20 REPORT—1852. 
experiments illustrated very curiously the diminished proportion borne by the effects 
of mutual influence of the parts to those of a non-uniformity in the field of force, in 
similar bodies of smaller ferromagnetic capacity. 

On an Instrument for exhibiting the Colours of Liquids by Transmitted Light. 
By R. W. Townsenp. 
This consisted of a short portable trough for containing the liquids, at the ends 
of which parallel mirrors being placed, by the reflexion of the visual ray or of 
light backward and forward several times, the effect was produced of transmitting the 
ray proceeding from the eye (or a beam of light) virtually through considerable 
thicknesses of the liquid. The author had been led to construct this in order to test the 
common explanation of the deep blue colour of the waters of the Rhone, where they 
enter the Lake of Geneva, and in other places. But his experiment with the in- 
strument did not lead to the conclusion that the natural colour of all pure water 
was blue. Pure spring or rain water when perfectly clear exhibited no colour when 
thus viewed ; but a sunbeam transmitted thus through the water received a beautiful 
deep yellow-green colour. He verified the experiment by afterwards using a very 
long trough without mirrors, and found the results the same. 
On Molecular Action. By Joun Tynvatt, Ph.D., F.R.S. 
In this investigation the author has examined the influence exerted by the peculiar 
structure of wood upon the transmission of heat through the substance. A sen- 
sitive thermoscope was found in a bismuth and antimony couple, and by means of 
cushions of mercury which pressed upon the bodies under examination, perfect and 
uniform contact was obtained. The bodies were reduced to the cubical form. Four 
faces of each cube were parallel to the fibre of the wood; one pair of these faces 
intersected the ligneous layers perpendicularly, and the other pair was parallel to the 
layers. The velocity of calorific transmission was examined in the above three di- 
rections, and the following law of action established by experiments on fifty-seven 
different kinds of wood, both English and foreign :— 
“« At all points not situate in the axis of the tree, wood possesses three rectangular 
axes of calorific conduction: the first and greatest axis is parallel to the fibre of the 
wood; the second and intermediate axis is perpendicular to the fibre and to the 
ligneous Jayers which mark the growth of the tree; while the third and least axis 
is perpendicular to the fibre and parallel to the layers.” 
Two other systems of axes were pointed out by the author as existing in wood ; 
the axes of cohesion and those of fluid permeability. In order of magnitude and 
direction these axes coincide with the axes of calorific conduction, and all three 
systems coincide with the axes of elasticity discovered by Savart. 
On Poisson’s Theoretic Anticipation of Magnecrystallie Action. 
By Joun Tynvatt, PA.D., FLRS. 
Professor Wm. Thomson has drawn attention to the fact, that the discovery of 
magnecrystallic action by Pliicker was anticipated in Poisson’s Theory of Magnet- 
ism; and in a recent number of Liebig and Kopp’s Annual Report, the author’s 
investigations are referred to as particularly confirmatory of this view. Dr. Tyndall, 
however, conceives that the hypothesis of Poisson is by no means sufficient to 
account for magnecrystallic phenomena. Poisson supposed that in crystallized 
bodies the magnetic elements were possibly ellipsoidal; and conceiving the larger 
axes of these ellipsoids all to lie in the same direction, he inferred that a differential 
action, such as that first observed by Pliicker, would be the result. But exactly the 
same results are obtained by a peculiar arrangement of the particles of amorphous 

— 
Pe am 
bs 
