458 Miss Earp on the Effect of the Replacement oj 



Temperature Cent. Specific Gravity. 



25 

 30 

 35 

 40 

 45 

 50 

 55 



•831 



•8306 



•828 



•826 



•8758 



•8753 



•8717 



We are now arranging a piece of apparatus which will give, 

 not the absolute value of the specific gravity, but with great 

 accuracy relative rates of the change of specific gravity with 

 temperature *. We shall make experiments of the same kind 

 upon other animal oils. 



XLIV. Note on the Effect of the Replacement of Oxygen by 

 Sulphur on the Boiling- and Melting-points of Compounds, 

 By Miss A. G. EarpI. 



IN various papers published in the Philosophical Magazine J 

 Carnelley has called attention to the effect produced on 

 the boiling-point and melting-point of compounds by replacing 

 one element in the compound by another belonging to the 

 same group. He gives numerous examples (mostly organic 

 compounds) to show that in the case of the halogen com- 

 pounds, when one halogen is replaced by another of a higher 

 atomic weight, both the boiling- and melting-point are corre- 

 spondingly raised. 



As a further instance of the same kind of thing he gives the 

 following series of the ethyl carbonates and sulpho-carbonates 

 to show that the boiling-point is raised in proportion to the 

 amount of sulphur introduced in the place of oxygen. He 

 also points out that the same series shows that a definite effect 

 is produced by a change in the arrangement of the molecule 

 without any change in the number of sulphur atoms. 



< 



O a H 5 



-C,H, 



CO 



cs/ 



O— C 2 H 5 

 S-C 2 H 6 

 O-0 2 H g 



\0— 2 H 5 



B.P. 1: 



B.P. 156°. 



B.P. 1(51 



SC 2 H 5 



cc/ 



c< OC 2 H 5 



x SO>H, 



CS: 



/SC 2 H. 



^SC H, 



B.P. 196 c 



B.P. 200 c 



B.P. 240°. 



* We described at the Meeting results obtained for other specimens of 

 sperm- oil, with the new apparatus, which exhibited no discontinuity. 

 Yet we can find no reason to doubt Mr. Knight's measurements. 



t Communicated by M. M. Pattison Muir. 



% Phil. Mag. Oct. 1879. 



