M. Lourenco on Glycol Compounds. 41 



Hence it is probable that there is no sound which is propagated 

 faster than a thunder-clap, the genesis of which by the electric 

 discharge being extremely violent and almost instantaneous, and 

 accompanied by a large development of heat. 



If the theory here advanced be true, the report of fire-arms 

 should travel faster than the human voice ; and the crash of 

 thunder faster than the report of a cannon. 



It will be admitted, I think, that the expression for the 

 velocity in equation (8) is capable of furnishing any required 

 amount of velocity. The difficulty of putting it to the test of expe- 

 riment lies in our utter inability to say, in any proposed case, what 

 is the value of a. All that it seems possible to do is to observe 

 v, and thence calculate a by the equation referred to ; and then 

 to judge, by the comparison of different observations, whether 

 the calculated values of a — a -1 seem to agree with the observed 

 violence of the electric discharges. 



Sheffield, June 11, 1860. 



[To be continued.] 



IV. Chemical Notices from Foreign Journals. By E. Atkin- 

 son, Ph.D., F.C.S.y Teacher of Physical Science in Cheltenham 

 College. 



[Continued from vol. xix. p. 390. J 



LOURENCO* has prepared several of the compound ethers 

 of glycol. The ethers with a single acid radical are formed 

 according to the reaction 



h*}° 2+ h}°= b U 2 + H 2 0, 



Glycol. Monobasic " J 



acid. 



in which R is an acid radical. The preparation is effected by 

 heating equivalent quantities of the substances together in a 



€ 2 H 4 " 1 

 sealed tube. In this manner the monoacetate C 2 H 3 >9 2 , 



e 2 H 4 " 1 H J 



the monobutyrate G 4 H 7 OV0 2 ; and the monovalerianate 



C 2 H 4 " I H J 



G 5 H 9 ^O 2 have been obtained. The monoacetate prepared 



H J 

 by this method corresponded in properties with that obtained by 

 another process f. The monobutyrate and monovalerianate are 



* Bulletin de la Societe Chimique, p. 90. 

 f Phil. Mag. vol. xvi. p. 433. 



