362 PROCEEDINGS OF THE AMERICAN ACADEMY 



not identical with cumole from cuminic acid, (as assumed by Mans- 

 field, and generally credited,) nor even isomeric with it ; but that it 

 has the formula which has been assigned to xylole. 



5. That the body obtained from coal-tar naphtha boiling at 170° is 

 quite a different body from cymole obtained from oil of cumin, (with 

 which it has been considered identical, as was also assumed by Mans- 

 field,) — these bodies differing from each other by C, H2. 



6. That cumole from cuminic acid, and cymole from oil of cumin, do 

 not even belong to the benzole series. 



7. That the parabenzole of Church was in all probability simply a 

 mixture of benzole and toluole. 



In the second memoir it is shown : — 



1. That the boiling-point difference for the addition of Co H, in 

 homologous series of hydrocarbons is generally 30° ; which is a much 

 larger difference than has generally been supposed. 



2. That, of the five series of hydrocarbons examined, only one series 

 was found exceptional ; and this series presents the difference of about 

 20° ; which is but little larger than the number, 19°, which Kopp found 

 to be so common with other classes of substances. 



3. That the formulae of Schroder, Lowig, and Gerhardt for the cal- 

 culation of boiling-points, so far as these relate to the hydrocarbons, 

 are purely artificial. 



4. That certain series of derivatives from the benzole series of 

 hydrocarbons present boiling-point differences corresponding to an 

 elementary difference of C2 Hj, considerably smaller than the number 

 19° of Kopp. 



5. That the custom of taking boiling-points with the bulb of the 

 thermometer in the vapor, is more liable to lead to an erroneous deter- 

 mination — at least in certain cases — than if the bulb be placed in 

 the liquid. 



Five hundred and forty-first Meeting. 



November 9, 1864. — Statute Meeting. 



The President in the chair. 



The Corresponding Secretary read a letter from Frederick 

 Overbeck of Rome in acknowledgment of his election into 

 the Academy. 



