of 1878 on Pike’s Peak, by the remarkable definiteness of filamentary
structure close to the sun’s limb, and had never found in any
photographs, not even in the excellent ones of Campbell taken at the
Indian eclipse of 1898, anything approaching what he saw in the few
seconds which he was able to devote to visual observations at the
height of fourteen thousand feet. His wish to examine this inner
coronal region with a more powerful photographic telescope than any
heretofore used upon it, was gratified by the most valued loan by
Prof. E. C. Pickering of the new 12-inch achromatic lens of 135 feet
focus, just obtained for the Harvard College Observatory. This lens,
furnishing a focal image of more than 15 inches diameter, was mounted
so as to give a horizontal beam from a cœlostat clock-driven mirror by
Brashear, of 18 inches aperture, and used with 30-inch square plates.
To supplement this great instrument, a 5-inch lens of 38-feet focus,
loaned by Professor Young, was pointed directly at the sun. This
formed images upon 11 × 14 plates moved in the focus of the lens by a
water clock. Specially equatorially mounted lenses of 6, 4 and 3-inch
aperture, driven by clock work, were provided for the study of the
outer corona, and the search for possible intra-mercurial planets.
For the bolometric work, the massive siderostat with its 17-inch
mirror, and a large part of the delicate adjuncts employed at the
Smithsonian Institution in recent years, to investigate the sun’s
spectrum, was transported to Wadesboro. The excessively sensitive
galvanometer reached camp without injury even to its suspending fibre,
a thread of quartz crystal 1-15,000 inch in diameter.
Besides these two chief aims (the photography and bolometry of the
inner corona), several other pieces of work were undertaken, including
the automatic reproduction of the ‘flash spectrum’ by means of an
objective prism with the 135-foot lens, the photographic study of the
outer coronal region, including provision for recognizing possible
intra-mercurial planets, already alluded to, visual and photographic
observations of times of contact, and sketches of the corona, both from
telescopic and naked-eye observations.
The assignment of the observers was as follows: Mr. Langley, in general
charge of the expedition, observed with the same 5-inch telescope used
by him on Pike’s Peak in 1878, which was most kindly lent for this
special comparison by Professor Brown, of the United States Naval
Observatory; C. G. Abbot, aid acting in immediate charge, assigned
with C. E. Mendenhall to the bolometer; T. W. Smillie, having general
direction of the photographic work, made exposures at the 135-foot
telescope; F. E. Fowle, Jr., assigned to the 38-foot telescope; Father
Searle, directing the assembled telescopes for the outer coronal
region, and for intra-mercurial planets, assisted by P. A. Draper
and C. W. B. Smith, exposed two cameras of 3-inch aperture and 11
feet focus, and two of 4½-inch aperture and 3½ feet focus, all four
of these telescopes being mounted on a single polar axis driven by
an excellent clock; De Lancey Gill, assisting Mr. Smillie, removed
the flash spectrum objective prism at second contact, and made a
single long exposure with a 6-inch photographic lens of 7½ feet focus
equatorially mounted; Assistant G. R. Putnam, who, by the kindness of
the superintendent of the United States Coast Survey, was detailed
for latitude,[C] longitude[D] and time observations, also observed
contacts, directed the striking of signals by Mr. Little, and rendered
other valuable services. Mr. Putnam was assisted in recording contacts
by Mr. Hoxie. R. C. Child, observing with a 6-inch telescope of 7½
feet focus, made sketches with special reference to inner coronal
detail, and was in addition charged with all electrical circuits for
chronograph and automatic photographic apparatus. Father Woodman, with
3½-inch telescope, observed contacts and made sketches.
[C] 34°, 57′, 52″ N.
[D] 5h., 20m., 17.8s. W.
The first detachment, consisting of Messrs. Abbot, Fowle, Kramer
(instrument maker) and Smith (carpenter), reached Wadesboro May 4th,
and were soon joined by Messrs. Draper and Putnam. The latter returned
to Washington after a short but satisfactory latitude and longitude
campaign, reaching Wadesboro again just before the eclipse. Other
members of the party reached camp on and after the middle of the month.
