33° 
to the Venetian Senate ; and in the third he is repre- 
sented as an old man, in his house at Arcetri, dictating 
the geometrical demonstration of the laws of falling 
bodies to his disciples Torricelli and Viviani, On the 
arch above the statue, the astronomical discoveries of 
Galileo—the Italians claim for him the Milky Way, the 
Nebula of Orion, the Phases of Venus, the Mountains 
of the Moon, the Satellites of Jupiter, the Solar Spots, 
and the Ring of Saturn—are represented very effectively 
on a blue ground, Bas-reliefs in marble on the pillars of 
the arch represent his terrestrial discoveries—his country- 
men claim for him the Pendulum, the Hydrostatic 
Balance, the Thermometer, the Proportion Compass, the 
Keeper of Magnets, the Telescope, and the Microscope. 
Beneath the frescoes and around the statue are niches, 
containing some of Galileo’s instruments, his telescope, 
an objective made by the astronomer himself, a propor- 
tion compass, and a magnet, with a keeper which he con- 
structed for it. Immediately surrounding the statue we 
notice the busts of his most celebrated followers, Castelli, 
Cavalieri, Torricelli, and Viviani. In the hall there are 
six cases containing old apparatus, chiefly that of the 
Academy of Cimento. The various thermometers figured 
in the “ Saggi di Naturali esperienzi” of the Academy 
are here to be seen; the vessels they used for showing 
the incompressibility of water; hygrometers ; together 
with astronomical and geodesical instruments. Here, 
also, is the large burning-glass constructed by Bregaus 
of Dresden, employed by Averani and Targioni in their 
experiments on the combustion of the diamond, and after- 
wards employed by Sir Humphry Davy. The various 
inventions and discoveries of the Academy are shown in 
bas-relief on the pillars of white marble. 
The memorial is altogether worthy of the man, and of 
the fine taste of the Florentines. It is, perhaps, the only 
sanctuaire scientifique which exists, but we may hope that 
the example of the Florentines will be followed in this 
and other countries. The Milanese have recently bought 
the collection of apparatus and the MSS. of Volta (for a 
sum, we believe, of 100,000 lire); a suitable museum for 
them will, no doubt, soon be fitted up. It is much to be 
wished that Faraday’s apparatus could be collected to- 
gether in one place, as a memorial to the man. This 
reminds us that soon after the death of Faraday a sub- 
scription was set on foot for the purpose of providing 
some suitable memorial, but we are unable to remember 
whether the designs of the committee were fully carried 
out, and whether the subscription attained the desired 
amount ; if not, it is to be hoped that the matter will be 
kept well before the public. 
We have spoken above of the discoveries attributed to 
Galileo by his countrymen. We are inclined to think 
that some of his claims have been pressed too far ; but 
on such a subject an almost endless controversy might be 
carried on, for we may remember that even the invention 
of the telescope has been claimed for others of his own 
countrymen (Antonio de Dominis and Baptista Porta), 
and by the Dutch ; and the invention of the thermometer 
has been attributed to Cornelius Drebbel, Sanctorio 
of Padua, and others. But if we put all this aside, 
Galileo still stands out pre-eminently as one of the fathers 
of experimental philosophy ; he did not create it, but he 
introduced a taste for it, and enlarged it, and he possessed 
in an eminent degree the true spirit of philosophical in- 
quiry, the ardent love of research, the “ Provando et 
Riprovando” which the Academy of Cimento adopted as 
its motto, 
G, F, RODWELL 
THE SPHYGMOGRAPH AND THE PULSE 
HERE are few valuable instruments or methods of 
: research which have been brought before the scien- 
tific world under circumstances less auspicious than one, 
NATURE 
tras 3 eC ars Nae Rah be! i 
| Aug. 21, 187. 
the inventor of which, the illustrious M. Marey, has quit 
recently visited this country. The sphygmograph, shortl} 
after its first construction, was introduced into thi 
country as an instrument which gave promise of being ar 
invaluable aid in diagnosis, and of such universal appli 
cability as the stethoscope and thermometer. Neverthe 
less, after an existence of mofe than ten years, it may bi 
said that the general impression respecting it is that it 
a failure, that it has not answered its expectations, an 
that it may as well be put aside, together with othe 
curiosities of the physiological laboratory. How this rest 
has come about is not difficult to discover. The instr 
ment is a complicated one, and its indications are eve 
more so. The stethoscope. when introduced, gave resull 
at first sight palpable to the most ordinary minds, an 
the amount of mechanical knowledge necessary for t 
comprehension of some of its most striking result 
scarcely exceeded that of the principle of the commo! 
pump. But with the sphygmograph the case is different 
Its indications are so detailed and so precise that befo 
they can be understood, it is absolutely essential 
several intricate and elaborate problems of hydrodynamic 
and physiology should be thoroughly investigated, a 
more than one of these have not, we are surprised to sz 
yet left the hands of the mathematicians in any decid 
form. How then is it to be expected, as it has been t 
many, that the sphygmograph should be found a valuabl 
assistance in the diagnosis and prognosis of diseasé 
before the physicist and physiologist can give an explané 
tion of the language in which it appeals to them? Ther 
is no doubt that the instrument must be in the hands ¢ 
the student of the healthy body for some time to com 
before its true value in the elucidation of disease will b 
appreciated ; and all additions to our knowledge concern 
ing it must be carefully weighed. ; 
In a thesis for the M.D. Cantab.,* Dr. Galabin ha 
published several results of his sphygmographic work | 
the study of renal disease, and what is more to the poin 
on the present occasion, he gives his own ideas as to th 
analysis of the same trace in health. The fact of th 
author’s being. an accomplished mathematician, as we 
as a student of biology, gives more than ordinary weigh 
to his remarks, and enables him to put several points 
a light which is clearer and more precise than usual. — 
The author does not enter fully into the reasons i 
favour of his views, and does little more than simpl 
state them ; but as they differ in some respects from thos 
generally accepted, they present features of interest t 
workers on the subject. He is one of those who con 
sider the trace as it appears on the recording paper a 
a decidedly duplicate phenomenon, resolving it into th 
true pulsation, together with the oscillations of the leve} 
which necessarily result from the momentum acquired by 
its sudden movement. This he illustrates by superim 
posing on an ordinary pulse curve, as taken by the sphyg 
mograph, an ideal one, such as, according to his concef 
tion, it would be if the instrument correctly followed th 
changes in the diameter of the artery under observation 
the latter being little more than a uniform rapid ris 
followed by a similar but slower fall, that is slightl 
broken by the “dicrotic ” wave, which is produced by thi 
closure of the aortic semilunar valves. The excessiy 
height of the primary rise is supposed to be due to th 
powerful impulse given to the lever at the commencemen 
of the flow of fluid in the artery ; and the small secon 
dary, or “tidal” wave, which occurs just before th 
“ dicrotic,” is supposed to indicate the true arterial expan 
sion, which the lever meets on falling from the height 6 
its impulse. We quite agree with part of this explané 
tion, being fully convinced, from many reasons, thal 
the primary rise, or so-called “ percussion” wave 
is not a percussion wave at all in the ordinar 
* “On the Connection of Bright’s Disease with Changes in the Vascul 
System.” By A, L, Galabin, M.A. M.D., Fellow of Trinity Coll , Camb, 
