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BAROMETRIC PRESSURE 




PAUL BERT 
Born October 17, 1833. Died November 11. 1886. 






BAROMETRIC PRESSURE 



Researches In Experimental Physiology 



PAUL BERT 



Translated from the French by 

MARY ALICE HITCHCOCK, M.A. 

Formerly Professor of Romance Languages at the 
University of Akron 



and 



FRED A. HITCHCOCK, Ph.D. 

Associate Professor of Physiology at 
The Ohio State University 






I. 



COLLEGE BOOK COMPANY 

COLUMBUS, OHIO 

1943 



Copyright 1943 

By 

COLLEGE BOOK COMPANY 

F. C. Long, Proprietor 



THE F. J. HEER PRINTING COMPANY 

Columbus, Ohio 

1943 



FOREWORD 

It can be said of Paul Bert as it has been of Vesalius, Harvey 
and Boyle, that the full significance of his work could not be fully 
appreciated until long after his death; but it is tragic that the chaos 
of a far-flung war was required to bring Bert's work into its full 
meaning and perspective. At a time when altitude physiologists 
and flight surgeons are being feverishly trained by all countries at 
war, it becomes of first importance to English-speaking peoples that 
the great classic of altitude physiology should be made available 
in the English language. Copies of the original French edition are 
exceedingly rare, and one therefore cannot praise too warmly the 
industry of Professor and Mrs. Hitchcock in preparing the English 
rendering, and the patriotic foresight of the publishers in thus mak- 
ing the text available to the flying personnel of our Armed Forces. 
That such a task could be accomplished in the midst of war is of 
itself gratifying, for it bears evidence that our perspectives and our 
scholarly traditions are being maintained and will survive during 
these years of stress and fury. As Professor Sigerist recently re- 
marked in reviewing Howard Adelmann's translation of Fabricius, 
"Today when everyone thinks in military terms I would like to 
stress that the publication of such a book at such a time also repre- 
sents a victory equally important to the capture of a strategic 
hill and more endurable. One can have full confidence in the fu- 
ture of a nation which in the midst of a bloody war possesses the 
intellectual and technical resources to produce such a document of 
scholarship." 

The details of Bert's life are not widely known and it seems ap- 
propriate here to give a brief sketch of his meteoric career. Among 
his contemporaries Bert was probably better known for his pioneer 
studies on skin grafting — work that did much toward fostering the 
specialty of plastic surgery during the war of 1870 — than he was 
for his studies in altitude physiology. Indeed in a notice published 



in the Lancet on November 20, 1886, shortly after his death, there is 
no mention of La pression barometrique and little to suggest that 
Bert was a great physiologist. 

Born at Auxerre on October 17, 1833, Paul Bert received his 
early education in the Department of Yonne. He had chosen en- 
gineering for his profession and had entered the College de St. 
Barbe with a view to preparing for the polytechnic school. He was 
dissuaded from this in favor of the law and passed his bar exam- 
inations successfully. But he soon found the law boring to his 
inquisitive mind and, for the third time, modified his course of 
study on becoming acquainted with Gratiolet, the Director of the 
Anatomical Museum in Paris. He eventually obtained his M.D. 
degree in 1863 at the age of thirty. During his years at Paris he 
had come under the influence of Claude Bernard in whose labora- 
tory he served as an assistant. Bernard recognized his ingenious 
mind and predicted a brilliant future. His thesis, published in 
1866, on the grafting of animal tissues, attracted wide notice, and 
it won for Bert in 1865 the prize in experimental physiology offered 
by the Academie des Sciences. After teaching zoology for several 
years at the Faculte des Sciences at Bordeaux, he was appointed in 
December 1869 as Bernard's successor to the Chair of Physiology 
at the Faculte des Sciences at Paris. Bernard at the time occupied 
two chairs, one at the Sorbonne, the other at the Faculte, and he 
resigned the latter to make place for his brilliant pupil. 

During the last two years of the Second Empire, Paul Bert made 
himself conspicuous in the political world by his uncompromising 
republicanism and at the fall of the Napoleonic dynasty in 1870, he 
was rewarded by Gambetta with the Prefecture du Nord. Elected 
Deputy in 1871, he became noted for his constant opposition to re- 
ligious congregation, which led eventually to the decrees of expul- 
sion against the Jesuits, Dominicans and other orders. He was in- 
sistent that the state schools should be taught not by nuns and 
friars, but by non-sectarian personnel. In 1881 he was made Min- 
ister of Public Instruction in Gambetta's famous Grand Ministere, 
but he fell with his chief after an ephemeral exercise of power. 

Following the death of Gambetta, Bert's political influence was 
on the wane and he returned to his scientific pursuits, obtaining a 
vacant chair in the Academie des Sciences. At the beginning of the 
year, the attention of the French Government was forcibly drawn 
to the highly unsatisfactory state of affairs in French Indo-China's 
Province of Tongking, and it decided to send out a Resident Gen- 
eral vested with special powers to effect a thorough reorganization. 

VI 



Paul Bert was chosen for the post since he had always supported 
the French colonial policy, and he departed for the East in Febru- 
ary, 1886. He was enormously active during his first five months at 
Hanoi and did much to effect a complete reorganization of the Tong- 
king government; but in November he became suddenly ill and died 
of dysentery on November 11th, at the early age of fifty-three. 

Paul Bert's activities had turned to altitude physiology about 
1869 as a result of his friendship with a Dr. Jourdanet who had be- 
come interested in mountain sickness through personal experience 
while travelling in Mexico. Jourdanet was a wealthy patron of the 
arts and sciences, and he gave Bert the essential financial support 
for altitude studies, making it possible for him to develop several 
low-pressure chambers for man and animal. In the course of his 
investigations, Bert had sponsored an ascent in a balloon, Zenith, 
in which various determinations were to be made of the constitu- 
tion of the upper air (April 15, 1875) . This ill-fated expedition was 
undertaken by three balloon enthusiasts, MM. Sivel, Croce-Spinelli, 
and the only survivor of the expedition, Gaston Tissandier. The ac- 
count of the trip may be given in Tissandier 's words: 

"I now come to the fateful moments when we were overcome by the 
terrible action of reduced pressure. At 22,900 feet . . . torpor had seized 
me. I wrote nevertheless . . . though I have no clear recollection of writ- 
ing. We are rising. Croce is panting. Sivel shuts his eyes. Croce also 
shuts his eyes. ... At 24,600 feet the condition of torpor that overcomes 
one is extraordinary. Body and mind become feebler. . . . There is no 
suffering. On the contrary, one feels an inward joy. There is no thought 
of the dangerous position; one rises and is glad to be rising. I soon felt 
myself so weak that I could not even turn my head to look at my com- 
panions. ... I wished to call out that we were now at 26,000 feet, but my 
tongue was paralyzed. All at once I shut my eyes and fell down powerless 
and lost all further memory." 

The fatalities on the Zenith were due, in some measure, to com- 
petitive braggadocio, for the English balloonist, Glaisher, in 1862 
had ascended to 24,000 feet and the Tissandier expedition wished to 
outdo him. They had little notion of the dangers, nor were they 
aware of the peril of the fixation of ideas that develops under low 
oxygen tension. 

Paul Bert began to work actively on respiratory problems early 
in the seventies, and in 1874 published a preliminary monograph of 
167 pages entitled: Recherches expcrimentales sur Vinfluence que les 
modifications dans la pression barometrique exercent sur les phcno- 
mcnes de la vie. This is taken up in part with a description of his 
admirably constructed low-pressure chamber. In 1878 he published 

VII 



the book here translated which has become one of the great land- 
marks of physiology — a book which stands as the very cornerstone 
of modern altitude physiology, La pression baromctrique. Re- 
cherches de physiologie expcrimentale , containing 1178 pages and 
89 text figures. The first 522 pages deal with the history of altitude 
physiology up to that date; and if Paul Bert did nothing else, we 
should be lastingly in his debt for this masterly historical presenta- 
tion — a model, be it said, for any student wishing to write in the 
field of medical history. The second part, occupying 518 pages, con- 
tains experimental protocols; the third and final part, which runs to 
118 pages, contains his resume and conclusions, and is again a model 
of concise, orderly and logical scientific presentation. 

What precisely did Bert prove? There had been sharp diver- 
gence of opinion whether mountain sickness was due to diminution 
of barometric pressure per se, or to diminution of oxygen pressure. 
Bert performed critical experiments, keeping the absolute pressure 
of oxygen constant while lowering the total atmospheric pressure, 
repeating them time and again both in animals and man. By so 
doing he proved beyond all doubt that the principal symptoms of 
altitude sickness arise from reduced partial pressure of oxygen and 
not from diminution of total pressure. He thus applied for the first 
time to human respiration Dalton's concept of partial pressure 
which has become the basis of all subsequent work in the field of 
altitude physiology. 

In one of his vivid lectures on the history of physiology, Sir 
Michael Foster said that science travels in circles: the concept fol- 
lowed yesterday may be dropped today and rediscovered tomor- 
row. One of those who did not accept Paul Bert's conclusions was 
that picturesque physiologist of Italy, Angelo Mosso, who main- 
tained that at altitude one breathed so deeply that carbonic acid 
was lost with resulting alkalosis, and that oxygen-want played 
only a small part in mountain sickness, the major symptoms be- 
ing due to "acapnia"— loss of carbon dioxide. Few in this century, 
save Yandell Henderson, have paid due attention to Mosso and 
acapnia, but we are coming once again to heed what he said. More 
is known now about acid-base relationships in blood and tissues. 
The carotid sinus reflexes have also been discovered. When blood 
of low oxygen saturation reaches the carotid sinus, a reflex in- 
crease in depth and frequency of respiration occurs. The partial 
pressure of oxygen is a primary and determining stimulus as Bert 
maintained; but under conditions of low oxygen tension, hyper- 
ventilation of serious proportions may occur, and we have reason 

VIII 



to believe that pilots in the higher altitude ranges may in some 
circumstances hyperventilate to such an extent as to bring on 
tetany and even loss of consciousness. 

Thus the pendulum swings; and if we wish to gain perspective 
for tomorrow, we look to the past and to the work of men like 
Robert Boyle, Paul Bert and Angelo Mosso who give us courage 
and inspiration to face the future. 

John F. Fulton. 
Yale University, 
August 15, 1943. 



IX 



TRANSLATORS' NOTE 

In his preface Paul Bert comments on his use of direct quota- 
tions in the historical part of this book in the following words, "In 
my bibliographic research I have repeatedly seen the affirmations 
of an author changed to negations by a series of translations and 
analyses." Again in a footnote on Chapter II he calls attention to 
the fact that a passage which he quotes from the French translation 
of the account of the balloon flights of Glaisher and Coxwell did not 
occur in the English text and adds, "Can it have been added by a 
fanciful translator? Traduttore, traditore" (translator, traitor). 
This evident distrust of our author for translators has been con- 
stantly in our minds and our translation is, therefore, somewhat 
more literal than it might otherwise have been. This policy has 
resulted in the use of certain words and expressions that are old 
fashioned; for example, we have used the word hematosis to mean 
arterialization of blood and we have retained the expression car- 
bonic acid, even where our author is obviously referring to carbon 
dioxide. 

In only two respects have we departed from the plan followed 
in the French edition. First, the footnotes, instead of being placed 
at the bottom of the page on which the reference occurs, have been 
grouped together and put at the end of the several chapters. This 
method is made mandatory by the mechanics of modern type set- 
ting, and also greatly improves the appearance of the page. Second, 
we have added an index. In the French edition there was no index 
and the detailed table of contents together with the list of illustra- 
tions was placed at the end of the book. In the English edition these 
have been moved to the front of the book and the index put at the 
end. 

We wish to acknowledge our indebtedness and express our grati- 
tude to the John Crerar Library of Chicago for the uninterrupted 
use of a copy of the original French edition of La Pression Baro- 
metrique over a period of more than two years. Copies of the book 

XI 



were also loaned us for shorter periods by the Library of Congress 
and by the Aero-Medical Laboratory at Wright Field. Photographic 
copies of the illustrations in the original edition from which the 
plates for the present volume were prepared were furnished us by 
the staff of the Wright Field Aero-Medical Laboratory. We are 
grateful to Colonel Otis O. Benson, Jr., who arranged to have this 
done. 

Various agencies of the Ohio State University were of consider- 
able assistance in a number of ways. Funds to help defray the cost 
of clerical assistance were furnished by President Bevis, and by 
the Graduate School upon the recommendation of Dean Alpheus 
Smith. The staff of the library furnished assistance whenever 
called upon, and Mr. Oscar Thomas and Mr. John B. Fullen of the 
Alumni Office were of great assistance in a variety of ways; we are 
especially grateful to them both. 

Finally, we want to thank Professor John F. Fulton of Yale 
University not only for the preparation of the foreword, but also for 
his enthusiastic support and valuable advice throughout the entire 
project, and Mr. F. C. Long of the College Book Company, without 
whose vision and faith in Paul Bert the publication of the complete 
translation would have been impossible. 

It is with some hesitation that we turn the manuscript over to 
the printer. It contains errors and imperfections. Many of these 
could be corrected by further revision, but such revision takes time 
and in the present state of the world it seems desirable to make 
Paul Bert's classic work available to the many English speaking 
investigators in the field of aviation medicine with as little delay 
as possible. We have therefore foregone further revision and polish- 
ing. We know nothing would please Paul Bert more than the 
knowledge that his work had been of use to the Allied Nations in 
their struggle to free his beloved country from the shackles of its 
traditional enemy. Paul Bert was a liberal, a humanitarian, and 
a loyal patriot, as well as an outstanding scientist. During the 
months that we have worked on the translation of his great book 
our admiration and respect for him have grown. It is our sincere 
hope that we have made none of his affirmations negations and 
that we have been translators without being traitors. 

M. A. H. 
F. A. H. 



XII 



TO DOCTOR JOURDANET 



My dear Colleague: 

It is to you that I owe, not only the first idea of this 
work, but also the material means to execute it, which 
are so difficult to collect. I have been very happy to 
see physiological experimentation on one of the most 
important points of my study confirm entirely the 
theory which your intelligence had deduced from nu- 
merous pathological observations collected on the high 
Mexican plateaux. For all these reasons I should dedi- 
cate this book to you, and I do so with the greater 
pleasure because you are one of those persons who 
would make gratitude easy to even the most thankless 
natures. 

Paul Bert. 



XIII 



PREFACE 

No one doubts the considerable influence which changes in baro- 
metric pressure can exercise on living beings; we are even inclined 
to exaggerate its importance. If the barometric column rises or 
falls some millimeters, nervous or asthmatic people experience 
favorable or painful symptoms which they attribute to the heavi- 
ness or the lightness of the air. If this were really the cause, a 
walk from the banks of the Seine to the top of the Butte Mont- 
martre or the converse should produce similar results in the same 
people. 

But outside this group of data, to which I shall return in a mo- 
ment, many remain which present a much greater interest, and 
which deserve to be studied with perseverance. 

Are we dealing with increase in pressure? When, in the shafts 
of a mine or in the caissons intended to become the piers of a 
bridge, workmen are protected against the invasion of the water 
by air compressed by powerful machines to several atmospheres, 
they experience strange and sometimes dangerous symptoms dur- 
ing or after their stay in compressed air. Likewise divers who 
gather pearls, sponges, or coral, or attempt the salvage of sunken 
ships, furnished with diving apparatus and breathing an air whose 
pressure is proportional to the depth they reach, are frequently 
stricken by paralysis or death. On the other hand, medicine, mak- 
ing use of observations that are already old, has attempted with 
considerable success to make use of the influence of air at suitably 
low pressures, since the time of Junod, Pravaz, and Tabarie. 

Are we dealing with decrease in pressure? We can mention 
first the symptoms which threaten aeronauts when their ascent 
brings them to heights above 4000 meters: nausea, vertigo, hemor- 
rhage, syncope; then the phenomena which have been known much 
longer by all those who have attempted the ascent of mountains 
of over 3000 to 4000 meters, mountain sickness, about whose cause 

XV 



so many strange hypotheses have been suggested. Finally we 
find here data of a much greater importance. It is no longer a 
matter of a few workmen, a few invalids, or a few tourists, but of 
whole populations which normally and regularly live, construct 
cities, group themselves as peoples, in these lofty places where 
painful and sometimes unendurable sensations await the traveler. 

We feel that here our problem affects not only the hygiene of 
peoples, but also to a certain point, their history and politics. In 
the Himalayas, in the Cordillera of the Andes, populous cities are 
built at heights greater than that of our Mont-Blanc, where no one 
completely escapes mountain sickness; in Mexico, thousands of 
men live on the plateaux of Anahuac, at an average height of 
2000 meters; the great civilizations of the Mayas and the Nahuas 
had their maximum of development between 2000 and 4000 meters 
above sea level. 

The reader can see by this brief survey in what important 
points the question affects the experimentation to which I have 
conscientiously devoted myself. It will consequently seem natural 
that such phenomena have given rise to numerous publications by 
doctors or travelers; but he will no doubt be surprised that so little 
has been attempted in laboratory experimentation to explain their 
cause. The simplest idea apparently would have been to construct 
apparatuses permitting one to reproduce changes in barometric 
pressure, isolating them from secondary conditions, uncontrolled 
variables, which inevitably accompany them in the state of nature, 
and to examine the immediate results of these changes on man and 
on animals. Now very little has been done in this direction. On 
the other hand, we shall find incomplete observations, pretentious 
dissertations, and probable or absurd explanations in great number. 

My purpose has been to fill this considerable gap, and to solve 
these important problems by a purely experimental method. 

In taking my position thus on solid ground, I had to set 
aside systematically three kinds of questions which could not be 
attacked in the laboratory, and for which consequently absolute 
conditions of proof could not be collected; that is: daily variations 
of the barometer, therapeutic applications and acclimatization in 
lofty places. 

I do not regret the first question, which does not seem to me 
even to belong to our subject of study. Slight modifications in air 
pressure revealed by the barometric column in a given place are 
accompanied by too many other meteorological phenomena (hygro- 
metric, electric, etc.) for anyone to determine the part, certainly 
very small, which they play in the condition of certain invalids. 

XVI 



\ ■ 

As to the other two questions, I have made great use of data 
given by authors who have discussed these topics, and I think that 
my own studies will not be without value in guiding physicians 
and hygienists in the midst of the innumerable difficulties which 
these questions involve. But I have not handled them directly, not 
only because of my medical incompetence, not only because labora- 
tory experiments on birds, dogs, or even men could hardly settle 
them, but also for a special and rather personal reason. 

Eight years ago, when Dr. Jourdanet, well known for his re- 
markable studies on the climatology of Mexico and for his theory 
of the anoxemia of altitudes, offered— with a generosity for which 
I hope the results of my work might be worthy recompense— to 
put at my disposal all the material means required by the re- 
searches whose importance and difficulty I had publicly indicated x 
in 1868, a sort of tacit agreement was established between us. I 
was to limit myself to studying experimentally in the laboratory by 
means of my instruments the modifications which changes in baro- 
metric pressure would produce in the vital manifestations of ani- 
mals or plants. Whatever the extent of my experimental equip- 
ment, these changes evidently could not be of long duration, so 
that if they were to produce convincing results, it was absolutely 
necessary that they should be extensive. Besides, this is the pe- 
culiar characteristic of laboratory experiments. 

M. Jourdanet properly reserved for himself the study of the 
effects produced by slight variations in barometric pressure, acting 
either for a rather brief time upon invalids — a test the exquisite 
delicacy of which will always terrify experimenters a little— or for 
years upon the same individuals, or for centuries upon successive 
generations, joining their effect to those of so many causes known 
or unknown; dangerous problems, but very likely to fascinate a 
wise and eager spirit, aided by an eloquent pen. 

We both accomplished our tasks; two years ago, M. Jourdanet 
published his fine book, Influence of Air Pressure on the Life of 
Man: Altitude Climates and Mountain Climates. 2 

As for me, delayed by efforts outside the field of science, too 
often called from my laboratory by important civic duties, it is 
not until today that I present the properly arranged results of my 
long researches. 

The present book which, if I am not mistaken, holds interest not 
only for physiologists, but also for physicians, engineers, and even 
travelers, is divided into three parts: history, experiments, con- 
clusions. 

XVII 



I have given the greatest pains to editing the history. I have 
tried to collect all that has been written on the subject of my study. 
It seemed to me that it would be very interesting for the reader to 
have thus before him all the pieces of evidence, with infinite 
variety of narration, frequent contradiction, and often instructive 
repetitions. I thought it best to give the actual works of the authors 
quoted: I distrusted even the most conscientious analyses; in my 
bibliographic research I have repeatedly seen the affirmations of 
an author changed to negation by a series of translations and anal- 
yses. Besides, summarizing and analytical chapters rest the mind 
of the reader; but each of the facts given there finds its proof in 
the preceding extracts. 

In the second part my personal experiments are recorded. The 
titles of the chapters show the order in which I planned their 
exposition. A glance at the table of contents indicates that after 
studying directly the influence of changes in barometric pressure, 
I have devoted a few chapters to new researches on the physio- 
logical action of carbonic acid, on asphyxia, and on blood gases. 
The reader will see in perusing these chapters that I have not 
wandered as far from my subject as this mere statement of topics 
might imply; the numerous references to this part of my book that 
I make in my conclusions give evident proof of this fact. 

In reporting my experiments, which number about 670, I have 
used the enumerative method; all those which seem to me inter- 
esting have been reported at length. This method has two advan- 
tages: first, it furnishes proof of all the conclusions, and second, it 
sometimes permits the reader to find in the account of the experi- 
ments what the author did not see there himself. Summaries added 
to each chapter facilitate rapid perusal of the results obtained. 
Finally I call attention to the fact that on each point the experi- 
ments are listed according to their date of performance; one can 
thus take account of observations which escaped attention at the 
beginning of the research, of improvements made by the experi- 
menter, and consequently of the constantly lessening number of 
causes of errors. 

Finally the third part is entitled: Recent Data, Summary and 
Conclusions. I first discuss the history which in the first part I 
carried down only to my own work. Then I draw conclusions from 
my whole series of researches. It will be seen that here my agree- 
ment with M. Jourdanet could not be carried out literally, and that 
I could not keep from trespassing somewhat on the domain 
reserved for him. 

The third and last chapter, whose title is General Conclusions, 

XVIII 



contains only three pages. May this temperance in the summary 
bring me pardon for the eleven hundred and fifty pages which I 
thought necessary in order to bring the reader to this point! I 
leave to others the delicate task of deciding whether this antithesis 
deserves criticism or praise. I shall merely remind the reader, 
pleading at last extenuating circumstances, that since the Institute 
did me the honor in 1875, on the recommendation of the Academy 
of Sciences, of bestowing upon my work the grand biennial prize, 3 
it seemed to me that it was my duty to spare myself neither time 
nor trouble to make the publication of my work more worthy of 
this great award. 

Before finishing this preface, I must thank M. Grehant and M. 
Dastre, my assistants in the chair of physiology of the Faculty of 
Sciences, Dr. Jolyet, assistant director of the laboratory, and M. 
Paul Regnard, assistant in the course, who aided me in my research 
with affectionate devotion. 

P:B 
October, 1877. 



1 See my Lessons on the Comparative Physiology of Respiration; Paris, 1870, pages 121-130. 

2 Paris. C>. Masson. 1875. Second edition. 1876. 

3 This award of the first order is given every other year, according to the terms of the con- 
stitutional decree, "to the work or discovery which has made the greatest contribution to the 
honor or the service of the country" in the last ten years, in rotation for each of the branches 
of human learning represented by the five classes of the Institute. 

The triennial prize, by the decree of April 14, 1855, was decreed to M. Fizeau, in 18o6; 
it was triennial only once, and by the decree of December 22, 1860, at the request of the Institute, 
it became biennial, and since then the awards have been as follows: 

To Thiers (Academie franQaise), 1861. 

To Jules Oppert (Academie des inscriptions et belles-lettres), 1863. 

To Wurtz (Academie des sciences) , 1865. 

To Felicien David (Academie des beaux-arts), 1867. 

To Henri Martin (Academie des sciences morales et politiques) , 1869. 

To Guizot (Academie franQaise), 1871. 

To Mariette-Bey (Academie des inscriptions et belles-lettres), 1873. 

To Paul Bert (Academie des sciences), 1875. 

To Chapu (Academie des beaux-arts), 1877.— (Editor's note.) 

XIX 



TABLE OF CONTENTS 

First Part 
HISTORICAL 

Page 

Title I. Diminished pressure 3 

Preliminary chapter: the lofty regions of the globe. 3 

Europe " 

Asia 10 

America *2 

15 



Africa 



Islands 15 

Summary 16 

Eternal snows ^ 

Living organisms 18 

First chapter. Mountain journeys — 22 

1. South America 22 

The Conquerors. Acosta. De Herrera. Frezier. Bouguer. 

La Condamine. Don Ulloa. A. von Humboldt. Wars of Inde- 
pendence. S. Haigh. Miers. Caldcleugh. Schmidtmeyer. 
Brand. De la Touanne. Temple. Bollaert. D'Orbigny. Poep- 
pig. Boussingault. Meyers. Ch. Darwin. Smyth and Lowe. 
Arch. Smith. CI. Gay. Von Tschudi. De Castelnau. Weddell. 
De Saint-Cricq. Gillis. Lloyd. Grandidier. Burmeister. 
Markham. Martin de Moussy. Mateo Paz Soldan. Guilbert. 
Pellegrino Strobel. Focke and Mossbach. Pissis. Wisse. 
J. Remy. Steubel. 

2. Central and North America 59 

Wafer. Dollfus and 'de Montserrat. Burkhardt. Elliotson. 
Glennie. Gros. Truqui and Craveri. Laverriere. Scientific 
Commission of Mexico. Von Muller. Fremont. Gunnison. 
Hines. Williamson. Coleman. 

