MOVING PICTURES OF MICROBES
During the past two or three years the cinematograph has entered a new
field, which, fifteen years ago, would have been regarded as quite
beyond its reach. With truly wonderful ingenuity the camera is attached
to the microscope in such a way as to make possible the production of
the actual processes of germ life.
The microscope is always a source of infinite interest. The thought
of a whole world of organisms, existent, material, yet so small as to
be invisible, has a peculiar fascination, and we are eagerly curious
to get some conception of their structure and movements. But the
possibility not merely of magnifying the red and white corpuscles of
the blood till they appear like huge hoops, or the parasite of the
sleeping sickness to a length of some two feet, to follow the attacks
of these foes upon the human organism--such a possibility makes one
feel that there is no limit to the power of man over the natural world.
Micro-cinematography is surely one of the serious triumphs of animated
photography. Here again the latter offers itself as a coadjutor to
scientific research, and proves its title to rank among the educational
influences of the age.
Micro-cinematography may be divided into two broad classes--the study
of bacteria, the most minute living organism which the scientific
photographer has ever attempted to catch in motion, and popular
microscopy, or the study of insects, plants, pond life, and so on.
Bacteriological micro-cinematography is an abstruse and difficult
subject for investigation. The microbe is so sensitive to various
influences, and so difficult to handle, that it is a formidable task to
bring it within reach of the sensitised celluloid film and seize it in
its normal condition and environment.
A French professor, Dr. J. Comandon, of Paris, has been for years
absorbed in the study of the blood, its structure, functions, and the
continuous warfare that is waged between the corpuscles, and a host of
parasites as seen under the microscope and the ultra-microscope.
One supposes that the microscope is an ideal instrument for the
investigation of those objects which are so minute as to be beyond
the capacity of the human eye. This, however, is far from being the
case. Briefly described, the microscopic investigation of bacteria is
carried out by one or more of three broad processes, which are regarded
almost as standardised methods. All three, however, possess numerous
shortcomings. Often the bacteria has to be destroyed; and the slide
has to be stained by means of aniline dyes, in order to bring up the
details of the object sufficiently strongly for examinations; for the
majority of the organisms under investigation are transparent, and
their image stands out faintly against the brilliant light. Greater
success is possible with the ultra-microscope than with the microscope.
By its means objects so minute as to be invisible, even with the
microscope, can be thrown as bright points upon a black background,
not necessarily with sizes and forms clearly defined, but yet in such
a way as to enable their positions and movements to be ascertained and
followed.
The disadvantages of ordinary microscopic investigation are obvious.
In many instances as the investigator has to kill the germ before he
examines it, he has perforce to content himself with the study of
coloured corpses of these infinitesimally small organisms.
It occurred to Dr. Comandon that possibly the microscope could be
combined with the cinematograph in such a manner that the microbes
could be photographed distinctly and brilliantly upon the film, and
subsequently projected upon the screen with tremendous magnification,
without the organisms suffering any distortion or other ill-effects.
He realised that if this could be achieved, the scientist would
be provided with a more powerful weapon for the examination of a
particular microbe than hitherto has been available. Furthermore, if
the object could be thrown on to the screen with perfect detail, then,
owing to the tremendous magnification obtained, the study of the life,
movement, and habits of the parasite would be possible under easy and
congenial conditions.
The eminent French investigator approached Messrs. Pathé Frères,
and unfolded his ideas. The technical difficulties in the way were
prodigious, and the field was untested, both in microscopy and
cinematography. However, as there was the possibility of some startling
results being achieved, Pathé Frères decided to collaborate, and
promised to provide Dr. Comandon with every facility he desired.
The work was commenced without delay, and the manufacturers proceeded
with the construction of the special apparatus that was required. This
had to be of an elaborate character, owing to the peculiar conditions;
and exasperating failures attended the early work.
Although a cinematograph picture only measures approximately 1 inch in
width by three-quarters of an inch in depth, the first magnification
was considerable, ranging in the case of bacteria to 300 diameters or
more. This had to be carried out with punctilious sharpness of detail,
because when it came to projection, the magnification was multiplied
enormously, and any error in the original picture or negative would be
proportionately increased.
Bacteria are extremely sensitive to light and heat. Sunlight spells
certain death to the microbe, and as a ray of electric light is
the nearest artificial approach to the luminosity of our sun, its
destructive component, the ultra-violet rays, had to be eliminated.
