721 
of Edinburgh, Session 1877-78. 
leaves it to the clinical observer to experiment on man with such 
substances as sodium benzoate, sodium salicylate, baptism, euonymin, 
sanguinarin, &c., and thereby to ascertain whether or not these 
substances also stimulate the human liver; and of necessity it is also 
left to him to ascertain in what diseased state the employment of 
this or of that substance is most advantageous. 
Other general conclusions have been already stated at the close of 
Part I. 
2. On a New General Method of Preparing the Primary 
Monamines. Bv E. Milner Morrison, D.Sc. 
3. On the Preparation and Properties of Pure Graphitoid and 
Adamantine Boron. By E. M. Morrison, D.Sc., and E. 
Sydney Marsden, B.Sc. 
4. On Colour in Practical Astronomy, spectroscopically 
examined. By Professor Piazzi Smyth. 
Monday , 1st July 1878. 
Sir WYVILLE THOMSON, Vice-President, in the Chair. 
The following Communications were read : — 
1. On the Disruptive Discharge of Electricity. By Alexander 
Macfarlane, D.Sc., and P. M. Playfair, M.A. 
[Abstract.) 
During the months of May and J une of this session, we have 
endeavoured to investigate certain questions suggested by our 
experience of the discharge of electricity through the gases and 
through oil of turpentine. 
Ordinary paraffin- oil, when used as a dielectric, exhibits the same 
phenomena as oil of turpentine. Gas is liberated by the passage 
of the spark, and at the same time carbon is deposited. Once 
produced, the gas bubbles make the passage of the spark more easy 
through bringing the electrified surfaces nearer to one another; hence, 