3. Etna 69 

Bembo. Filoteo. Fazello. Borelli. Riedesel. Demeunier. 
Houel. Delon. Dolomier. Spallanzani. Ferrara. De Gour- 
billon. De Forbin. De Sayve. 
XXI 



Page 

4. Peak of Teneriffe 73 

R. Boyle. Edens. Feuillee. Glas. Riche and Blavier. Von 
Humboldt. Cordier. L. de Buch. Dumont d'Urville. Le 
Guillou. Ch. Sainte-Claire Deville. Itier. Madame Murray. 

5. Alps _' 77 

Bourrit. Laborde. De Saussure. Beaufoy. Forneret and Dor- 
theren. De Lusy. Van Rensselaer. Hamel. Clissold. Clark 
and Sherwill. Hawes and Fellowes. Auldjo. Meyer. Parrot. 
Vincent and Zumstein. Molinatti. Hugi. H. Cloquet. Martin 
Barry. Atkins. Mademoiselle d'Angeville. Desor. G. Studer. 
Spitaler. Forbes. Lepileur. Bravais. Martins. Chomel and 
Crozet. Tyndall. Tyndall and Frankland. Pitschner. Piachaud. 
Lortet and Marcet. Durier. A. Tissandier. Hardy. Tuckett. 
Kennedy. C. Grove. Visconti. Gamard. Joanne. Ormsby. 
H. Russell. 

6. Pyrenees 120 

Rob. Boyle. Dralet. Ramond. Arbassiere. Cordier and Neer- 
gaard. Parrot. De Franqueville. Russell-Killough. Le Mula- 
hacen. 

7. Caucasus. Armenia. Persia 123 

Engelhardt and Parrot. Kupffer. Sjorgrun. Radde. Douglas 
Freshfield. Gardiner. 

Rob. Boyle. Tournefort. Parrot. Chodzko. Radde and Siev- 

ers. Hamilton. 

Taylor Thomson. R. F. Thomson. 

8. Central Asia i 128 

Marco-Polo. Hiouen. Tsang. Chinese Itinerary. Missionaries. 

S. Turner. Th. Hardwicke. Moorcroft. Fraser. Webb. 
Gerard Brothers. Johnson. V. Jacquemont. Wood. Burnes. 
Father Hue. Hoffmeister. Th. Thomson. Dalton Hooker. 
Robertson. Mistress Hervey. Oliver. Cheetam. Semenof. 
Schlagintweit Brothers. Godwin-Austin. The Pundits. The 
Mirza. Hayward. Faiz Buksh. Henderson. Hume. Drew. 

9. Africa 161 

Burton. Mann. Rebmann. De Decken. New. 

10. Volcanoes of the Pacific 162 

Low. Brooke. Braddel. Rutherford Alcock. Gubbins. Jef- 
freys. Byron. D. Douglas. Loenenstern. Wilkes. 

Chapter II. Balloon Ascensions 171 

Charles and Robert. Leullier-Duche. Testu-Brissy. Blanchard. 
De Lalande. Robertson. Garnerin. Zambeccari. Biot and Gay- 
Lussac. Andreoli. Beaufoy and Sadler. Madame Blanchard. 
Eug. Robertson. Green. Comaschi. Hobard. Barral and Bixio. 
Welsh. Glaisher. Croce-Spinelli and Sivel. Simons. 

Chapter III. Theories and Experiments 195 

Acosta. Fr. Bacon. Academy del Cimento. Van Musschenbroeck. 
Robert Boyle. Huyghens and Papin. Beale. Veratti. Cigna. 
Darwin. Borelli. Bouguer. Ulloa. Haller. De Luc. Bourrit. 

XXII 



Page 
De Saussure. Fodere. Halle and Nysten. Courtois. Legallois. 
Dralet. Gondret. Fraser. Govan. Gerard Brothers. Hodgson. 
H. Cloquet. Clissold. Roulin. J. Davy. Rostan. Cunningham. 
Burdach. Poeppig. Boussingault. De Humboldt. Junod. Magen- 
die. Favre. Barry. Martins. Rey. Tschudi. A. Smith. Hill. 
Maissiat. Flechner. Brachet. Castel. Vierordt. Lepileur. A. 
Vogt. Father Hue. Przevalski. Pravaz. Payerne. Marchal de 
Calvi. Speer. Mayer-Ahrens. Lombard. Valentin. Heusinger. 
Giraud-Teulon. F. Hoppe. Fernet. Longet. Gavarret. Duval. 
Lombard. Martins. Guilbert. Jourdanet. His discussions with 
Coindet. Cavaroz. Tardieu. Foley. Liguistin. Leroy de Meri- 
court. Gavarret. A. Dumas. Scoutetten. Kaufman. Coindet. 
Gavarret. Von Vivenot. Flemeing. Bouchard. Beclard. Hudson. 
Piachaud. Lortet. Marcet. Forel. Clifford-Albutt. Dufour. 
Javelle. Tyndall. Durier. Russell-Killough. Mistress Hervey. 
Henderson. Drew. Burton. Hunt. Jaccard. Armieux. Gosse. 
Jourdanet. The Academy of Medicine in 1875. Virlet d'Aoust. 

Chapter IV. Summary and Criticisms 315 

1. Conditions of the appearance of mountain sickness 315 

2. Symptoms of mountain sickness 328 

3. Theoretical explanations 335 

Pestilential exhalations. Electricity. Lack of oxygen in the 

air. Fatigue, cold. Theories of M. Lortet and M. Dufour. 
Lessening of the weight supported by the body. Escape of 
blood gases. Expansion of intestinal gases. Relaxing of the 
coxo-femoral articulation. Other mechanical actions. Excess 
of carbonic acid in the blood. Theory of de Saussure and 
Martins. Theory of M. Jourdanet. 

Title II. Increased Pressures 353 

Chapter I. High pressures 355 

1. Diving bells 355 

Sturmius. Halley. Spalding. Brize-Fradin. Hamel. Colladon. 

2. Apparatuses constructed in the Triger method 358 

Papin. Triger. Trouessart. De la Gournerie. Blavier. Pol 
and Watelle. Comte. Bouhy. Brunei. Cezanne. Regnauld. 
Babington and Cuthbert. Francois, Bucquoy. Foley. Nail. 
Hermel. Limousin. Bayssellance. Gallard. Triger. Barella. 
Eads. Bauer. Malezieux. Unpublished information. 

3. Divers with suits 390 

Borelli. Halley. Leroy de Mericourt. Denayrouze. Gal. 
Sampadarios. 

Chapter II. Low pressures 411 

Junod. Tabarie. Pravaz. Milliet. Sandahl. Tutschek. G. 
Lange. Vivenot. Freud. Elsasser. Panum. G. Liebig. 
Mayer. Marc. 

XXIII 



Page 

Chapter III. Theoretical Explanations and Experiments 440 

Borelli. Musschenbroeck. Haller. Achard. Brize-Fradin. Halle 
and Nysten. Poiseuille. 'Maissiat. Hervier and Saint-Lager. 
Pravaz. Pol and Watelle. A. Guerard. Milliet. Eug. Bertin. 
Hoppe. Francois. Bucquoy. Hermel. Foley. Caffe. Babing- 
ton and Cuthbert. Sandahl. Tutschek. Vivenot. G. Lange. 
Elsasser. Panum. G. Liebig. Gavarret. Leroy de Mericourt. 
Bouchard. Gal. 

Chapter IV. Summary and Criticisms 489 

1. Physiological action of compressed air. 

A. Phenomena due to compression. 

B. Phenomena due to decompression. 

2. Theoretical explanations. 

A. Phenomena due to compression. 
Physico-mechanical explanations. Chemical explana- 
tions. 

B. Phenomena due to decompression. 



Second Part 
EXPERIMENTS 

Chapter I. Chemical conditions of the death of animals subjected to 

different barometric pressures in closed vessels 505 

Subchapter 1. Pressures below one atmosphere 507 

1. Experimental set-up 507 

2. Experiments : 513 

A. Experiments on birds 513 

B. Experiments on mammals 542 

C. Experiments on cold-blooded animals 550 

3. Conclusions 552 

Subchapter 2. Pressures above one atmosphere 552 

1. Experimental set-up 552 

2. Experiments 555 

A. Compressions with ordinary air 555 

B. Superoxygenated air; pressures between one and 

two atmospheres 560 

C. Compressed air at very high pressures. 

Lethal action of oxygen 565 

D. Compression with air of low oxygen content 570 

E. Compression with superoxygenated air 571 

F. Compression with ordinary air; elimination of 
carbonic acid 574 

3. Conclusions 577 

Subchapter 3. Summary and conclusions 578 

XXIV 



628 



Page 
Chapter II. Gases contained in the blood at different barometric 

pressures ' 581 

Subchapter 1. Operative methods and experimental discussion __. 581 

Subchapter 2. Blood gases under pressures less than one atmos- 
phere 594 

1. Experimental set-up 594 

2. Experiments - 600 

Subchapter 3. Blood gases under pressures greater than one 

atmosphere 615 

1. Experimental set-up 615 

2. Experiments - 618 

Subchapter 4. Blood gases in asphyxia compared to decreased 
pressure ■-— 

Subchapter 5. The quantity of oxygen which the blood taken 
from the vessels can absorb at different barometric 
pressures 641 

1. Pressures lower than one atmosphere 643 

2. Pressures greater than one atmosphere 654 



Chapter III. Phenomena presented by animals subjected to pressures 

less than one atmosphere 660 

Subchapter 1. Symptoms of decompression 661 

1. Respiration _' 666 

2. Circulation 669 

3. Digestion 672 

4. Nervous and muscular effects 673 

5. Nutrition 675 

Chemical phenomena of respiration. Urinary excretion. 
Sugar of the liver and blood, glycosuria. Temperature. 
Development. 

6. Lower limit of pressure 685 

7. Death 687 

Subchapter 2. Comparison of the phenomena of decompression 

with those of asphyxia in closed vessels 689 

Subchapter 3. Means of warding off the symptoms caused by de- 
compression 694 

Chapter IV. Action of compressed air on animals 709 

Subchapter 1. Toxic action of oxygen at high tension 709 

2. The diminution of oxidations caused by oxygen poisoning 743 

3. Aquatic or invertebrate animals 751 

Subchapter 2. Action of compressed air at low pressures - 754 

1. Short stay in compressed air 756 

A. Experiments made upon myself 756 

XXV 



Page 

B. Production of urea; experiments on dogs 764 

C. Chemical phenomena of respiration 765 

D. Pulmonary capacity 768 

E. Intra-pulmonary pressure 771 

F. Arterial pressure 773 

2. Prolonged stay in compressed air 775 



Chapter V. Influence of changes in barometric pressure on plant life 780 

Subchapter 1. Pressures less than one atmosphere 782 

1. Germination ._ 782 

2. Vegetation 787 

Subchapter 2. Pressures above one atmosphere 788 

1. Germination 788 

A. High pressures with air of low oxygen content 792 

B. Normal pressure; superoxygenated air 793 

C. Low pressures; superoxygenated air 794 

2. Vegetation 797 

Subchapter 3. Summary 798 



Chapter VI. Action of changes in barometric pressure on ferments, 

poisons, viruses, and anatomical elements 799 

Subchapter 1. Fermentations by organisms 800 

1. Putrefaction 800 

A. Meat 800 

B. Blood 817 

C. Eggs 819 

2. Coagulation of milk 820 

3. Alteration of the urine 823 

4. Brewer's yeast 826 

5. Wine ferments 827 

6. Molds 831 

Subchapter 2. Diastatic fermentations 834 

1. Saliva and diastase 835 

2. Pepsin 837 

3. Inversive ferment of yeast 838 

4. Myrosin 838 

5. Emulsin 839 

Subchapter 3. Action of oxygen at high tension upon anatomical 

elements 839 

Subchapter 4. Use of oxygen at high tension as an experimental 

method 842 

1. Dry rot of fruit 843 

2. Ripening of fruits 844 

3. Venoms 845 

4. Viruses 846 

XXVI 



Page 

A. Vaccine 846 

B. Glanders 847 

C. Anthrax 847 

Subchapter 5. Summary 849 

Chapter VII. Effects of sudden changes in barometric pressure— . 852 

Subchapter 1. Effects of sudden increases in pressure 852 

Subchapter 2. Effects of sudden decreases in pressure beginning 

with one atmosphere 853 

Subchapter 3. Effect of sudden decrease in pressure beginning 

with several atmospheres 859 

1. Decompression without interruption 859 

A. Experiments on sparrows 859 

B. Experiments on rats 861 

C. Experiments on rabbits 861 

D. Experiments on cats 861 

E. Experiments on dogs 863 

2. Slow decompression in several stages 874 

3. Summary and conclusions from the preceding experiments 878 

Subchapter 4. Prophylaxis and treatment of the symptoms of sud- 
den decompression 890 

Subchapter 5. Summary 895 

Chapter VIII. Various questions 896 

Subchapter 1. Action of carbonic acid on living beings 896 

1. Lethal tension of carbonic acid in ambient air 896 

2. Lethal concentration of carbonic acid in the blood 899 

3. Accumulation of carbonic acid in the tissues 910 

4. Symptoms and mechanism of carbonic acid poisoning 914 

5. Action of carbonic acid on lower living beings 924 

6. Summary and conclusions 927 

Subchapter 2. Asphyxia — 928 

Subchapter 3. Observations on the gases of the blood 935 



Third Part 
RECENT DATA, SUMMARY AND CONCLUSIONS - 947 

Chapter I. Decreased pressure 949 

Subchapter 1. Observations, theories, and recent discussions 949 

Bouchut. Chabert. Dufour. Forel. Thorpe. Tempest An- 
derson. Calberla. Ward. Vacher. Croce-Spinelli, Sivel and 
G. Tissandier. Stoliczka. Campana. Jourdanet. 

XXVII 



Page 

Subchapter 2. Summary and practical applications 980 

1. Aeronauts 981 

2. Mountain travellers 991 

3. Dwellers in high places 998 

4. Animal and plant life at high elevations 1005 

5. Medical applications 1006 

Chapter II. Increased pressure 1009 

Subchapter 1. Observations, theories, and recent discussions 1009 

1. High pressures 1009 

Guichard. Heiberg. 

2. Low pressures. Medical apparatuses 1014 

J. Pravaz. G. Liebig. Leonid Simonoff. 

Subchapter 2. Summary and practical applications 1021 

1. High pressures 1021 

2. Low pressures^ _i 1024 

3. Sudden decompression 1027 

4. Practical applications. Therapeutics and hygiene 1027 

5. Conclusion from the point of view of general natural history 1032 

Chapter III. General conclusions 1036 

Addenda I. Relations between heights and barometric pressures 1039 

II. The new work of Dr. Mermod 1041 



Index — 1045 



XXVIII 



Fig. 


1. 


Fig. 


2. 


Fig. 


3. 


Fig. 


4. 


Fig. 


5. 


Fig. 


6. 


Fig. 


7. 


Fig. 


8. 



LIST OF ILLUSTRATIONS 

Page 

Lortet. Respiratory tracing taken at Lyons (200 meters) 112 

Lortet. Respiratory tracing taken at the summit of Mont 

Blanc (4810 meters), after resting an hour 112 

Cupelain: Chamounix (1000 meters) - 113 

Grands-Mulets (3000 meters) at midnight, half an hour before 

starting H3 

Summit of Mont Blanc (4810 meters) 113 

The construction of a bridge pier by the use of caissons 369 

Diver equipped with the Denayrouze regulator, complete suit 391 
Diver equipped with the Denayrouze regulator, helmet re- 
moved 392 

Fig. 9. The aerotherapeutic establishment of Dr. Carlo Fornanini at 

Milan 412 

bis. Respiratory modifications in compressed air 423 

Circulatory modifications in compressed air - 424 

Circulatory modifications in compressed air 424 

Circulatory modifications in compressed air 425 

Circulatory modifications in compressed air 425 

Circulatory modifications in compressed air 430 

Apparatus with four plates for experiments on decreased 

pressure 508 

Mercury pump set up for the extraction of the gases of the 

blood 510 

Composition of confined air which has become lethal at pres- 
sures below one atmosphere 524 

Variations in the tension of the oxygen contained in com- 
pressed air which has become lethal at various pressures 

less than one atmosphere 527 

Relations between the oxygen tension, duration of life, and 

capacity of vessels 531 

Cylindrical glass apparatus for high pressures (25 atmos- 
pheres) set up for superoxygenated air 554 

Confined air which has become lethal under pressure 568 

XXIX 



Fig. 


9. 


Fig. 


10. 


Fig. 


11. 


Fig. 


12. 


Fig. 


13. 


Fig. 


14. 


Fig. 


15. 


Fig. 


16. 


Fig. 


17. 


Fig. 


18. 


Fig. 


19. 


Fig. 


20. 


Fig. 


21. 



Fig. 


23. 


Fig. 


24. 


Fig. 


25. 


Fig. 


26. 


Fig. 


27. 


Fig. 


28. 


Fig. 


29. 


Fig. 


30. 


Fig. 


31. 


Fig. 


32. 


Fig. 


33. 


Fig. 


34. 


Fig. 


35. 



Page 
Fig. 22. Confined air which has become lethal under pressures from 

20 centimeters to 24 atmospheres 576 

Graduated syringe for the extraction of blood 582 

Mercury pump set up for the extraction of the gases of the 

blood 583 

Small mercury reservoir 588 

Bellows for artificial respiration 591 

Large apparatus for the study of low pressures 595 

Dog prepared to be placed in the cylinders of Fig. 27, and for 

the extraction of blood under decreased pressure 596 

Different forms of cannulae for the extraction of blood under 

decreased pressure 598 

Extraction of the blood of an animal under decreased pres- 
sure 599 

Decrease of the quantities of Oa and C0 2 contained in the 

arterial blood, when the barometric pressure is diminished 608 

Percentage decrease of the 0= and the C0 2 of the arterial 

blood when the barometric pressure is diminished,-- 611 

Large compressed air apparatus, cylinder of sheet steel cap- 
able of withstanding a pressure of 12 atmospheres 616 

Extraction of blood from an animal placed in compressed air 618 

Variations of the gases of the blood at pressures above one 

atmosphere 623 

Fig. 36. Increase of the oxygen of the arterial blood from to 10 

atmospheres and from to 26 atmospheres 624 

Dog breathing air from a rubber bag 629 

Variations of the gases of the blood and the oxygen of the 
air in asphyxia in closed vessels, when the carbonic acid 
is absorbed 633 

Variations in the gases of the blood in asphyxia compared 
to decreased pressure 635 

Decrease of the gases of the arterial blood and the venous 

blood when the tension of oxygen breathed decreases 639 

Flask arranged for saturating blood with oxygen under dif- 
ferent decompressions 644 

Water motor shaking the flask containing the blood to be 
saturated with oxygen 645 

Capacity of the blood for absorbing oxygen at pressures be- 
low one atmosphere 648 

Apparatus to bring blood into contact with the air at a speci- 
fied decrease in pressure 650 

Apparatus for saturating blood with air at high pressures 654 

Oxygen capacity of the blood from a vacuum to 18 atmos- 
pheres of air 656 

Modification of the number of respiratory movements under 

the influence of decompression. (Dogs, rabbits) 667 

Same (Guinea pig, Experiment CCXXVII) 668 

XXX 



Fig. 


37. 


Fig. 


38. 


Fig. 


39, 


Fig. 


40. 


Fig. 


41. 


Fig. 


42. 


Fig. 


43. 


Fig. 


44. 


Fig. 


45. 


Fig. 


46. 


Fig. 


47. 


Fig. 


48. 



Fig. 


50. 


Fig. 


51. 


Fig. 


52. 


Fig. 


53. 


Fig. 


54. 


Fig. 


55. 


Fig. 


56. 


Fig. 


57. 


Fig. 


58. 


Fig. 


59. 


Fig. 


60. 


Fig. 


61. 


Fig. 


62. 



Page 
Fig. 49. Simultaneous modifications of the number of respiratory- 
movements R and pulse P under the influence of decom- 
pression; (Cat, Experiment CCXXI) 670 

Same (Dog, Experiment CCXVIII) 671 

Same (Dog, Experiment CCXVII) 671 

Consumption of oxygen and production of carbonic acid at 

different pressures 677 

Asphyxia without carbonic acid 691 

Maxima and minima of cardiac pressure in asphyxia without 

carbonic acid 692 

Bird in air progressively rarefied and oxygenated 695 

Respiration of superoxygenated air expanded by decrease 

of pressure 697 

Sudden modifications in the pulse rate by intermittent respi- 
ration of superoxygenated air 699 

Modifications in the pulse rate, during decompression, result- 
ing from the continuous respiration of oxygen (Experi- 
ment CCLVI) 705 

Same (Experiment CCLVII) 707 

Dogs poisoned by oxygen 739 

Dog during tonic convulsions of oxygen poisoning 741 

Apparatus of M. Jourdanet for the therapeutic use of com- 
pressed or expanded air 757 

Fig. 63. Gas meter for the measurement of the respiratory move- 
ments 758 

Fig. 64. Apparatus with double valve for the study of respiration___ 759 
Fig. 65. Apparatus for the chemical study of the respiration of an 
animal kept for any specified time in air of constant 

composition ^ 766 

Fig. 66. Apparatus for the observation of variations in the intrapul- 

monary air tension 771 

Variations of the intra-thoracic tension. Normal pressure___ 772 

Same. Compressed air 772 

Tension of the blood in the femoral artery. Normal pressure 773 

Same. Compressed air 773 

Tension of the blood in the carotid artery. Normal pressure 774 

Same. Compressed air 774 

Same. Normal pressure 774 

Oxygen consumption and carbonic acid production by a piece 

of meat in an atmosphere of constant oxygen content 813 

Death by carbonic acid; changes in the air of the bag (Experi- 
ment DCXV) 915 

Death by carbonic acid; changes in the composition of the 
gases of the blood, the respiration, and the circulation 
(Experiment DCXV) 917 

XXXI 



Fig. 


67. 


Fig. 


68. 


Fig. 


69. 


Fig. 


70. 


Fig. 


71. 


Fig. 


72. 


Fig. 


73. 


Fig. 


74. 


Fig. 


75. 


Fig. 


76. 



Page 
Fig. 77. Death by carbonic acid; relation of the respiration and the 
circulation to the carbonic acid content of the blood 

(Experiment DCXV) 919 

Fig. 78. Death by carbonic acid; last respiratory movements (Experi- 
ment DCXV) 920 

Fig. 79. Death by asphyxia in a closed vessel; gases of the air (Exper- 
iment DCXL) 932 

Fig. 80. Same; gases of the blood (Experiment DCXXXIV) 932 

Fig. 81. Relation between the oxygen content of the air and that of 

the blood 933 

Fig. 82. Pulse at the Riffel Pass (2780 meters), during an attack of 

mountain sickness 955 

Pulse at the Sattel-Tolle (4300 meters) 955 

Pulse at the Riffel (2569 meters), rest on the return trip 956 

Pulse at Morges (380 meters), absolute repose 956 

The basket of the Zenith at a high altitude 966 

Diagram of the high altitude ascension on April 15, 1875 970 

Portrait of Sivel 972 

Portrait of Croce-Spinelli 973 



Fig. 


83. 


Fig. 


84. 


Fig. 


85. 


Fig. 


86. 


Fig. 


87. 


Fig. 


88. 


Fig. 


89. 



XXXII 



Part I 



HISTORICAL 



Title I 
DIMINISHED PRESSURE 



Preliminary Chapter 
THE LOFTY REGIONS OF THE EARTH 

The effects produced upon the organism by a great and sudden 
decrease in the barometric pressure can be observed in three dif- 
ferent cases: mountain journeys, balloon ascensions, and experi- 
ments under pneumatic bells. 

These last two methods were absolutely unknown to the an- 
cients. Galileo, as everyone knows, was the first to have a clear 
idea of the pressure of the air; it was not until 1640 that Toricelli 
invented the barometer, or until 1650 that Otto de Guericke in- 
vented the pneumatic machine. In 1648, at the suggestion of our 
great Pascal, Perier made at Puy-de-D6me the memorable experi- 
ment in which he saw the height of the barometric column de- 
crease in proportion to the increase of the altitude of the place 
where it was observed. 

For balloons, the discovery is still more recent. The first hot air 
balloon which carried aloft Pilatre du Rozier and the Marquis 
d'Arlandes, ascended from Paris November 22, 1783; a few days 
after, December 1, Charles made an ascension with the hydrogen 
balloon which he had just invented. This balloon, however, was 
not able to carry the observers high enough for the decrease of 
pressure to make its effect felt upon them. In fact, the experiment 
proved that this effect is not clearly evident in a balloon below an 
altitude of 5,000 or 6,000 meters. Consequently, among the thou- 
sands of ascents which followed that of Charles and Robert, only 
a very small number can be of interest to us in our particular 
purpose and therefore be reported in this historical review. 



4 Historical 

As to the third condition, the ascent of high mountains, at first 
glance it seems astonishing to have to state that the ancient authors 
have left us no precise information permitting us to believe that 
they noted, during the ascent of lofty mountains, any physiological 
symptoms worthy of attracting attention. 1 

In fact, in the part of the world known to the ancients, there 
are mountains of considerable height. At its extreme eastern 
limits, 2 Mount Ararat and the chief peaks of the Caucasus raise 
their heads covered with eternal snow more than 5,000 meters 
above sea level; the chains of Liban and Taurus contain many 
peaks more than 2,500 or even 3,000 meters high; the famous Mount 
Argaeus reaches a height of 3,840 meters; among the hills of Hemus 
and Rhodope, some rise to 3,000 meters; Mount Athos is 1,975 meters 
high, Parnassus 2,470, Taygetus 2,400, and it is at 2,975 meters, on 
the towering brow of Olympus, that the poets placed the abode of 
the gods. Mount Etna (3,310 meters) for two thousand five hun- 
dred years has been threatening the Greek cities settled at its feet. 
The Phenicians and the Carthaginians, whose daring had established 
colonies as far away as the Fortunate Isles, knew the smoking peak 
of Teneriffe (3,715 meters). Finally, the Pyrenees and the Alps 
were insufficient barriers against the armies of Carthage and Rome. 