Again, as the rays from the electric arc in the lantern focussed a
strong heat upon the object, and as this likewise would bring about the
sudden demise of the organism, the heat rays had to be mitigated as
much as possible.
[Illustration: DR. COMANDON’S APPARATUS FOR TAKING MOVING PICTURES OF
MICROBES.
The peculiar difficulties attending cinematographic work with germs
demanded the preparation of special appliances. About twelve months
were spent in experiments.]
These two adverse factors were removed entirely by a novel arrangement.
The illustration shows one of the apparatuses used by Dr. Comandon to
secure his wonderful pictures. It is mounted on a rigid bench, and the
parts which have to be moved to and fro to obtain adjustment, slide
upon a horizontal triangular metal base, to which they are clamped in
the requisite positions to secure rigidity. The lantern is mounted at
the extreme end, and the light, supplied from an electric arc of 30
amperes, is concentrated into a thin ray, or pencil, which falls upon
the object to be photographed, through which it passes to the film. The
illumination may be either direct--that is, it may pass in a straight
horizontal line from the lantern--or it may be reflected by means of
a mirror in a direction perpendicular to the axis of the instrument,
or at right angles, as in the ultra-microscope. The principle adopted
varies according to the subject under observation. The organisms
contained in a drop of blood, for instance, are dropped on to a
carefully cleansed glass plate, which is inserted in the microscope in
the usual manner.
At the opposite end of the bench is the cinematograph camera, which
in this case is provided with extending bellows, as in the ordinary
camera, for purposes of focussing. At the back of the camera is a small
attachment whereby the bacteria, greatly magnified, can be focussed
sharply and clearly upon the film. On top of the camera is mounted
a small box containing the spool of unexposed sensitised film. When
the contents of this are exhausted the box can be removed quickly and
easily, and another charged film box substituted. The film drops from
this box through the gate in the camera, and issues below into a second
film box, which can be removed similarly when filled, to permit another
empty case to be introduced. The mechanism of the camera itself is
the same as that of the usual animated photographic camera, and it is
operated in the same way, by the turning of a handle.
For the purpose of absorbing the heat rays, which in the
concentrated beam of light would kill the microbes within a short space
of time, a glass cell is inserted outside the lantern through which the
focussed beam of light is passed. A stream of cold water is circulated
continually through this water condenser, thus absorbing the greater
proportion of the heat contained in the ray of light, without affecting
its luminosity in any way. It will be observed that this is a reversion
to the first projecting system evolved by the firm of Lumière for the
cinematograph.
[Illustration:
[_Copyright, Pathé Frères._
CINEMATOGRAPH FILMS OF MICROBES.
1. The phenomenon of agglutination in a fowl’s blood.
2. The blood of a fowl suffering from _Spirochæta gallinarum_.]
In order that the organism under photography should not be subjected to
the action of the light any longer than is necessary, a revolving disc,
or shutter, is placed between the microscope and the lantern. This
shutter is fitted with opaque sectors or blades, corresponding to those
in the camera, which at regular intervals eclipse the lens to enable
the film to be jerked forward the depth of a picture intermittently
after each exposure. This cut-off revolves with the camera shutter, so
that when the lens aperture is closed, the light is also cut off from
the organism slide in the microscope. By this arrangement the light
passes through the slide of bacteria only during the fraction of a
second that the celluloid film in the camera is exposed.
The evolution of this ingenious apparatus occupied several months of
continuous work and hard thinking. Indeed, nearly a year was spent in
experiments before a perfect film, suited to public exhibition, was
produced.
As a result of the persevering and patient experiments on the part of
Dr. Comandon and Messrs. Pathé Frères, a new and strange world has been
revealed. The cinematograph, in conjunction with the microscope, has
opened the gates of a kingdom long considered beyond the reach of all
but the privileged few. Not only this; the bacteriological scientist is
provided with facilities to study at ease intricate subjects which had
hitherto baffled his skill. What the microscope is to the naked eye,
the micro-cinematograph is to the microscope.
Some of the pictures obtained by Dr. Comandon are startling to such a
degree as to be incredible. It was my privilege to see one of the first
experimental films thrown upon the screen in the Paris Laboratory.
