432 PHILOSOPHICAL TRANSACTIONS. [anNO I76O. 



are to be preferred in medical intentions, whenever the strongest of the chaly 

 beates are required, and can be borne; he here, from facts and observations 

 made on the several waters of this sort, which had fallen under his notice, gives 

 a short sketch of their general operation and good effects, as a foundation for fur- 

 ther improvements. 



These waters, then, generally operate as an emetic or cathartic, or both ; and 

 have recommended themselves, in external and internal use, as a powerful deter- 

 gent, repelling, bracing, styptic, cicatrizing, antiscorbutic, and deobstruent 

 medicine, as has appeared by the notable cures they have effected, not only by 

 external use in inveterate ulcers, the itch, mange, scab, tetterous eruptions, 

 scald head, and sore eyes; but also by internal use in hot tetterous eruptions, 

 dysenteries, internal haemorrhages, in gleets, the fluor albus, and diarrhoea, in 

 the worms, agues, dropsies, and jaundice. 



Such has been the success, that has not unfrequently crowned the empirical 

 use of these waters; which, though in some of these cases, it might undoubt- 

 edly have been better conducted in the hands of the prudent physician, may 

 however suffice to convince us, that the vitriolic waters are a branch of the ma- 

 teria medica, not to be despised nor overlooked, in the cure of many stubborn 

 chronical diseases. 



XL VI. An Account of that Part of America, which is nearest to the Land of 

 Kamtchatka; extracted from the Description of Kamtchatka by Professor 

 Krashennicoffj 2 vols. 4to. Petersburg, 1759. p. ATJ. 



As accounts (and some of them taken from later navigators) of the part of 

 America here mentioned, are to be found in every modern system of geography, 

 it was deemed unnecessary to reprint this paper. 



XLT n. Remarks on the Mutations of the Stars. By Tho. Barker, Esq. of 



Lyndon, in Rutland, p. 498. 

 It is well known that there have been several alterations among the fixed stars: 

 for instance, Ptolemy's ultima fluvii, a first magnitude star, is in Dr. Halley's 

 catalogue of the southern constellations only a 3d magnitude: and in much less 

 time, the $ of the Great Bear, which Bayer seems to have judged just of the 

 same size with the other 6, is become far duller than any of them. Some stars 

 also have quite disappeared, while again new ones, not seen before, have been 

 discovered; and there are others periodically larger and smaller. Two very re- 

 markably bright, yet short-lived stars, have been also seen, one in Cassiopea, 

 the other in Serpentarius ; which breaking out at once, with greater lustre than 

 any other fixed star, gradually faded, and changing to different colours, in about 

 a year and half were no longer visible. But no one has yet remarked that any 

 lasting star was of a different colour in different ages; Greaves, on the contrary, 