The reason for the silence of the authors is easily found. As 
von Humboldt very correctly said, the ancients feared mountains 
much more than they admired them. They spoke of them only with 
fear, with a secret horror; the magnificent spectacles they offer to 
the gaze did not affect them; the emotions they arouse, the noble 
ideas they inspire were unknown to the ancients. Love of the pic- 
turesque is a very modern sentiment; the ancients, and even our an- 
cestors up to the last century, would have regarded with an aston- 
ishment mingled with disdain our intrepid climbers of the Alps. 
Polybius first passed through the Alpine valleys; the highest moun- 
tains, Mont Blanc, Monte Rosa, the Jungfrau, have no names in 
the classical languages. 

The only mountain which the ancients climbed without being 
forced to is Etna. Seneca requests his friend Lucilius Junior to 
climb to the top of the volcano in his honor (Letter 79) ; these 
excursions were frequent in the time of Strabo, :i and according to 
a poem attributed today to this same Lucilius, priests burned in- 
cense on the edge of the crater to appease the gods; the emperor 
Hadrian, who was a great traveller, conceived the idea of climbing 
to the top of Etna to see the sunrise. None of these accounts speak 
of physiological symptoms; but we shall see that at the height of 



Lofty Regions of the Globe 5 

this volcano they are slight, attack only part of the travellers, and 
might be confused with the ordinary effects of fatigue. The same 
thing is true in crossing the Pyrenees and the Alps. The passes of 
the Pyrenees, through which regular communications were estab- 
lished between Gaul and Hispania, are hardly 1,500 meters high. 
Whatever opinion one has about the site of the passage of Hannibal, 
either at the Little Saint-Bernard (2,160 meters), or the pass of 
Mount Viso (2,700 meters), or Mount Cenis (2,080 meters), or in 
the valley of Beaufort between Albert- Ville and Chamounix, the 
heights reached were not very great. Augustus had two roads made 
through the passes of the Great Saint-Bernard (2,490 meters) and 
the Little Saint-Bernard, 4 and King Cottus, his contemporary, cut 
the road of Mount Cenis. In the Middle Ages, the Simplon (2,020 
meters) and the Great Saint-Bernard were much frequented; 
chroniclers have left us descriptions of these journeys or these 
expeditions in which the terrible difficulties of the roads, the ex- 
cessive fatigue, and the cold explain sufficiently the pitiful state 
of the travelers, many of them, like Elfrid, archbishop of Canter- 
bury, perished in the snow. 

To attract the attention of the travellers to physiological symp- 
toms they would have had to make more lofty ascents, and to have 
suffered discomforts evidently unexplainable by ordinary causes. 
The lofty summits of the Alps presented the necessary conditions, 
as we shall see; but since their ascents offered no practical interest, 
they were undertaken only toward the end of the last century. 
But twenty years after the discovery of America, the conquest of 
Mexico and Peru and military expeditions across the Cordilleras 
brought the Spaniards into conditions where the symptoms of de- 
compression appeared definitely. So attention was soon attracted 
to them, and they were noted in ascents where they are neither 
great nor constant, like those of Etna and the Peak of Teneriffe. 
However, our Alps for a long time still remained unexplored; 
though the important cities and the rich valleys of Switzerland 
attracted many travelers, no one had the idea of climbing these 
dangerous peaks covered with snow, peopled with strange beings, 5 
and about which the most gloomy tales were told. It was not until 
the second half of the eighteenth century that people decided to 
admire them and that the idea of reaching their summits germi- 
nated in a few minds. It was the scientific point of view that 
guided the first ascents. In the account of his ascents de Saussure 
noted with keen alertness the symptoms brought on by a stay in 
rarified air. Since then, similar observations are numerous. Still 



6 Historical 

more recently, officers, scholars, and English travelers have carried 
their explorations into the loftiest regions of the Himalayas. Their 
accounts, added to those of men who have ascended the Alps and 
of travellers in America, which have become more numerous, have 
familiarized physicians with the symptoms of mountain sickness. 

In the following pages I shall report most of the interesting facts 
collected thus by eyewitnesses, often from their own personal ob- 
servation. But in this preliminary chapter I should like to recall 
to the memory of the reader the different mountain regions in 
which the traveller is exposed to distress in consequence of the 
decrease of pressure. This simple enumeration will show him the 
practical importance of the question which we shall discuss here, 
that is, the manifestation by acute and violent symptoms of the 
effect of decreased pressure. 

Rarely does mountain sickness appear with marked intensity in 
our temperate regions below an altitude of 3,500 meters. In the 
tropics, one must mount to more than 4,000 meters to experience 
it definitely in ordinary conditions. We shall return to these limits 
and take account of the different circumstances which hasten or 
delay the symptoms, I mean by that, cause them to appear at a 
lower or higher altitude. For the moment, these approximate 
heights serve as a basis for the review we intend to make. 

Europe. Let us take Europe first; the Alps, the Pyrenees, and 
the Caucasus are almost the only mountain chains which offer us 
peaks high enough for their ascent to cause any other ill conse- 
quences than the weariness and the dangers customary in moun- 
tains. 

Let us first examine the Alps. This enormous mass of moun- 
tains which includes in a curved line two hundred leagues long 
innumerable peaks laden with eternal snows, descends rapidly on 
the south to the low plains of Lombardy, while on the north it 
slopes more slowly towards the high plateaux of Wurtemberg, 
Bavaria, and Bohemia, interrupted by secondary mountains. 

The heart of the system is formed by the group of Saint-Gothard, 
whose waters flow at the same time through the Rhine into the 
North Sea, through the Rhone into the Mediterranean, and through 
the Tessin into the Adriatic; and yet this region is one of the least 
elevated of the Central Alps. It is immediately dominated on the 
north by Galenstock (3800 meters) and Todi (3600 meters); on 
the east, by the group surrounding the Little Saint-Bernard, among 
others the Rheinwaldhorn (3400 meters) ; on the west, by the 
enormous mass of the glaciers of the Bernese Alps, in the midst of 



Lofty Regions of the Globe 7 

which rise the Jungfrau (4170 meters), the Aletschhorn (4200 
meters), the Schreckhorn (4080 meters), the Brietsch (3950 
meters), the Monk (4100 meters), and the Finsteraarhorn (4270 
meters) . Advancing toward the east, we see Mount. Bernin (4050 
meters) and Mount della Disgrazia (3680 meters) separating the 
valley of the Valteline, in which flows the Adda, from that of the 
Engadine, in which the Inn conducts by the Danube to the Black 
Sea the waters brought to it from numerous peaks more than 3000 
meters high, such as the Piz d'Err (3390 meters), the Piz Linard 
(3410 meters) , the Piz Languard (3270 meters) , etc. On the other 
bank of the Adda, the Tyrolese Alps display still loftier peaks; the 
Adamello (3560 meters), the Wildspitze (3770 meters), the 
Venediger (3675 meters), the Gros-Glockner (3890 meters), and 
especially the Orteler (3920 meters) . 

But it is towards the west and on the left bank of the Rhone 
that the giants of the Alps rise. First, around the Simplon (3200 
meters), are Monte-Leone (3560 meters), the Fletschhorn (4020 
meters) , and the Weismies (4030 meters) ; then the base of Monte 
Rosa, with its three surmounting peaks; the Dome du Mischabel 
(4550 meters) , the Matterhorn or Mount Cervin (4480 meters) , and 
Monte Rosa itself, the highest peak of which, the Pointe de Dufour, 
rises to 4640 meters. Next come the Dent-Blanche (4360 meters) , 
the Weisshorn (4510 meters) , the Grand Combin (4320 meters) , 
and farther to the west Mont Blanc (4810 meters) , which, sur- 
rounded by numerous almost inaccessible pinnacles, dominates all 
the other mountains of Europe. 

Beyond, the chain drops rapidly, although it still displays a few 
lofty summits, such as Mount Iseran (4045 meters), Mount Cenis 
(3620 meters), the Vanoise (3860 meters), in the Graies Alps; 
Mount Viso (3840 meters) . Mount Olan (4215 meters) , in the Cot- 
tian Alps; Mount Pelvoux (3955 meters), the Pointe des Ecrins 
(4100 meters) , the Grandes Rousses (3475 meters) , in the Alps of 
Dauphine. The Maritime Alps are still less lofty; finally come the 
Apennines, the highest peak of which, Monte Corvo, in the Abruzzi, 
is only 2910 meters high. But beside these giants, what an ap- 
pearance the Capitol makes with its 47 meters above sea level! 

At the end of the chain, a rather high mountain, Mount Alto 
(1080 meters), faces Sicily, the hilly soil of which, like that of 
Sardinia, has no peaks reaching 2000 meters. Above all these sec- 
ondary mountains the crater of Etna rises to 3310 meters. 

Among these high peaks, these abrupt pinnacles, which are 
climbed only by those inspired by love of science, a taste for grand 



8 Historical 

views, or merely vanity, depressions called cols allow many travel- 
lers at certain points to cross the principal chain from Switzerland 
or France to Italy. These passes are generally very high. The best 
known and the highest are: in the Maritime Alps, the passes of 
Tende (1870 meters), of Longet (3150 meters), of the Argentiere 
(1905 meters), and of Maurin (2980 meters); in the Cottian Alps, 
the passes of Traversette (2995 meters), of the Agnello (2700 
meters), of Sayse (3360 meters), of Mount Genevre (1850 meters); 
in the Graies Alps, the pass of Mount Cenis (2080 meters) , and of 
the Little Saint-Bernard (2160 meters) ; in the Pennine Alps, the 
pass of the Grand Saint-Bernard (2490 meters) , that of the Geant 
(3360 meters) , of the Seigne (2530 meters) , the pass of Balme (2200 
meters) , the pass of Saint-Theodule (3320 meters) ; in the Helvetian 
Alps, the Simplon pass (2020 meters), the pass of Gemmi (2300 
meters), the pass of Grimsel (2160 meters), that of the Fourca 
(2460 meters), of the Saint-Gothard (2110 meters), of Bernardin 
(2060 meters) , etc. The road of the Valteline, the highest carriage 
road in Europe, crosses the pass of Stelvio at 2810 meters, going 
from the basin of the Po to that of the Danube. 

Along the Adriatic, the Alps continue by the mountains of 
Croatia, Montenegro, and Serbia, with the Balkans at the north 
and on the south the Rhodope mountains and the chain of Pindus 
which gives birth to the hills of Greece. In these very hilly regions, 
the summits of which are however not very high, we need mention 
only the Dormitor (2260 meters) in Herzegovina, the Kom (2290 
meters) in Montenegro, the Kriwosta (2440 meters) in Roumania; 
then the giant of the Rhodope mountains, the Rilo Dagh (2815 
meters), and finally the mountains of Greece of which we have 
already spoken. 

The Danube, which receives the waters of the north slope of 
the Alps, rises in the mountain group of the Black Forest, in which 
there are a few peaks of moderate height; after running towards 
the east, it encounters the chain of the Carpathians, in which there 
are such peaks as the Tatra (2655 meters), the Gailuripi (2925 
meters), the Ruska-Poyana (3020 meters), and which pushes it 
towards the south. 

The mountains of the interior of France have no interest for us 
from the standpoint of our present purpose, since the highest, 
Mount Dore, is only 1890 meters high; the little chain which crosses 
Corsica is more interesting; its highest point, Mount Cinto, rises to 
2710 meters. 

But the Pyrenees, in a length of 150 kilometers and a maximum 



Lofty Regions of the Globe 9 

width of 120 kilometers, have a large number of peaks which, al- 
though they do not have the imposing mass or the height of the 
Alpine groups, are nevertheless important for our purpose. In the 
eastern Pyrenees there are first the Canigou (2785 meters) , then 
the Puigmal (2910 meters) and the Corlitte (2920 meters), domi- 
nating on each side the pass of the Perche (1620 meters) ; finally 
from this pass to the valley of Aran, on a very lofty crest, a series 
of peaks reach a height of 2800 meters, the highest of which is the 
Montcalm (3090 meters). 

Beyond the valley, the western Pyrenees begin with the group 
of the Maladetta, which contains their highest point, the peak of 
Nethou (3405 meters). This is the center of the Pyrenees group, 
which in a length of some hundred kilometers contains a great 
number of summits rising above 3000 meters: the peak of Perdi- 
ghera (3220 meters) , the cylinder of Marbore (3330 meters) , Mount 
Perdu (3350 meters), Vignemale (3300 meters), Marmure (2950 
meters) , the southern peak of Ossau (2885 meters) ; and to the 
north of the principal chain, the peak Campvieil (3175 meters), 
and the southern peak of Bigorre (2880 meters) , on which a mete- 
orological observatory has just been established. The passes or 
ports of this region also attain a considerable height: port of Viella 
(2455 meters) , port of Venasque (2420 meters) ; the lowest is the 
port of Gavarnie (2280 meters) , the highest is the Portillon (3045 
meters) . 

Towards the west, the chain drops rapidly; then, the Pyrenees 
proper give way to the Cantabric Mountains, which extend to the 
end of Galicia. In this whole extent, only a few summits rise above 
2000 meters. In the rest of Spain, the Sierra Guadarrama and the 
Sierra de Gredos, which dominate Madrid and pour upon it the 
dreaded wind of the mountains, rise at certain points to more than 
3000 meters; finally along the sea, at the highest point of the Sierra 
Nevada, the twin summits of the peak of Veleta (3470 meters) and 
the Cerro de Mulhacen (3555 meters) surpass the highest of the 
Pyrenees. 

In the rest of Europe, there are no mountains which can attract 
our attention. Ben Nevis, the highest mountain in the British 
Isles, is only 1330 meters high; in Iceland, Orafa Jokul is 1950 
meters; in the Scandinavian Alps, the highest mountains are Snee- 
hatten (2300 meters), Skagstolstinder (2450 meters), and Ymes- 
Feldj (2600 meters) ; in the Ural Mountains, there are no peaks 
reaching the height of 2000 meters; the highest, T611-pos-Is, is only 
1680 meters. 



10 Historical 

Asia. But on the borders of Europe and Asia, a considerable 
chain, the Caucasus, extending from the Caspian to the Black Sea, 
bordering on the north upon plains, and on the south upon the 
mountainous regions of Armenia whose ramifications we shall fol- 
low presently, is crowned by peaks which leave far below them 
the Pyrenees and the Alps themselves. Peaks of 3000 to 4000 
meters are numerous there and they are dominated by Kasbek 
(5030 meters) , Kaschtantan (5220 meters) and Elbruz, 'to which the 
legend fastens Prometheus (5620 meters) . Only one carriage road 
crosses the chain at the foot of Kasbek, by the Caucasian gates of 
the ancients, at a height of more than 3000 meters. 

At the south of the Caucasian chain, in the hilly territory of 
Armenia there rise a series of peaks, some of which reach the height 
of 40.00 meters: Alagos (4090 meters), Kapudschich (3920 meters); 
above them towers the Grand Ararat (5155 meters) . From this 
group there extends towards the southwest the chain of the Taurus, 
which contains several summits more than 3000 meters high, the 
highest of which are Metdesis (3570 meters) and Mount Argea 
(3840 meters) ; in the Liban, a fork of the Taurus, the highest 
summit, Dor-el-Chodib, is only 3065 meters high. At the south, 
the mountains of Kurdistan, with Dschehil (4550 meters) ; to the 
southeast, the Elburs mountains, with Sawalan (4810 meters) and 
Demavend (5620 meters), dominate the vast plains of Iran. 

The center of Asia displays an orographic system much more 
complex and masses of mountains much more imposing. The trav- 
eler who goes up the Ganges sees rising on his right, from Boutan 
to Cashmere, over a stretch of more than 600 leagues, the formi- 
dable range of the Himalayas; from between the parallel lesser 
chains descend innumerable tributaries of the great Indian river. 
In this range are found the highest mountains in the world; the 
ridge reaches an average height of 5000 to 6000 meters; we can 
count by the hundred summits of more than 6000 meters; peaks 
less than 7000 meters high are generally marked scornfully on the 
English maps by mere numbers, and it seems as if mountains do 
not deserve to have a name unless they reach a height of 8000 
meters. 

We shall mention: in Boutan, Dalla (7030 meters), the Oodoo 
Mountains (7540 meters) , Chamalari (7300 meters) ; in Sikkim, 
Mount Doukia (7070 meters) and Kantschin-Janja (8580 meters) ; 
this latter yields only to Gaurisankar or Mount Everest in Nepal, 
the highest mountain on earth, which raises its summit to the pro- 
digious height of 8840 meters; we should gain this height by heap- 



Lofty Regions of the Globe 11 

ing the Jungfrau (4170 meters) upon Monte Rosa (4640 meters) ; 
it is more than seven times the height of Vesuvius (1190 meters). 
Also in Nepal, Jangmar (7930 meters), Djibjibia (8020 meters), 
Jassa (8135 meters), Marschiadi (8080 meters), Barathor (7950 
meters) , and finally Dawalaghiri (8185 meters) , long considered 
the highest of all, but now known to be surpassed by Guarisankar. 

Then the Himalayan chain opens to allow the passage of the 
Setledj, which carries to the Indus the waters of the northern 
slope and those of the sacred lake of Manasarovar (4650 meters) . 
Beyond, it ends in the extraordinary maze of the mountains of 
Cashmere, in the midst of which opens the delightful valley of 
Srinagar, the "earthly paradise" of the Hindus. 

At their eastern end, the Himalayas are joined to the Langtan 
Mountains, the heart of chains of relatively moderate height, which 
form the high relief of China and Indo-China. 

The Himalayas thus form, on their southern slope, the gigantic 
talus of a high mountain plateau, as it were. This is Tibet, which 
over an immense extent rises above 3000 meters, and whose waters, 
collected in the Brahmapoutra, flow first towards the east, then, 
encountering the mountains of China, turn to the southwest, to 
join those of the Ganges. On the north, this plateau is bounded 
by the chain of Kuen-Loun; its western extremity is traversed 
by the chain of Karakorum, the summits of which rival those of 
the Himalayas, such as Dapsang (8620 meters), Diamer (8130 
meters) , and Gusherbrum (8040 meters) . 

Passes, the elevation of which naturally increases as the highest 
ridges are approached, permit a crossing of the foothills of these 
principal chains, and finally of the chains themselves. Many of 
these passes, which are much travelled, are at a height of more 
than 5000 meters; the famous pass of Karakorum is 5650 meters 
high; the Yangi-Diwan Pass, one of the routes from Cashmere to 
Khotan across the Kuen-Loun chain, is 5820 meters high; the high- 
est ,; of all in the British Empire, the pass of Parang, has an eleva- 
tion of 5835 meters. 

The traveler who climbs the steps of this sort of gigantic stair- 
way descends between them much less than he has ascended; thus 
he reaches a vast desolate plateau; this is the Pamir (visited in 
the thirteenth century by Marco Polo), or the Bam-i-Dunya, that 
is, the roof of the world, whose average altitude is more than 4500 
meters. On the east, this roof slopes down to the lofty plains of 
upper Tartary, and its waters, through the river Tarim, are lost in 



12 Historical 

the desert of Gobi. Towards the west, they collect in the Oxus 
which carries them to the Lake of Aral. 

Other chains, of a considerable absolute elevation, rise above 
these high plateaux. On the northeast, Thian-Schan, whose cul- 
minating point is Bogda-Oola, borders the great desert, and joins 
Altai and the mountainous ridge which separates the basin of the 
Arctic Ocean from that of the Pacific. To the southwest, Hindou- 
Kouch, which prolongs Karakorum and is fully as high at-the begin- 
ning, joins the chain of Elburs by the mountains of Korassan. To 
the south, Soliman-Kouch stretches along the river Indus. 

America. The orographic system of America forms a striking 
contrast to that of Asia. Here there is no central group from which 
diverging chains extend, like so many gigantic arms. On the con- 
trary, a ridge, certain summits of which are dominated only by 
those of the Himalayas, stretches along the shores of the Pacific 
Ocean from Patagonia to Alaska. In the part farthest toward the 
south, the Cordillera is simple and of moderate height; but towards 
the north its average elevation gradually increases and reaches two 
maximum points, in Bolivia and at the Equator. At the same time, 
while its western side remains consistently abrupt, so that moun- 
tains 6000 meters high are sometimes less than 20 leagues from the 
sea, there appear on the eastern side foothills whose size constantly 
increases, so that in Bolivia there is a group 100 to 150 leagues wide 
with an average height of 4000 meters, in which there stand out 
particularly two parallel chains bounding the lofty valley of the 
lake of Titicaca (3915 meters) . These two chains, with their inter- 
mediate valley cut by knots, where rise the Maranon and the 
Ucayali, on which are built La Paz, Puno, Cuzco, Quito, and other 
cities, first drop, spreading out to the knot of Pasco, then rise again 
and reach their highest point just at the Equator. Here the eastern 
ridge forks in its turn and ends at the sea, by the chain of Vene- 
zuela and the Nevada of Santa-Marta, whose principal summit, the 
Horqueta (5500 meters) , rises almost on the edge of the sea of the 
Antilles. 

The western Cordillera, considerably reduced in height, next 
forms the isthmus of Panama, stretches along the Pacific in Central 
America, rises again, and spreads out in Mexico. Thence extend, 
as in South America, two great parallel chains, this time much 
farther from each other, and much less lofty. On the east, the 
ridge of the mountains of New Mexico, of the Rocky Mountains, 
of the Mountains of the Chipways, separates the waters of the 
Atlantic from those of the Pacific. The western chain remains near 



Lofty Regions of the Globe 13 

the ocean, and is interrupted in its course to allow free passage for 
the Colorado and the Columbia. 

Along the immense extent of this mountainous ridge rise moun- 
tains, mostly volcanic, of prodigious height. Canon Bourrit seems 
to us extremely impertinent when he maintains that "compared to 
the Swiss Alps, these mountains of South America are only dwarfs 
mounted on great pedestals"; 7 there is, however, a basis of truth 
in what he says and this is interesting for our purpose. 

Precisely at the equator, from the terraces of the city of Quito, 
the astonished eye beholds eleven volcanic mountains covered with 
eternal snows. Some, like Cayambe (5950 meters), Iliniza (5250 
meters), Chimborazo (6420 meters), are now extinct; others, like 
Pichincha (4860 meters), Antisana (5880 meters), and Cotopaxi 
(5945 meters), still send forth smoke or flames. Chimborazo has 
long been considered the highest peak of the Andes; that is a mis- 
take. Higher still are Aconcagua (6835 meters) in the Andes of 
Chile, and especially Illimani (7310 meters) and Sorate (7560 me- 
ters), which border on Lake Titicaca. 

A host of mountains, such as Tolima (5525 meters) and Purace 
(5185 meters) in Colombia; Cotocachi (4950 meters), Sangay (5044 
meters), Sinchalagua (5200 meters), Tunguragua (5020 meters), 
Llanganati (5395 meters), Altar (5240 meters), Sara-urcu (5140 
meters), in the Republic of Ecuador; Misti (6100 meters), Chipicani 
(6180 meters) , Jachura (5180 meters) , Tacora (5700 meters) , Pari- 
nacota (6330 meters), Nevado Vilcanota (5360 meters), Lirima 
(7470 meters), in Peru; Sahama (7015 meters), the peak of Fari- 
nacobo (6714 meters), Gualatieri (6690 meters), Cerro de Potosi 
(6620 meters), Atacama (5300 meters), Coolo (6870 meters), Soo- 
lolo (6795 meters), Quenuta (6870 meters), and Pomarape (6580 
meters) in Bolivia; Nevada de Famatina (5820 meters) , in the Ar- 
gentine Republic; Cerro del Plomo (5435 meters), Cima del Merce- 
dario (6800 meters), Juncal (5960 meters), Tupungato (6180 me- 
ters), Maypu (5385 meters), San Jose (6100 meters) in Chile, are 
far higher than the Alps or even the Caucasus. 8 

The passes crossed by travelers going from the Pacific coast to 
the great cities of the Cordillera or directly to the basins of the 
Orinoco, the Amazon, or the La Plata, always reach at their highest 
points altitudes capable of affecting the organism. The great road 
which the Incas had constructed from Cuzco to Quito crosses the 
pass of the knot of Assuay at 4735 meters; from Potosi to La Paz, 
the traveler remains constantly at heights of 4000 meters and more; 
the post-house of Talapolco is at an altitude of 4190 meters. In 



] 4 ■ Historical 

the Republic of Ecuador, the passes through which one can go 
from Quito to the sea are above 4000 meters; the road from Lima 
to Pasco passes at Alto de Lachagual at a height of 4710 meters; 
that from Lima to Tarina, at 4800 meters. In Peru, the pass of 
Vilcanota, between Cuzco and the sea, is at a height of 4425 meters; 
the road from Arequipa to Puno passes at 4750 meters; the post- 
house of Ancomarca, between Arica and La Paz, is 4330 meters 
high; the pass of Qualillas 4420 meters high, that of Tacora 4390 
meters, and that of Chullunquiani 4620 meters high. Finally, of 
the two railroads which cross the Cordillera, the one which goes 
from Puerta Mejia to Lake Titicaca has its highest point at Crucero 
(4460 meters) ; thence it proceeds to Cuzco, remaining at a height 
between 3500 and 4300 meters; the one last constructed, between 
Callao and Oroya, passes at a height of 4760 meters, through a 
tunnel which had to be excavated at almost the height of Mont 
Blanc. 