It depicted the main blood stream of the frog magnified about 25,000
times. The corpuscles were plainly visible, being about the size of
dinner plates. But most extraordinary was the form and movement of
the parasite in the blood stream. This foreign organism resembled
a tadpole in general appearance, and it darted with lightning-like
rapidity to and fro, pressing home its attack upon the corpuscles of
the blood with tremendous energy. One could scarcely believe that the
eye was following the movements of an organism which under natural
circumstances is beyond the scope of that organ. One had the sensation
of gazing into a pond, where the spawn of the frog was in course of
incubation, with specimens of the reptile in its first stages, darting
hither and thither through the water.
Dr. Comandon introduced the spectator to still greater wonders in the
under world. One may see in movement on the screen a drop of blood such
as courses through one’s own body. There are the red corpuscles, or
cells of circular shape as large as saucers, and some are to be seen
piled upon one another like coins. The extent of the magnification
in this film may be seen when it is borne in mind that a cubic space
measuring 61/1000000 of an inch contains some 5,000,000 and 6,000 red
and white blood cells respectively.
But the most fascinating spectacle to which we have been introduced by
Dr. Comandon is the attack of the parasites upon the blood corpuscles,
and the defensive tactics followed by the latter. There is one film
showing blood infected with the trypanosome, discovered by Sir David
Bruce, who was dispatched to Uganda by the Royal Society to investigate
sleeping sickness. This malady is communicated by a species of the
Tsetse-fly, which wreaks tremendous devastation among herds of
cattle and horses in South Africa. For the purpose of this film Dr.
Comandon inoculated a mouse with the parasite, and by the aid of the
micro-cinematograph he shows the action of the disease germ through
successive stages until the animal succumbs.
In the early part of the film the parasites are few in number; they
are seen to dart to and fro among the blood cells with striking vigour
and rapidity, jostling the corpuscles violently in all directions, and
causing them to bounce against one another like india-rubber balls. As
the film advances, showing the progress of the disease, the parasites
are to be seen increasing rapidly in number. At last they appear to
overwhelm the blood corpuscles, this multiplication continuing until
death supervenes some four or five days after injection. The film was
shown lately before a gathering of medical men, and created widespread
interest, as it introduced them to a phase in the life of the parasite
which hitherto had been beyond their comprehension.
Another film shows the “phenomenon of agglutination.” The white cells
of the blood act as the policemen of the stream and maintain a vigilant
outlook for criminals in the form of parasites. When the microbe
offenders come within the strong arms, or embrace, of this guardian,
either they are seized, or serum substances are thrown out by the white
corpuscles, which agglutinate, kill, and dissolve these enemies.
The film shows the blood of a fowl infected with spirochætes. In the
first instance, the microbes are to be seen swimming about actively
in the plasma--the liquid in which the red and white corpuscles are
held. The bird is recovering from the malady; one sees the white cells
engaged in their task of restoring law and order in the blood stream.
The spirochætes commence to congregate, become sluggish in their
movements, forming first strings, and then star-shaped groups. The
white cell appears on the scene, and these enemies gather round him
in a dense clump. The policeman grasps them in a sticky embrace from
which they cannot escape, and in a short time all the spirochætes have
joined one or other of the gatherings about a policeman. The latter
continues to throw out the agglutinate, which locks the enemies as
tightly together as if they were handcuffed. At first they wriggle
and endeavour to escape, but the white blood cell is too powerful.
Their struggles become weaker and weaker until at last they cease. The
policeman completes his victory by devouring the corpses.
One must see these pictures in animation upon the screen to observe the
wonderful definition, detail, and brilliancy which they reveal. The
magnification is immense--the thousandth part of an inch is increased
to three feet or more. When the picture on the screen measures some 16
feet in width, the organism is magnified as much as 50,000 or possibly
100,000 times; a flea is so increased in size that it represents a
fearful prehistoric monster as large as an ordinary dwelling house. A
magnification of 100,000 times the diameter of the original, however,
by no means indicates the limits of the eminent French investigator’s
work. When the necessity arises, the enlargement can be carried to a
far greater degree without any sacrifice of essential details.
Dr. Comandon’s dogged perseverance in the face of disappointments has
been crowned with complete success. Micro-cinematography is on the
threshold of a vast field in which it has tremendous opportunities, the
limits of which it is impossible to define.