318 
fruits of Singapore and the Malay States are still further 
removed by time and distance. 
At the Exhibition there is shown, from India,a small 
dried apricot (Prunus armentaca, L.), an important 
article of food in the Punjaub Himalayas.and in the 
North-west Provinces, which deserves attention as a 
probable source of an import trade for the English 
market. This fruit is known in India as the mish-mush, 
or ‘Moon of the Faithful.” Dr. Watt remarks that it is 
largely eaten by all classes, fresh or dried, but chiefly 
fresh, and sometimes in preserve by Europeans. Some- 
times the apricots are pressed together, and rolled out 
into thin sheets or “ moons,” 2 or 3 feet in diameter, like 
a blacksmith’s apron. From Afghanistan large quanti- 
ties of the dried fruit are imported into India, and distri- 
buted by trade far into the plains of Bengal. 
Kew D. Morris 
MICROSCOPIC ORGANISMS IN AIR AND 
WATER} 
qs Report is part of the “ Annuaire de l’Observa- 
toire de Montsouris” for the year 1885, and is 
worthy of careful study at the present time, when bac- 
teriology is recognised as a special and important 
department of science. These investigations have been 
carried on at Montsouris since the year 1875, and through 
them Dr. Miquel has been enabled to throw much light 
on the meteorological aspect of the subject—an aspect 
that has received but little attention from investigators, as 
compared with the pathological. Every one will ac- 
knowledge that in entering upon a new field in scientific 
investigation it is extremely important that the line of 
research should proceed upon as broad a basis as possible, 
and that the work of experimentation and observation 
should not be confined to one aspect of the new study, 
however important it may be. Fallacies are sure to arise 
when any department of science is too narrowly special- 
ised, from want ot that more general knowledge which 
would prevent the adoption of erroneous views. This is 
especially liable to be the case in bacteriology, in which 
the objects of study are so minute and yet so widely dis- 
tributed in nature. Dr. Miquel’s researches—important 
as they are in themselves—are doubly welcome at the 
present time, as tending to popularise a field in which 
workers are urgently needed, as well as contributing 
largely to our knowledge. The example of Paris—the 
only city in which systematic investigations of the sort 
are now undertaken—should stimulate other towns which 
possess properly equipped meteorological laboratories, to 
conduct observations on the bacterial organisms contained 
in air, rain, and soil. The results obtained at Montsouris 
could then be confirmed or confuted by the results ob- 
tained at other laboratories under widely different climatic 
and meteorological conditions, and the enunciation of 
general laws and principles would in time become pos- 
sible. We shall endeavour to place before our readers 
in this article some of the more important results and 
deductions made from them by Dr. Miquel, from the 
observations at Montsouris ; but it should be distinctly 
recognised that any conclusions arrived at by Dr. Miquel 
are applicable only to Paris and its neighbourhood, and 
cannot at present be accepted as true for other places 
where the climatic conditions are different. 
Tables are given in the Report, showing for each week 
of the years 1883-84 (a) the average number of bacterial 
micro-organisms present in a cubic metre of air, (4) the 
average barometrical pressure, (c) the average tempera- 
ture of the air, (¢) the average state of humidity of the 
air [percentage of saturation], (e) the amount of rainfall, 
(Ff) the electrical state of the air, (g) the direction and 
7 “‘Septitme Mémoire sur les Organismes Microscopiques de |’Air et des 
Eaux,” par M. le Dr. Miquel, Chef du Service Micrographique a I’Observa- 
toire de Montsouris. 
NATURE 
[August 5, 1886 
average velocity of the wind, (#) the average amount of 
ozone present in the air. From the observations recorded 
in these tables, Dr. Miquel has arrived at the following 
conclusions :—(1) An increase in the number of bacterial 
organisms contained in a cubic metre of air generally 
takes place when the barometrical pressure is high: this 
rule is not absolute, but the exceptions are rare. (2) 
Temperature does not cause such sudden increments ; 
very often, it is true, a large increase in the number ot 
microbes present in the air takes place in summer, but 
it is important to note that a sustained high tem- 
perature causes a manifest lessening in their number. 
The thermometer is capable of explaining certain 
seasonal variations, but not the weekly variations. 
(3) The maximum number of bacterial organisms 
present in the air corresponds almost always with a low 
hygrometric condition of the atmosphere; this is ex- 
plained by the fact that the degree of humidity is always 
very high during rain, and when the superficial layers of 
the soil are soaked in water, periods during which the air 
is always very poor in bacteria. (4) It would appear a@ 
prior? that the number of bacteria should increase with 
the strength of the wind, but observation negatives this 
assumption. A maximum number of microbes is found 
frequently during periods of calm—when the velocity of 
the wind is only 5-10 kilometres per hour—and minima 
have been observed during periods when the velocity of 
the wind was more than 30 kilometres per hour. (5) The 
direction of the wind exercises a considerable influence at 
Montsouris. The greatest number of maxima are noted 
when the wind is N.E., and the greatest number of 
minima when the wind is S.W. (6) When the amount of 
ozone in the air is large, the number of microbes present 
is small. The north winds blow over from Paris and 
contain but little ozone. They are rich in microbes. The 
presence of ozone in the air appears to have the power of 
destroying bacterial organisms, and, on the contrary, 
absence of ozone and humidity of the air—unless rain is 
fallng—allow of an increase taking place in their 
number. 
From observations at Montsouris, extending over a 
period of five years—1880-84—the average number of 
bacterial organisms in a cubic metre of air is stated to 
be: in winter 260, in spring 495, in summer 650, in 
autumn 380; the mean annual number being 445. In 
February the air is poorest in bacteria [the average of 
these five years is 165]. “fowards the middle of summer 
the maxima present themselves [July 700]. 
Observations have also been conducted for a period of 
four years—1881-84—on the state of the air, as regards 
bacteria, in the centre of Paris. These observations were 
made on the air of the Rue de Rivoli, and afford a 
marked contrast in the number of micro-organisms to the 
far purer air of Montsouris, a suburb of Paris, and where, 
it is important to remember, the Observatory is situated 
in the centre of a park. The average of these four years’ 
observations shows that the air of the Rue de Rivoli con- 
tains 3480 bacteria per cubic metre. The seasonal 
fluctuations are nearly the same as at Montsouris, the’ 
minimum being in February (1700) and the maximum in 
July (5010). The average number of bacteria present in a 
cubic metre of air, for the year 1881, was 6295, whilst the 
average number for 1884 was only 1830. This enormous 
decrease—which is observed in the intervening years to 
a slighter extent—is attributed by Dr. Miquel to the better 
drainage and scavenging of the city, and to the better 
cleansing of the gutters and watering of the streets in dry 
dusty weather, in 1884 than in 1881. The death-rate 
from zymotic diseases--in which are included typhoid 
fever, small-pox, measles, scarlatina, whooping-cough, 
diphtheria, dysentery, erysipelas, puerperal fevers, and 
choleraic diarrhcea of infants—has also fallen very con- 
siderably—27 per cent., if increase of population is taken 
into account—during this period. The death-rate of 
ee 
