14 
NATURE 
[AZay 5, 1870 
Mr. JAMES GLAIsHER has given two lectures for the 
“Sunday Lecture Society” on the evenings of April 24th and 
May Ist., on ‘The Balloon” and on ‘‘Rain.” In the latter 
he gave an interesting account of how rain is derived and how 
measured ; some most carefully prepared tables were exhibited, 
together with diagrams and some excellent photographs of the 
varied forms of snow crystals. The lecture for May 8th will be 
by Mr. Henry Moody on ‘*The Prevention of Infectious 
Diseases.” The importance of this subject, in reference to the 
great object of the society, the social welfare of mankind, will be 
illustrated by the example of Bristol. From being one of the most 
unhealthy, Bristol has become one of the most healthy of cities. 
In the summer and autumn of 1832 the ravages there by cholera 
were enormous ; the deaths alone approaching to 1000! In 1866, 
on the contrary, when the poor at the East-end of London were 
dying by hundreds, the deaths in Bristol were but 26 ; and it will 
be pointed out that this vast difference has arisen from the pre- 
cautions and general sanatory measures adopted by the inhabitants 
and authorities of the City of Bristol. 
M. QUENAULT reports the discovery at Hauteville-sur-mer, 
near toa rock called Maulieu, of a bed of vegetable mould in 
which repose trunks of trees, still holding by their roots, along 
with a layer of turf, At high tide this bed is covered to the depth 
of about twelve inches. The oak alone has preserved its hard- 
ness, the other woods having become quite soft, but still presery- 
ing their colour and even their bark. He supposes the immer- 
sion to have taken place in the eighth century. 
THE ninth reunion of the learned societies of the Sorbonne 
took place on the 20th of April, when M. Le Verrier was ap- 
pointed president, M. Milne-Edwards vice-president, and M. 
Blanchard, secretary of the Section of Sciences ; M. le Marquis 
de la Grange, president, M. Léon Renier, vice-president, and 
M. Chabouillet, secretary of the Section of Archeology ; M. 
Amédée Thierry, president, and M. Hippeau, secretary of the 
Section of History. M. Le Verrier stated that the lectures in- 
stituted at the Sorbonne, which have already been in existence 
ten years, have had already the most beneficial results ; they have 
formed bonds between the savants of France and of the other 
countries of Europe, and have contributed to raise scientific and 
literary labours to a higher and higher platform. 
WE have received Washington papers of the 13th, 14th, and 
15th of April, containinga report of the 13th semi-annual ses- 
sion of the National Academy of Sciences, held in that city. 
The most important papers read were: ‘‘On the coming 
transits of Venus,” by Prof. Simon Newcomb; ‘On meri- 
dional arcs, measured in connection with the United States 
coast survey,” by Mr. J. E. Hilgard; ‘*Craniological ob- 
servations,” by Dr. George Otis; ‘‘ The Northmen in 
Greenland,” by Dr. Hayes ; ‘ Considerations of the apparent 
inequalities of long periods in the moon’s mean motion,” by 
Prof. S. Newcomb ; ‘‘On the influence of the interior structure 
of the earth on precession and nutation,” by Prof, J. G. Barnard ; 
“On a new classification of clouds,” by Prof, Poey, of Havana ; 
“On fluctuations of the barometer,” by Dr. B. F. Craig. 
Prof. Joseph Henry occupied the chair. We purpose giving 
abstracts of some of these pages on a future occasion. 
A NATURAL History Society has recently been established at 
Winchester College ; and a Botanical Section has been formed in 
connection with the Hants and Winchester Scientific and Literary 
Society. 
Mr. LLEWELLYNN Jewirr has issued a prospectus of a pro- 
posed publication, by subscription, of an entirely new, large, and 
comprehensive history, topography, and genealogy of the county 
of Derby. 
A PAPER appears in the last number of the “‘ Proceedings of the 
Royal Society,” by Dr. Herbert Davies, on the law which regu- 
lates the relative magnitude of the areas of the four orifices of the 
heart. He remarks that although to ordinary observation these 
orifices appear to exhibit no mutual relationship of size, there can 
be no doubt that an instrument so accurate in the adaptation of its 
valvular apparatus, and so exact in the working of its different 
parts, must reveal on close examination the existence of laws 
which not only determine the force required to be impressed upon 
the blood traversing its chambers, but also the relative 
sizes of these apertures to one another. On _ converting 
Dr. Peacock’s measurements of the circumference of the 
several orifices into numbers representing these areas it is 
found that in the male the respective mean areas are 
Tricuspid : . P : 1j sq. inch, 
Pulmonic : A f , I yt 
Mitral . 2 5 . ; se + 
Aortic . 5 . 
and on pushing the inquiry further, it is found that there is a dis- 
tinct law presiding over them which is discovered on comparing 
the ratios of the areas of corresponding orifices. Thus— 
Area of tricuspid 1.78 
= —— = 1°4 nearl 
Area of mitral 1.27 4 y 
Areaofpulmonic _ 1 _ / 
Area of aortic a ae 1°3 nearly 
or in other words, the area of the tricuspid appears from these 
calculations to bear nearly the same relation to the area 
of the mitral, which the area of the pulmonic does to that 
of the aortic orifice ; z.¢., were the tricuspid, for example, twice 
the size of the mitral orifice in area, the pulmonic would be 
twice the size of the aortic orifice in area, the two ratios differing | 
from each other only by one-tenth. The same law probably 
holds in the hearts of most animals, the areas of the four 
orifices bearing an exact mathematical relationship to each other, 
so that if the areas of any three of the openings be known, the 
area of the fourth orifice can be correctly calculated. A know- 
ledge of this law, it is obvious, may prove of great impor- 
tance in estimating the amount of contraction or dilatation 
of orifice which may be present in disease. Dr. Davis then 
proceeds to give the reasons for this arrangement, for which — 
we must refer our readers to the original. 
TuatT the white corpuscles of the blood can pass through the - 
walls of the blood-vessels is now admitted by so many observers, — 
that it may fairly be regarded as an established fact. But the 
entrance of a solid body from the outside of the capillaries into 
their interior has, so far as we know, only been observed in one or 
two exceptional instances. Quite recently, however, M. _ 
Saviotti has published a paper in the Cenfra/é/att, in which he 
describes the passage of entire pigment cells from the paren- 
chyma of the web of the foot of the frog through the walls of — 
the capillaries and smaller veins, into their lumen, where having 
arrived, they are swept away by the blood current as < pheno- 
menon of common occurrence, and easily followed. To render 
this evident he excites local inflammation in the w:b by the 
application of a dilute (2 per cent.) solution of sulphuric acid. 
After the lapse of some time the pigment cells of the part 
affected are found to have congregated together round the 
minute yessels in a somewhat contracted condition, their long 
branching process Lecoming materially shorten:d. The con- 
tractility which these cells are known to possess, however, is not 
entirely abrogated. One or more of the processes may be seen 
to insinuate itself through the wall of the adjacent capillary. 
After penetration it may become much elongated, and be even 
altogether carried away by the current cf blood, to the 
movements of which for a time it offers an impediment ; 
or it may, so to speak, drag after it the rest of the cell, which 
after remaining a little while adherent to the inner surface of the 
vessel at the point where it has entered, is swept, or itself swims 
away. Is not this a singular fact? Of whct nature must the 
capillary wall be, that will thus admit the irgress and egress of 
