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XXXVIII. On a Method of determining the Specific Gravity of 

 ; Liquids. By Thomas Tate, Esq.* 



THIS method of determining the specific gravity of liquids 

 depends on the principle, that the lengths of the columns 

 of two different liquids, supported by the same atmospheric 

 pressure, are to each other inversely as their specific gravities. 



A B C E represents a glass tube, 

 with an enlargement at C D, bent 

 somewhat in the form of the AViir- 

 temberg siphon, and fixed at E to 

 the rod of a retort-stand ; E F a deep 

 jar filled with distilled water ; A G a 

 small glass vessel containing the li- 

 quid whose specific gravity is to be 

 determined. The tubes AB and 

 D C are graduated into inches and 

 tenths, the divisions on the former 

 being measured from the top of the 

 tube A, and on the latter from the 

 top of the tube E. The length of 

 AB or E C may be about 13 inches, 

 and C D about 3i inches ; the dia- 

 meter of the portions A B and E D 

 may be ^ an inch, and that of the 

 portion C D about 1 inch. The jar 

 E F should be deep enough to sub- 

 merge the tube EC. The tops of 

 the tubes at A and E should be plane 

 sections at right angles to the axes 

 of the tubes. The instmment is used 

 in the following manner : — 



The glass G, being at first empty, is raised by a thin block 

 of wood, causing the bent tube A to touch the bottom of the 

 glass ; the jar E F, nearly filled with distilled water, is elevated 

 until the water stands at C, the top of the wide tube D C : 

 whilst the jar is held in this position, the liquid, whose specific 

 gravity is to be found, is poured into the glass G ; the jar is then 

 let down to its original position, leaving the mouth of the tube 

 E a little above the level of the water in the jar (the water in 

 the tube D C will have fallen a little, whilst the liquid will have 

 risen in the tube A B) ; the glass G is then depressed by re- 

 moving the thin block of wood, thereby causing the mouth of 

 the tube A to stand a little above the level of the liquid in the 



* Commuiiicated by the Author. 



