?. 
256 
which these snakes give me, as I chance upon 
them in my rambles, is, that they are cowardly 
but cunning. Blessed with acute hearing and 
sharp sight, they use both of these faculties to 
the best advantage in the two important events 
of their daily lives,— the capture of their 
food, and eluding their enemies. After thirty 
years of familiarity with the snakes found in 
this neighborhood, I can truly say of them, as 
serpents they are wise, and add, they are 
harmless as doves. : 
Cuaries C. Apsort, M.D. 
PRESENTATION 
MEDALS 
OF THE RUMFORD 
TO PROFESSOR ROWLAND. 
THE special business announced for the meet- 
ing of the American academy of arts and 
sciences on the evening of Feb. 13 was the 
presentation of the Rumford medals, which, at 
the annual meeting in May, had been awarded 
to Prof. Henry A. Rowland of Baltimore. Be- 
fore presenting the medals, the president of the 
academy, Professor JosEpH LOovERING, made 
the following address : — 
The medals awarded to Professor Rowland have 
been struck at the Philadelphia mint, and appropri- 
ately engraved under the direction of the Rumford 
committee. Their delivery to the recipient has been 
postponed for several meetings, under the hope and 
expectation that Professor Rowland would find it 
convenient to be present, and receive the medals in 
person. His attendance with us now is warmly wel- 
comed, and adds greatly to the interest of the occa- 
sion. [ask your kind attention to a brief statement 
of so much of the scientific work of Professor Row- 
land as justifies the award of the Rumford premium, 
and of the relation in which these researches stand to 
the present condition and needs of physical science. 
Astronomy, at least that part of it which relates 
to celestial mechanics, has presented for many gen- 
erations unchallenged claims to a precision not at- 
tainable in any other science. The comparative 
simplicity of its problems, involving only the familiar 
and measurable units of mass, space, and time, has 
enabled it to attain and to hold this distinguished 
position, in spite of the fact that all the senses except 
vision are excluded from its study. If it has received 
any assistance from the experimental laws of me- 
chanics, much more have these laws been illuminated 
by the motion of the planets, where friction and 
other resistances do not interfere. 
After Grove, in 1842-43, had published his lectures 
on the correlation of the various physical forces; 
after Mayer, Helmholtz, and others had published 
their conclusions (the deductions partly of theory, 
and partly of experiment) that these different forces 
were mutually convertible; and after the view first. 
seized in prophetic vision by Bacon, Locke, and Win- 
throp, was experimentally established by Rumford, 
SCIENCE. 
Davy, Joule, and numerous coadjutors, and with — 
ever-increasing clearness, that the assumed caloric 
was imaginary, and that heat was only one kind of 
motion in ordinary matter, —then it was possible to 
introduce unity, harmony, and precision into all the 
physical sciences by making the familiar units of 
measurement universal. As other forms of energy 
(mechanical, electrical, magnetic, chemical, capillary, 
radiant, and gravitation) can be converted, directly 
or indirectly, into heat-energy, heat has become a 
universal standard of energy, current everywhere in 
science, and redeemable. Hence it has become of 
prime importance to determine the mechanical equiva- 
lent of heat: the amount of heat, for example, which 
corresponds in energy to a given mass falling through 
a given height in a given latitude. In this way heat 
and all its dependencies will be measured by the units. 
of ordinary work. For more than forty years, physi- 
cists in difference countries, and by various methods, 
led by Joule, have been engrossed with this measure- 
ment, reaching results which have slowly but happily 
converged towards a common agreement. 
Professor Rowland, after a historical and critical 
review of the methods and results of older cultivators 
in this rich field, has turned up the soil anew, deep- 
ening the furrows. 
The fruits of his long and patient labor were made 
known to the academy in 1879, in vol. xv. of the 
Proceedings. New apparatus was devised; the com- 
parative merits of mercurial and air thermometers 
were discussed; and the various constants of science 
which enter into the case were re-examined. The 
research is a model of ingenious and conscientious 
experimentation, and was not published until it had 
received from its author the same severe criticism 
which he had applied to the work of others. That 
his final conclusion harmonizes so well with the best 
of Joule’s, increases our confidence in both. A 
larger discrepancy might have given a greater show 
of originality; but science would have paid for the 
novelty by a loss of security, and another revision of 
the whole subject would have been entailed upon it. 
When Newton announced his dynamical theory of 
the solar system, as simple as it was comprehensive, 
it made slow headway against the fanciful hypothesis 
of Descartes which was intrenched in all the univer- 
sities of Europe. And yet Newton’s theory reposed 
upon a firm mathematical foundation; while that 
of Descartes submitted to no quantitative tests, and 
contradicted all the known laws of mechanics. The 
history of astronomy from that time almost to the 
present moment tells of ever new victories achieved 
by the combined attacks of the telescope and mathe- 
matical analysis in the province of celestial mechan- 
ics, presenting the law of gravitation as supreme 
dictator to planetary and sidereal systems. But 
these triumphs, complete in their details, and grand 
in their cosmical range, were limited to questions 
which concern the distances, motions, dimensions, 
and masses of the heavenly bodies. 
tation can assign a value to the quantity of matter in 
planets and binary stars; but it asks and can answer 
no question in regard to the quality of this matter, 
[Vou. IIL, No. 56. 
The law of gravi- 
