468 '^Messrs. Playfair and Joule on 



,^'^1 vxi \ydknrjoQ>iindi pi „ ;i,i. : >, /fir. j./iut, .'nnnv ".. i'll 



IOse§ rt^ iWatjii; ,WW\ ^9h ■ lacility that it , is alnaost impossible^, 

 to obtain it in a state well-fitted for experiment. In two speT* 

 cimeiis of salts, prepared at different times, the volume for thia 

 above quantity of salt was 29*7 and 29-8 ; but as in most cases. 

 it was only 29'0, we give the result most generally obtained, j 



fbi(, Arseniate of soda, vol. of salt 232-0 ... 1*736 !o 



^^^ub-arseniate of Soda, SNaO, As05 + 24.HO = 4<^5-2:^T^^^ 

 eighth part of an equivalent, 53*15 grains, of this salt dissoIv6'(l^ 

 in 1000 grains of water, with an increase of 27*0 in one ex-' 

 periment, and 26*9 in another, at a temperature aboiit 5*5 . "' 



I. Sub-arseniateofsoda 216-q. j^.^;.,^'^''.^^^^^^ 



..•fvm|^fhoa.r 1^ 



(HUVO ... Mean . . 215*6 



The same quantity of salt immersed in turpentine caused 

 an increase of 29*4 and 29*5 in two experiments. 



-nii li'Sub-arseniate of soda, vol. of salt 235*2'^"''^ f*fe08 



.'1' IIi"a ^.:,j^.uj- .. ^^.;V';-/-^' -i;. •; ^"; 236*0 1*801 



1i'-:u\ Oil) ni nnrj .ylr/n'iB orlrjiifig no htow 1)— — : — , / 



Mean : . •. 235*6 1-804; 



Cane-Sugar, C^c^HnO^^^i 171-60.— 25*8 grains of sugar 

 dissolved in 3140 grains of water caused an increase of 14*8 

 at 32"^; 42*9 grains, or the fourth of an equivalent, gave an 

 increase of 25-0 at 60° in two experiments. 



I. Cane-sugar, vol, in solution 98-4 



II. ... 100-0 



. -IHi hfiis f9%pn K)tM'0 ••• . lOO'O 



■*->)'< " '"Mean . . 99-5 



300 grains of sugar-candy thrown into alcohol previously 

 saturated with it, caused an increase in the first experiment 

 of 188*0, in the second of 188*75; in a third experiment, 

 49-65 grains thrown into turpentine caused an increase of 

 31*0; and the same quantity, in a fourth experiment, of 31-1, 

 the temperature in all the cases being about 60°. 



In this section a class of salts presents itself, in which the 

 volumes are clearly not represented by any multiple of 11 ; 

 yet they are uniform in their isomorphous relations, and are 

 sensibly multiples of the same number. To discover whether 



