342 Chemical Society. 



ever strange, it is true that the results appear, almost all, to have 

 been miscalculated. The specific gravity of hydrogen, instead of 

 being calculated 0-0687, should have been 0-06986, or with Rud- 

 berg's dilatation, 0-06988. With the received specific gravity of 

 oxygen, this would give 12-67 for the equivalent of hydrogen; 

 Dumas's specific gravity of oxygen would give 12-64. On all these 

 considerations, I regard the numbers authorised by the experiments 

 where Berzelius has taken part to be 12'6 for hydrogen." 



" On a more simple and correct Mode of Reducing the Indi- 

 cations of the ordinary Saccharometer and Hydrometer to each 

 other," by Robert Warington, Esq. 



The great utility of some ready means of effecting these opera- 

 tions was first pointed out on the following grounds: — 1st, from 

 the great variety of saccharometers in general use ; 2ndly, from their 

 being constructed of brass, which, from its liability to loss of weight, 

 from abrasion and corrosion, causes frequent errors of indication ; 

 3rdly, from some of these instruments, as in that employed by the 

 Excise, reading off degrees of specific gravity of which the saccha- 

 rometer equivalent is found by referring to a printed table sold with 

 the instrument ; and, 4thly, to the practical chemist, from the great 

 cost of these instruments, and from his always having in his hands 

 the means of accurately ascertaining the specific gravity of any sam- 

 ples of worts, or other material on which he may be called to experi- 

 ment, and therefore only requiring a correct formula for reducing 

 such specific gravities to those of the saccharometer. 



The saccharometer is a hydrometer of great delicacy, having its 

 zero point corresponding to the specific gravity of distilled water, and 

 its scale, which has usually a range of specific gravity from TOGO to 

 ri50, divided into 54 principal divisions, each of which is again 

 subdivided into 5 or 10 equal parts. The object which is professed 

 to be attained in this instrument, is the indicating the number of 

 pounds of saccharine matter contained in "the barrel" of the infu- 

 sion of malt and other grain. The imperial barrel contains 36 gal- 

 lons of distilled water of 10 pounds each, or 360 pounds of water. 

 Of wort, whose indication is 1 on the saccharometer, a barrel weighs 

 361 pounds ; 2 on the saccharometer, 362 pounds, and so on for the 

 54 divisions of the scale. This instrument does not fulfil its professed 

 object, as, — 1st, it does not indicate directly the absolute quantity of 

 solid matter per barrel, but only the change of density which this 

 occasions ; 2ndly, it is equally effected by the other ingredients in 

 the infusion of malt, as mucilage, vegetable albumen, &c., as by its 

 sugar. The saccharometer must therefore only be regarded as an 

 instrument of comparison. 



The rule usually followed in calculating the specific gravity from the 

 saccharometer indication, is to add 360, the weight of the barrel of 

 water, to the saccharometer indication, and then multiply the result 

 ])y 2-77' or 2§ths being the value of each saccharometer pound ex- 

 pressed in terms of specific gravity; 360 multiplied by 2-77* being 

 equal to 1000, the specific gravity of water. Hence, if 36 be the 

 observed saccharometer indication, the specific gravity is 36 -|- 360 

 X 2-77* = 1100. Reversing the operation, and dividing the number 



