VOL. XXI.] PHILOSOPHICAL TRANSACTIONS. 427 



Of the Ongi?i of JVhite Vitriol and the Figure of its Crystals. By Dr. Alartin 



Lister, F.R.S. N° 236, p. 331. 



Among the desiderata, relating to fossil salts, the origin of white vitriol is 

 obscure, and its crystals undescribed. All I can find of this matter is, out of 

 Borrichius de Docimastice Metallica, that it is produced from a certain lead ore 

 boiled raw. None that I know of, of our English lead ores, gives us any suspi- 

 cion of any such vitriol. It is true I have by me some sorts of white lead ore, 

 spar-like, plentifully yielding lead : but I cannot say that either those or any 

 coloured lead ores gave me any reason to suspect, after diverse experiments upon 

 them, that they yielded white vitriol. 



As to the crystals of white vitriol, they are very difficult to describe, and 

 seem to be a congeries of infinitely small needles ; for which reason it is of a 

 most speedy operation, and irritates the stomach suddenly, before they can be 

 well dissolved or broken.* 



On the Cures performed by Mr. Greatrix, the Stroher. By Mr, Thoresby, 



F.R.S. N°256, p. 332. 



The first instance I shall mention of his cures was my brother John D — n, 

 who was seized with a violent pain in his head and back when about 14 years of 

 age; one of my sisters at that time had the small-pox, and my motherjudging that 

 he was taken with the same distemper, used no means to remove if, till by ac- 

 cident Mr. Greatrix coming to our house, and hearing of his illness, desired to 

 see him ; he ordered the boy to strip to his shirt, and having given present ease 

 to his head by only stroking it with his hands, he fell to rub his back, which he 

 most complained of, but the pain immediately fled from his hand to his right 

 thigh ; he followed it there, it fell to his knee, from thence to his leg, but he 

 still pursued it to his ancle, thence to his foot, and at last to his great toe ; as 

 it fell lower it grew more violent, especially when in the toe it made him roar 

 out, but upon rubbing it there it vanished, and the boy cried out it is quite 

 gone. It never troubled him after, but he took the small-pox about 3 weeks 

 after. The next instance was Mrs. D — , she uas seized when a girl with a 

 great pain and weakness in her knees, which occasioned a white swelling ; and 

 having used divers means to noeff'ect, after 6 or 7 years' time Mr. Greatrix 



* White vitriol is a salt compounded of vitriolic or sulphuric acid and calx or oxyd of zinc. In 

 the modern chemical nomenclaturCj it is called sulpha' e and fupersulphate of zinc. The form of 

 the crystaK has been well described by Bergmann. Dr. Lister's mechanical account of the operation 

 of this metallic salt upon the coats of the stomach is inadmissible. 



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