REPORTS 
ON 
THE STATE OF SCIENCE. 
On the Spedfic Gmmty of Sulphuric Acid at diferent deyrees of rfi7«- 
twn, and on the relation ivhich exists between the Dwelopmetit of 
Heat and the coincident contraction of Volume in Sulphuric Acid 
when mixed with Water, By Ciiu. Langbeeg, Professor of Na¬ 
tural Philosophy in the University of Christiania. 
In many cliemtcal and physical researches where sulphuric acid takes such 
a prominent part, it is of importance to determine witli facility and accuracy 
the quantity of sulphuric acid which the diluted acid contains. The 8i)ecific 
gravity a-ems here, as with other fluids diluted with water, to afford the 
easiest method of arriving at this result, and it is therefore ecnerally used. 
iWany experiment have been made to dctermiiio the specific gravity of sul¬ 
phuric acid at different degrees of dilution, and tables are published by 
iJalton, Parkes, Ure. &c. Of these tables, that of Urri in his Dictionary of 
Lhcmistiy, IS generally acknowledged to be the most correct; but no certain 
scale exists either for the accuracy of Ure's or the other tables, although the 
importeiicc of thwo tables, as wcU as the special difficulties that are insepa- 
h precise determiuation of the specific gravity of sulphuric acid, 
T V demanded an examination of their accuracy. It is 
tlip m to do by calculating Ure's experiments according to 
tEia a ^ squares, and thus to determine the probable error of 
n( n ?* ®?P®'^*oonls, and the most probable value of the specific gravity 
ol die sulpljuric acid deduced from Ure^s tables. 
turp experiments of Ure, which were all made at a tempera- 
trravits •, ^ collected in the appended Table I., where thu specific 
not every per-centage is found by direct experiment and 
express the specific gravity as a function of the 
quantity of acid contained in the fluid by ffie formula 
the specific gravity and p the quantity of sulphuric acid 
eannnf tu. ®®*\taiijwl in 100 parts of the diluted acid. That this formula 
easilv ho ^or those acids which arc very much diluted, will 
lino hw K tsken as the abscissa, s as the ordinate of a curved 
thatVrnL curve according to Ure’s tables, it will be found 
p — t) to aboutp = 59 it is convex against the axis of the absciss®; 
1847. 
* Dictionary of Chemistry, pp. 103 and 106. 
