VOL. XLVII.] PHILOSOPHICAL TRANSACTIONS. 131 



&C. &C. 



Whence, making 



suming A + Bar + cr' + dt^ + E'^*> &c. to express the series sought, the several 

 values of a, b, c, d, &c. will be exhibited by the very equations brought out in 

 the resolution of the preceding problem. 



F", On the Use of the Bark in the Small-pox. By Geo. Bayly, M. D., p. 27. 



An account is here given of a gentlewoman of a fat, corpulent habit, who at 

 the age of 73 had the small-pox in the natural way. During the first 3 days of 

 the eruption the patient went on well ; but on the 8th day the pustules were at a 

 stand ; they sunk in, and her life was despaired of. At this period Dr. B. di- 

 rected blisters to be applied to the legs, and prescribed 3SS. of the powder of 

 Peruvian bark, and a few grains of serpent. Virginiana every 3 hours ; by the 

 use of which the pustules were made to rise and brought to a maturation. The 

 bark and serpentaria were afterwards given in decoction. By a long continuance 

 of these medicines (with the use of the lancet once, and with the help of occa- 

 sional purges) the patient was restored to health. 



To this is subjoined the case of a healthy young man, who, in July 1 746, 

 had the small-pox by inoculation. The eruption came on at the right time ; but, 

 3 or 4 days after, in dressing the incisions, 3 or 4 purple spots were observed 

 about them, which occasioned Dr. B.'s being called in. The pustules, which 

 were very numerous, were here and there livid, and in the arms and thighs of a 

 dark colour, tending towards a mortification. He immediately prescribed 353. of 

 bark to be given, and repeated once in 3 hours ; which was accordingly done 

 for 1 1 days successively ; during which time he took 47 doses of bark, viz. in 

 all, 3 oz. wanting -i- a dr. 



VI. A Method of v\,aking Artificial Magnets without the Use of, and yet far su- 

 perior to, any Natural ones. By John Canton,* M. A., andF. R. S. p. 31. 



Procure a dozen bars ; 6 of soft steel, each 3 inches long, one quarter of an 



* Mr. Canton, a very ingenious natural pliilosopher, was born at Stroud, in Gloucestershire, 

 17I8; where his father, a broadcloth weaver, at a proper age put him to learn his own business. 

 But young C. having at school acquired some knowledge in the elementary branches of mathematics, 

 and a taste for philosophical subjects, he spent his time by stealth in reading books of that kind. 

 His singular habits and early acquirements procured him the notice of several learned men, and 

 among others the Rev. Dr. Henry Miles of Tooting, who prevailed on the father to permit the 

 young man to come up to London to try his fortune there ; which he accordingly did in 1737, when 



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