J 06 



Mr. Graham's Reply to Mr. Phillips. 



to it and passing through the cap in the top of the glass tube, 

 the lower end of the wire being flattened and bent at right 

 angles as in the annexed figure, in which 

 G is the glass tube, W one of the wires 

 resting on C, which is connected with the 

 brass tube T. The other end of the coil, 

 W, dips into the tube T, filled with mer- 

 cury. The ends of the wires and the flat 

 piece at C should be well amalgamated 

 and covered with a clean surface of mer- 

 cury. If the end of the lever be struck 

 rapidly with the palm of the right hand, 

 the left pressing on the short end at D, 

 the sparks at C may be made to follow 

 each other in rapid succession. 



If a mixture of two volumes of hydrogen and one of oxy- 

 gen be introduced into the tube by means of a bent or flexi- 

 ble tube, and the spark made to appear at C, the mixture will 

 be exploded. If the lever be gently struck, the spark still 

 may be made to strike off in the mixture without exploding 

 it, whereas with a smart blow the experiment never fails. 



XXII. Reply to Mr. Phillips's Observations on the Use of 

 Chemical Symbols. By Thomas Graham, Esq., M.A., 

 F.R.S. E., Lecturer on Chemistry in the Andersonian Institu- 

 tion, Glasgow. 



To Richard Phillips, Esq., S,c. 

 Dear Sir, 

 TN reference to your objections to the notation employed in 

 my paper on phosphoric acid, allow me to make the fol- 

 lowing observations. 



The system of notation which I follow is that last proposed 

 by Berzelius ; and convenient as that system is, and as it is ge- 

 nerally adopted on the Continent, I think the introduction of 

 any other at present calculated rather to retard than to advance 

 the progress of chemistry. You are therefore entitled to ask 

 why, in the paper referred to, one atom of water is represented 



by H, while in the tables of Berzelius it is represented by H. 



My answer is, that in common with Gay-Lussac, and all the 

 chemists of this country who have lately published, I consi- 

 der water as composed of one atom of oxygen and one atom of 



hydrogen, a constitution expressed by H in the symbolic lan- 

 guage of Berzelius. Berzelius himself uses the expression H, 



