95 



stone of that district became charged with bitumen, the 

 latter penetrated into a cavity which it traversed in long 

 stalactite drops. Subsequently the cavity was more or less 

 filled with crystals of calcite and sulphide of iron, which 

 were deposited by the water charged with those substances 

 around the drops of bitumen. The heat by which the bitu- 

 men found its way into the rocks must have disappeared 

 before the crystals were formed ; for had the latter been 

 the result of hydrothermal action, they may have been 

 coated, but certainly could not have been traversed by the 

 solid bituminous stalactites. 



" On the Boiling Points of the normal Paraffins and some 

 of their Derivatives," by C. Schorlemmer, F.R.S. 



It is generally asserted that the boiling points of the 

 members of homologous series increase regularly for each 

 increase of CH2. Thus it is stated that in the series of the 

 alcohols and fatty acids the boiling point is raised 19° for 

 each addition of CH2, whilst in other series this difference 

 is sometimes smaller, sometimes larger, but always the 

 same in the same series. But in many cases the boiling 

 points calculated by this rule do not agree at all with those 

 which have been observed. One reason for this discrepancy 

 is that the compounds of which the boiling points have been 

 compared are not true homologous bodies, i.e. that they 

 have not an analogous constitution although they differ 

 in the composition by CH2 or a multiple thereof. During the 

 last year, however, we have become acquainted with some 

 true homologous series, namely, the series of the normal 

 paraffins and the normal alcohols and their derivatives. 



In a paper read before the Royal Society I have already 

 pointed out that the difference between the boiling points 

 of the lower members of these paraffins is not the same. 