The first comers found a very satisfactory shed already erected and
piers begun. Not a day passed from the time of the arrival of the
apparatus, May 7th, to the day before the eclipse, that was not fully
occupied in perfecting the arrangements.
The most striking portion of the installation was the line beginning at
the northwest pier, with its equatorial and cœlostat, continued from
thence south of east by the two great diverging tubes of the 135-foot
telescope and spectroscope. These tubes were covered with white canvas,
presenting the appearance of two immensely prolonged ‘A’ tents, ending
beyond the photographic house, where the 38-foot telescope tube
pointed east and upward at an angle of 42° with the horizon. When the
equatorial, with its large special conical tube camera, with all this
long-branching extent of white canvas ending in the uplifted tube of
the 38-foot telescope, was seen in the light of the moon, the extensive
field with these preparations, exhibited a still more picturesque scene
than by day.
Less imposing, and perhaps more ungainly was the combination of four
great cameras under the main shed, designed to search for new planets
and to depict the outer corona. These might well be described as like
a cabin and outbuilding, mounted on a polar axis, yet, despite their
awkward proportions, they were made to follow very accurately.
The morning of the eclipse dawned cloudless and very fairly clear. Deep
blue sky, such as the writer had seen on Pike’s Peak, of course, is not
among the ordinary possibilities of an eclipse, but the milkiness of
the blue was less pronounced than is usual in the summer season, and
all felt that the seeing promised well.
At fifteen minutes before totality a series of rapid strokes on the
bell called every one to his post, and one minute before the expected
contact five strokes were given as a final warning. Coincidentally
with the actual observation of the second contact by Mr. Putnam, the
first two strokes upon the bell sounded, and the work began. After
82 seconds (the duration of totality from the Nautical Almanac was
92 seconds), three strokes were given as a signal to stop the long
photographic exposures. Scarcely more than five seconds after this the
sun’s crescent reappeared. The duration of totality, as observed by Mr.
Putnam, was approximately 88 seconds.
To visual observers the sky was notably not a dark one. No second
magnitude stars were observed with the naked eye, and most of
the on-lookers saw only Mercury conspicuously, though Venus was
distinguished at a low altitude and Capella also was seen. So high a
degree of sky illumination can not but have operated unfavorably in the
study of the outer corona or in the search for intra-mercurial planets,
and this is to be remembered in connection with what follows.
BEFORE TOTALITY.
A deepened color in the sky, a fall of temperature and a rising breeze
were distinctly noticeable. No change in direction of the wind was
noted. Shadow bands were seen, but those who attempted to measure their
velocity found them too rapid and flickering for any great exactness
in this determination. There was tolerable unanimity among independent
observers as to their size and distance apart (about five inches),
though some thought this less as totality approached.
It was noticed that the birds grew silent just before and during
totality, but true to their nature, the English sparrows were last to
be still and first to begin their discussion of the eclipse, after the
return of light.
DURING TOTALITY.
The attention of all visual observers was at once caught by the
equatorial streamers. Father Woodman’s comparison of the appearance of
a structure of mother of pearl was generally recognized as good, but
different observers differed on the color estimate. A yellowish green
tinge was noted by the artist of the party, Mr. Child, while to others
the light was straw colored or golden.
The general coronal form to the naked eye was nearly that of the
small annexed photograph, which, though taken by one of the smaller
objectives, gives a good view of the relative intensities. The same
extensions of the equatorial corona could be followed by the naked eye
from 3 to 3½ solar diameters.
The visual telescopic observations of the writer gave little indication
of the finely divided structure of the inner corona which he had
noticed at Pike’s Peak. Structure, to be sure, was evident, but not
in such minute subdivision as had then been seen, and though one
remarkable prominence as well as several smaller ones was visible, the
coronal streamers did not give to the writer the impression of being
connected with these prominences, though the relationship of some of
them to the solar poles was abundantly manifest.