But the road most frequented by travelers till now in going 
from one ocean to the other, was the one which crosses the Andes 
from Mendoza to Santiago. It runs from Buenos Aires to Val- 
paraiso (417 leagues), and from either of these points gives easy 
access by sea to other ports of the Atlantic or Pacific. There are 
four passes, which are, from north to south: that of "Los Patos," 
from Cordova to San Juan, long abandoned; that of Cumbre of 
Uspallata, more frequented (3920 meters) ; and that of Portillo, 
which requires the crossing of two passes, one of which has an 
altitude of not less than 4360 meters. Finally, the last, which is the 
lowest in the Andes in Chile, that of Planchon, which goes straight 
to the port of Conception, reaches the altitude of 2500 meters. 

Over the long extent of Central America, the Cordillera remains 
at an average height; among the innumerable volcanoes with which 
it bristles, that of Acatenango (4150 meters) in Guatemala, alone 
exceeds 4000 meters. 

The city of Mexico, like the city of Quito, is surrounded by 
mountains: Coluca (4580 meters), Ixtaccihualt (4790 meters), 
Chicle, over which Robertson junior passed in a balloon, and Popo- 
catepetl (5420 meters). Citlaltepetl or the peak of Orizaba (5400 
meters) is about 60 leagues away. 

In the Rocky Mountains we should note particularly Uncom- 
pahgre Peak (4430 meters) ; Pike's Peak, on the summit of which 
(4340 meters) a meteorological observatory has just been installed; 
Mount Lincoln (4300 meters) ; Long's Peak (4310 meters) and Fre- 
mont Peak (4130 meters) , between which the great railroad from 



Lofty Regions of the Globe 15 

New York to San Francisco passes at an altitude of 2500 meters; 
side by side, Mount Brown (4850 meters) and Mount Hooker (5100 
meters) . The mountains along the Pacific make way for the Oregon 
between the Sierra Nevada in California, the highest summits of 
which are Mount Whitney (4500 meters), Mount Tyndall (4380 
meters), and Mount Shasta (4400 meters), and the chain of the 
Cascades, with Mount Baker (3390 meters), Mount Hood (3420 
meters) , and Mount Rainier (4400 meters) as the highest peaks. 

At the northern end, on the very shore of the ocean, rise the 
highest peaks in North America, Mount Fairweather (4620 meters) 
and Mount Saint-Elias (5440 meters) . Finally, in Alaska, the vol- 
cano Gorjaloja ends the immense American chain, which has 
stretched for more than 4500 leagues. 

Africa. Africa is far from possessing chains of mountains which 
can compare with the Himalayas, the Andes, or even the Alps. 
And yet the belt of mountains at a short distance from the sea, 
which surrounds the vast plateaux of the interior, rises at different 
points to considerable heights. The Atlas range, which in French 
and Tunisian possessions never reaches 3000 meters, exceeds this 
height sometimes in Morocco, where Mount Miltsin measures 3470 
meters. In Abyssinia, the circle of mountains around Gondar and 
Lake Zana rises at certain points to 4425 meters (Abba-Jaret) , even 
to 4620 meters (Raz-Daschan) ; the pass of Buhait is 4520 meters 
high. On the shore of the Atlantic, the peak of Fernando-Po rises 
to 3260 meters, and opposite it, the Kamerun Mountains, perhaps 
the Bdav {6xw a ) °f Hanno, reach to 4000 meters. In the colony of 
Natal, the chain of Drakenberg displays summits more than 3000 
meters high: Cathkin Peak (3150 meters) . Finally, almost on the 
equator, near the shore of the Indian Ocean, the Kenia mountains 
are 5000 meters high, and Kilimandjaro raises its crest, clothed in 
perpetual snow, to 6110 meters. Let us add that in the interior a 
lofty mountain has been noted, the peaks of which are more than 
3000 meters high; it is Alantika, which is connected to the Kamerun 
Mountains. 

Islands. The islands, which remain to be discussed, contain only 
a small number of mountains the height of which is great enough 
for their ascent to bring on physiological disturbances. The highest 
point of the Australian Alps, Mount Kosciusko, is only 2190 meters 
high. But in New Zealand, several exceed 3000 meters, and the 
giant of the southern island, Mount Cook, is 3770 meters high. New 
Guinea contains several volcanic mountains which are no less lofty- 
than those of New Zealand; the Owen Stanley range, the highest, 



16 Historical 

measures 4020 meters; but I object to including among them this 
Mount Hercules, 10,929 meters high, the discovery of which an 
English captain, M. Lawson, very recently announced, and on which 
he claims to have ascended to 8435 meters. In the island of Hawaii, 
among several still active volcanoes, Mauna Loa is 4250 meters 
high, and Mauna Kea 4195; on the neighboring island of Maui, 
Mauna Haleakala reaches an altitude of 3110 meters. The innumer- 
able volcanoes which form the island of Java also have lofty sum- 
mits; Gounong-Simeron measures 3300 meters, Semeroe 3730 me- 
ters. In Sumatra, I will mention Indrapura (3870 meters) and 
Dempo (3300 meters); in Borneo, Kini Ballu (4175 meters). The 
mountainous ridge of Formosa has summits of 3000 to 4000 meters. 
In Japan, among other lofty mountains, the volcano Fujiyama, the 
"Unequalled Mountain," with its height of 4320 meters dominates 
the roadstead of Yeddo. Finally, at the South Pole, the lofty vol- 
canoes of Victoria Land, Erebus (3800 meters), Melbourne (4500 
meters), and on the north Polar Circle, those of Kamchatka, the 
highest of which is Klioutchef (4805 meters), end this volcanic 
girdle which edges the Pacific Ocean on all its circumference, Amer- 
ican or Asiatic. 

On the island of Ceylon, the peak to which the pilgrims come 
to worship the Cri-Pada, the print of the foot of Buddha or Adam, 
rises only to 2420 meters. The mountains of Madagascar reach 3350 
meters, at their highest point, Ankaratra. Piton de Neige, on 
Reunion, measures 3070 meters. Finally, mention of the volcanoes 
of Teneriffe (3715 meters) and of Etna (3310 meters) ends this 
long list of all the places on earth the elevation of which is great 
enough for an ascent of them to cause physiological disturbances 
the severity of which necessarily attracts the attention of travelers. 

Summary. All of the foregoing can be summarized rapidly in 
a striking form. Let us suppose that the quantity of water on the 
earth should increase enough so that the sea level would rise 3000 
meters. What would remain, emerging above an almost limitless 



ocean 



The largest stretch of land would be formed by the high pla- 
teaux of Thibet, Vokan, and Pamir, from which would rise numer- 
ous mountains 4000 to 5000 meters high; its area would be two or 
three times that of France. From it would diverge series of islands 
which would mark the chains of Thian-Shang, Indou-kouch, and 
Soleiman, and the mountains of Yunam and China. 

At the other end of a terrestrial diameter, a long strip extending 
from the equator to the Tropic of Capricorn, spreading out at its 



Lofty Regions of the Globe 17 

two ends and particularly towards the south, in the region corre- 
sponding to Bolivia, would be prolonged towards the south and the 
north by strings of lofty islands, crowded against each other; that 
is all that would be left of the Andes. 

The plateau of Armenia, separated from the emerging crests 
of the Caucasus, would form the last bit of land, much smaller than 
the other two, which would be flanked by a few summits of the 
Taurus and the Elburs mountains. 

Then the region of the Alps would have become a compli- 
cated archipelago, with innumerable isles and islets, Oberland, 
Grisons, the main range of Monte Rosa and that of Mont Blanc. 
Of the Pyrenees there would remain only a few peaks near the 
Maladetta. Mulahacen and Etna alone would be the only others 
still emerging in Europe. 

In Africa, there would be only the Abyssinian crescent and 
isolated points: a few islands in the Moroccan Atlas, the Peak of 
Teneriffe, that of Fernando-Po, the Kamerun Mountains, Kilimand- 
jaro and Kenia, some peaks of the Drakenberg, and Ankaratra in 
Madagascar. 

North America would still have left above the waters a certain 
number of summits belonging to the volcanoes of Guatemala and 
Mexico, to the Rocky Mountains, to the Cascades, and the Sierra 
Nevada; further to the north, Mount Saint Elias and the volcanoes 
of Alaska, facing those of Kamchatka. Finally, of Oceania which 
would have disappeared there would remain only the volcanoes of 
the southern lands, New Zealand, Haiti, New Guinea, the islands 
of the East Indies, Formosa and Japan. 

These are the regions, thus reduced in surface, the study of 
which .concerns us here. The survey we have made of them shows 
that these mountains differ from each other greatly, not only in 
their height, but also in their general character. Some rise rapidly, 
with a single rush, so to speak, to their full height; this is the type, 
for example, of the mountains of the islands and those of the west- 
ern slope of the Cordillera of the Andes. In others, the strata are 
heaped progressively upon each other, and summits of prodigious 
height do not seem, because of their high bases, to equal isolated 
peaks which they really surpass. In the third part of this book, 
we shall show that these different orographic characteristics are 
very important in our study. 

Eternal Snows. The latitude of these mountains has an equal 
importance. In fact, it is closely connected with the question of 



18 Historical 

temperature. Now the line at which the eternal snows begin cor- 
responds very accurately with the temperature. 

In our Alps and Pyrenees, about 43°-47° north latitude, this 
line is a little above 2700 meters; on Etna (38° lat. N.) it rises to 
2900 meters. In the main mountain ranges of the center of Asia, of 
Pamir (40° lat. N.), in the mountains of Boutan (27° lat. N.) , it 
varies between the enormous heights of 4000 to 6000 meters, higher, 
naturally, in the regions nearest the equator, and also, curiously 
enough, on mountain slopes facing north; on Gaurisankar, the 
snow begins at 5300 meters towards the north, whereas towards 
the south it begins at 4900 meters; the chain of Karakorum is at 
certain points bare of snow up to 6500 meters (Schlagintweit) . In 
Abyssinia (13° lat. N.) the line is about 4300 meters, and on Kili- 
mandjaro (3° lat. S.) it is a little more than 5000 meters. The Cor- 
dillera, in its long extent from south to north, does not lend itself 
to an average estimate. At the equator, the volcanoes around 
Quito have the line of eternal snow at about 4800 meters. Speak- 
ing generally, this snow line is lower as the distance from the 
equator becomes greater; at Popocatepetl (19° lat. N.), it is only 
4300 meters. But in the Andes of Bolivia, and especially in the 
mountains which edge Lake Titicaca on the west (16° lat. S.), it 
rises considerably up to 6000 meters: much above the level in the 
mountains of the east, where it is about 4800 meters. In the Andes 
of the Chilean shore, on the volcano Corcobado (2290 meters) , in 
43° lat. S., that is, at the same distance from the equator as Mala- 
detta, it is only 1800 meters. On Mount Hooker (52° lat. N.) it is 
2600 meters, on Mount Elias (60° lat. N.) 1500 meters, and on Baren- 
Berg (2096 meters) on the island of Jan Mayen (71° lat. N.) at 
only 400 meters. On Tierra del Fuego, on Mount Sarmiehto. (2075 
meters), in 54° lat. S., the line is at 1100 meters, much lower than 
on Mount Elias, which, however, is much nearer the pole. 

Living Organisms. The extent of vegetation varies in altitude 
with the snow line, which perpetually limits it. Whereas in our 
Alps the timber line is at about 1800 meters, in the tropical Andes 
the grapevine, the cinchonas, and the oaks extend up to 3000 meters. 
In the Himalayas, the limit is higher yet, because apricot trees are 
cultivated at an altitude of more than 3000 meters, and birches 
and poplars grow up to an elevation of 4200 meters. 

Animals naturally follow vegetation; birds conform to this rule, 
and if on the sides of Chimborazo the condors sometimes soar at 
the prodigious height of 7000 meters, that is because 2000 to 3000 



Lofty Regions of the Globe 19 

meters lower, pastures stocked with llamas, ostriches, etc., assure 
them abundant food. 

Human dwellings obey the same law. In central Europe, only 
a few villages are at a greater altitude than 1500 meters; the high- 
est in the Pyrenees, Porte, is at an altitude of 1625 meters; Saint- 
Veran, in the Upper Alps, and Soglio, in the Rhetian Alps, are 2050 
meters high. Above that height, there are only a few chalets un- 
occupied in winter. The monastery of Saint Gothard is at an alti- 
tude of 2090 meters, that of Bernina at 2300 meters; the highest 
of the summer pastures to which the Alpine shepherds go is that 
of Fluhalpe, at 2550 meters, and we know that a sufficient number 
pf monks can be kept at the monastery of the Grand Saint Bernard 
(2470 meters) only by means of the double attraction of heavenly 
rewards and fat Italian prebends promised to the monks after some 
years of painful sojourn on the mountain. 

In the Rocky Mountains, Central City is at an elevation of 
3460 meters on the side of Long's Peak (40° lat. N.). 

In the Andes, not only villages but also populous cities are built 
in large numbers in lofty places. Mexico City is at 2290 meters, 
Santa Fe de Bogota at 2560 meters, Quito with its 60,000 inhabit- 
ants at 2910 meters, Cuzco at 3470 meters, Micuipampa at 3620 
meters, La Paz at 3720 meters, Puno at 3920 meters, Tacora at 4170 
meters; Potosi, which formerly had more than 100,000 inhabitants, 
is at 4165 meters, Oruro at 4090 meters, Torata at 4175 meters, 
Portugalete at 4290 meters, Cerro de Pasco at 4350 meters; in Peru 
and Bolivia, the larger part of the population lives above 3000 
meters. 9 Villages and dairy farms are at still higher levels. The 
mines of Chouta are operated at 4480 meters, those of Huancavelica 
at 4655 meters, those of Villacota at 5042 meters (Pissiz) . The post- 
house of Rumihuani, on Illimani, is at 4740 meters. The railroad 
from Arequipa to Puno, as we have seen, crosses the Cordillera at 
an elevation of 4460 meters, and that from Callao to Oroya at its 
highest point has a tunnel at 4760 meters; now these gigantic feats 
required the prolonged sojourn of a great number of workmen. 

In the Himalayas, man has established his dwelling at heights 
just as astonishing. According to the Schlagintweit brothers, the 
capital of Little Thibet, Leh, is built at 3505 meters; in the same 
country, Muglab and Kibar, cities built of stone, are at 4150 and 
4220 meters; the village of Chushul, highest in the Himalayas among 
those which are inhabited all year long, is at 4390 meters; the 
Buddhist monastery of Hanle, in Ladak, is at 4610 meters; about 
twenty lamas live there. The villages inhabited only during the 



20 Historical 

summer are frequently situated between 4500 and 4900 meters; 
Norbu, for instance, is at 4860 meters. In summer, the herds feed 
in pastures as high as 5000 meters, like that of Larsa, at 4980 
meters. 10 On the high plateaux of Vokhan and Pamir, the Kirghiz 
bring their yaks and sheep to the elevation of 4700 meters. The 
Mirza sent by M. Montgomerie to Thibet even mentions a village, 
Thok-Djalank, at the extraordinary height of 4980 meters. 

The Andes and the Himalayas include the only two regions of 
the earth where populations numbering millions of souls live 
regularly above 3000 meters. On the lofty plateaux of Mexico, the 
regions inhabited by a great number of men are as low as about 
2000 meters; in Abyssinia, they are lower yet; Gondar is at 2220 
meters and the village of Endschetkab, which seems to be the 
highest in Abyssinia, at 2960 meters. 

About the same thing is true of the mountain dwellers in 
Armenia: Ispahan is situated at 1340 meters, Erzeroum at 1860 
meters and Kars at 1900 meters. In Europe, as we have seen, the 
level is still lower. 

Men who live at these heights are certainly in conditions very 
different from those encountered at sea level. At 5500 meters, a 
liter of air weighs exactly half as much as at sea level; at 3300 
meters, a third less; at 2300 meters, a quarter less. Are these 
special conditions helpful or harmful to the material or intellectual 
development of man? I shall try to discuss this question in the 
third part of this book. I must remind my readers, furthermore, 
that slow, progressive influences, which the sojourn in lofty moun- 
tains may exert on successive generations, will be given little atten- 
tion. For these important questions in hygiene and politics, I refer 
my readers to the noteworthy book of M. Jourdanet. In this work, 
and especially in the part devoted to the discussion of historical 
records, I shall deal only with sudden and evident symptoms caused 
in men and animals by an abrupt and considerable change in alti- 
tude and consequently in barometric pressure. And so in the fol- 
lowing pages I shall refer to the accounts of travellers, generally 
telling their own experiences. 

I have divided this historical part into three distinct chapters. 
The first contains the reports of which I have just spoken; I have 
classified them by orographic regions and listed them chronologi- 
cally. I certainly do not claim that this list is absolutely complete; 
but I think I have omitted nothing that is really interesting. 

In the second chapter the accounts of aeronauts are reported. 
Finally, in the third I have arranged the laboratory experiments, 



Lofty Regions of the Globe 21 

carried out with the purpose of studying the effect of diminished 
pressure, the theoretical interpretations which various physiolo- 
gists have given a priori of the symptoms observed in mountain 
ascents, and finally the explanations suggested by the travelers 
themselves, with the popular opinions about these strange illnesses. 
Of course in this chapter I stop at the discussions which my own 
researches have aroused; my purpose is to show the state of 
knowledge when I began my experiments. Finally, the last chap- 
ter summarizes both all the data observed and all the theories 
suggested. 



'See, however, in Chapter III, the quotation from Bacon. 

2 The altitudes which I give in this general review were taken generally 
from the last edition of Stieler's Hand-Atlas. Those which I did not 
find in this atlas were taken, for Europe, from the Orographie of Brug- 
niere; for France, from the Geographie of M. Levasseur; for South 
America, from the works of Pentland and M. Pissiz. I used also the 
information furnished by the recent work of Berghaus (Hdhentajel 
von 100 Gebirgsgruppen aus alien Erdtheilen, Geogr. Jahrbuch. 1874). 
My intended purpose evidently does not require absolute precision; 
therefore I did not hesitate to use some rather old documents; for the 
same reason, I omitted the units in the altitude figures. 

3 Strabo, Geography, Book VI, Chap. Ill, Section IX. 

4 Ibid., Book IV, Chap. VI, Section IV. 

6 See Schuechzer, Ovpeoupoirris Helviticus. Lugd. Bat., 1725. 

Harcourt, On the Himalayan valleys: Kooloo, Lahoul and Spiti. Journal 
of the royal geogr. soc, Vol. LXI, p. 245-257; 1871. 

7 Nouvelle description des glacicres et des glaciers des Alpes, second 
edition, Vol. II, p. 87. Geneva, 1785. 

"Besides the sources indicated above in a note, for these altitudes I 
borrowed frequently from Kloden, Handbuch der Erdkunde, Berlin, 
1869, and from Stein, edition of Wappens: Handbuch der Geographie, 
Leipzig, 1863-70. 

9 Jourdanet, Influence de la pression de Vair sur la vie de Vhomme, Vol. 
I, p. 108. Paris, 1875. 

10 Schlagintweit, Results of a scientific mission to India and High Asia in 
1854-1858. 3 vol. 1861-1863; Vol. II, p. 477. 



Chapter I 
MOUNTAIN JOURNEYS 



1. South America. 

It is to the accounts of travellers who followed .the first Amer- 
ican conquerors that we owe our knowledge of the discomforts 
that attack man when he reaches a certain height on a mountain 
side. To gain this elementary information, science had to wait 
until Cortez attacked Mexico in 1519 and until Pizarro, twenty-five 
years later, took Quito and conquered Chile and Peru. And yet 
the conquerors themselves gave little heed to the increase of suf- 
fering brought them by an unknown disease; at least their his- 
torians do not mention it. In the account of the two expeditions 
which by order of Cortez ascended to the crater of Popocatepetl 
(5420 meters) in 1519 and 1522, the details of the second of which 
were told by Herrera, 1 mountain sickness is not very clearly indi- 
cated. 

The companions of Francis Pizarro (62 horsemen and 102 foot- 
soldiers), in the daring march which took them in October, 1532, 
from the Pacific coast to Cuzco, the heart of the empire of the 
Incas, had to cross the lofty passes of the Cordillera ol the Andes 
through a thousand perils. The historian, Xeres, 2 who is the nar- 
rator of this marvellous expedition, speaks only of "the great cold 
experienced on these heights". However, they were below the 
region of perpetual snow; the ground was covered with a plant 
like the "esparto corto" (page 65) . Ferdinand Pizarro, sent by his 
brother from Caxamalca to Parcama and Xauxa, on March 3, 1533, 
passed over "a very steep mountain of snow, into which the horses 
sank up to their bellies" (page 157) ; but mentioned no special com- 
plaint. 

In 1534, Pedro de Alvarado with 500 men and 225 horses under- 
took the conquest of Peru; disembarking at Cape San Francisco, he 

22 



Mountain Journeys 23 

reached the road from Cuzco to Quito at a point south of Ambato; 
it is evident then that he crossed the Andes near Chimborazo. He 
must have ascended to an altitude of more than 4800 meters, since 
he was in the midst of snows; the sufferings of his army were 
terrible: 

There died (according to Herrera) fifteen Spaniards and six women, 
several negroes and two thousand Indians. When they issued from the 
snow, their faces were death-like. Several Indians who escaped lost 
their toes and even their feet; some were blind. 

The great expedition of Don Diego d'Almargo, in the conquest 
of Chile, had still more terrible results. Leaving Cuzco in 1535, he 
tried to cross the mountain, in spite of his captains. The Inca Gar- 
cilasso de la Vega 3 has given a touching account of the sufferings 
of the army. 

As the land they entered was so wild, suffering soon resulted: for 
a few days after, they found strange obstacles in the road they took. 
The first was that they could not walk on account of the snow . . . the 
second, that food began to fail . . . and the third, that, according to the 
calculation of the cosmographers and the astrologers, since the moun- 
tains raised their summits into the middle regions of the air, the tem- 
perature was so low, because everything there is covered with snow, 
particularly in such a season as our adventurers had chosen, namely, 
winter when the days are the shortest and coldest of the year, that 
many Spaniards, Negroes, Indians, and horses were frozen and be- 
numbed. But the Indians, though lightly clad, had the best of it. 
Of the 15,000 of them, morethan 10,000 died and more than 150 of the 
.Spaniards , . . . 

It was probably in the lofty regions of Tacora, on the road be- 
tween La Paz and Arica, that this expedition took place, so un- 
fortunately undertaken in the middle of the southern winter. 

In 1541, i shortly after the death of Pizarro, four Spaniards, who 
were part of an expedition which had left Asuncion at the order 
of Irala, went to Lima, passing by Potosi and Cuzco. An envoy of 
the governor of Peru had made the same journey; "Miguel Ruedo 
and Ahaic were so exhausted by the hardships of the journey," 
says Ulrich Schmidel, who accompanied the expedition, "that they 
were obliged to stop at Potosi" (page 222) . 

These accounts, as we see, give as explanation of the sufferings 
and disasters only fatigue, lack of food, and cold. The Jesuit 
father Acosta, 5 who travelled in South America about the end of 
the sixteenth century, was the first to note the special distress due 
to a special cause, the air of lofty places. Let us add that he gave 
a striking description of it. 



24 Historical 

From the translation printed in Paris in 1596 by Robert Renault 
Cauxois, I copy the most interesting part of his account. 

In certain parts of the Indies, the air and the wind blowing there 
dizzy men, not less but more than at sea .... 

In Peru there is a high mountain called Pariacaca, and having 
heard tell of the variation it caused, I went there, prepared the best I 
could according to the information given by those called Vaquianos or 
experts; but in spite of all my preparation, when I began to mount the 
stairs, as they call the highest part of this mountain, I was suddenly 
attacked and surprised by an illness so deadly and strange, that I was 
almost on the point of falling from my horse to the ground, and al- 
though there were several in our company, each hastened his step 
without waiting for his companion so that he might leave this evil 
spot quickly. Being left alone then with an Indian, whom I asked to 
help me sit on my horse, I was seized by such a spasm of panting and 
vomiting that I thought I should give up the ghost. After vomiting 
food, phlegm, and bile, one yellow and the other green, I next threw 
up blood, so that I felt such distress in my stomach that I can say if it 
had lasted I am sure I would have died. That lasted only three or four 
hours until we had descended pretty low and had reached a tempera- 
ture more suited to nature, at which point our companions, about 
fourteen or fifteen in number, were very much exhausted, some of 
them asked for confession on the road, thinking they were really going 
to die, others dismounted and were wrecked with vomiting and diar- 
rhea; I was told that in the past some had lost their lives from this 
distress. I saw a man lying on the ground in a passion, crying out 
with the rage and pain caused him by this passage of the Pariacaca. 
But usually it does no important harm, except this annoying and dis- 
agreeable trouble as long as it lasts. And it is not only the pass of 
Mount Pariacaca that has this characteristic, but also this whole chain 
of mountains, which extends more than five hundred leagues; no mat- 
ter where one crosses it, he feels this strange distress, although it is 
worse in some places than in others, and worse in passes up from the 
seashore than in those from the plains. I myself crossed it, besides by 
Pariacaca, by Lucanas and Soras, and in another place by Colleguas, 
and in another by Cauanas, that is, by four different places in my 
various comings and goings, and always in this place, I felt this dizzi- 
ness and distress that I have mentioned, although never as much as the 
first time at Pariacaca, and all who have passed that way have had the 
same experience. . . . 

Not only men feel this distress, the animals do too, and sometimes 
stop so that no spur can make them advance. For my part, I believe 
that this place is one of the highest spots on earth. 

This whole chain of mountains is practically deserted, without any 
villages or habitations of men, so that one can hardly find little houses 
or retreats to lodge travellers at night. There are no animals either, 
good or bad, except maybe a few vicunas, which are the sheep of the 
country, which have a strange and marvellous characteristic, which I 
shall mention in the proper place. The grass is often burned and 
blackened by the wind I mentioned, and this desert lasts through the 



Mountain Journeys 25 

twenty-five or thirty leagues of the pass, and in extent stretches more 
than five hundred leagues, as I said (page 87). 

