358 Miscellaneous IntelHgewc, 



appeared in the evening of October 17th. Seen from Seath- 

 waite, in Borrodale, Cumberland, it formed, about 9 o'clock, 

 an arch extending from east to west nearly, having its higher 

 part inclined towards the south. About 9 h. 15, its extremities 

 had moved 12 or 13 degrees northwards, and the whole arch 

 was vertical, being in a plane passing through the magnetic east 

 and west. About 9h. 30', it had retired to its former place 

 and inclination, and afterwards gradually diminished in inten- 

 sity, until it disappeared. Even small stars were visible 

 through it the whole of the time. — Tilloch. Mag. 54, p. 383. 



§ 2. Medicine, Anatomy, S)C. 



1. Neio Mercurial Ointment. — Mr. Donovan has lately pub- 

 lished, in the Annals of Philosophy, a series of experiments on 

 the compounds of mercury. They relate to the chemical con- 

 stitution of these compounds, and the proportion of their ele- 

 ments ; but are concluded by an examination of the common 

 mercurial ointment, and an account of a new one. 



Four troy ounces of mercurial ointment were kept at 212° 

 for some time ; they separated into two strata ; when cold, the 

 upper stratum, of a light grey colour, was separated ; the under 

 stratum was exposed at 212° on blotting paper, which absorbed 

 the remaining lard. The very heavy residue was triturated with 

 a little magnesia, and immediately gave 495 grains of mer- 

 cury ; further trituration with magnesia gave 225 grains more. 

 The earthy mass, treated in difFerent ways, gave a quantity of 

 globules, estimated at 60 grains, and a little oxide appeared. 

 Thus, out of 960 grains, contained by the 4 oz. of ointment ori- 

 ginally, 770 grains were collected, leaving 190 grains, the quan- 

 tity of mercury, apparently oxidized, or47| to each ounce. 



The upper stratum appeared to contain oxide of mercury In 

 chemical combination ; and Mr. Donovan believing that the me- 

 tallic mercury could have no effect on the animal economy, at- 

 tributed the powers of the ointment to the small quantity of 

 oxide with which the fat is combined. To ascertain if this were 

 the case, this upper part was given to three females requiring 

 the use of mercury. Each rubbed in a drachm every night; 



