The EjfeBs of continued Heat. 421was injured ; one measure of this and oneof nitrous air occupying the space of 1.4measures.

After this I placed distilled vinegar in thesand furnace ; and this, in the interval be-tween the 9th and the 30th of September,had made a deposit of some black matter,and the tube was coated with it quite round,at the surface of the liquor. Also, in a sliorttube, the same vinegar was. a little opaque,and there was some black matter on one sideof the tube,* half an inch above the surfaceof the fluid. In this state these tubes con-tinued to the last, when they had depositeda brownish sediment.

Having exposed a small quantity of -water impregnated with fluor acid air , quitetransparent, in a glass tube hermeticallysealed, to the heat of a common fire, I ob-served that, presently after it began to boil, itbecame of a dull blue colour, and a whitishvapour rose from it, as high as the middle ofthe tube. Aftertvards, the heat increasing,it became transparent again, without deposit-ing any thing, even when cold.

E e 3

Repeating