407 
of Edinburgh, Session 1868 - 69 . 
our senses. In the course of his argument he advances the pro- 
position that light is the “ immediate cause of burning,” and that 
the light which appears in combustion is “ the extrication of phlo- 
giston, fixed light, or a certain modification of the solar substance 
which had existed in the inflammable bodies, chemically united 
with their elements.” Finally, he winds up with the doctrine that 
“light, heat, phlogiston, and electricity, are so many different 
modifications of the solar substance.” Converting these “sub- 
stances” into qualities of matter, and striking out the lingering 
remnant of phlogiston, we have here the modern doctrine that 
heat, light, and electricity are mere varieties of the same quality of 
matter, and that the Sun is the primary source of them all. 
Theother chexnico- physical paper is “on the Force Exerted by 
Water in Freezing,” deduced from some experiments made in Canada 
in 1786 by Major Williams of the Royal Artillery. He exposed to 
intense frost a thirteen- inch shell filled with water, and plugged by 
an iron bolt. The metal of the shell was about an inch and a-half 
in thickness round the fuse-hole, and two inches and a quarter 
opposite the hole ; and the plug, which weighed two pounds and a 
half, was driven into the hole with great force. At the moment of 
freezing the plug was driven out with such violence as to be carried 
325, 387, and even 415 feet ; and at the same moment a column 
of ice was thrust out of the fuse-hole of the length of four, six, and 
even eight inches and a half. If the plug, however, was secured by 
means of springs, like spiking nails, the shell was split, and the ice 
was thrust out in plates from the fissure. 
From its first foundation the Royal Society of Edinburgh has 
been lavish in its contributions to the several departments of 
Natural Science. At least forty papers were read during the first 
twenty years, and many of them have been published in the Trans- 
actions, on the branches of Zoology, Botany, Topography, Meteor- 
ology, Mineralogy, and Geology. 
In the branch of Zoology, however, there was extreme barren- 
ness at that period in the Society. Mr Kerr, in 1790, notices an 
“Animal ignotum” in the University Museum ; and this is all we 
learn of the animal. That astounding personage, the Great Sea 
Serpent, makes his appearance once on our boards, under the 
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VOL. VI. 
