Math Literary and Philosophical Society. 221 



treme accuracy, and at the same time be more portable, less 

 liable to break, and in every respect more useful than the baro- 

 meter. He began liy takine; small thermometric tubes, giving 

 them iare;e i)ulbs, and extending them to three inches for every 

 degree of Fahrenheit's scale. These he found very sensible; but 

 for general purposes he considers that one inch to every degree 

 of Fahrenheit (each of which he divided into a tliousand de- 

 grees) is the most convenient; that the eapiliary tubes should 

 not be so small as to present any great resistance to the expan- 

 sion of the mercury; and that a tube of common diameter, having 

 a bulb inserted in a metal box about four inches long and 1'4 

 wide, will indicate every foot of elevation. To this box water is 

 added, and a small lamp placed under it, so that the water may 

 boil ; and as the operator ascends, the ascent of the mercury at the 

 boiling point indicates the difterence of height between anv one 

 place and the common surface of the earth, or the level of the 

 sea. Mr.Wollaston made an experiment with his instrument by 

 boiling water on the counter of a bookseller's shop in Pater- 

 noster-Row, and again boiling it in the dome of St. Paul's, and 

 found that this thermometer exactly corresponded with the geo- 

 metric measurement of that building. 



March \'3, 20, and 27 vvere occupied in reading part of a Ions 

 and elaborate paper on the natural history of cinnamon, by Mr. 

 Marshall. The author began with a botanical description of the 

 Ijaurus Cinnamormim, in which he corrected the errors of all 

 preceding writers, and particularly those of Thunberg, who has 

 been generally followed by subsequent botanists. He described 

 the soil, modes of gathering it, packing it with pepper on board 

 of ships, specific differences or varieties of cinnamon, its names 

 in various languages ancient and modern, &c. It apjjears that 

 oil of cinnamon is made by distilling the fresh bark with salt 

 water ; and that 80 lbs. of bark yield only 2^ ounces of volatile 

 or supernatant oil, and 5| ounces of a darker coloured and hea- 

 vier oil : that the former floats on the surface of the water, and 

 the latter sinks to the bottom ; so that both are easily collected 

 from the water, and from each other. Somewhat less oil is ob- 

 tained from dry bark. 



The Society then adjourned over, in consequence of the holi- 

 days, two Thurdays. 



BATH LITERARY AND PHILOSOPHICAI, SOCIETY. 



Monday, Feb. 17. Mr. Cranch conuuunicated to the Society 

 the substance of some papers transmitted to him from Dorches- 

 ter, near Boston in New England, relative to a mummy tlisco- 

 vered in an immense subterranean cavern in the State of Ken- 

 tucky. 



The 



