WATURE 
- THURSDAY, JANUARY 7, 1897. 
PHYSICAL SCIENCE A HUNDRED YEARS 
AGO. 
Humphry Davy, Poet and Philosopher. By TY. E. 
Thorpe, LL.D., F.R.S. (Century Science Series.) 
Pp. 240. (London: Cassell and Co, Ltd., 1896.) 
HE time is now fast approaching when people will | 
be reckoning up the achievements of the closing 
century. Undoubtedly the great characteristic of the 
times in which we and our fathers and grandfathers have 
lived is the enormously rapid advance which has been 
made in our knowledge of the earth itself and of the 
forces of nature. Middle-aged people can remember the 
time when trains were much less frequent and rapid, the 
telegraph a rather expensive luxury, and when telephones 
were not. If they happen to have crossed the ocean in 
a modern “liner,” or have heard of what can be done 
with modern explosives, or chance to have fallen into the 
hands of the modern surgeon or physician armed with 
anesthetics, antiseptics and hypnotics fresh from the 
laboratory of the synthetical chemist, they are ready to 
acknowledge that things are greatly changed since their 
young days. But it is only after the perusal of such a 
book as this, that the ordinary reader comes to realise 
that all these things are not belated inventions which 
ought to have been given to us sooner, but that the very 
foundations of all physical science were hardly laid a 
hundred years ago. If we try to sum up the position in 
1796, we find that though some advance had been made 
in theoretical mechanics and dynamics, there was very 
little knowledge about heat, light, electricity, or chem- 
istry. It was known, for example, that if sulphur, 
glass, or sealing-wax was rubbed, or bits of zinc and 
copper immersed in salt and water, sparks and shocks 
could be got out of the arrangement, but up to 1800 the 
phenomena of electrolysis were wholly unknown, and 
not till even later were the magnetic properties of the 
current discovered The “corpuscular” theory of light 
held its own till the early days of the nineteenth century, 
and “caloric” was still regarded as a sort of matter 
which could enter into chemical combinations, and could | 
be squeezed out of bodies like water from a sponge. 
Chemistry at the same time was only just emerging from 
the disorder attending the dying struggles of the phlo- 
. gistic doctrine, and even the Lavoisierian system, which 
had taken its place, was disfigured by many errors which 
could only be rectified by a long series of experiment 
more exact than anything which had ever before been 
possible. 
This was broadly the state of physical science when 
Davy appeared upon the scene. Black and Cavendish 
Priestley was ending his days inadistantland. England 
was at war with France, and there were no chemists of 
great note in the Germany of that day. This was also 
long antecedent to the time when chemical and physical 
laboratories for instruction existed in the universities or 
elsewhere, and the young Davy owed his introduction 
to physical science and his opportunities for study, as 
so many of the past generations of chemists and “ natural 
hO. 1410, VOL. 55 | 
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| 
philosophers ” have done, to his association with medicine. 
Born in Penzance in 1778, he was apprenticed, at the 
age of seventeen, to an apothecary and surgeon practis- 
ing in that far western country town where his father’s 
family had been settled since the days of Elizabeth. 
Here, with no other guide than Lavoisier’s “ Elements 
of Chemistry,” he set to work, and in the course of little 
more than a year he had made such progress, and at 
the same time such a reputation, as to obtain release 
from his indentures on his appointment as assistant to 
Dr. Beddoes at the new Pneumatic Institution at Bristol. 
In less than two years from this time we find him re- 
ceiving the offer of a post at the Royal Institution in 
London, then newly started on its career under the in- 
fluence of Count Rumford. 
The story of Davy’s rapid progress towards fame 
is in its main features familiar to the majority of 
educated Englishmen, but probably few persons have 
hitherto so completely realised, as will the readers of 
this book, the poetic element in Davy’s character, 
and the large share it had in determining his choice 
of associates, as well as the extent to which it appears 
to account for the quality of some of his scientific work, 
and the vivacity and ardour with which he pursued 
his discoveries. Apparently Davy only missed being a 
writer of poetry in consequence of the attractions of the 
laboratory, and to speak of him as “‘ poet and philosopher ” 
is to do him no injustice. So early as 1799, soon after 
his arrival in Bristol, his friend Mrs. Beddoes intro- 
duced him to her sister, Maria Edgworth, and to Southey 
and S. T. Coleridge, with whom the acquaintance ripened 
into a warm friendship. Not many years later we find 
him in the company of Scott and Wordsworth in the 
lake country, and with the former, at any rate, the intimacy 
was sustained. 
Concerning Davy’s scientific work, there will perhaps 
always be some difference of opinion as to the relative 
merits of his various discoveries. Some may incline to 
think the isolation of the metals from the alkalis the 
most important ; while others consider the completeness, 
both experimental and logical, of his inquiry into the 
nature of oxymuriatic acid (chlorine), which resulted in 
the establishment of the elemental character of this sub- 
stance, entitle it to be regarded as his most perfect 
scientific achievement. 
The invention of the safety lamp is, of course, in the 
popular idea Davy’s greatest title to fame; but while 
undoubtedly the establishment of the principle of its 
construction represents an important service to science, 
it seems surprising that he should not himself have 
introduced some of the, rather obvious, improvements 
which were made soon after his time by practical men 
with the object of removing some of the defects of the 
| lamp in its original form, as a protection against the 
were elderly men whose active work was over, and | 
dangers of the mine, and of which Davy must himself 
have been aware. The claim that was put forward by 
George Stephenson is discussed fairly in the book, and 
disposed of justly. 
Davy was, of course, much fascinated by the “ galvanic 
phenomena,” and it is therefore remarkable that he 
should have said so little concerning the arc, which he 
was probably the first to observe, and of which he 
ultimately gave a good description. But there is no 
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