518 SCIENCE. 
bered, has invited a diplomatic conference to be held 
in Washington upon this subject next year, addressed 
the meeting as follows: — 
“ Now that the important questions submitted to our dcliber- 
ations have received, as I hope, their final solution, and that an 
agreement due to the merit of the cause has been reached, I 
ought, before the convention separates, to declare that the gov- 
ernment and the learned societies of the United States are in- 
spired in this matter, as almost all my eminent colleagues are 
aware, first, with the necessity of the change, and secondly, and 
more especially, with the desire of favoring the interests of science 
as well as those of commerce by land and sea. 
<‘ On the one hand, the civil day, as it now exists, has been pre- 
served; on the other, for scientific and commercial reasons of 
high importance, a prime meridian and a zero of time, applicable 
to allnations, have beenintroduced. These decisions open a new 
era, which will be more and more appreciated, as the progress 
of nations, of international relations, and of science, — which 
knows no latitude nor longitude, — shall bring to light, in their 
assured development, all the advantages of the new system. 
‘“* About ten days ago the great railway-companies of the United 
States and Canada, operating 161,000 kilometres of lines, adopted 
the Greenwich meridian as the origin of time. I consequently 
think that I may express the hope that all the governments repre- 
sented at the seventh conference of the Geodetic association will 
accept, on the recommendation of this conference, the invitation 
of the United States to send delegates to the international con- 
gress which is to be held next year at Washington, with the 
effect of resolving the question of the unification of longitudes 
and of time, and probably of proclaiming the great reform as an 
accomplished fact.”’ 
The mode of reckoning tine proposed by the Geo- 
detic association is substantially to use Greenwich 
mean solar time with the astronomical day. This is, 
perhaps, not absolutely inconsistent with the con- 
tinuance of the system now in use in this country, 
of using Greenwich minutes and seconds with the 
most convenient hour,—a plan substantially the 
same as that first propounded by Professor Benjamin 
Peirce at the very beginning of the agitation for a 
new system. The geodetic congress assures us, 
that while there is nothing impractical in Greenwich 
time, pure and simple, the adoption of the time of 
the nearest whole hour from Greenwich is absolutely 
out of the question, because it would force people to 
get up and go to bed at unseemly or inconvenient 
hours. Indeed, their language would seem to imply 
that apparent as distinguished from mean time is im- 
peratively required. ‘‘ We do not, of course, wish,” 
they say, ‘‘ to suppress local time in common life, for 
that is necessarily and absolutely ruled by the appar- 
ent course of the sun: we do not dream of forcing the 
population of certain countries to rise at noon, nor of 
forcing others to dine at midnight.”’ For people ac- 
customed to regulate their actions by the striking of 
the church-clock, the change of time is certainly 
something more than a mere turning-round of the 
dial of the time-piece; and the European populations 
do go by the striking of bells much more than ours, 
no doubt. Nevertheless, the coming congress must 
be impressed by the eagerness with which our new 
system has been almost universally adopted, and even 
forced by the people upon the authorities. It is, per- 
haps, not surprising that it has been the scientific 
men, the theoretical men, who have been the last to 
judge the change to be practicable. 
[Von. IIL, No. 64: 
THE ORGANISMS OF THE AIR. 
Les organismes vivants de l’atmosphere. Par M. P. 
MiGvuEL,chef du service micrographique a l’obser- 
vatoire de Montsouris. Paris, Gauthier- Villars, 
1883. 8+ 310 p. 8°. 
So much that has been written on the sub- 
ject of the bacteria is merely a recapitulation 
of what has already been done, or a presenta- 
tion of results based upon insufficient observa- 
tions, that it is a pleasure to find a work filled 
with careful investigations carried out on an 
extensive scale. 
The book before us contains no new or 
startling discoveries, but rather gives an al- 
most mathematicai proof of certain generally 
received ideas on the distribution of the 
microbia, and serves conclusively to refute 
certain errors whieh have been widely ac- 
cepted. 
The facts have been obtained by a daily 
analysis of the air taken in the Pare de Mont- 
souris, near Paris. For the sake of compari- 
son, air has also been taken from the centre of 
the city, the hospitals, and sewers. 
After a brief historical sketch of the subject, 
comes a description of the organic and inor- 
ganic particles which have been deposited from 
the air, and which can be distinguished by aid 
of the microscope. Among the most interest- 
ing of the inorganic constituents are minute 
fragments of meteoric iron, which can be col- 
lected by passing a magnet over the dust, 
and of which Mr. Tissandier has made a 
special study. From the organic world are 
found vessels and bits of plants, as well as the 
cast-off shells of infusoria and their eggs, as 
proved by cultivation. 
In order to study the particles suspended in 
the air itself, they must first be collected by 
aspirating a given quantity over a thin glass 
covered with glycerine, and then carefully ex- 
amining the deposit. ‘The cells thus obtained 
can be roughly divided, for purposes of classi- 
fication, into four classes : — 
1. Grains of starch. 
2. Inert pollen of phanerogams, and the 
zoospores of unknown algae and cryptogams. 
3. Spores of cryptogams and zoospores 
capable of producing a perfectly determinate 
alga, lichen, or other fungus. 
4. Entire vegetables, usually unicellular 
plants, among which are to be noticed the 
green algae, the conidia, the yeasts, the débris 
of confervoids, diatoms, ete. a 
The starch comes mostly from the manu- 
factures, but also from natural sources. 
The pollen is never found germinating in the 
