants, or animal bodies, 

 washed down with rains, and lodged under groimd, should not there be dis- 

 posed into such like figures, as well as above it : probably in some cases much 

 better, as in a colder place; and where, therefore, the work not being done in 

 a hurry, but more slowl} may be so much the more regular. 



Raphaelis Falretti Urhinatis de Aquis et Aquccductihus Ceteris Romce Disserla- 

 tiones tres. In Quarto. Roma, ]680. N° 155, p. 466. 



This book describes the ancient aqueducts of Rome, and occasionally notices 

 the relation between the ancient and the modern Roman measures of length, as 

 the foot, the mile, &c. 



0?^ the Doctrine of Sounds. By Narcissus, Lord Bishop of Ferns and Leighlin. 



N° 156, p. 472. 



There is perhaps no better way of showing the usefulness of the theory of 

 sounds, than by making a comparison between the faculties of hearing and 

 seeing, as to their improvements, &c. In order to which, it is to be observed, 

 that vision is threefold, direct, refracted, and reflected ; answerable to which, 

 we have optics, dioptrics, and catoptrics. In like manner hearing may be 

 divided into direct, refracted, and reflected; to which correspond the three 

 parts of the docrine of acoustics ; which are yet nameless, unless we call them 

 acoustics, diacoustics, and catacoustics, or phonics, diaphonics, and cataphonics. 



Direct vision has been improved two ways. 1. As to the object, by the arts 

 of producing, conserving and imitating light and colours, which are the objects 

 of vision. 2. With respect to the organ or medium, by making use of a tube, 

 without glasses, or a man's closed hand, to look through. So likewise direct 