After he had made this description, and we will admit that 
exactness could not have been joined to picturesqueness more skil- 
fully, Acosta discusses the cause of these symptoms which he says 
he experienced in four other crossings of the great Cordillera. We 
shall report in a chapter devoted to a summary of theoretical ex- 
planations the ideas of this reverend gentleman, ideas which are 
really marvellous for insight and clearness. 

It is hard to determine the exact point at which Acosta crossed; 
Pariacaca is a name that has disappeared in Peru as well as in 
Ecuador. It is almost certain that it was below the snow line, for 
his account, so exact and so detailed, does not speak of the snow; 
its height above sea level was therefore probably 4500 meters at 
the most. 

It is very strange to see that after describing so admirably and 
after explaining the painful sensations he had experienced while 
crossing the lofty mountains, Acosta does not consider them as 
accounting for the disasters undergone by the Spanish armies. Yet 
he knew them very well; he speaks of them; but here his clearness 
of mind seems to abandon him. 

There are other deserts or uninhabited places, which in Peru they 
call Punas (to speak of the second point which we promised) where 
the quality of the air cuts body and life from men without their feel- 
ing it. In the past the Spaniards travelled from Peru to the kingdom 
of Chile across the mountain; today they usually go by sea, and some- 
times along the coast; and although this route is tiresome and incon- 
venient, there is never as much danger there as on the mountain road, 
in which there are plains in passing through which several men have 
died and perished, and others have escaped with great luck, and some 
of them were maimed. In this place there blows a little wind which is 
not too strong or violent. But it is so penetrating that men fall dead 
of it almost without feeling it, or maybe their fingers and toes are left 
there; which may seem a fabulous tale, and yet it is a trUe thing. I 
knew and long frequented General Hierosme Costilla, former adminis- 
trator of Cusco, who had lost three or four toes, which had fallen off 
when he passed through the deserts of Chile, because they had been 
attacked and penetrated by this little wind, and when he happened to 
look at them, they were all dead and fell off of their own accord 
without giving him any pain, just as a rotten apple falls from the tree. 
This captain related that of a good army which he had led through this 
place the preceding years, since the discovery of this kingdom of Al- 
magro, a great part of the men remained there dead, and that he saw 
their bodies stretched out on the desert, without any bad odor or 
decay. ... No doubt this is a kind of cold so penetrating that it ex- 
tinguishes the vital heat by cutting off its power; and also because it 



26 Historical 

is very cold, it does not corrupt or cause decay in dead bodies, because 
putrefaction proceeds from warmth and humidity (page 89). 

A celebrated Spanish historian, who wrote shortly after Acosta, 
Antonio d'Herrera, took up the ideas of the learned Jesuit, and, 
without quoting him, copied almost in full the passages which we 
have just put before our readers/' But it is evident that he could 
not include the whole of the explanation of Acosta; at least it 
would be useless to include here his chapter: Reasons why it is so 
dangerous' to pass through the "Puertos Nevados" which lead to 
Chile, and the passes of the province of Quito through which Belal- 
cazar and Alvarado crossed with their armies. 

A century and a half passed without the historians and the 
travellers speaking of the physiological symptoms which Acosta 
had noted. The "Lettres Edifiantes", 7 in which there are so many 
details, generally childish but sometimes interesting, do not allude 
to them, although their writers were evidently several times in 
the same conditions as their predecessor. My researches in the 
authors of the seventeenth century have revealed nothing pertinent 
to our subject. 

But a document published at the beginning of the eighteenth 
century shows us that in the Andes it had been known for a long 
time that at certain points more or less severe symptoms attack 
men and animals. We even find in this document an explanation 
which recurs up to the present. A Frenchman, Frezier, 8 visited 
the coasts of Chile and Peru from 1712 to 1714; he speaks at length 
of the rich mines in the interior of the country, and after discussing 
the origin of the metals, he adds: 

It is certain that strong exhalations issue constantly from the 
mines; the Spaniards who live above them are obliged to drink very 
frequently Mate, the grass of Paraguay, to moisten their lungs, and 
thus prevent a sort of suffocation. Even the mules which pass through 
these places, although they are much less rugged and steep than others 
along which the mules run, are obliged to rest almost every moment 
to regain breath. But these exhalations are much more evident within; 
they are so powerful over bodies not accustomed to them that a man 
who enters for a moment comes out as if crippled. . . . The Spaniards 
call this illness Quebrantahuessos, that is, it breaks the bones (page 
150). 

Frezier had no opportunity to make personal observations. But 
a few years later, in 1736, three French Academicians, Bouguer, La 
Condamine, and Godin, went to Peru to measure a degree of the 
meridian there. It was at the time of this celebrated expedition 
that the symptoms of decompression were first studied and dis- 



Mountain Journeys 27 

cussed scientifically. In one of their trips, Bouguer and La Con- 
damine remained three weeks on Pichincha, at an altitude of about 
4860 meters. There they experienced discomforts which Bouguer '■' 
describes in the following terms: 

We were all at first considerably inconvenienced by the keenness 
of the air; those of us who had more sensitive lungs felt the difference 
more and were subject to slight hemorrhages, which no doubt came 
from the fact that the atmosphere, since its weight was less, did not 
by its compression help the vessels sufficiently to retain the blood, 
which, however, was still capable of the same action. Personally I 
did not notice that this inconvenience increased much when we hap- 
pened later to ascend higher; perhaps because I was already accli- 
mated, or perhaps also because the cold prevents the expansion of the 
air from being as great as it would be otherwise. Several of us, when 
we were ascending, fell fainting and were seized by vomiting; but these 
symptoms were more the result of fatigue than of the difficulty of 
breathing .... We sometimes felt a very severe cold, when the ther- 
mometer indicated only a moderate degree (page 261). 

Bouguer then expounds a hypothesis of which we shall speak in 
the third chapter; according to him, the symptoms experienced are 
due in part to fatigue, in part to a sort of scurvy. 

In the two volumes which La Condamine 1 " devotes to the ac- 
count of his journey, and which are anyway half filled by his vio- 
lent disputes with Bouguer, I could find only the following pas- 
sage referring to his stay on Pichincha: 

Don Antoine d'Ulloa, while ascending with us, fell in a faint, and 
had to be carried to a nearby cave . . . Personally I felt no difficulty in 
breathing. As to the affections which M. Bouguer mentions and which 
apparently refer to the tendency to bleed from the gums, with which 
I was then inconvenienced, I think it should not be attributed to the 
cold of Pichincha, since I felt nothing like it in other places of equal 
altitude, and since the same symptom attacked me again five years 
after at Cotchesqui, the climate of which is temperate. (Vol. I, p. 35.) 

But the most circumstantial and exact information is furnished 
us by Don Ulloa, a young naval officer whom the Spanish govern- 
ment had sent to protect the French mission, and who later played 
a great part in his nation. His accounts 11 give at the same time the 
story of the symptoms experienced temporarily by mountain climb- 
ers, and those which are the consequence of a stay of several 
months in certain regions of the Cordillera of the Andes. Here 
also for the first time we find suggested the services which a sojourn 
in lofty altitudes can render to therapeutics: 

Those who are not accustomed to frequenting these places are also 
exposed to another discomfort, besides the cold of which we have just 



28 Historical 

spoken; it is the Mareo of the Puna; and it is rare that they are not 
attacked by it. It is a disease quite like that which one feels at sea: 
it displays all the symptoms of it and follows the same course. The 
head whirls; one feels very hot; and painful nausea comes on, followed 
by bilious vomiting. Strength fails, the body weakens, fever appears; 
and the only comfort one finds is in vomiting. Some people are even 
so weakened that they would cause anxiety, if it were not certain that 
the -trouble was nothing but this Mareo. That lasts usually one or two 
days, after which health is restored. This inconvenience is greater or 
less according to the natural constitution of the person; but few escape. 
When anyone has felt it once, it is extraordinary that he should be 
attacked by it again in passing by Puna or coming from low countries 
or any country in which there is a high temperature (page 116). . . . 

There is also observed in these climates another symptom to which 
animals are subject. As soon as they pass from the plains to these 
eminences or Punas, as from countries where there are dwellings to 
the summits which surround them, breathing becomes so difficult for 
them, that in spite of the different pauses they make to get their breath, 
they fall and die there (page 118). 

Ulloa then discusses the different explanations suggested in his 
time to account for these phenomena, and energetically rejects the 
idea of toxic emanations due to minerals buried in the earth, an 
idea which is current even today among the common people and 
even in the educated classes of Bolivia and Chile. Then he adds: 

The men who have recently come to this climate also experience 
something similar to what I said about animals; while walking, they 
feel a suffocating and very painful fatigue, which forces them to rest a 
long time; that happens to them even in the flat lands; now there can 
be no other cause for this phenomenon than the keenness of the air; 
but as the lungs become accustomed to this atmosphere, the discomfort 
lessens. However, they still experience some difficulty in breathing 
when they wish to climb some slope; this is inevitable, but is not felt 
in other countries where the atmosphere has a regular density. 

This lightness of the air is favorable to those who have become 
asthmatic in a denser air. This asthma is known by the name of 
ahogos or suffocation; it is rather common there; that is why those who 
are attacked by it in the low countries go up into the mountains; al- 
though they do not entirely recover there, they live there nevertheless 
without pain: on the contrary, those who became so in high altitudes 
are well in the lowlands; so change of air is a certain alleviation in this 
sort of disease. The science of medicine might profit by these experi- 
ences, sending the patients of one country into another, although 
elsewhere there is not so great a difference of altitude. 

Difficulty of breathing is noted also to a certain degree in the high- 
lands of the province of Quito, but it is less painful there: no doubt 
that is because one of these countries is on the equator, or nearly so, 
whereas the other is remote from it. The conclusion is that the Punas 
or summits of Peru are less cold and the air less cutting than in the 



Mountain Journeys 29 

other countries. But it is well to note that what has been said of 
Guancavelica is general for all the lands extending towards the south. 
That these details may be better understood, I shall observe here 
that what is called Punas in Peru, is named Paramo in the kingdom of 
Quito (page 120). 

It was in the last year of the eighteenth century that the il- 
lustrious Alexander von Humboldt undertook that great expedition 
into South America, which was the source of so many important 
discoveries in the history of man, the physics of the earth, and 
natural history. 12 In 1802 he made a stay on the lofty plateau of 
Quito, overlooked by the gigantic peaks of Pichincha, Cotopaxi, 
Chimborazo, and Antisana. 

In March and in June 1802, he made ascents which have be- 
come famous of the last two volcanoes; he immediately gave a brief 
account of them in two letters, written the same day; I quote from 
them passages which are interesting from our point of view. 

The first is addressed to Citizen Delambre; 13 it relates particu- 
larly the ascent of Chimborazo: 

It was believed till now in Quito that 2470 fathoms was the great- 
est height at which men could resist the rarity of the air. In the month 
of March 1802, we passed a few days in the great plains which sur- 
round the volcano of Antisana, at a height of 2107 fathoms, where 
cattle, when chased, often vomit blood .... On May 16, we explored a 
path on the snow, a gentle slope on which we climbed to 2773 fathoms. 
The air there contained 0.218 of oxygen . . . the Reamur thermometer 
stood at only +13°; it was not cold at all, but blood issued from our 
lips and eyes. (P. 174.) 

In the expedition which I made June 23, 1862, to Chimborazo, we 
proved that with patience one can endure a greater rarefaction of the 
air. We crossed 500 fathoms higher than La Condamine at the Cora- 
zon, and we carried instruments on Chimborazo to 3031 fathoms, seeing 
the mercury drop in the barometer to 13 inches, 11.2 lines; the ther- 
mometer stood at 1.3° above zero. Our lips bled again. Our Indians 
abandoned us again as usual. Citizen Bompland and M. Montufar, son 
of the Marquis de Selvalegre, of Quito, were the only ones who were 
resistant. We all felt a discomfort, a weakness, a desire to vomit, which 
certainly arises as much from the lack of oxygen in these regions as 
from the rarity of the air. I found only 0.20 of oxygen at this immense 
height. (P. 175.) 

The other letter is addressed to his brother, Wilhelm von Hum- 
boldt; in it, more than in the preceding letter, he speaks of the 
ascent of the volcano Antisana: 14 

On our journey to the volcano of Antisana, the weather was so 
favorable that we ascended to the height of 2773 fathoms. At this alti- 



30 Historical 

tude the barometer fell to 14 inches, 7 lines, and the rarity of the air 
made blood issue from our lips, our gums, and even our eyes; we felt 
an extreme weakness, and one of those who accompanied us on this 
journey fainted. . . . 

We succeeded in approaching to about 250 fathoms from the sum- 
mit of the immense column of Chimborazo. . . . We mounted to a height 
of 3031 fathoms, and we felt inconvenienced in the same manner as on 
the summit of Antisana. Even two or three days after our return 
to the plain, we continued to feel a discomfort which we could at- 
tribute only to the effect of the air in these lofty regions, an analysis 
of which gave us 20 per cent of oxygen. (P. 329.) 

Thirty-five years later, 15 von Humboldt returned with details 
about the account of these ascents. He dwells particularly upon 
the physiological symptoms, and develops some very interesting 
theories in this regard. 

June 22, 1802, he was in the plain of Tapia, at an altitude of 
2890 meters. The first part of the ascent had no particular inter- 
est for our purpose: 

At an elevation of 15,600 feet, all the Indians but one abandoned 
us. . . . They claimed that they suffered far more than we did. There 
were only four of us left then: M. Bonpland, . . . M. Carlos Montufar, 
... a half-breed from San Juan, a nearby village, and I. (P. 413.) . . . 

We all began by degrees to be very uncomfortable (they were 
then at a height of about 5,000 meters) . The desire to vomit was ac- 
companied by fits of dizziness and was much more painful than the 
difficulty of breathing. The half-breed from San Juan, a poor and 
sturdy peasant, who had wished to follow us to the end out of the 
kindness of his heart and not from any selfish interest, suffered more 
than we did. Our gums and lips bled. The conjunctiva of the eyes in 
all of us without exception was bloodshot. These symptoms of extra- 
vasation in the eyes and of a discharge of blood from the gums and lips 
did not disturb us, because we were acquainted with them from many 
examples. In Europe, M. Zumstein began to bleed at a much lower 
elevation, on Monte Rosa. 16 (P. 417.) . . . 

Once, on the volcano of Pichincha, I felt, without any bleeding, 
such a violent pain in my stomach, accompanied by vertigo, that my 
companions found me stretched out unconscious on the ground. The 
altitude was only 13,800 feet (4480 m.), and consequently not im- 
portant. But on Antisana, at the great height of 17,022 feet (5527 m.), 
Don Carlos Montufar bled profusely from the gums. All these phe- 
nomena vary greatly, according to the age, the constitution, the deli- 
cacy of the skin, and the previous muscular efforts which one has 
made; however, they are for each individual a sort of measure of 
the rarefaction of the air and the altitude he has reached. According 
to my observations, they appear in the Andes in white men, when the 
barometer stands between 14 inches and 15 inches 10 lines. (P. 418.) 

We shall see later what successive opinions, and considerably 



Mountain Journeys 31 

different ones, the illustrious naturalist held about the explanation 
of these various phenomena. 

But before going on to other accounts, I should include here a 
fragment of one of the works of Humboldt, 17 in which he gives in- 
formation full of interest for the subject of our study about the 
usual habitat of the condor and the maximum height to which it 
rises: 

The region which one may consider the habitual sojourn of the 
condor begins at a height equal to that of Etna, and includes layers of 
the air from 1,600 to 3,000 fathoms above sea level. The largest speci- 
mens found in the chain of the Andes of Quito have a wing-spread of 
14 feet, and the smallest only 8 feet. By these dimensions and by the 
visual angle at which this bird appeared sometimes perpendicularly 
above our heads, one may judge to what prodigious height it rises when 
the sky is clear. Seen, for example, at a visual angle of four minutes, 
he would be at a perpendicular distance of 1,146 fathoms. The cavern 
(machay) of Antisana, situated opposite the mountain of Chuesolongo, 
and from which we took the measurement for the soaring bird, is 
2,493 fathoms above the level of the Great Ocean. So the absolute 
height which the condor attained was 3,639 fathoms; there the barom- 
eter is hardly twelve inches high. It is a very remarkable physiological 
phenomenon that this same bird, which for hours soars in circles in 
regions where the air is so rarefied, suddenly swoops down to the sea- 
shore, for instance, along the western slope of the volcano of Pichincha, 
and thus in a few instants passes through all climates, as it were. At 
a height of 3,600 fathoms, the aerial and membranous sacs of the con- 
dor, which were filled in lower regions, . must be extraordinarily in- 
flated. Sixty years ago Ulloa expressed his surprise that the vulture 
of the Andes could soar at a height where the air pressure was only 
14 inches. It was believed then, on the basis of experiments made with 
the pneumatic machine, that no animal could live in a medium so rare. 
As I have already stated, on Chimborazo I saw the barometer drop to 
13 inches 11.2 lines. My friend, M. Gay-Lussac, breathed for a quarter 
of an hour in air the pressure of which was only 0.3288 meters. At 
such great heights, in general man finds himself in a very painful state 
of asthenia. On the contrary, in the condor the act of respiration ap- 
pears to take place with equal ease in media in which the pressure 
varies from 12 to 28 inches. Of all living beings, this is certainly the 
one which can at will rise furthest from the surface of the earth. I 
say at will, because small insects are carried still higher by ascending 
currents. Probably the height reached by the condor is greater than 
we found by the calculation given. I remember that on Gotopaxi, in 
the plain of Suniguaicu, covered with pumice stones, and at an eleva- 
tion of 2,263 fathoms above sea level, I saw this bird at such a height 
that it seemed only a black dot. What is the smallest angle at which 
objects dimly lighted can be distinguished? The weakening of the rays 
of light by their passage through the layers of air has a great effect 
upon the minimum of this angle. The transparency of mountain air is 
so great at the equator, that in the province of Quito, as I have shown 



32 Historical 

elsewhere, the poncho or white cloak of a person on horseback can be 
seen with the naked eye at a horizontal distance of 14,022 fathoms, and 
consequently at an angle of 13 seconds. (P. 78.) 

The revolutions by which the Spanish colonies of America shook 
off the yoke of the mother country resulted in the crossing by 
troops of several thousands of men of certain passes of the Andes 
usually frequented by only a few travellers. The stay in rarefied 
air certainly brought an increase of suffering to these little armies; 
but the historians seem to have paid but little attention to it, pre- 
occupied as they are by the natural effect of the cold, the lack 
of food, and the excessive fatigue. 

Early in the year 1817, General Saint-Martin, at the head of 
3000 Independents, invaded Chile by the difficult pass which leads 
from Mendoza to Santa Rosa, the highest point of which has an 
elevation of more than 4300 meters. 

The expedition (says M. Gustave Hubbard 1S ) presented such great 
difficulties that the troops from Santiago and the governor of Chile re- 
fused to give credence to such a dangerous attempt .... A great num- 
ber of men perished from cold in the rarefied and frigid atmosphere 
through which they had to pass .... When the army left Mendoza it 
had 9,281 mules; only 4,300 were left on the other side of the Andes, 
and out of 1,600 horses only 500 survived. (Vol. I, p. 346.) 

The army which Bolivar led against Morillo in June 1819 from 
Venezuela to New Grenada, across the Andes of Colombia encoun- 
tered the same difficulties. The Englishmen who formed a con- 
siderable part of his expeditionary forces died in great numbers. 
The celebrated historian Gervinus says in this reference: 19 

The way is unmistakably marked by the bones of numerous vic- 
tims who die during these crossings. ... In fact, those who, overcome 
by weariness and cold, abandon themselves to the peculiar drowsiness 
to which the traveller in lofty places becomes an easy prey fall into a 
numbness which takes their strength from them (emparamados from 
paramos, a name given to the highest plateaux) and delivers them over 
to death without any hope of rescue (page 88). 

Upper and lower Peru also witnessed such expeditions. In 1821, 
the Spanish viceroy La Serna, forced to abandon Lima, retreated 
across the Cordillera, and established himself in the high valley of 
Jauja. Thence his troops often descended to attack the Independ- 
ents, until Bolivar undertook against them the campaign which 
ended in the battle of Ayacucho (1824), and the whole of which 
was carried on at a height of more than 3000 meters. It was at a 
still greater height, 4500 meters, that General Santa Cruz defeated 
the Spaniards in 1822 on the slopes on Pichincha. 



Mountain Journeys 33 

The Spanish writer Torrente, 20 in his history of the Spanish- 
American revolution, is correct in attributing to the altitude a 
considerable share in the sufferings of the armies during these 
marches at high altitude: 

When one crosses the Cordillera of the Andes of Peru, one usually 
suffers from two maladies: spasms and nausea. The latter is more 
common, especially for those who come from the low, hot land along 
the coast. The keenness of the air in this atmosphere hampers respi- 
ration and makes it very laborious, increases the pulse rate, speeds up 
the circulation, produces intense headaches, and causes the blood ves- 
sels to swell quickly, and the unfortunate victim to perish, with an 
issue of blood from the mouth, the eyes, and the nostrils. It is true 
suffocation which attacks animals also if their burdens are increased or 
their pace hastened ever so little. The losses of the small army of the 
viceroy La Serna were greater during the retreat from Lima to Jauja, 
because a large number of his soldiers were still convalescing. 

The author adds, repeating popular superstitions: 

It seems that the veins of precious metals and antimony which run 
through the territory of Peru are the cause of this atmospheric combi- 
nation which is so injurious to health. What would tend to prove it is 
the fact that its effects are much less noticeable on points of greater 
altitude, such as certain parts of the Cordillera of Chile, the Sierra of 
Pichincha, and other mountains of Quito. 

This nausea is known in the country by the name of Soroche, and 
it is experienced even in certain low lying villages, situated in metalli- 
ferous localities. (Vol. Ill, p. 164 and 169, note.) 

We have seen Saint-Martin crossing the Cordillera from Men- 
doza to Santiago, thus carrying out an expedition which Manuel 
de Almagro 21 considers "as far more difficult and worthy of ad- 
miration than that of Bonaparte at the Grand Saint-Bernard, which 
has been much exaggerated" (p. 34) . This route, as we have said, 
is the one usually followed by travellers who wish to cross Amer- 
ica. Two passes exist, one by Cumbre (3920 meters) , the other by 
Portillo (4360 meters). The former is more frequented. Most 
accounts mention the symptoms of decompression; but on this road 
they are usually not serious. 

However, Samuel Haigh, 22 who ventured into the passes of 
Cumbre from Mendoza to Santiago during the austral winter of 
1818, felt them considerably. A snow storm which assailed him 
compelled him to take refuge with his companions at a hill where 
the "casucha" of Las Vacas offered them a shelter: 

While climbing the hill on which it is built, (he says) I was at- 
tacked for the first time by the puna or soroche. This is an illness 
peculiar, I think, to high mountains; it is the result of the extreme 



34 Historical 

rarefaction of the air which therefore causes difficulty in breathing. 
Three times I was forced to lie down on the ground before reaching the 
top of the hill, and I experienced shortness of breath with pain and op- 
pression in the chest and a sensation of nausea. The puna attacks some 
persons so severely that blood issues from their mouths and nostrils. 
However, I must say, our sufferings really began. (P. 104.) 

But all are not equally affected, especially when, as usually 
happens in the favorable season, the journey is made on mule- 
back. Miers, 23 who crossed in May 1819, explains this very well: 

Those who wish to undertake this journey will be dismayed t>y 
the accounts of the difficulties caused by the puna, a name given to 
the sensation of short and difficult respiration, which often attacks us 
when we ascend into rarefied air. This is the terror and the subject 
of conversation of all who have crossed the Cordillera, who tell you 
that they escaped these terrifying symptoms only by eating a great 
many onions, and by tasting no alcoholic liquors, except wine, which is 
considered the antidote of the puna. These precautions, however, are 
not necessary, for very few persons who make the ascent on horseback 
experience this discomfort, except those who have a lung ailment; but 
many of those who have climbed Cumbre on foot, overexerting them- 
selves in driving the mules, have been affected. I do not think that 
anyone would suffer much from the puna unless he overexerted him- 
self. I have twice ascended and descended Cumbre on foot without 
being affected. Moreover neither my wife nor my child, only six 
months old, felt the least difficulty in breathing with the thermometer 
at 35°F. and the barometer at 19 and Vs inches, although we might 
have expected that in a child of this age with such delicate lungs one 
would first observe modifications in respiration, even though they were 
due only to excessive rarefaction of the air. (Vol. I, p. 321.) 

The account of the Scotchman Caldcleugh - 4 is particularly inter- 
esting, because this traveller crossed the Andes twice in opposite 
directions. The first time, March 17, 1820, in very bad weather, a 
snowstorm, he crossed by Portillo and Piuquenes, going from Men- 
doza to San Jose. He does not mention any symptoms. (Vol. I, 
p. 285—323.) 

But on June 2 of the following year, while going from the Punta 
of San Luis to Cordova (Argentine Republic), he crossed at a 
much lower point, the Sierra of Cordova. He stopped at a little 
hut at an elevation of 3200 meters and passed the night there. The 
next day, ascent of the pass: 

The snow was frozen hard. . . . Two of the peons suffered severely 
from an illness called puna, which attacked them shortly after we had 
left the hut. This illness seemed to me to consist of heavings of the 
diaphragm, accompanied by great exhaustion and loss of spirits. Those 
attacked by it lie down, give themselves up, and often die before 
reaching the descent. Great quantities of garlic and onion are con- 



Mountain Journeys 35 

sidered specific against this condition. But the surest treatment is to 
take the patients as quickly as possible to a less lofty place. It has 
been commonly noted that those of the peons who are old and addicted 
to bad habits suffer more from the puna than the others, and this note 
applied perfectly to the two whom I had to send back. One of them 
was extremely sick, and the other under whose care he departed was 
slightly affected. At present I do not know whether he managed to 
cross the valley. 

