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It is remarkable, that Tartar vitriolat. Sal 
Gem. Sal mirabile , Sal maritimwm , Nitre , 
being Salts compofed of different Acids and an 
Alkaline Salt, fhould fo far exeeed in gravity 
the Vitriolic Salts, compofed of the mod heavy 
Acid and a metallic Earth. Is not this owing to 
its forming lcfs folid Chryftals, and to its contain- 
ing large quantities of Air concealed in its Pores? 
The great difference in the weight of the Nitre y 
in the feveral experiments of Fahrenheit , Newton , 
and Freind , may poflibly be owing to the quantity 
of its concealed Air. 
TAB. X. 
Of Fluids . 
MERCURY. Ward. C. (See Tab. I. among 
the Metals.) .... 14.000 
Oleum Vitrioli. Fahrenheit. . . 1.8775"* 
Oyl of Vitriol. Newton. C . 1.700 
Spiritus Nitri Hermeticus. Freind. . 1.760 
Id. Mufschenb . . . .1.610 
Lixivium cineris clavellati, fale quantum 
fieri potuit impregnatum. Fahrenheit . 1.7713* 
Id. alio tempore prreparatum. Fahrenh. 1.7634* 
Oil of Tartar. Cotes. Ol. Tartari per dc- 
liquium. Mufschenb. . . 1.570 
Spiritus Nitri, cum Ol. Vitrioli. Freind , 1.440 
Id. Mufschenb. . . . 1.338 
Spiritus Nitri communis. Item, Bezoardi- 
cus. Freind . . s .1.410 
Spirit 
