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Oils in _ instancs, with Alcohol with Sulphur in vaper with Oils. Make a Catalogue
8th Apr. 1771.
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A Balneum Mariae regulated by a Papin's Digester
V B body of an piece water M M the balneum here head moveable
As the Heat of which a fluid under evaporation is susceptible
is as the pressure it sustains, by keeping the pressure
always equal the same the Heat may be rendered also always equalthe same.
also Now as the pressure of an atmosphere of vaporthe same
is as the quantity [or weight] of that vapor in a given
space by contriving that the quantity shall be always the
same, the pressure is consequently always the same — How
this may be effected
when the pressure of the fluid owing to it: elasticity acquired by the heat overcomes the pressure of the weight upon the valve it will lift it up and at the instant a quantity of vapor will transpire, that will become room for an equal quantity of vapor to be formed from the fluid which evaporates will produce generate a degree of cold by that cold the pressure will be again diminished and the weight upon the valve will gain the ascendant and shut it down - by this adjusting of two contrary forces will be kept constantly in equilibrio.
Qu. how to indicate the degree of heat? how can thermometers be plugged into the Balneum. Glass would melt in great heat. An iron Bar might perhaps be let in through it to the case to serve as a pyrometer when great heat produced by Qument employed
When the Heat in the Balneum is small a glass Thermometer may be fixed into it capped with a glass receiver communicating at the lower end with the Balneum that the heat of in the Balneum may be supplied uniformly all round it. and not only to the Ball - Qu. would this make any sensible difference?
Identifier: | JB/107/001/001 "JB/" can not be assigned to a declared number type with value 107.
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1771-04-07 |
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107 |
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001 |
chymistry |
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001 |
a balneum mariae regulated by a papins digester |
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text sheet |
4 |
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recto |
2 |
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jeremy bentham |
[[watermarks::[gr in circle with crown] [monogram] [pro patria motif]]] |
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includes diagram |
34992 |
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