Shortly afterwards they reached the summit, at an elevation of 
3840 meters. He suffered no personal distress. 

Schmidtmeyer, 25 in the account of his crossing the Cordilleras 
from east to west by the volcano of Cumbre, speaks of no physiolog- 
ical symptom. But at the end of the book, he fills this gap: 

I should have spoken sooner of this exhaustion accompanied by 
difficulty in breathing which one experiences when crossing the range; 
I often heard it spoken of in Chile. But we remained on muleback up 
to the highest point of the pass, which we therefore reached without 
the slightest effort. One of our men, however, suffered from it con- 
siderably, but I do not know whether it was an extreme case. Usually, 
on the high peaks of the Andes, one experiences great difficulty in 
moving; that is the opposite of what happens on other mountains. 
(P. 349.) 

Proctor -° (1824), Head 27 (1825), who followed the same route, 
in the same direction, make absolutely no mention of the puna. 
Lister Maw, 2S who in November 1827 left Truxillo (Peru) for the 
basin of the Amazon, does not speak either of the effect of the 
pressure, except at Contumasa (2190 meters) , where he says po- 
etically: 

The rarity of the atmosphere tended greatly to raise our spirits. 
But Lieutenant Brand 29 is more explicit; he mentions these 
symptoms, and even tries to explain them, but without having 
experienced them himself, and yet he made his first journey from 
Mendoza to Santiago over Cumbre in the midst of the austral 
winter (August 22, 1827), He had to endure terrible cold, even 
down to 15° below zero. 

August 22, he ascended Cumbre; the thermometer stood at 
34° F.: 

As I had often heard of the puna, or difficulty in breathing, from 
travellers who complained of it bitterly, I gave particular heed to it; 
I cannot say that I felt any more inconvenience than would have hap- 
pened to me if I undertook such labor, so long continued, even if I 
, had not been at this elevation. I suffered only from a very acute 
thirst, which the snow aggravated instead of satisfying. . . . But I do 
not intend to contradict what has been said of the puna, which has 
assailed many travellers severely. (P. 147.) . . , 



36 Historical 

On my return across the Andes, in December, 1827, I saw that the 
mules stopped frequently to breathe, especially when climbing Cumbre, 
where they stopped at each zigzag, as if they suffered from pain in the 
lungs, and, like Acosta, I found that neither shouts nor blows could 
make them advance until it suited them. But that is not peculiar to 
Cumbre or to the other mountains of the Cordillera, for mules often 
stop thus, as if they felt pain in their lungs. 

It happened likewise to the peons, who suddenly, while walking, 
stopped, shouted "puna, puna" and then continued ascending. It 
seemed as if they knew the places where this would happen to them 
when on foot, for they frequently said: "Here there is much puna." 
I can attribute this only to the existence in these places of minerals 
which alter the air more or less, whence comes their effect upon the 
lungs. (P. 149.) 

The French officer De la Touanne,' who took part in the ex- 
pedition of Bougainville, and who followed the same route as 
Brand, was so severely attacked as to fall on the ground; he 
crossed the pass January 29, 1826. 

I estimated that the point where we were is at least 2,000 fathoms 
high. . . . The air is very much rarefied at this elevation; I had dis- 
mounted from my mule, letting him go ahead with the caravan, and I 
was examining some stones at the right and the left of the path. When 
I afterwards wished to increase my pace to overtake my travelling 
companions, respiration suddenly failed me; I fell down, my chest 
oppressed and breathing with difficulty. A peon had to bring me my 
mule; and from these slight symptoms I could judge what the arrieros 
and the travellers who have to cross this pass in bad weather must 
suffer. (P. 50.) 

After this testimony from travellers who only crossed the moun- 
tain, here is what is said by an English engineer, Ed. Temple,- 1 who 
lived for a year 1826-1827, at Potosi (4165 meters), where he was 
employed in the exploitation of the rich mines of that country: 

While walking, I often experienced that difficulty in breathing 
which is caused by the extreme rarity of the air, and to which even 
the natives and the animals are subject. The royal sport of horse rac- 
ing cannot take place here, for the horses seem to suffer more from the 
zorochi than men do; I have often heard that they fall and die, if they 
are hurried when they are climbing a hill. (Vol. I, p. 296.) 

I shall also quote the passages in which the English traveller 
Bollaert,' 12 who in the month of June, 1827, ascended the mountain 
Tata Jachura (5180 meters), describes the sufferings he experi- 
enced during the ascent. 

We had slight nosebleeds, buzzings in the ears, headache, dimness 
of vision, and our bodies were numbed by cold, all of which were 
caused by the puna or soroche, that is, the expansion and cold of the 
atmosphere. (P. 121.) 



Mountain Journeys 37 

I now come to the important journey of d'Orbigny 33 and the in- 
teresting description he gives of mountain sickness. 

In his first journey, he is going from Arica to La Paz: 

May 21, 1830, I reached the point where the ravine of Palca joins 
another dry ravine. . . . There I left vegetation and humidity. . . . 

Soon I began to mount the side of Cachun, and on its summit I 
felt at the same time as the first effects of the rarefaction of the air a 
very keen cold, due to the elevation. (Vol. II, p. 377.) . . . 

The slope became still steeper. ... I felt more and more the severe 
effects of the rarefaction of the air, a very violent headache and a great 
difficulty in breathing; my arrieros, their mules, and even my dog, my 
faithful Cachirulo, were forced to stop every twenty or thirty meters, 
tormented like me by the soroche. . . . 

Whenever one feels the illness due to the rarefaction of the air, 
the natives say that he has the soroche. They fail to recognize the real 
cause, the great elevation above sea level, and attribute it to mineral 
emanations from antimony, called in Spanish soroche. It is this suf- 
fering, this difficulty in breathing in the very lofty parts of the Cordil- 
leras that has given them the name of puna brava. Some travellers use 
for the Peruvian Cordilleras the word Paramo,, not used in the coun- 
try, and which does not take the place of the word Puna, meaning a 
lofty plateau, dry and deprived of trees. 

After many fatigues, we reached the top of the last slope; I was 
at last on the crest of the Cordillera. (P. 378.) . . . Ever since my 
arrival at the summit of the Cordillera, I had been suffering terribly 
irom the rarefaction of the air. I felt frightful pains in my temples; 
I had nausea like that produced by seasickness, I breathed with dif- 
ficulty. At the least movement, I felt violent palpitations and general 
discomfort, added to an exhaustion which all my efforts failed to over- 
come. I had very strong proof of what habit can do. While I was suf- 
fering thus, I saw two natives, sent as couriers, nimbly and easily 
climbing on foot places incomparably higher than those in which I was 
in order to shorten their journey. . . . Yet they were at an elevation 
equal to that of Mont Blanc. In the evening I had a severe hemor- 
rhage from the nose which relieved me a little; yet I passed a night 
which was all the more terrible because I was without shelter, ex- 
posed to a keen and cutting cold which froze all the water in the 
neighborhood. (P. 380.) . . . 

May 23. I still felt the effects of the rarefaction of the air; head- 
ache and palpitation of the heart did not leave me a moment of repose. 
. . . My muleteers told me that a few months before a Spaniard who 
was taking the same route as they was so much affected by the rare- 
faction of the air that the very first day he experienced very alarming 
symptoms, and being unable to continue, he died the following night, 
without being able to get the least relief. They mentioned many other 
instances in which the travellers whom they accompanied had suffered 
atrociously from what they call the soroche. (P. 387.) . . . 

May 24. As I descended I breathed more easily, and I hoped that 
before the day ended at least a part of the discomfort I felt from the 
rarefaction of the air would cease. (P. 390.) 



38 Historical 

May 29, d'Orbigny arrived at La Paz (3720 meters) : 

As I had felt much better when I had descended from the western 
plateau to the Bolivian plateau, I expected to feel no more effects from 
the rarefaction of the air; but in the city of La Paz it was far different. 
At night I felt as if I were suffocating in my room. I could not climb 
the steeply sloping streets without being stopped every ten paces by 
palpitations and lack of breath. If I talked with animation, suddenly 
speech failed me; when invited to several houses to take part in a 
general entertainment, I could not waltz twice around without stop- 
ping, suffocated by the same symptoms; and I almost died one day 
when I tried to walk to Los Obragos, a village one league away, to 
reach which I had to climb a very steep slope. 

This discomfort lasted during the whole of my first stay in La Paz. 
Persons born in the country feel no effects at all. All assured me that 
one finally gets acclimated, and I myself had the proof of this on my 
return three years later. However, I should advise persons with weak 
lungs not to subject themselves to this test, which gave me the most 
pain in all my travels. (P. 404.) 

However the acclimatization of which d'Orbigny boasts was not 
as complete as one might think. It is true that in the account of 
his second stay in 1832 at Potosi, Oruro, and La Paz he does not 
mention any symptoms (Vol. Ill, p. 283 et seq.) ; but he returns to 
the subject when he tells of certain ascents: 

I had to stop (July 5, 1832), while I was going from Cochabamba 
to the country of the Moxos, beside a frozen lake nearly 5000 meters 
above sea level. We felt the excessive cold all the more because we had 
no shelter, and the air was so rarefied that I could hardly breathe. 
(Vol. Ill, p. 176.) . . . The next day, on the way down, . . . with the 
region of the clouds, vegetation began; up to that time I had felt an 
oppression in my chest, so I cannot express the pleasure I felt when I 
began to breathe more freely a less rarefied air (P. 117.) 

A German traveller, Ed. Poeppig, discusses the subject at greater 
length; he was staying at Cerro de Pasco (4350 meters) : 

The new-comer to Cerro de Pasco is subject to serious inconven- 
iences; walking, even on level ground, tires him extraordinarily; in 
streets sloping upward, respiration becomes short and painful, he is 
seized by headaches, by afflux of blood to the lungs, certain signs that 
he will not be able to escape the attacks of the puna any more than 
other foreigners. In vain does he try to brace himself energetically 
against the sickness; it conquers him and triumphs over the strongest 
wills. Just as during a violent attack of seasickness, the spirits are de- 
pressed, the senses blunted, disgust and hypochondrial discourage- 
ment transform the most robust, the most animated, the most coura- 
geous in a surprising manner. The physical sufferings, when the attacks 
of this sickness begin, are more painful and more varied than in the 
usual forms of seasickness. When the puna (also called Veta, Sorocho, 



Mountain Journeys 39 

or Mareo) is felt only moderately, the patient complains of a difficulty 
in breathing, which compels him to stop after about ten steps, and he 
tries in vain by deeper inhalations and a greater expansion of the chest 
to draw more of the life-giving element into his lungs. He feels as if 
he were shut up in a room without air, and the distressing sensation is 
increased by the failure of all his attempts to conquer his loss of 
strength'. The feet can hardly support the body, the knees bend, and 
every opportunity to rest, no matter how frequent, even after only a 
few steps, is welcome. It is a torment to climb streets sloping up- 
ward, and while he heaves himself painfully towards home, it is a 
real joy to find a doorway, a corner where he can stop and lean against 
something, burdened as he feels. The distress lessens only during 
absolute repose; but the conviction of the absolute necessity of the ill- 
ness, the incapacity for any intellectual effort, and the sense of loss of 
precious time bring on ill humor and discouragement, so that a vigorous 
man acts like a little child. 

Those who are most seriously affected by this illness are often 
seized with syncopes, symptoms of an afflux of blood to the head and 
the lungs, with an indefinable distress; and without fever, even with a 
feeling of inner chill, with hands and feet numb, their pulse beats at 
the rate of 108 to 120 times per minute. The unconquerable fatigue, 
the tendency to sleep are far from bringing on refreshing drowsiness, 
so that they cannot find repose. In fact, night brings the strongest 
feelings of suffocation, it is a real martyrdom; unable to endure a pros- 
trate position any longer, the unhappy patient seeks comfort beside 
the scanty fire which hardly keeps alive in the fireplace, at the risk of 
breathing air laden with coal fumes. The eyes are so weak that one 
can hardly read; in some, moreover, slight headaches appear, whereas 
in others there predominate discomforts and disorders of the digestive 
organs which resemble seasickness, from which, however, the puna 
is distinguished by its course as well as by its causes. 

When this painful stage is nearly over, often very distressing 
critical symptoms appear. After 6 or 7 days, the violent symptoms 
usually ameliorate in those who have strong lungs and a good consti- 
tution; otherwise, weeks may pass before the patient improves. An 
eruption of urticaria appears over his whole body, or is limited to the 
lips, on which it causes scabs, bleeding, or unendurable pain. ... In 
persons with thin skin and fair complexion, blood may issue from the 
skin without any wound, so that while the puna lasts, many dare not 
shave. In spite of the severity of the symptoms, there are hardly any 
cases in which they have caused death, and there is no danger except 
for those with weak lungs and especially those with heart disorders. 
(Vol. II, p. 84.) 

Poeppig then explains the reactions of different temperaments 
and different races, and gives therapeutic advice; he admits a cer- 
tain degree of acclimatization for Europeans. 

He next states that the residents of the country, even those born 
there, are not absolutely immune to the illness, especially when the 
nights are cold. The Indians have a sort of immunity. Beasts of 



40 Historical 

burden have symptoms like those of men; dogs feel no effects; cats 
are scarce in Cerro and in lofty places, and their young are hard 
to raise; hens do not lay there and seldom brood. 

The account 35 given by M. Boussingault of the ascent of Chim- 
borazo, made December 16, 1831, is in strange contrast with what 
we have just reported. We have seen that d'Orbigny was seriously 
attacked by mountain sickness at about the height of 3700 meters; 
Poeppig has described to us the sufferings of Europeans who have 
come to Cerro de Pasco (4350 meters) ; now M. Boussingault and 
Colonel Hall, his companion, climb nearly to the summit of Chim- 
borazo (to 6004 meters) and report almost no serious discomfort. 

M. Boussingault left Rio Bamba, where he had been staying for 
some time, December 14, 1838. He was accompanied by Colonel 
Hall, with whom he had already made ascents of Antisana and 
Cotopaxi. December 14, they slept at the farm of Chimborazo 
(3800 meters), which they left on December 15 at seven o'clock in 
the morning, guided by an Indian from the farm. When they had 
reached the height of Mont Blanc, the breathing of the mules was 
hasty and panting: 

It was noon. We were walking slowly, and as we were advancing 
upon the snow, the difficulty of breathing while we were walking be- 
came more and more noticeable; we easily regained strength by stop- 
ping every eight or ten steps, without sitting down. At equal heights, 
I think I have observed that it is more difficult to breathe on the snow 
than on rocks; I shall attempt later to give an explanation of this. 
(P. 155.) 

This first attempt failed; the snow, which had become too deep, 
checked the progress of the travellers, who sank in it up to their 
waists; they went back down to the farm. 

The next day, they started at seven o'clock by another route, 
the one followed by Humboldt, and ascended on muleback to 4945 
meters. There they had to dismount, since the mules could no 
longer carry their weight; it was a quarter of eleven. The two 
travellers continued to ascend on foot. 

We stopped to breathe every six or eight steps, but without sitting 
down. . . . But as soon as we reached a snowy surface, the heat of the 
sun became suffocating, our respiration was painful, and consequently 
our pauses for rest became more frequent, more necessary. 

We kept absolute silence during our advance, since experience had 
taught me that nothing was as exhausting as conversation at this 
height; and during our halts, if we exchanged a few words, it was 
almost in a whisper. It is largely to this precaution that I attribute 



Mountain Journeys 41 

the health which I have consistently enjoyed during my ascents of 
volcanoes. This wholesome precaution I imposed despotically, so to 
speak, upon those who accompanied me, and on Antisana an Indian 
who broke the rule by calling at the top of his lungs to Colonel Hall, 
who had strayed from us while we were passing through a cloud, was 
attacked by vertigo and had a slight hemorrhage. (P. 159.) 

They finally reached the foot of a peak of trachyte which barred 
their way; it was a quarter of one, the height reached was 5680 
meters, the thermometer stood at 4 degrees, and the air was very 
full of moisture, a condition which is constant on the glaciers of 
the Andes, according to M. Boussingault. Finally, after a rather 
long rest, after studying the terrain carefully, they once more 
began their climb: 

We were already beginning to feel more than we ever had the 
effect of the rarefaction of the air; we were compelled to stop every 
two or three steps, and often even to lie down for a few seconds. When 
once seated, we recovered immediately; our sufferings occurred only 
while we were moving. (P. 250.) 

Finally they arrived at a height of 6004 meters, an elevation 
which no one had yet reached; however this was not quite the 
summit of Chimborazo: 

After a few moments of rest, we were entirely recovered from our 
fatigue; none of us felt the symptoms experienced by most of those 
who have ascended lofty mountains. Three-quarters of an hour after 
our arrival, my pulse rate, and that of Colonel Hall too, was 106 per 
minute; we were thirsty, we were evidently in a slightly feverish con- 
dition, but it was not at all painful. (P. 251.) 

The rarefaction of the air generally produces very marked effects 
in persons who climb high mountains. ... As for us, we had, it is 
true, experienced difficulty in breathing and extreme fatigue while 
walking, but the symptoms ceased with the motion; when we were 
resting, we thought we were in a normal condition. Perhaps the mild- 
ness of the symptoms produced in us by the rarefaction of the air 
should be attributed to our prolonged stay in the lofty towns of the 
Andes. 

When one has seen the bustling in cities like Bogota, Micuipampa, 
Potosi, and still others, at an altitude of 2600 and 4000 meters; when at 
Quito, at an elevation of 3000 meters, one has witnessed the strength 
and prodigious activity of the toreadors; when one has seen young and 
delicate women dancing all night long in localities almost as high as 
Mont Blanc, where the famous de Saussure could hardly find enough 
strength to consult his instruments, and where his vigorous moun- 
taineers fell fainting while digging a hole in the snow; finally, when 
one remembers that a celebrated battle, that of Pichincha, took place 
at a height nearly that of Monte Rosa, one must admit that man can 



42 Historical 

become accustomed to breathing the rarefied air of the highest moun- 
tains. (P. 245.) 

But a German traveller, Dr. Meyers," 1 who in his journey around 
the world from 1830 to 1832 stayed for some time in Peru and in 
April, 1831, made the ascent of the volcano of Arequipa (5640 
meters), speaks of mountain sickness in terms which recall the 
description of Poeppig: 

At two o'clock in the afternoon we reached the summit of the 
mountain; my strength was exhausted, and we were suffering from the 
painful illness called sorocho. Little by little the symptoms of a nerv- 
ous or feverish state from which we had been suffering during the 
whole ascent had increased. Respiration took place with increasing 
difficulty, and gradually vertigo appeared, nausea, vomiting, then nose- 
bleed and fainting; in this condition we were forced to lie down on the 
ground, but rest restored our strength and permitted us to walk on 
again. 

The illness from which we were suffering deserves to be studied 
here; all travellers have heard of it, as soon as they have set foot on 
the coast of this country, expressing the intention of travelling in the 
mountains. In Peru they call it sorocho, and in Quito mareo de Puna 
or Puna. It appears under different forms. One of its symptoms, which 
is found both in the lower regions and on the summit of the Cordilleras, 
is a sensation of difficulty in breathing at the least effort. If one is on 
horseback, he feels no effect of the sort; but there appears at different 
degrees of intensity a sort of half-feverish condition, which is evidenced 
by burning heat over the whole body, headaches, dryness of the tongue, 
a burning thirst, and loss of appetite. The pulse rate rises to 100 or 110 
at the slightest movement. The face reddens, the skin cracks in differ- 
ent places so that blood issues; at the same time a general fatigue 
appears. That is the usual condition, the first test of those who make 
ascents, whether in Quito, Peru, Chile, the mountains of Asia or even 
the highest of those in our Europe. . . . 

This feverish condition is made worse by exertion and also by the 
influence of the violent, dry and cold winds which are so common in 
the Cordillera; the well-informed residents of this country attribute 
this illness to these winds. . . . The burning effect of the sun in lofty 
places also helps to aggravate these symptoms ... it is a factor in the 
headaches and the half-feverish condition. There are some persons 
who attribute the illness to exhalations from the metallic veins and 
deposits of sulphur so common on the summit of the Cordilleras. 

The sorocho has been compared to seasickness, and it has even been 
said that those who are not subject to the latter are spared by the 
former. That seems to us a mistake. The half-feverish condition which 
we described previously is the basis of this illness, and when it becomes 
worse, it brings on the characteristic symptoms of diseases of the brain, 
the respiratory organs, and the digestive organs. One of these three 
organs is always particularly affected, so that different forms of the 
illness result. When the chest is particularly affected, difficulty in 



Mountain Journeys 43 

breathing is added to the general fever; a sensation of weight in the 
chest appears, and the respiratory rate, like the pulse rate, increases; 
then come lacerations of the lungs, symptoms of choking, and even 
hemorrhages, a very rare phenomenon. . . . 

The death which has been observed in beasts of burden came, in 
our opinion, from suffocation; we ourselves, in ascending the volcano 
of Arequipa, experienced such respiratory difficulties that we had to 
stop every ten steps. Loaded animals, which are not allowed to do so, 
go on until they drop. In other cases, the illness attacks the digestive 
organs in particular, and then there appear nausea, qualms, extreme 
weakness, and finally vomiting, which gives a little relief. Affections 
of the brain are much more dangerous; they are also characterized by 
nausea and syncope, by a peculiar condition resembling drunkenness, 
and even by madness. 

In general it is admitted that at great heights the pulse rate is more 
rapid; that is because respiration itself has become much more rapid in 
a rarefied air. But neither respiration nor circulation is accelerated if 
one keeps perfectly quiet; several times, on the plateau of Tacora, after 
sleeping our pulse rate was no more than 70 or 72 per minute, whereas 
a few hours later the mere act of riding made it rise to 100 and 110. 
(P. 34 et seq.) 

They reached the summit of the mountain in a state of absolute 
exhaustion, and descended in a feverish condition which had not 
completely disappeared the next day. (P. 38.) 

The account of the illustrious naturalist Charles Darwin iT agrees 
perfectly with what we reported above in regard to the Chilean 
Cordillera. On May 20, 1835, he crossed the Andes, going from 
Santiago to Mendoza through the pass of Portillo (4360 meters) : 

About noon we began the tiresome ascent of Peuquenes, and then 
for the first time we felt some slight difficulty in breathing. The mules 
stopped every fifty steps, and the poor brave animals, after a few 
seconds, started again of one accord. Shortness of breath in rarefied 
air is called by the Chileans puna; and they have very ridiculous ideas 
about its cause. Some say: all the waters here have the puna; others: 
where there is snow, there is the puna; which no doubt is true. It is 
considered a sort of disease, and they showed me crosses on the graves 
of people who had died "punado." Except in regard to people who had 
lung or heart diseases, I think that these ideas are mistaken. No doubt 
at these elevations a very sick man will experience greater difficulty 
in breathing than others, and if he dies, this may have been the cause. 

The only sensation I felt was a slight oppression in the head and 
chest; this sensation is similar to what one feels when he leaves a warm 
room and exposes himself to icy air. There was much imagination in 
this; for, having found fossil shells on the highest peak, I forgot the 
puna completely in my joy. But certainly fatigue from walking is ex- 
treme, and breathing becomes deep and laborious. I cannot understand 
how Humboldt and others could have ascended to an elevation of 19,000 
feet; beyond doubt a residence of some months in the lofty region of 



44 Historical 

Quito had fortified their constitutions against such fatigue. However 
I was told that at Potosi (about 13,000 feet) foreigners do not become 
accustomed to the atmosphere until they have dwelt there a whole year. 
The natives all recommend onions for the puna ... as for me, I found 
nothing equal to fossil shells! (Vol. Ill, p. 393.) 

The English officers Smyth and Lowe, 38 who undertook a jour- 
ney in 1834 to find a navigable passage to the Atlantic by way of 
the Pachitea, the Ucayali, and the Amazon, crossed the Cordillera 
much nearer the equator. They left Lima September 20, 1834. 
September 25, a little beyond Pucachaca, the illness attacked them: 

The air became very cold ... we began to feel what is commonly 
called the veta or marea (seasickness), which consists of an acute pain 
through the temples and the lower and back part of the head, and 
which completely prostrates those attacked by it. ... (P. 25.) 

They reached Cerro de Pasco September 28: 

Because of the altitude, and especially while we were ascending, 
we felt a difficulty in breathing which oppresses the lungs, especially 
in new-comers; but after some time, the lungs become accustomed to 
the condition of the atmosphere, and this illness disappears. (P. 42.) 

Moreover, these facts were so well known in the mountainous 
regions of South America, that in 1842 a Scotch physician, Archi- 
bald Smith, 3 ' 1 summarized in the following words the notes he had 
collected during a journey to Peru: 

Veta, Soroche, la Puna, Mareo de la Cordillera. A headache with 
throbbing and a painful sensation of fullness in the temples, combined 
with a great oppression and tension of the lungs, and frequently with 
stomach disorders, are the symptoms usually felt during the first days 
when crossing the Cordilleras or staying in Cerro de Pasco. If one 
walks quickly, especially if one climbs a hill, he feels extreme fullness 
in the chest, the temporal arteries throb violently, and headaches come 
on. If one tries to run, these symptoms appear immediately, and he 
is glad to stop and regain breath. Breathing a frosty air, July 3 at 
midnight, in a miserable hut in the pass of Tucto (4855 meters), gave 
me an excruciating sensation along the tracheal artery; until I began 
the descent, I constantly felt afraid that some blood vessel had opened 
in my lungs . . . On another occasion, on another route . . . my breath- 
ing was panting and difficult. 

