417 



only in the case N". 2 this quotient remains really constant. It is 



now of importance to draw attention to the t'a.c\, that m amtradiction 



with the hitherto prevailimj views, the prese?ice of type 2 on one 



side, and of ti/pes 1 and 3 on the other side, appears to be in no 



clear connection nnth the absolute value of the quotient -— , nor nnth 



at 



the absolute values of / or u thenis-elves. 



II. In agreement with the results of previous investigators, it 



appears to be possible, although only in some arbitrary way, to 



divide the studied liquids into tuw principal groups, with respect to 



the value of -^. In the first group A belong all liquids, whose 

 dt 



quotients — really are very near lo Eötvös' "constant" : 2,27 Erg 

 ^ dt 



pro every degree Celsius. However it must be said here, that only 



a mean value of '- evidentlv can be considered in these cases, and 

 dt 



onhj over a sparehj extended temperature-interval; for, just as we 



already mentioned sub I, these liquids will by no means always 



show a linear dependence of / and t, corresponding to the type 



2, and therefore such a linear dependence may be supposed in most 



cases only for rather short parts of the curves in question. 



To this group A we can bring e. g. : a number of ethers, like 

 Ethyl- Isobutyrate (2,lö) ; Isolmtyl-fsobutyrate (2,18); Diethyl- Oxalate 

 (2,26); Diethyhnalonaie (2,52); Diethyltartrate (2,35); Ethyl- Acetylo- 

 acetate (2,19) ; further: Chloroform. {2, 0<o) ; Bimethylaniline {'2,2'S); 

 Phenetol (2,14); Anethol (2,25); Methylbenzoate (2,21); Ethylbenzoate 

 (2,29) ; Methylsalicylate (2,30) ; Ethylsalicylate (2,23) ; Methylcinna- 

 mylate (2,43); a-Picoline (2,02); etc. 



With most of these and analogous substances however, we can 



da / On 1 



state a considerable increase ot — at loiver temperatures (type 3), and 



dt 



for many of them a value in the vicinity of 2,27 may be accepted 



only within a very narrow range of temperatures, e. g. between 



25° and 80° C 



(/ft 

 To the group B all liquids belong, whose quotients j show 



values appreciably loiver than 2,27 Erg pro 1° 0. To this group the 

 following substances can be brought: Water (1,04); Ethylalcohol 

 (0,94j; Propylakohol (J ,10); Isobutyhilcohol (1,10); Acetone [Ifi) \ 

 Acetic Acid (1,3); Pyridine (1,6); etc. However with several of these 



