12'1 REFOST — 1872. 



tried as coated -vritli shellac varnish. The comparison between the shellac and 

 the Hay's composition is exhibited in Plate IV., in Avliich the plain lines 

 marked a, c, and n represent the result with the shellac, and the dotted lines 

 marked a', c', and n' that with the Hay's composition. These two results I 

 consider practically identical, since such small difference as is observable 

 might possibly arise from some other difference in the condition of the plane ; 

 and it is observable that with the 5-foot plane n, d' the scarcely perceptible 

 difference is opposite in character to that shown by a', a and b', b. 



The results with Peacock's composition are not shown in Plate V., being 

 practically identical with the other two. 



The tallow surface was tried on the 10-foot plane onlj-, and gave no diffe- 

 rence, the diagrams falling between that of the shellac and that of Hay's 

 composition. 



The glued surface was tried as a specimen of a slimy, fish-like surface, 

 which should partly wash off in the water. The glue was allowed to harden 

 before being put in the water ; and to test its change of condition consequent 

 on immersion, three experiments were tried successivelj' at the same velocity. 

 The resistance was thus found to be throughout on the increase, the first 

 experiment being about two per cent., and the third about four per cent, 

 greater than that of the shellac surface, apparently implying that the resis- 

 tance was increased by the softening of the surface. 



The tinfoU surface is the only surface I have yet tried which I have 

 found to have a resistance greatly different from that of varnish ; and hei'e it 

 is remarkable that the difference tends to be much less in the greater lengths 

 of surface. It is consequently most unfortunate that, owing to the delay I 

 experienced in getting the tinfoil for the purpose, it became impossible to 

 try it on a greater length than the IG-foot plane in time for this Eeport. 

 The comparison of the tinfoil surface with that of the varnish was made on 

 lengths of 16 feet, 1 foot (5 inches, and 1 foot. The results with the 16-foot 

 plane tinfoiled are shown by the dotted Hne marked c" in Plate IV. ; those 

 with the 1-foot and l-foot-6-inch tinfoiled are shown in Plate V. by the 

 dotted lines marked b' and c" respectively. For comparison with these, 

 Plate V. also shows the results of the same lengths varnished, by the plain 

 lines marked b and c respcctivelj'. 



It will be seen by these diagrams that not only is the difference of resistance 

 between tinfoil and varnish proportionately less in greater lengths of surface, 

 but is also proportionately less at greater speeds ; consequently the law of the 

 increase of resistance in terms of velocity is obviously different in the case of 

 the tinfoil from what it is in the case of the varnish and the otlier surfaces 

 ■which were tried. 



Report on the Antagonism betioeen the Action of Active Substances. 

 By Thomas R. Fraser, M.D., Secretary to the Committee, consisting 

 of Sir R. CiiRiSTisoN, Bart., Dr. Laycock^ and Dr. Fraser. 



The subject of the antagonism between the actions of active substances 

 has engaged considerable attention from an early period of medical history. 

 Many examples of its occurrence have been brought forward, whicli may 

 be conveniently classified into those that treat of the antagonism of lethal 

 actions, and those that treat of the antagonism oinon-hthal actions. 



