I&JJ Edinburgh Insfhiiie, 



EDIISBUUGH INSTITUTE. 



At a gtneral meeting of the members of this TnsfUiitioft, 

 on 'I'iiesdav, February 2, for hearing communications on 

 Mibjects connected wiih science, literature, and the artSj, 

 Dr, Millar in llie chair, the following papers were received: 



i, Aecoinit of a new method of ascertaining the quantity 

 of spirituous liquors by weight, proposed as a substitute for 

 iiieaAurerhenf ; — communicated by Mrs. Lovi. 



The patent acrometrical beads were invented by Mr?.. 

 Lpvi, the patentee, some years ago. They consist of small 

 hallow glass balls, with short stems, blown of different spe- 

 cific gravities, from 80O to 1800, and corresponding to the 

 even numbers 800, 802^ 804, &c. each bead having the 

 ?^pecific gravity it denotes engraven on the npper part of its 

 !<urface. Those used lor spirituous liquors are 30 in num- 

 ber, and extend from 890 to 91 8. In using them, a 

 tmall quantity of the liquid, whose specific gravity is to be 

 ascertained, is put into a pinal, and several beads are suc- 

 cessively immersed in it, till one is found that remains 

 suspended below I he surface of the liquid, without sinking 

 to the bottom. 'I he number on this bead indicates the 

 specific gravity oi' the li(]uid. A thermometer accompanies 

 the beads, for taking the Lemperatnre of the liquid ; and the 

 correctifin nccefsaiy to be made when this exceeds or falls 

 below 60 , the standard temperature, is exhibited by a 

 sliding rule. 



The-;e beads exhibit the specific gravity of liquids much 

 more correctly ilian the common hydrometers do, and 

 "thev are not liable 10 go out of order. Except breaking, 

 they are not exposed to ai^y pccident that ctm in the least 

 xkgree impair .their accuracy ; vvhereas it is well known 

 that the c'imr.ion metallic hydrometer is injured by th'; 

 thcrrica! action of the air, and the fluids it is used to mea- 

 sure; has its bulk dir::inish<'d by a partial depression of its 

 surface, or its weight incicased by admitting portions of 

 the liquid iiilo its inside; and, even in its most perfect 

 state, IS an instrument upon which little dependence can b«- 

 placed. 



The specific giavily of spirits being determined with fa- 

 cility by the i;cads, the (juaiititv in gallons, or measures of 

 any other denomination, mav be found by weight with the 

 utmost certainly. For, since the weight of a cubic foot of 

 water, and the number of cubic inches in a wine gallon, 

 have been carefully ascertained, the specific gravity of any 

 other liquid will cqablc us to ascertain the weight of a wine 



gallon 



