166 Miscellanies . 



23. Purijicaiion of olive oil, for chronometers, ^c. — (H.Wilkin- 

 son, in Trans. Soc. of Arts, &c. Vol. XLVIII, p. 43.)— The best 

 olive oil, in considerable quantities, is kept in jars for one year or two, 

 (in a state of repose,) during which time most of the water and mu- 

 cilage subside. Two or three gallons are skimmed from the surface 

 of a large jar, and afford better oil than any subsequent portion. One 

 gallon being placed in a cast iron vessel of twice that capacity, is heat- 

 ed for one hour, over. a slow clear fire, to 220°, and must never be 

 hotter than 230°, nor descend below 212°. Thus the water and 

 acetic acid are evaporated. The oil is then exposed to a cold of 30° 

 to 36°, for two or three days ; (winter is of course preferable ;) the 

 congealed portion is separated by a muslin filter ; the solid part may 

 be used for common purposes, and the fluid part is then filtered 

 through newly prepared animal charcoal, coarsely broken, and sus- 

 tained on bibulous paper, in a wire frame, within a funnel ; this re- 

 moves rancidity, if any is present, and the oil becomes perfectly 

 bright and colorless. 



Messrs. Barraud and son, (the celebrated chronometer makers in 

 London,) attest that this oil is superior to any other, and that they 

 have used no other for the last four or five years. 



The process is simple and easy, but it demands considerable time ; 

 it has been used by the discoverer for ten or twelve years. 



24. Method of clearing the Baltimore rail-way of snow during 



the late winter. — It was „.. ,.„.. . . „ . ^, 



invented by Mr. Winans, 

 and consists of an angular 

 frame, shod with iron, - ^ ^ ^ ' ^ - ^k . ^^' R ail . 



followed by a sled, shod with irons ollique to theline of the runners ; 

 the first pushing the snow each way off; the latter scraping snow 

 and ice more closely, as the oblique irons in succession scrape the 

 rails. It was drawn by five or six horses at a trot ; and was effect- 

 ual, though the snow was two feet deep on a level ; in the deep pass- 

 es, much more. — [Communicated by Mr. J. L. Sullivan.) 



25. Discourse, delivered before the Historical Society of Michi- 

 gan, by Henry R. Schoolcraft. — This discourse contains very inter- 

 esting notices of the northern and interior portions of this continent, 

 particularly in relation to the past and present condition of the abo- 

 riginal tribes ; and of their connexion with, and relation to, the 

 French, English and Anglo-Americans. A historical society, whose 