AFTER TOTALITY. _Results._
Comparing notes after totality, all observers reported a successful
carrying out of the programme. The greatest interest centers in the
direct coronal negatives taken with the 135-foot telescope. Mr. Smillie
exposed six 30 × 30 plates during totality, with times ranging from one
half a second to sixteen seconds, and three others were exposed by him
immediately after the third contact.
At this writing only a part of the negatives taken have been developed.
Their general quality may be inferred from the examples here given,
after due allowance for the great loss suffered by translation onto
paper even with the best care.
[Illustration: FIG. 1. GENERAL VIEW OF THE CORONA. TAKEN WITH 6 INCH
LENS OF 7½ FEET FOCUS. 82 SECONDS EXPOSURE.]
Fig. 1 is a view taken with one of the smaller objectives (6 inches),
given here to afford the reader an idea of the general disposition of
the coronal light. The upper part is the vertex in the inverted field.
[Illustration: FIG. 2. PROMINENCES ON SOUTHWEST LIMB OF SUN. TAKEN WITH
12 INCH LENS OF 135 FEET FOCUS. 8 SECONDS EXPOSURE.]
Fig. 2 is a portion of one of the great 15-inch circular images
obtained with the 135-foot focus telescope. It was obtained in the
great disc in the last exposure during totality of 8 seconds, showing
one of the principal prominences then on the sun’s disc, with the
disposition of the lower filaments near it.
[Illustration: FIG. 3. NORTH POLAR CORONAL STREAMERS. TAKEN WITH 15
INCH LENS OF 135 FEET FOCUS. EXPOSURE 16 SECONDS.]
Fig. 3 is a portion of one of the same set of plates, but taken with
a 16-second exposure. The part near the sun has, of course, been
intentionally over-exposed, in order to better exhibit the remarkable
polar streamers, extending here to a distance of about six minutes from
the sun, but seen still further in Mr. Child’s telescopic drawing (not
given.)
[Illustration: FIG. 4. DARK ROOM AND TUBES OF 135 FOOT AND 38 FOOT
TELESCOPES. 5 INCH EQUATORIAL IN FOREGROUND, PROF. LANGLEY OBSERVING.]
Fig. 4 is a view of a small part of the great apparatus on the field,
including the terminus of the horizontal tube with its canvas covering,
which has been described as like an extended ‘A’ tent. The photographic
room is seen at the end of the tube, and beyond that the tube
containing the lens loaned by Professor Young pointing directly skyward.
That it will be impracticable to give here all of the disc of the moon
in the large photographs, will be evident when it is considered that
the lunar circumference on each plate is about 4 feet; but it will be
inferred from the examples that the prominences and polar streamers as
well as their features, appear in imposing magnitude and detail.
Many of what it is hoped will be the most interesting photographs still
await development, but Mr. Smillie’s thorough preparation is promising
adequate results.
HEAT OF THE CORONA.
Mr. Abbot, with aid of Mr. Mendenhall, appears to have measured the
heat of the corona, and in spite of previous efforts, this is probably
the first time that it has been really shown to exist. For five minutes
before second contact, the bolometer was successfully exposed to the
region of the sky close to the narrowing crescent of the sun where the
corona was shortly to appear. A diaphragm was interposed in the beam
having an aperture of only 0.4 sq. cm. Deflections, rapidly diminishing
from 80 to 6 mm. were obtained, the last being about 40 seconds before
totality. Then the diaphragm was opened to 290 sq. cm. and a negative
deflection of 13 mm. was observed after totality, where these positive
deflections had just been found, showing that the corona was actually
cooler than the background which had been used at the room temperature.
Next the black surface of the moon was allowed to radiate upon the
bolometer, and the still larger negative deflection of 18 mm. was
observed.
The important result was that the corona gave a positive indication of
heat as compared with the moon.
This heat, though certain, was, however, too slight to be sub-divided
by the dispersion of the prism with the means at hand.
