atmolyser

[Eng. atmolys (e); -er.] That which produces atmolysis, the partial separation of gases or vapours of unequal diffusibility. Tube atmolyser: An instrument for effecting this result. It consists of a tube of unglazed earthenware, about two feet in length, placed within a shorter tube of gla in contact with an air-pump. The air between the two tubes being to a large extent exhausted, the mixed gases are allowed slowly to traverse the earthenware pipe, when much of the lighter one escapes through the pores into the other. ( Fownes .) IMG:content-0858.png:[blocks in formation] ! by Sir John Leslie for measuring the quantity of moisture exhaled in a given time from any humid surface. It consists of a very thin ball of porous earthenware, from one to three inches in diameter, having a small neck firmly cemented to a long and rather wide tube of gla , to which is adapted a bra cap with a narrow collar of leather to fit closely. It is filled with distilled or pure water, and its cap screwed tightly. It is then suspended out of doors in a situation where it is exposed freely to the action of the wind, but is sheltered from rain. As the water evaporates from the external ATMOMETER. surface of the ball, it transudes through its porous substance, and the waste is measured by the corresponding descent of the liquid in the stem. To test the amount of this descent there is a finely-graduated scale. When the water has sunk to the bottom of the stem the latter requires to be filled anew.