VOL. v.] PHILOSOPHICAL TRANSACTIONS. 53p 



very easy, short, and infallible way, exactly to know how much is the absolute 

 weight of the air that is impendent over any particular place. 5. With little less 

 easiness and brevity, but with the same infallibility, may be weighed any one 

 part of the said air, for example, a cubical foot. 6. The only way of measuring 

 the height of the atmosphere. 7- How it may be experimented, whether light 

 at the distance of 40 or more miles be moved in any observable time? 



These propositions have occasioned very warm disputes in Italy, where they 

 were first stated ; as may appear by what has been published against this author 

 by Signer Montanari and Signer Finetti, to which we must refer the reader. 



Extracts of two Letters, ivritten hy Mr. Adam Martindale, from Ro- 

 therton in Cheshire, Nov. 12, a?id Nov. 26, 1670, concerning the 

 Discovery of a Roc Je of Natural Salt in that Country. iV" 66, />. 2015. 



In Cheshire there has been lately found a rock of natural salt, from which 

 issues a brine stronger than any of the springs before used in our salt works. 



This rock of salt is between 33 and 34 yards distant from the surface of the 

 earth; about 30 whereof are already dug, and they hope to be at the flag, which 

 covers the salt rock, about three weeks hence. I doubt it will be several months 

 before I can accommodate you with a parcel of it; that which the auger brought 

 up being long since disposed of, and the workmen not daring to remove the 

 flag, till the frame be finished and well settled for securing the work from the 

 circumjacent earth. That parcel of natural salt, which the instrument brought 

 up, was as hard as alum, and as pure ; and when pulverized, became an excel- 

 lent, fine, and sharp salt. 



An Account given hy J. Battista Donius, a Florentine Patrician, con- 

 cerning a JVay of restoring the Salubrity of the Country about Rome, 

 Extracted from the ninth Italian Giornale de Letterati; and translated 

 as follows. N^ 66, p. 2017, 



The champagne of Rome, (which is that tract of land that is destitute of in- 

 habitants and trees, and extends itself for many miles, taking in Latium, and 

 part of the ancient Sabines and of Tuscany) would be of great use to the state, 

 and of subsistence to the people, if it could be inhabited without that great dan- 

 ger to health, which now it is so much noted and feared for, physicians judging 

 that from the summer solstice to the autumnal equinox, the air of it is so bad 

 and noxious that it would be great rashness to dwell there; a malignity which in 

 former ages it was free from, at least in that of Cicero, who, as appears by his 

 letters, lived there in the summer months, went from one place to another, 



3 Y 2 