The negatives taken to depict the outer corona show from three
to four solar diameters extension for the longest streamers. The
equatorial ‘wings,’ as they recede from the sun, are finally lost in an
illuminated sky, without any indication of having actually come to an
end.
No attempt to carefully examine the plates taken for intra-mercurial
planets has yet been possible. It is, however, as has been remarked,
doubtful if the very faintest objects will be found, in consideration
of the considerable sky illumination during totality. However, Pleione
in the Pleiades (a star of the 6.3 magnitude), is plainly seen on one
of the plates, and some smaller ones are discernible.
On the whole, the expedition may be considered as promising to be very
satisfactory in its results, and that it was so is largely owing not
only to the efficient care of Mr. Abbot, but to the many gentlemen who
have assisted me with the loan of valuable apparatus, with counsel,
with voluntary service and with painstaking observation, to one and all
of whom I desire to express my obligations.
MALARIA AND THE MALARIAL PARASITE.[E]
BY PATRICK MANSON, M. D., LL. D.,
LECTURER ON TROPICAL DISEASES AT ST. GEORGE’S HOSPITAL AND
CHARING-CROSS HOSPITAL MEDICAL SCHOOLS AND AT THE LONDON SCHOOL OF
TROPICAL MEDICINE.
[E] Abstract of a lecture delivered at the Medical Graduates’
College and Polyclinic, and printed in the _Lancet_ of May 19.
This lecture is devoted to a description of the parasite and of its
life cycles. The existence of a parasite in malarial disease has been
suspected for a long time, but only very recently have we had absolute
assurance that such a parasite exists. Some time in the thirties Meckel
described in the human blood certain black particles which he found
in leucocytes and in certain pale, leucocyte-like bodies the nature
of which he did not know. When he saw these bodies he certainly saw
the malarial parasite. His observations were repeated and extended in
the forties and the fifties by Frerichs and Virchow, and they, too,
undoubtedly saw the malarial parasite. But it is one thing to see and
quite another to recognize; discovery is recognition.
The discoveries of Laveran, Golgi, Marchiafava, Bignami and others
resulted in considerable knowledge of the life history of the malarial
parasite and of the correspondence between its life cycle and the
clinical cycle of the disease. Laveran discovered the parasite; Golgi
described the cycle of the tertian and quartan forms; the others added
new data, especially concerning the more malignant parasites. The
malarial parasite in its mature form has the appearance--I shall take
the tertian parasite as a type--of a mass of pale protoplasm occupying
practically the whole of the red blood corpuscles. Scattered through
this mass of protoplasm are a number of black specks or little rods of
intensely black pigment. Later in the life of the parasite a peculiar
thing happens: all these little specks of black pigment concentrate
usually towards the center of the organism whilst the pale protoplasm
arranges itself into little spherules, the whole constituting what is
known as the ‘rosette body.’ Later in the life of the parasite the
surrounding blood corpuscle breaks away and this rosette body floats
free in the liquor sanguinis and then breaks up into its constituent
spores, setting free at the same time the black pigment clump.
Phagocytes attack many of these free spores and probably absorb most
of them, as well as the little pieces of pigment. The result is the
pigmented leucocyte, so characteristic of malarial blood. A few of
the spores escape and in virtue of some peculiar faculty, which is
not at present understood, enter fresh blood corpuscles and appear
there as pale specks in the hæmoglobin. These pale specks, if watched
in perfectly fresh blood, are seen to be possessed of very active
amœboid movement. They throw out pseudopodia in various directions and
wander about through the hæmoglobin of the corpuscle. After a time
they increase in size by assimilating the hæmoglobin. By and by there
appear somewhere in the parasite those specks of black pigment which
we saw in the mature animal. Later they increase still further in
size until they come to occupy half, and finally nearly the whole, of
the blood corpuscle. Again there is concentration of pigment and the
formation of little sporules. This is the cycle, as described by Golgi,
of the tertian and quartan parasite. The cycle of the tropical or
æstivo-autumnal parasite corresponds in plan almost exactly with that
of the quartan and ordinary tertian parasite.
