SOS Relation lelwcen tJie Spcrijic Gravities and 



put in by means of a well known instrument, which Is 

 composed of a small dish Icrnuaating in a tube drawn to 

 a fine point : the top of the dish being covered with the 

 thumb, the liquor in it is prevented from running out 

 through the tube by the pressure of the atmosphere, but 

 instantly begins to issue by drops, or in a very small stream, 

 upon raising the thumb. The liquor lastly added being thus 

 iutroduced into the phial till ii exactly counterpoised the 

 weight, which, having been previously computed, was put 

 into the opposite scale, the phial was shaken, and then well 

 stopped with its glass stopple, over which leather was tied 

 very tight to prevent evaporation. 



In this miumer 100 parts by weight of spirit of the last- 

 mentioned specific gravity of 8i?5 at G0° being first put into 

 the bottle, five parts by weight of distilled water were added, 

 so as to form a compound in these proportions. In the 

 next experiment 10 parts of water were added to 100 by 

 weight of the spirit ; 'n\ the ;\ext, 15 ; in the next, 20 ; and 

 so on, increasing the weight of water by five parts in each, 

 imtil 100 parts, or an equal weight of water, v»ere added to 

 the spirit. One hundred parts of water by weight were 

 then taken as the invariable quantity, and 5, in, 15, 20, 

 &c., parts of the same spirit successively added, so as to 

 produce 20 more weaker compounds; the last, or 100 to 

 100, being equal in strength to the last of the former series. 

 No mixture was used till it had remained in the phial at 

 lei^t a month, for the full penetration to have taken place ; 

 and it was always well shaken before it was poured out to 

 have its specific gravity tried. 



The mode of performing this operation which these gon- 

 tleracn preferred on this occasion, was that of actually 

 weiu;hing the liquor in a vessel which was capable of being 

 at aU times equally filled to a great degree of exactness, liav- 

 iniT first ascertained its weight when so filled with distilled 

 water. It v.'as a hollow glass ball, terminating in a neck, 

 which was formed of a portion of barometer tube l-4th 

 of ail inch in diameter, and li inch long. That used by 

 Dr. DoUfuss contained, when filled to a mark cut round 

 the neck with a diamond for that purpose, 5300 grains c)f 

 distilled water; but the one afterwards preferred by Mr. 

 Gilpin was su^aller, aiid contained when so filled only 29()j 

 granns of the same fluid at GO^ The buttle it.-elf weighed 

 ylG grains, and with its silver cap 9:5(5. It,> bulb was about 

 £-8 niches in diameter ; and Mr. Gilpin found, tliat on fill- 

 ing i: several Inucs successively to the same mark at equal 



tempcvaturesj 



