Philosophical transactions, Vol. L. Part I. For the year 1757. / Giving some account of the present undertakings, studies, and labours, of the ingenious, in many considerable parts of the world.

by Various; Royal Society

As it would be desirable to make them as small as possible, they should be made so as not to shew the common degrees of heat: and it would also, on that account, be convenient to omit the thread of glass placed within the shorter leg of the syphon in [fig. 3.] and [4.] This thread of glass is placed there in order to make the mercury fall into the ball A. [fig. 3.] or cylinder C. [fig. 4.] in smaller drops, and also to facilitate the filling the shorter leg with mercury. The latter purpose may be answered by having a ball blown towards the bottom of the shorter leg, as marked in [fig. 4.] at M: for as soon as the mercury driven out of the cylinder by heat gets to that ball, it will pass by the spirit of wine. The other purpose may probably be answered by having the tube contracted as much as possible at n.

In the foregoing instruments the tubes made use of were of a large bore, as most of the errors in them would increase by making use of smaller ones. Possibly less ones might be used without much inconvenience. The chief advantage will be, the making these thermometers more sensible of the changes of heat, than when large cylinders are used. This will be of service when the greatest degree of heat or cold continues but a short time.

It is better to use plain spirit of wine, than what is tinged, which seems more apt to cause a foulness in the tube, and thereby makes the surface of the mercury less well defined. I am induced to believe so, from observing, that the portion of spirits above the mercury in the tube [fig. 3.] which at first was strongly tinged with cochineal, in some months became perfectly colourless, the tinging particles being deposited in different parts of the tube, and causing a foulness there. The colour of the spirits in the cylinder does not appear to be altered.

The dark-shaded part in the several figures represents mercury, the dotted part spirit of wine.

Philos. Trans. Vol. L. Tab. XII. p. 311.

J. Mynde sc.

XXXIX. Observationes Anatomico-Medicæ, de Monstro bicorporeo Virgineo A. 1701. die 26 Oct. in Pannonia, infra Comaromium, in Possessione Szony, quondam Quiritum Bregetione, in lucem edito, atque A. 1723. die 23 Febr. Posonii in Cœnobio Monialium S. Ursulæ morte functo ibidemque sepulto. Authore Justo Johanne Torkos, M.D. Soc. Regalis Socio.

[See [Tab. XII.]]

Read May 23. 1751.