It was found that the life cycles of these parasites ran parallel
with the clinical cycle of malarial disease. It was found that when
the parasite had arrived at maturity the apyretic interval in an ague
was about to conclude, and that when the parasite had arrived at the
sporulating stage the patient had entered on the shivering stage of
his fever. During that and the succeeding hot and sweating stage the
spores had entered the red blood corpuscles, and when the parasite had
ensconced itself in the red blood corpuscle and begun to grow, the
fever had come to an end. It was found in tertian fever that the cycle
of the parasite took forty-eight hours to complete, exactly the length
of the cycle of the clinical phenomena. In quartan fever the cycle took
seventy-two hours, exactly the length of the clinical cycle of that
form of malarial disease. In the malignant or tropical fevers there was
found to be a similar correspondence between the cycle of the parasite
and the cycle of the disease. It was found that with each recurring
paroxysm of fever there was a renewal of the life of the parasite, and
that in this way the life of the parasite was continued from period to
period and from cycle to cycle for weeks or even, especially in the
case of quartan malaria, for months. Now this explains very well the
way in which the malaria parasite contrives to maintain its existence
in the human body, but it does not explain how it passes from host to
host, neither does it explain certain appearances that Laveran and
everybody else who has studied the subject have witnessed. In malarial
blood you sometimes see that peculiar body, the flagellated body, which
I have already alluded to as consisting of a sphere surrounded by from
one to six or seven long tentacles or arms in a state of continual
agitation. Neither does it explain the peculiar crescent-shaped body
which also so pointedly arrested Laveran’s attention.... Golgi’s
scheme leaves the passage of the parasite from host to host and also
the nature of these two bodies unexplained. What relation have these
two bodies to the life of the parasite? Their nature and purpose do
not receive any illumination from Golgi’s theory. You will find in all
forms of malarial infection, if you look enough, the flagellated body;
but, strange to say, you will not find it in malarial blood immediately
after it is withdrawn from the body. It is only after an interval of
minutes, perhaps a quarter of an hour, after the blood is withdrawn
that these flagellated bodies appear. Whence do they come? If you make
a preparation of malarial blood from a patient by pricking the finger
and spreading a little of the blood on a slide, fixing it immediately
with heat or alcohol and staining it, you will never see any of these
flagellated organisms. But if the slip be kept moist and in a warm
temperature for half an hour and then stained, the flagellated bodies
will be seen, proving that they develop only after the escape of the
parasite from the human body. Such a fact is very interesting and
obviously has some significance in connection with the life of the
parasite. Whence, I ask, come these flagellated bodies? If one of the
crescent-shaped bodies is observed continuously, the following changes
of shape may often be observed: It becomes shorter, loses its crescent
shape and gives off flagella, which may break off and swim about by
themselves. When they come in contact with a blood corpuscle they
straighten themselves out and indulge in a peculiar vibratory movement,
as if endeavoring to penetrate the corpuscle.
Many years ago King, in America, and others too numerous to mention
suspected that the mosquito had something to do with malaria, but in
what way they could not say. Not only civilized observers had this
suspicion, but the savage natives of certain tropical countries had the
same idea. Koch tells us that certain natives of German East Africa
who lived in a mountainous, and therefore non-malarial, part noticed
that when they descended to the malarial regions on the coast they
acquired a fever which they called ‘mbu.’ They said that they were
bitten there by certain insects which they also called ‘mbu’--mosquito
or gnat. They give the same name to the mosquito and to the fever,
therefore obviously these savages associate the insect and the fever
as cause and effect. Peasants in certain parts of Italy have the same
idea, believing that the bite of the mosquito may be followed by the
development of malarial fever.
Laveran, some years ago, in one of his numerous works on malarial
fever, said that possibly the malarial parasite was cared for by the
mosquito in the same way that the latter cares for the filaria of the
blood. He did not, however, formulate a definite theory on the subject.