Many young persons become accustomed to the effects of the rare- 
fied air, so that they have headaches and dyspnea only during strenu- 
ous exercise. Some persons, on the contrary, and especially the ple- 
thoric, cannot cross the Cordillera or live in Cerro de Pasco without 
headaches and respiratory difficulties; when they cross the Cordillera, 
traveling over these lofty and icy plains which the natives call Puna, 
they are very likely to suffer from epistaxis. (Vol. LVII, p. 356; 1842.) 



Mountain Journeys 45 

The evidence of the French botanist Claude Gay 40 is no less con- 
clusive. Now the authority of this scientist is great, since for nearly 
fifteen years, from 1828 to 1842, he explored the Cordillera of the 
Andes. He expresses himself thus: 

I left Lima (1841). . . . After a march of four days, we crossed the 
first Cordillera by the pass of Tingo, 4815 meters above the level of the 
sea. There we felt a strange discomfort, the result of the great rare- 
faction of the air, known in America by the name of soroche, pouno, 
etc. It can very well be compared to real seasickness; there are the 
same symptoms, the same distress, headaches, vomiting, and such pros- 
tration that it almost makes life a burden, and kept me from going to 
consult my barometers and thermometers, which were only two paces 
from me. . . . 

This illness lasted some time; but subsequently I finally became 
accustomed to this rarity of the air, and I could take magnetic readings 
at an elevation of 4685 meters and carry out several other tasks of ter- 
restrial physics without being noticeably inconvenienced. (P. 28.) . . . 

The Indians of Cuzco . . ., although constantly at an elevation of 
10,000 to 14,000 feet, are not at all inconvenienced by the great rarity 
of the air; they walk and talk with as much ease as we do in the low 
plains: and so there are found in these regions the loftiest towns and 
cities in the world; Ocoruco at 4232 meters, Condoroma at 4343. There 
are some post-houses, for example, that of Rumihuani, which are at 
an elevation of 4685 meters, and shepherds' houses at 4778 meters, that 
is, almost the height of Mont Blanc. (P. 33.) 

The celebrated German traveller J. J. von Tschudi 41 gives an 
almost complete monograph on this subject. 

At the great altitudes to which the Cordillera rises, the effect of 
the rarefied air upon the organism is seriously felt; it is evidenced 
especially by a condition of extraordinary fatigue and great difficulty 
in breathing. The natives call this effect Puna or Soroche, the Spanish 
Creoles call it Mareo or Veta, and attribute it to metallic emanations, 
especially those of antimony, which plays a very important part in 
their physics and metallurgy. 

The first symptoms of the Veta usually appear at a height of 12,600 
feet, and consist of vertigo, buzzing in the ears, and disturbances of 
vision, accompanied by violent headaches and nausea. These symptoms 
attack horsemen, but not so much as those on foot, it is true. The 
higher one ascends, the more these symptoms increase, and to them is 
added exhaustion of the legs so great that one can hardly move, with 
very painful respiration and violent palpitations. Complete rest checks 
these symptoms for an instant, but at the slightest movement they 
instantly reappear, and are often accompanied then by fainting fits 
and vomiting. The capillary vessels of the conjunctiva, the lips, and 
the nose burst, and blood issues in drops. The respiratory and diges- 
tive mucous membranes are the seat of similar symptoms; diarrhea 
and the spitting of blood are the evidence of the Veta in its worst form. 



46 Historical 

One can compare this disease approximately to seasickness (whence 
its name of Mareo) ; but it alone produces respiratory distress. It is 
not unusual to see these symptoms become so serious that they cause 
the death of travellers. In 1839 at Pachachaca I met an officer who 
was carrying dispatches from Lima to Cuzco, but who, one year, while 
crossing at the Piedra parada, died in consequence of pulmonary and 
intestinal hemorrhages caused by the Veta. All residents on the sea- 
coast and the Europeans who are crossing the high Cordilleras for the 
first time feel this illness which is usually not persistent in healthy 
persons, but which attacks severely those who are weak, nervous, with 
diseases of the lungs or heart, and also the plethoric and the obese. A 
German trader from Lima, a very corpulent man, who had gone to 
Cerro de Pasco on business, at the end of a few hours had to leave the 
city rapidly, and descend into the valley to escape the Puna. 

By a long stay in these lofty regions, the organism becomes ac- 
customed to this effect of rarefied air. Vigorous Europeans can even 
climb the highest mountains nimbly and move about there as freely 
as on the coast. I had the Veta only twice, but very severely; once on 
a lofty plateau, and once on the mountain of Antaichahua. The first 
time I crossed the Cordillera, I did not feel the least inconvenience, 
and I was able, getting off my tired horse, to walk a long way without 
feeling symptoms of the Veta, so that I thought I was completely im- 
mune to it. . . . 

The Indians of the mountains, who have been living since child- 
hood in this rarefied air, are not subject to the Veta. . . . The physicians 
of Lima are accustomed to send to the mountains persons who suffer 
from prostration, so that the pure air may give them back their 
strength; but there they are attacked by the Veta most severely, and 
often lose their lives in the Cordillera .... 

The Puna seems to have a worse effect upon certain domestic 
animals than upon man himself. This is particularly true of cats; these 
animals cannot live above an altitude of 13,000 feet. They have often 
been brought to lofty villages, but always in vain, for after a few days 
they were seized by terrible convulsions like those of epilepsy to which 
they succumb. . . . These sick cats do not try to bite, or to run away. . . . 
In this country they are called azorochados and are given antimony. 
The delicate breeds of dogs are also affected, but not so seriously. 

Travellers in the Cordilleras are also subject to symptoms known 
by the name of Surumpe. . . . These are eye affections due to the effect 
of the reflection of the sun on the snow. (Vol. II, p. 66 et seq.) 

In his ascent of the Cordillera, Tschudi for the first time saw 
horses attacked by the veta, at the elevation of about 4000 meters: 

First they walk more slowly, stop frequently, tremble all over, and 
are prostrated. The higher they ascend, the harder they tremble, and 
the oftener they fall. If they are not unsaddled, if they are not allowed 
to rest completely, they lie down on the ground. The arrieros bleed an 
animal in this condition in four places: at the end of the tail, on the 
palate, on the two ears; they often cut their ears and tail half -off 
and split their nostrils to the width of several inches. This last method 



Mountain Journeys 47 

seems to me to be rather useful, because the animals can then breathe 
a larger quantity of air. As a preventive garlic is placed in their 
nostrils. Mules and donkeys suffer less from the Veta, probably be- 
cause they know better how to rest. Horses born on the Sierra are 
almost immune to these symptoms. (Vol. II, p. 32.) 

A very striking episode in the account of Tschudi is the story 
of his twenty-four hour stay in the icy Puna of Peru, at an average 
elevation of 4300 meters: 

I was beginning to climb the mountain vigorously when I felt the 
dangerous effect of the rarefied air; while I was walking I experienced 
an unknown distress. In order to breathe I had to remain quiet; even 
then I could hardly succeed; if I tried to walk, an indescribable anguish 
seized me. I heard my heart beating against my ribs; my breathing was 
short and interrupted; there was an enormous weight upon my chest. 
My lips were blue, swollen, cracked; the capillaries of the conjunctiva 
burst and a few drops of blood issued. My senses were strangely 
blunted; sight, hearing, touch, were altered; before my eyes there 
floated a thick cloud, grayish, often reddish, and I shed bloody tears. 
I felt as if I were between life and death; my head whirled, my senses 
failed, and I stretched out trembling on the ground. In truth, if the 
most precious riches, if immortal glory had awaited me some hundreds 
of steps higher, it would have been physically and mentally impossible 
for me merely to stretch out my hand towards them. 

For some time I x'emained lying on the ground in this half-fainting 
condition, then I recovered a little, hoisted myself painfully on my 
mule, and I succeeded in going on. (Vol. II, p. 152.) 

The accounts given by de Castelnau 42 are no less explicit, and 
contain many interesting details: 

Our stay in September, 1845, at Chuquisaca, a city of some 11,000 
to 12,000 souls (Bolivian Republic), was rather gloomy. . . . Most of my 
companions were also affected by the soroche, an illness caused by the 
rarefaction of the air at high altitudes (according to the observations of 
M. Pentland, Chuquisaca is 9343 English feet (2847 meters) above sea 
level) : it is especially while climbing the uneven streets that one feels 
this painful sensation of suffocation; dogs, horses, and beasts of burden 
are equally subject to it there, and I have seen some beasts of burden 
from whose nostrils blood was dripping. In this case, muleteers usually 
make them swallow cloves of garlic. Animals have often died from such 
symptoms; this is especially true of horses. No matter how little they 
are urged on, they try to overcome the distress they feel, and some- 
times fall dead in the streets; mules, on the contrary, stop of them- 
selves and start only when they are rested, in spite of the ill treat- 
ment to which an unwise master may subject them. (Vol. Ill, p. 317.) 

At La Paz (3717 meters) , de Castelnau attended a bull fight: 

Unfortunately (he says) the bulls of La Paz, raised on the frozen 
plains of the Puna, and which besides probably had the soroche, which, 



48 Historical 

by the way, is terrible in this city; these bulls, I say, showed energy 
only in fleeing before base toreadors on foot who tried to hold them 
back by pulling their tails. The angry people rushed into the arena, 
'and by dint of tormenting these unhappy animals, finally obtained the 
desired result, that is, the death of two or three Indians. (P. 376.) 

One of the travelling companions of Castelnau, Weddell, climbed 
the volcano of Arequipa in October, 1847. He expresses thus the 
sufferings which he felt on this ascent: 

The difficulty in breathing which our animals experienced com- 
pelled us to renounce their assistance. ... In advancing we had to 
tack, and even so we could not advance ten steps without stopping, 
so as to let the oppression which had seized upon our lungs pass. As 
we mounted higher, not only did this oppression increase, forcing us to 
make longer pauses, but weariness of the limbs was also added: a 
symptom more distressing than the soroche, because a halt was not 
enough to check it ... . 

The last strength of my companion was exhausted and he had to 
leave me. Alone I continued my journey, panting; ... I could hardly 
advance more than two or three meters without stopping to get my 
breath. (P. 449.) 

In May, 1846, de Castelnau left Lima for Cuzco. He therefore 
had to cross high mountains. At the pass of Vinda (4720 meters) , 
the soroche attacked him very severely: 

Vegetation, even the stunted thistles, disappeared. M. d'Osery 
complained bitterly of the soroche, and he was forced to pause con- 
stantly, as was Florentino. Here this disease is called veta, and people 
believe that it is due to the presence of veins of antimony. . . . 

Hardly had we reached the little settlement of Casacancha when 
as I dismounted I was attacked by the soroche, the effects of which I 
had not felt until then; I vomited bile abundantly, and felt all of the 
symptoms of seasickness to which I am very subject. 

When in the morning, after a very bad night, I wished to mount, 
I felt the absolute impossibility of it. M. d'Osery could hardly drag 
himself along; Florentino, a former sailor, was stretched out on the 
ground; little Catana alone was playing as usual, and seemed to feel 
no effects of the soroche. At last, understanding how indispensable it 
was to reach less inhospitable regions, we succeeded in mounting in the 
afternoon; but after going less than one league, we literally fell at the 
door of a farmhouse, where we were well treated. (Vol. IV, p. 194) . . . 

The altitude of Cerro de Pasco is estimated at 13,673 English feet 
(4166 meters) . . In spite of the burning rays of the sun, one is chilled 
as soon as he is in the shade, and he is constantly under the painful 
effect of the soroche. . . . The climate is so fatal that priests try to 
keep their pastorate for only three or four years, in spite of its enor- 
mous benefices. . . . The population, in 1845, was 18,000 souls ... It is 
only to the silver mines that this population is due. . . . Barley will not 
go to seed there. (P. 196.) 



Mountain Journeys 49 

De Castelnau, after a few days, made an excursion to a nearby- 
cavern, situated at a height of 4400 meters, in which he found the 
bones of prehistoric animals, among others a sort of armadillo 
(probably a glyptodon) : 

We were suffering frightfully (he says) from the soroche, the 
stifling from which forced us to rest constantly; even the -Indians 
seemed affected by it. 

A French tourist with a picturesque account, M. de Saint-Cricq, 
who published his travels under the pseudonym of Paul Marcoy, 4 * 
felt similar symptoms while he was going from Arequipa to Puno. 
He had passed the night at the post-house of Apo (no date) : 

After an hour's walking, which had raised us some hundreds of 
meters, I began to feel a general discomfort which I attributed to the 
insufficiency of the atmospheric pressure. This phenomenon, which 
the mountain Quechuas call soroche, and to which they are immune, 
gifted as they are by nature with lungs a third more capacious than 
those of Europeans, is attributed by them to poisonous gases produced 
by antimony, (in Quechua soroche), even in places where this metal 
does not exist. A contraction of the diaphragm, dull pains in the dorsal 
region, twinges in the head, nausea and vertigo are forerunners of this 
strange disease, which are sometimes followed by syncope. But I did 
not go that far. My guide, warned of what I was feeling by my livid 
pallor and by my efforts to remain in the saddle, gave me a clove of 
garlic, urging me to crunch it. ... I obeyed . . . but the antidote . . . 
having produced no effect, my Esculapius advised me to give myself 
several blows with my fist on my nose, and since this would cause 
a hemorrhage, it should bring prompt relief; but this method seemed to 
me much too heroic, and I preferred to nibble a second clove.of garlic. . . 

About twenty minutes passed, and whether the remedy began to 
work or whether my lungs by degrees became accustomed to this thin 
air, I felt my discomfort passing away. (Vol. I, p. 76.) 

Lieutenant Gillis, 44 of the English Navy, gives similar informa- 
tion, collected, it is true, second hand, but summarized in a very 
intelligent fashion. 

In the first part of his work, devoted to the geographical de- 
scription of Chile, the author speaks of the routes from Santiago 
to Mendoza, and especially of the Piuquenes route: 

Very few travellers reach its summit (13,189 feet above sea level) 
without feeling respiratory troubles; and the poor mules suffer almost 
as much as their masters. In Chile, this illness is called puna, in Peru, 
veta, soroche, or mareo, indifferently by the natives and the Creoles. 
The latter, in their ignorance of its real cause, attribute it to exhala- 
tions of metallic veins, so common in the Andes. With variations in 
different cases, the disease produces extraordinary fatigue, prostra- 
tion, vertigo, temporary blindness, and nausea, quite frequently ac- 



50 Historical 

companied by hemorrhages from the nostrils and the eyes. Not all 
persons are subject to this effect, and it is clear that certain constitu- 
tions are more sensitive to it. The muleteers recommend garlic and 
onions as specifics. (Vol. I, p. 6.) 

The Englishman Lloyd 4 "' who crossed the great Sierra of Illimani, 
expresses himself as follows: 

Except for the disease called soroche, which is an affection of the 
lungs that is painful and often dangerous, caused by the extreme rare- 
faction of the air at this great altitude, almost no illness is known, 
except colds and dropsy. (P. 260.) 

The French botanist Weddell, 4 ' 5 whose sufferings when he was 
accompanying de Castelnau we have already reported, returned to 
Eolivia later. Coming from Arica, he had crossed the chain of the 
Cordillera without noteworthy symptoms, and after he had been 
in La Paz nearly two months, he had had no trouble; but on June 22, 
1851, while he was botanizing, he wished to climb a steep slope 
rapidly; he was suddenly attacked: 

I can hardly express my sufferings from the soroche (he says), in 
this ascent which demanded of me gymnastic efforts which I was far 
from expecting. The fact remains that when I had reached the top of 
the precipice with my flowers, and was stretched out exhausted and 
panting on the ground, I swore, but a little late, that I would not be 
caught that way again. During the first few moments following my 
climb, I thought only of getting my breath which seemed on the point 
of leaving me, and a few minutes afterwards, when I thought of ex- 
amining my pulse, its rate was still 160 per minute. I do not think 
I have ever felt greater oppression than during this unexpected botan- 
izing expedition. From that day I felt a physical discomfort which I 
could not account for, and I foresaw that I was going to be ill. (P. 187.) 

He was, in fact, and very seriously. 

Except on this occasion, Weddell pays very little attention to 
the soroche, although in many passages of his account we recog- 
nize suggestions of it, sometimes in men, sometimes in domestic 
animals. I find nothing to quote but this interesting remark about 
the Indian postillions, who always proceed at a run, on the road 
from La Paz to Puno: 

They never seem out of breath (he says), whereas in this same 
country, a European can hardly run ten steps without being obliged 
to stop. (P. 547.) 

As you will perceive, there is a very great difference between 
this statement and those made by travellers on the Himalaya; the 
Indian coolies, they tell us, are often sicker than the Europeans 



Mountain Journeys 51 

themselves. Weddell is not the only one to note this; the Grandi- 
dier brothers were also struck by it. 47 

August 1, 1858, these travellers left Arequipa for Cuzco: 

Here one experiences (says E. Grandidier in his account) a dis- 
tress unknown to tourists in the old world, that is, the soroche; the 
traveller who crosses the Cordillera feels pains all through his body; 
he has pain in his kidneys, in his head, his limbs feel as if they were 
broken, blood even gushes sometimes from his nose, eyes or ears. This 
general distress is due, not to the presence of antimony, as has been 
said without reason, but to the rarefaction of the air and the failure of ' 
breath. The soroche has even caused the death of some more suscep- 
tible persons. Mules are also subject to the effects of the soroche, and 
I have heard many examples of these animals dying in consequence 
of the rarefaction of the air. (P. 56.) 

And further on, while going from Paucartambo to Puno, their 
attention was directed to the natives on foot: 

The Indian follows the horseman on foot, always running without 
ever losing breath, however speedy the horse, and however high the 
mountains. The swiftness with which the Indian runs long distances 
surprises the European all the more because he cannot, like the native, 
overcome the oppression caused by the rarefaction of the air and run 
at this altitude without falling immediately. (P. 194.) 

In December, the two brothers arrived at La Paz: 

The road down to La Paz is wide and well kept; but the slope is 
so steep that one can only walk his horse down. This descent is about 
a league long, and it takes at least an hour to get to the city. A very 
much longer time is needed to climb it, because of the difficulty in 
breathing which the mules experience while ascending; nevertheless 
I was assured that the Indians mount it running and playing the flute: 
they are not subject to the soroche, and in this way they are like the 
llama, whose breathing apparatus is adapted to the Cordillera on which 
it lives. (P. 225.) 

The European who has recently arrived in La Paz feels the effects 
of a violent soroche; while he is walking through the town, he is 
forced to stop often to get his breath, so great is the difficulty of 
breathing and the oppression in the chest. The rarefaction of the air 
comes from the great elevation of La Paz above sea level; this eleva- 
tion is 3730 meters. (P. 227.) 

We have similar accounts from the German traveller Bur- 
meister, 48 who in the first part of March, 1860, was in the Cordillera, 
about latitude 28° S., and longitude 72° W. However, he speaks of 
these symptoms only by hearsay; moreover, the maximum altitude 
to which he ascended was 14,000 feet: 

During my journey (he says) I never suffered from what is called 



52 Historical 

the Puna, that is, the sickness which usually occurs on high moun- 
tains and which consists of difficulties in breathing, nausea, prostration, 
vertigo, and other symptoms. Only at first, when I entered the gorges 
near Estanzuela, I felt a heaviness in my head, as if I were going to 
have vertigo; but I had no other symptoms. . . . Probably I have been 
protected by the weakness of my constitution; for strong and portly 
people are more easily attacked by the Puna than those who are 
thin, spare, or weak. 

The symptoms of the same disease appear in animals, and particu- 
larly in horses, on the lofty paths of the mountains; they are charac- 
terized particularly by trembling of the limbs and violent hemorrhages, 
which, however, do not become fatal. Many horses, and especially 
the best, fall down on the ground on journeys in the mountains. The 
natives call this disease the Trembladera; they claim that in the moun- 
tains there are places where it is particularly likely to attack passing 
animals; they pointed out one in the Aconquija Sierra, the position 
of which, however, I could not determine. 

The Englishman Markham, 49 who in 1860 made a journey to 
Peru for the purpose of studying cinchona trees and finding a 
way of introducing them into the Indies, gives information of the 
same sort: 

On the heights of the Cordillera, men and animals are subject to a 
very painful disease, caused by the rarefaction of the air, and which 
the Peruvians call sorochi. I had been ill at Arequipa, so that I was 
probably predisposed to the attack of the sorochi, which affected me 
violently. Before reaching Apo (May, 1860), an excruciating headache, 
accompanied by acute suffering and pains in the lower part of the neck, 
made me very ill, and these symptoms grew worse during the night 
passed in the post house of Apo, so that at three o'clock in the morning, 
when we set out again, I was unable to mount my mule without as- 
sistance. (P. 89.) 

In the official description of the Argentine Confederation, Dr. 
Martin de Moussy/" who had dwelt for ten years in the basin of 
the Plata, gives a detailed description of the American form of 
mountain sickness: 

The name of puna is given to this painful sensation, this distress in 
breathing which some persons experience when they are at great 
heights. This sensation is certainly due to the rarefaction of the air, 
for, at 4200 meters, the general altitude of the plateau, the barometric 
column falls on the average to 0.46 meters . . . and it is impossible that 
such an enormous difference in the atmospheric pressure should not 
produce a profound impression upon the animal constitution. Further- 
more, this impression varies in different persons; some have difficulty 
in breathing, others suffer from cephalagia, a sort of headache, and a 
complete loss of appetite. Many feel no ill effects; but when they try 
to walk, almost everyone feels unusual fatigue. 



Mountain Journeys 53 

As to the puna properly so-called, the difficulty in breathing, it is 
not peculiar to the great heights of the Cordillera; there are certain 
places of no great altitude where it is felt much more than in others. 
We ourselves experienced it at the town of Molinos, which is at an 
altitude of only 1970 meters, and in a valley surrounded by granitic 
mountains about which there is nothing peculiar. We cannot discover 
a cause for this peculiarity, which also exists at different points of 
the Andes in Bolivia. 

Animals also experience this difficulty in breathing in their first 
crossings of the Cordilleras; but they become acclimated rather quickly 
and their vigor is so great that mules in good condition and reasonably 
loaded never weaken on ordinary journeys. (Vol. I, p. 217.) 

Mateo Paz Soldan also gives a description of the soroche in his 
Geography of Peru: 51 

Cerro de Pasco is situated on a slope 4352 meters above sea level. 
. . . The climate of this city is very cold, the temperature averages 44° 
F. by day and 34° by night, during the months from July to October, a 
season during which a great quantity of hail and snow falls. Some- 
times the thermometer falls to 30° and 28° in August and September; 
water boils at 180°. Storms, hail, and snow make this country un- 
inhabitable from the month of October on. Strangers there are sub- 
ject to the Soroche, an oppression in the chest, which in this country 
is called veta, and which is the result of the rarefaction of the atmos- 
phere, in so lofty a region .... Former miners are subject to a great 
many diseases and infirmities. ... If this country did not possess mines 
of inexhaustible richness, it would be absolutely impossible to live 
here. (P. 172.) 

About this period there appeared in the form of a thesis main- 
tained before the Faculty of Medicine of Paris a remarkable work 
by a young doctor, Ch. Guilbert, 52 who, attacked by consumption, 
went to La Paz and there found the cure or at least a considerable 
amelioration of his dangerous disease. I shall quote the whole of 
his very concise description of the soroche: 

The soroche or the disease of the puna begins in two different 
ways: some immediately have difficulty in breathing, and that has 
attracted greatest attention of the observers; in others, and in my opin- 
ion this is the largest number, nervous symptoms appear first. There 
are even some travellers who have no difficulty at all in breathing. 

The same difference is found in the duration of these two classes of 
symptoms. Whereas the nervous phenomena last only 12 to 48 hours, 
difficulty in breathing and circulation sometimes persists for several 
months. 

The nervous system is therefore often the first affected, and re- 
acts upon the digestive and the locomotive systems. One first feels 
nausea, accompanied by very significant spitting. ... At the same time 
there comes a very violent headache, compared to a ring of iron which 
binds the temples tightly. . . . After the nausea, vomiting appears, often 



54 Historical 

very painful, which increases the pain in the head. One also expe- 
riences vertigo, buzzing in the ears, sometimes drowsiness .... 

Another phenomenon is muscular fatigue. . . . This difficulty in 
muscular contraction is experienced even on horseback, and to such an 
extent that persons who are unable to move have to be taken down 
from their horses. But after the first few days, this great fatigue dis- 
appears completely after a very short rest. In the cities, new-comers 
are easily recognized; they stop for a few seconds every 40 or 50 steps. 

Respiration and circulation are speeded up in proportion to the 
elevation. The dyspnea is extreme, the inspirations very frequent. 

The heart-beats are stronger, more numerous; at the least effort 
one is attacked by violent palpitations which continue when he is riding 
as well as when he is walking. Even at night, one is often awakened 
with a start by strong palpitations in the midst of the calmest sleep. . . . 

The beating of the arteries is stronger, that of the intra-cranial 
arteries very painful, the pulse is vibrating, almost as in aortic insuf- 
ficiency. A rather frequent symptom is a nasal, buccal, or pulmonary 
hemorrhage; hemorrhages from the gastro-intestinal mucous membrane 
are rare. . . . But when one becomes used to the rarefied air, when equi- 
librium is established, and when the different systems are in harmony 
with the surrounding medium, hemorrhages are no more frequent than 
anywhere else ... An important symptom is the tendency to syncope, 
and so one must be very careful about bleeding the patient .... 

The nervous symptoms are the first to disappear; the headache lasts 
hardly 12 to 24 hours; the nausea and vomiting no longer . . . The third or 
fourth day, appetite revives a little; as soon as the patient can take a 
little nourishment, the heaviness in the head disappears in its turn, 
and there remain only the difficulty of respiration and the rapidity of 
the heart-beats, palpitations occurring at the least effort, and making 
the lack of breath still worse. Later, when equilibrium has been estab- 
lished, little by little all these symptoms disappear, generally at the 
end of a few weeks, and one becomes perfectly acclimated to these 
lofty regions. 

