182 EEPOKT OF THE 



2603.83 



5. S=- 



G -1-4.404 



6. S=3.846B " B=o, S=o 



7. £.=3.885 s " E=o,£=o 



6S5.516 



8.8=585.516 " g=l, S=o 



6 

 677.008 



9. B= " G=oo , E=o 



G -|- 4 454 



10. B-=.26S " S=o,P=o 



11. B=1.01s . " E=o,B=o 



152 



12. B=152 " g=l, E=o 



g 



670.218 



13. 



0-1-4.454 



But knowing the mean.spccific gravity of salt to be 2.125, wo may alBO calculate the spe- 

 cific gravity of the saturated solution (without allowance l'or conuensation) from the per 



centage of salt, by means of formula (2). This giveB -, _ ^ 



g'=1.1560 sia '% 



It is eviicut, therefore, that Dr. Ure's value of the condensation is too great, or else bis 

 per centago of salt in satur ted brine is too great. But that pjr centage is lesd than given 

 by must other autnuritijs, while by my own experiments upon commercial salt, it amounts 

 to 26.595. 



Agaiu, according to the oxperitn^nts of M5f. Francceur and Dulong, when a brine coiv 

 taius 10 nor cent, of salt, its sp-cific gravity is 1.0735; and when it contains 15 per cent., it 



is 1.1094. Now if we assume 10 for the per centage of salt hi Eq. (1), we get ^^ ^. M 



g'=1.0559, inst-ad of 1.0735. 



If we assume 15 lor the per centage of salt, 

 g'=1.0S62, instead of 1.1094. 



The increased specific gravity due to condensation in tlio first case, is .0186=. 186 per 

 cent, of 10, the per centage of salt. 



In the second case, it is .0232=155 per cent, of 15, thi'por centage of salt. 



Furthjr, in tue case of saturated lu'iue, it is .049=. 191 per cent, of 25.5, the per centago 

 of salt. The first an 1 last values are Suflici-intiy cousouaut, but not so the second. __Tho 

 mean of tlie first and last is .1SS per cent. Assuming this 

 i=g'-|- .00186 3 



Substituti ig the value of g' from Eq. (2), wo mijht thenco deduce s in terms of g. 



Another vi-w m ly be t iken of this subject. It is evi lent that we may regard all the coiv 

 densation us talci.ig place i.i tlu sill; anil the result will be the samj if we imagine it to 

 tako place b-fore thj solutiuu. We may then proceed to calculate what valuo of the specific 

 gravity of the salt would b •■ requisite in order to produce, wiLhout further condensation, a 

 brine of a given sj-oifie g.avity,aa1 containing a given per rentage of salt. 



If iu (2) we make g'=1.0735, w=90, s=10 and 2.125— .x, we get 

 x=3.1S6. 



If in (2) we m ike g'=1.094, w=85, s=15, and put x for_2.125, we get 

 x=2.919. 



If again wo mike g'=1.205, w=74.6, s=25.5, 

 x=2.838. 



These results are but little accordant ; and show that the condensation is not proportional 

 to the per centage of salt, or else that errors exist in the data. The mean of tho three values 

 is 2.981. 



If now in Eq. (2) we substitute 2.9S1 for 2.125, g' ought to become g, when wo should 

 have 



150.478 



(?) 



s S 160.478 — g 



w-| 100 — B-| 



2.981 2.981 



Whence, also, 



150.473 

 6— 150.478 , ,{\ 



