Chemical Notices : — M. Lourenco on Glycol and Glycerine. 135 



rat lire in its flow over the whole length. [It must be understood 

 here that the plate becomes warmer, on the whole, under the 

 lower parts of the stream of water, its upper surface being every- 

 where at the same temperature as the water in contact with it, 

 while its lower surface is, by hypothesis, at a temperature 1° 

 higher.] If, for instance, the plate be of Calton Hill trap-rock, 

 the water must, according to the result we have found, flow at 

 the rate of 141*1 times its length in a year, or of '3863 of its 

 length in twenty-four hours, to be raised just 1° in temperature 

 in flowing over it. Thus, water one French foot deep, flowing 

 over a plane bed of such rock at the rate of '3863 of a mile in 

 twenty-four hours, will in flowing one mile have its temperature 

 raised 1° by heat conducted through the plate. The rates 

 required to fulfil similar conditions for the sand of the Experi- 

 mental Gardens and the sandstone of Craigleith Quarry are 

 similarly found to be -2435 of the length and -9929 of the length 

 in twenty-four hours. 



XIX. Chemical Notices from Foreign Journals. 

 By E. Atkinson, Ph.D., F.C.S. 



[Continued from p. 62.] 



LOUKENCO* has succeeded in converting glycerine into 

 propylic glycol, and glycol into ordinary alcohol. The 

 formula of monohydrochloric glycerine only differs from that of 

 propylic glycol by containing chlorine in the place of an atom 

 of hydrogen. This relation, as well as that between monohy- 

 drochloric glycol and the corresponding monoatomic alcohol, is 

 indicated in the following formulce : — 



G 3 H 7 01 O 2 G 3 H 8 G 2 



Monohydrochloric glycerine. Propylic glycol. 



G 3 H 7 C10 4 G 3 H 8 4 



Monohydrochloric glycol. Propylic alcohol. 



G 2 H 5 C10 4 G 2 H 6 4 



Hydrochloric glycol. Alcohol. 



By treating these hydrochloric ethers with nascent hydrogen, 

 this chlorine is removed and replaced by hydrogen. 



When monohydrochloric glycerine, diluted with its volume of 

 water, was placed in contact with excess of sodium-amalgam, 

 and the mixture left at the ordinary temperature, the amalgam 

 was slowly decomposed with a slight disengagement of hydrogen, 

 and formation of an abundant deposit of chloride of sodium. 



* Comptes Rendus, May 20, 1861. 