So Guilbert thinks that one can become perfectly acclimated to 
lofty regions. He recalls the words of M. Boussingault, which we 
quoted above, and adds: 

Pichincha is 4996 meters high; the Bolivian general Santa Cruz 
defeated the Spaniards there in 1822. Two years after, at Ayacucho, a 
village situated at about the same height, the Colombian general Sucre 
defeated the viceroy La Serna. . . . 

At Corocoro (4430 meters) I saw very bloody bull-fights. These 
bulls, nimble and wild, might have given pleasure to the travellers 
mentioned by Lombard, 53 who saw at La Paz bulls which were gentle 
and unable to make the least effort without vomiting; these were bulls 
which had recently been brought to the mountains and which were 
affected by the soroche, which attacks animals as well as men. ... It 
is very rare to cross the Cordilleras without witnessing the sickness 
of some beast of burden, attacked by the soroche; it is hastily unloaded, 
rubbed, and after a moment of rest, allowed to follow at liberty. 



Mountain Journeys 55 

In the special chapter I shall give the very eclectic mixture of 
theoretical explanations which Guilbert accepts. 

The Italian professor Pellegrino Strobel, ,4 who crossed the dif- 
ferent passes between Santiago and Mendoza, was lucky enough 
not to be affected by the soroche; it is true that he seems not to 
have mounted very high: 

After what M. de Moussy wrote and what my friends had told me, 
I expected to experience on Planchon one of the sensations described 
under the name of puna. But — I do not know whether I should say 
happily or unhappily — neither here at 3000 meters above the Pacific, 
nor on Cumbre of Uspallata at about 4000 meters nor in any other part 
of the secondary chains of the Andes, was it granted me to feel the 
slightest difference in respiration or appetite, still less any headaches 
and other pathological symptoms or physiological phenomena; and yet 
on account of the weakness of my constitution and the narrowness of 
my chest, it seems as if I should have suffered from it more than any- 
one else. I must therefore admit that the puna does not depend solely 
upon the rarefaction of the air, but also upon other concomitant 
causes, which appear to be wholly unknown. (P. 25.) 

However two German travellers, Focke and Mossbach, ■"'•"• who 
speak from their own experience, declare that often men and 
beasts become ill at still lower altitudes: 

Starting at an altitude of 10,000 feet, one feels the beginning of 
mountain sickness, that is, a stunning headache; it is the Sorocho, which 
attacks also beasts of burden. They refuse to go on, and to cure them, 
they are bled under the tongue. (P. 391.) 

Finally, I have the statement of a high official of the Peruvian 
government, an intelligent man, that having gone to Perina-Cota 
(4800 meters) near Guayaquiri, he saw his mules become ill at an 
altitude of 3000 meters; out of 40 mules, 16 had to be unloaded. 
Some of his companions had nosebleed. During a stay of two weeks 
at this great height, he experienced regularly, about three o'clock 
in the morning, a feeling of suffocation which awakened him; the 
least movement then increased it considerably; these symptoms 
lessened during the day. The Indians who accompanied him suf- 
fered from the same illness. Even today, the generally accepted 
explanation is poisoning by metallic emanations; they try to check 
its effects by garlic sachets. 

I also learned from this gentleman that while the railroad 
tunnel from Lima was being bored, at an altitude of about 4800 
meters, all the workmen had been affected, even the most robust. 
I am sorry not to have been able to get written details of the 
phenomena observed during the execution of this extraordinary 



56 Historical 

work. It is finished now, and already the locomotive conveys the 
travellers up to regions which formerly they could not reach with- 
out the most strenuous efforts. Strangely enough, nevertheless a 
certain number of them became ill. In a letter addressed this very 
year to one of my friends, there is this very characteristic passage: 

A special train came for us at Callao, took us up Reinar to Lima, 
then from there into the Andes, climbing by successive planes to an 
altitude of 3450 meters. . . . We thus journeyed 130 kilometers. . . . The 
temperature had fallen, the rarefaction of the air was such that many 
persons could not accompany us to the end. They felt extreme oppres- 
sion and their eyes were bloodshot. 

It would be very desirable to have careful observations made 
on this railroad and on the Titicaca railroad too; it would be very 
easy for the professors of the Faculty of Medicine of Lima to do so. 

I shall finish these quotations from the principal general de- 
scriptions of mountain sickness in the Cordillera of the Andes by 
copying a very interesting letter written by M. Pissis to Dr. 
Coignard, who asked him at my request for information which his 
great experience in the mountains made very valuable to me. The 
learned geographer in this letter describes very vividly the symp- 
toms which he felt, but he does not venture upon any explanation: 

Paris, March 17, 1874. 
Dear Doctor: 

Here are the observations which you requested of me upon the 
physiological effects of the rarefaction of the air on lofty mountains. 
The general effects are headaches, nausea, great difficulty in breathing 
and a contraction in the region of the false ribs, as if one were tightly 
squeezed by a belt. These symptoms vary greatly, however, according 
to the age and the constitution of the patients; when I crossed the pass 
of Tacora (bar. 463 mm.) a negress eighteen to twenty years old, very 
sturdy, was extremely ill, she had a profuse nasal hemorrhage, whereas 
her mistress, a woman of about fifty years, of weak constitution, was 
hardly affected; the same difference is observed in animals; the strong- 
est horses are the most likely to die. Nasal hemorrhages are frequent 
in them also. After one has lived a certain time in lofty regions, these 
effects are no longer felt; the residents of Oruro in Bolivia, at 3,796 
meters (average barometric pressure 492 mm.) live as if they were on 
the seashore; the Indians run leagues without getting tired, and after a 
year's residence, I easily climbed fairly high mountains, which would 
have been impossible at my arrival. 

The highest point where I saw permanent dwellings are the mines 
of Villacote in the province of Chayauta; their altitude is 5,042 meters 
and the atmospheric pressure 421 mm. The Indians work there as 
they do elsewhere, but they get tired more easily when it snows, for it 
never rains in these regions; the workmen, even those in the depths of 
the mines, are ill, and yet the decrease in pressure when it storms is 



Mountain Journeys 57 

hardly 4 or 5 millimeters. The alpacas and the vicunas live in herds at 
these heights, the condors fly far above, and I have found a few turtle- 
doves there. Although accustomed to the pressure of Oruro, when I 
went to these mines, I was always ill, with nausea, headache and dif- 
ficulty in breathing, and I could not walk eight or ten steps without 
having to stop to get my breath. The manager, who has lived there 
for two years, could walk a little further, but always had difficulty in 
breathing. At a height of 4,000 meters, the rarefaction of the air has 
only a passing effect upon the health, the residents of Oruro and 
Potosi become very old, and lung diseases are unknown there; the 
residents are generally thin, very active, but have little strength, which 
perhaps is partly due to their almost exclusively vegetable diet. 

In Chile, the highest point I reached was on the side of Aconcagua 
at an altitude of 5,832 meters; the summit has an elevation of 6,834 
meters. At the point where I stopped, the barometer reading was 
382 mm.; I was very sick and it was impossible for me to climb higher; 
my eyes were badly bloodshot; all objects, even the snow, seemed red 
to me, and even with my glasses of very dark blue glass, I had great 
difficulty in reading my barometer. On the way down, at about 5,000 
meters, all these symptoms disappeared. 

In my numerous stops in the region of the Andes, I often saw 
condors wheeling about the sides of the highest mountains, but never 
soaring above their summits; but one should not be hasty in drawing 
a conclusion from that fact; for the heights they reach are so great that 
they appear only as little black dots; if there were any at the height 
of the summit of Aconcagua, they would certainly be invisible, even 
if one were at an elevation of 5,000 meters, that is, higher than Mont 
Blanc. At 4,000 meters one finds in the Andes of Chile guanacos, swans, 
ducks, turtledoves, and even humming birds. 

A. Pissis. 

If travellers who limited themselves to crossing the passes of 
the Cordillera or stopping on the lofty inhabited plateaux of Bolivia 
and Peru have experienced such symptoms, one may suppose that 
those who purposely attempted the ascent of the mountains which 
tower above the average level of the chain have experienced even 
more. However this is not always true. We have seen that Hum- 
boldt and Boussingault suffered much less on Chimborazo than 
other travellers at Cerro de Pasco or even La Paz. Other examples 
are no less strange. 

For instance, on January 14, 1845, Wisse 5G descended into the 
crater of Rucu-Pichincha to the depth of "four times the highest 
pyramid of Egypt", and climbed back; he does not mention any 
physiological symptom. 

We shall discuss these differences later. They are so great that 
certain travellers go so far as to deny that mountain sickness exists, 
because they never experienced it, and there reappear the explana- 



58 Historical 

tions about poisonous air, which both the Indians of the Andes and 
those of the Himalaya have accepted. 

The most remarkable account I know, in this respect, is that of 
the French traveller Jules Remy,' 7 who made the ascent of Pichin- 
cha (4860 meters) on October 2, 1856. The weather was magnifi- 
cent, it was warm on the summit of the mountain, where numerous 
humming birds were buzzing about. Remy felt no distress. 

My breathing is free, easy, excellent, and I feel no symptoms of 
distress, a fact worth noting, for it confirms my preceding observations, 
although contradicting those of other travellers who had stated that 
at these altitudes the decrease of the atmospheric column causes serious 
symptoms in different organs. 

Only on Cerro de Pasco, a mountain in Peru, celebrated for the 
silver mines operated there, are the morbid symptoms manifested in the 
. animal organism constant and universal, so far as we know. There one 
is infallibly attacked by a strange disease, the soroche. . . . 

But if it is noted that Cerro de Pasco is only about 10,000 feet above 
the ocean, and that after one has walked seven or eight leagues, normal 
health is suddenly restored, although one is then at a much greater 
altitude, one is compelled to admit that atmospheric pressure is not 
the cause of the soroche, which perhaps should be attributed to ema- 
nations from the ground. 

However, if one reads carefully this very account of J. Remy, 
he finds in it indications of the harmful effect of the altitude; but 
their slight importance had escaped our traveller. 

He displayed the same immunity in the ascent which, on No- 
vember 3, 1856, took him to the summit of Chimborazo; 58 naturally 
his negative conclusions were greatly reenforced here. The camp 
of the night before was made at an altitude of 4700 meters, a little 
below perpetual snow: 

The climb continued to be so steep that soon, under the weight of 
fatigue, we were obliged to stop frequently to get our breath; then 
thirst became extreme. . . . But we felt no symptom of discomfort or 
of any morbid affection, mentioned by most of the travellers who have 
ascended high mountains. 

As soon as we had stopped walking for a few seconds, even with- 
out sitting down, we went on with new ardor, with a sort of fury 
inspired in us by the sight of the summit so near us. It seemed evi- 
dent to us, from this new experience which confirmed so many pre- 
ceding ones, that at these altitudes the atmospheric column is still 
sufficient not to hamper respiration, and that the short breath and 
organic symptoms of which complaint is generally made by those who 
reach considerable altitudes must be attributed to some other cause. 

Having continued their journey in the midst of clouds, the two 
travellers thought, after observing the boiling point of water, that 



Mountain Journeys 59 

they had reached the summit of Chimborazo, which they estimated 
to be an altitude of 6543 meters. 

But not everyone is so lucky. In a recent journey, Stuebel, 59 
while warning the reader against certain exaggerations, confesses 
that he suffered considerably in the ascent of Cotopaxi. 

On February 8, 1873, at seven o'clock in the morning, the trav- 
ellers started from an altitude of 3615 meters; at two o'clock, they 
were at a height of 4498 meters. Without great difficulties, they 
reached the summit of the volcano of Tunguragua (4927 meters), 
without being tired and "without suffering headache." (P. 273.) 

March 8, ascent of Cotopaxi (5943 meters, temperature 3.5°) 
starting from the Saint-Elie farm: 

Some of my people had gone on in advance, others had stayed 
behind. They were tired, had become a little timid, and complained 
of headache. . . . The arena! has a slope of 35°; it wears down the 
strength, so that one must summon all his moral energy not to fall 
just as one is reaching his goal. ... It took us twenty-eight minutes for 
each hundred meters. (P. 282.) . . . 

We began to descend. ... I found little by little all my men; one 
had remained 50 meters from the edge of the crater, unable to reach 
the goal so near at hand; the others 400 meters away, and most of the 
muleteers much lower. Like me, all were suffering from a very violent 
headache. Only one felt no effects and was not fatigued; he was carry- 
ing my barometer, which, however, is pretty heavy. One muleteer did 
not get above a height of 5,600 meters. I could testify that the vomiting 
is the effect of the air of these great heights, but not of a passing 
weakness of the stomach. 

But neither in this ascent nor in the preceding ones, did I see 
blood issuing from the noses, mouths, and ears of my people. These 
are circumstances upon which other travellers like to dwell. Certainly 
it must seem strange that M. Reiss and I mentioned no case of the 
sort. Now we reached a height of 6,000 meters three times, and 5,000 
meters several other times, an altitude to which few travellers have 
ascended. We have always taken with us a certain number of men of 
different races. . . . The scientific result of these ascents, in which man 
reaches the summits only by using all his strength, will always be of 
slight importance. (P. 285.) 

2. Central and North America. 
Central America. The republics of Central America contain no 
peaks the elevation of which is comparable to those of the grand 
Cordillera. So it was with great surprise that I found in the tales 
of an English navigator of the seventeenth century, Wafer, 60 a very 
definite mention of mountain sickness. 

Wafer took part in the expedition of Dampier, and was one of 
the troop who tried to cross the Isthmus of Darien, in 1681. He was 



60 Historical 

severely wounded, and with four other Englishmen fell into the 
hands of Indians, who, after various adventures, restored him to 
liberty. They then left the vicinity of the southern sea for the 
ocean to the north: 

We crossed (he says) several very high mountains, but the last 
one was the highest of all; it took us four days to ascend it, although 
there were some low spots here and there. As soon as we had reached 
the summit, I felt that my head was whirling strangely; I told this to 
my companions and the Indians, who answered that they were all in 
the same condition. Apparently the illness came from the great height 
of this mountain and the thinness of the air. . . . Our vertigo left us as 
we descended. (P. 174.) 

It should be noted that Wafer and his companions, even the In- 
dians themselves, his guides, were in a state of fatigue which was 
near complete exhaustion. But in spite of this added circum- 
stance, the importance of which we shall see later, I cannot account 
for the condition in which Wafer must have been when he says that 
he veered enough towards the northwest to reach Chiriqui (3430 
meters) , or further yet, Pico Blanco (3600 meters) , which is nearer 
the sea to the north. 

The only explorers who, in modern times, ascended the highest 
volcanoes" of Central America, MM. A. Dollfus and deMontserrat, 61 
never mention in their detailed and interesting accounts the special 
illness of great heights; yet they knew it, having experienced it, as 
we shall see later, in their journey to Popocatepetl. 

The high inhabited plateaux of Mexico have caused similar ob- 
servations, and we shall see, in the chapter devoted to the an- 
alysis of theoretical explanations given by authors, that it was in 
regard to these plateaux that the discussion which was most fruit- 
ful for the topic of this book arose. I shall copy here two interest- 
ing quotations relating to symptoms observed in animals: 

Horses and mules in Mexico (says Burkhardt) 62 are subject to a 
disease which is little or not at all known in Europe. If while the sun 
is hot they are driven to great efforts or to rapid and continuous move- 
ment, they are often seized by palpitations and an acceleration of the 
pulse and circulation so great that they have strong convulsions over 
their whole bodies. 

Profuse bleeding is the only remedy against this disease, which 
the Mexicans call asoleado. ... So before buying a horse or mule, the 
purchaser takes care to make the animal gallop a little, and then to 
notice whether palpitations in the withers give evidence of the disease. 
Animals often fall, as a result of this affection, if they are compelled to 
work uninterruptedly. (Vol. I, p. 63.) 



Mountain Journeys 61 

I borrow the other quotation from Heusinger," ; who took it from 
Elliotson: 

M. Lyell says that the Englishmen who own mines on the plateau 
of Mexico, at an elevation of 9,000 feet above the sea, took greyhounds 
there to hunt hares; but they could not endure hunting in the rarefied 
air, they were out of breath before reaching the game. On the contrary, 
their young born in this place are not affected by the rarefied air; they 
hunt and overtake the game as well as the best greyhounds in England. 
(Vol. I, p. 260.) 

But I must not forget that my chief interest here is not the 
somewhat chronic and vague symptoms which follow the prolonged 
residence on rather moderate heights, but those which suddenly 
attack travellers who are ascending very lofty mountains. 

From this standpoint, among the mountains whose height is 
above the limit at which appear physiological symptoms due to the 
altitude, Popocatepetl (5420 meters) should be particularly men- 
tioned. 

Since the time (1519) when the brave Ordaz ascended it at the 
command of Hernando Cortez, and as reward for his courage re- 
ceived the authorization to bear a volcano on his coat of arms, and 
when a second Spanish expedition was sent by the same con- 
queror to get sulphur there (1522) , 04 no mountain climber had trod 
the summit of the giant of Mexican mountains. The first European 
to ascend it is the English lieutenant, W. Glennie, April 20, 1827. 

The sensations experienced by M. Glennie (says the secretary of 
the Geological Society in the extract he gives of a letter from this 
traveller) 65 are those already described by travellers to great heights, 
that is, prostration, respiratory difficulties and headache, this last symp- 
tom appearing first at the elevation of 16,895 feet (5147 meters). It 
was found that tobacco and alcoholic liquors produced an extraordi- 
narily rapid effect upon the sensorium. 

A few years later, April 27, 1834, Baron Gros, 66 attached to the 
French Legation in Mexico, made the ascent in his turn. 
When he had reached the limit of vegetation, he cried: 

We began to feel that we are no longer in the sphere where it is 
possible to live. Respiration is hampered; a sort of melancholy which 
is not without charm seizes us. (P. 50.) 

He passed the night at this height. Before lying down, the 
travellers mounted a little higher "to accustom our lungs some- 
what by degrees to breathing an air so unfitted for them." (P. 51.) 



62 Historical 

The next morning, Gros and his six companions set out again: 

We walked one behind the other, our alpenstocks in our hands. . . . 
We proceeded very slowly, and were forced to stop every fifteen paces 
to get our breath. The flask of sweetened water was very useful to me; 
for being obliged to breathe with my mouth open, my throat became 
so dry that it was painful. (P. 53.) 

At 9 o'clock, we had reached the Pico del Fraile. . . . Our guides 
through superstitious fear refused to go on ... . The oppression which 
I felt was less severe than I had feared, and my pulse rate was only 120 
per minute. (P. 54.) 

The travellers continued their journey alone, finding the in- 
struments which they had to carry "terribly heavy." To get a rest, 
they ate lunch: 

But only a little; it would be unwise at this height to eat a little 
too much or to drink any alcoholic liquor, for the nervous system is 
excited thereby inconceivably. (P. 55.) . . . 

At noon, we had reached the summit of perpendicular rocks; but 
our strength began to fail, and every 10 paces we were forced to make 
a long pause to breathe and to permit the circulation of the blood to 
grow somewhat slower. 

We had to shout to be heard at a distance of twenty paces. The 
air is so thin at this height, that I tried in vain to whistle, and M. Eger- 
ton had great difficulty in drawing a few notes from a cornet which he 
had brought with him. 

At half past two, M. de Geroult was on the highest point of the 
volcano. He leaped with joy. (P. 57.) 

We were exhausted. I had a violent headache and a strong pres- 
sure on the temples; my pulse rate was 145 per minute, and 108 after 
I had rested a little; but I felt hardly more distress than on Pico del 
Fraile. All four of us were frightfully pale; our lips were a livid blue, 
and our eyes were sunken in their orbits; and so, when we were rest- 
ing on the rocks, our arms above our heads, or when we were lying on 
the sand, with our eyes closed and our mouths open, and under our 
crape masks so that we could breathe more easily, we looked like 
corpses .... We saw three crows fly 200 feet above us. (P. 67.) .... 

A great many attempts have been made to ascend to the summit 
of the volcano; almost all have failed for different reasons. Some 
travellers, when they had reached a certain height, vomited blood, 
which compelled them to give up their undertaking. However, in 1825 
and 1830, some Englishmen reached the crater. M. W. Glennie is the 
first, I think, to have seen it. (P. 68.) 

The travellers went down again and passed the night in the 
same place as the night before: 

We were too tired and especially too excited to sleep well. When I 
was awake, I could talk of nothing but the crater, and if I succeeded 
in getting to sleep, I was climbing up there all over again, the oppres- 
sion came on again, and I was awakened with a start. (P. 64.) 



Mountain Journeys 63 

MM. Truqui and Craveri, in their ascent in September, 1855, 
were more fortunate: 

I ought to say (remarks one of them)'" that we experienced almost 
no difficulty in breathing during the ascent; at least, we thought that if 
we did feel any oppression, it should be attributed only to the fatigue 
of a long and difficult climb, (P. 316.) 

In January, 1857, under the guidance of M. Laverriere, Director 
of the School of Agriculture of Mexico, a scientific ascent of Popo- 
catapetl was made, and this expedition was part of a series of 
researches on the natural history of Mexico undertaken with the 
most praiseworthy ardor by the government of General Comonfort. 

M. Laverriere in his notes and memoranda collected the data 
which were of physiological interest in this ascent which was so 
fruitful from the standpoint of physics and geography. I am 
quoting in full his communication, for which I thank him sincerely: 

Among the tasks which had devolved upon us was the ascent of 
Popocatepetl, situated southeast of the city of Mexico. I expected to 
begin our operations by this ascent, because the season at that time 
seemed to me particularly favorable. 

In fact, all who before us had attempted the ascent of Popocatepetl 
had failed or had only partially succeeded. Forgetting the latitude and 
the peculiarities of the climate of Mexico, they had made their attempts 
at times when such explorations are made in Europe, that is, spring or 
summer. I thought, on the contrary, that our expedition should be made 
in winter, a period when the atmosphere in Mexico is perfectly trans- 
parent and suitable for observations, and when, because of a relatively 
lower temperature, the snows which cover the upper part of the cone 
occupy a greater surface on its slopes, which lessens the distance to be 
traversed in the deep and unstable sands which cover them, while fur- 
nishing by their hardness a firmer footing for the traveller. 

Consequently our little caravan, composed of Dr. Sonntag, astro- 
nomical engineer, a major-domo, two students from the School of 
Agriculture, and three servants, left Mexico (2278 meters) on Saturday, 
January 17, 1857, in very hot weather; on January 18 passed through 
Chalco situated on the lake of the same name; on January 19 through 
Amecameca (2493 meters), and entered the vast pine forests which 
cover the first foothills of the volcano, reaching the ranch of Tlamacas 
(3899 meters) on the evening of January 20. 

The ranch of Tlamacas, situated at the foot of the north slope of 
the volcano, is composed of a few cabins in which the sulphur occa- 
sionally brought from the interior of the crater is refined. It occupies a 
clearing near the timberline, and near it are found several varieties of 
pines, noteworthy for their hardiness, the excellence of their timber, 
and the abundance of their resin, and capable of being acclimatized in 
Europe. 

We passed the night in this spot. At six o'clock in the evening the 



64 Historical 

thermometer stood at — 0.3° C, and — 2° C. an hour later. In spite of a 
good fire and our blankets, our sleep was uneasy and rested us but 
little; the Indians, on the contrary, slept like logs, and the next day 
they were up early, in good health and spirits, while we were stret- 
ching our limbs and looking surly. 

Wednesday, January 21, at five o'clock in the morning, everyone 
mounted and set out in silence; the Indians followed on foot. The cold 
was so penetrating that in spite of our thick garments we vied with 
each other in shivering. A quarter of an hour afterwards, we left the 
wood and approached the sandy stretch, going straight towards the 
steep slope of the volcano. The horses sank up to their hocks, going 
on slowly and painfully. Soon we had to stop frequently to let them 
breathe, for the air was so stinging and the path so steep that they 
could hardly get their breath. 

At half past eight we reached La Cruz (4290 meters). The horses 
were worn out, covered with sweat, panting. We dismounted and 
sent them back to Tlacamas. Numbed by the cold, we rested a little 
while on the sand warmed by the sun whose heat began to be scorch- 
ing. 

At nine o'clock, each one started out, his alpenstock in his hand, 
following our Indian guide, Angel, who with his feet wrapped in some 
rags, led the way with a step remarkably easy compared with ours. 

We followed him with difficulty, in spite of the care we had taken 
to lighten our garments and footgear as much as possible. Soon we 
reached a strip of ice which precedes the snow. It was crossed without 
too many difficulties, thanks to the notches cut with an axe by an In- 
dian sent on ahead with orders to blaze a trail up to the summit of 
the volcano. 

At the line of perpetual snow (4400 meters on the slope at this 
season of the year) I began to feel acute fatigue. I was wet with sweat, 
my breath was short and hurried, and it seemed to me as if enormous 
weights were fastened to my feet. Near me, a Mexican from Amecam- 
eca, named Saturnino Perez, who wanted to accompany us, was climb- 
ing with a stronger step; but his pale face, his bluish lips, his wild eyes, 
the contraction of his mouth, and the dilation of his nostrils showed 
plainly enough the effects of the altitude upon his constitution, hardy 
and robust though it was. The slope was steep, it is true; but as the 
snow was packed, we experienced less difficulty in advancing than if 
we had been on sand or ice. Only the air was so thin, so dry, so cold, 
that this advantage was more than compensated. 

Soon, since our strength failed, we had to halt, a very short halt, 
for the cold seized us straightway. Every forty or fifty steps we were 
forced to stop for a minute or two. Our lungs seemed to refuse to act; 
they hardly had the strength to raise the chest, which collapsed heav- 
ily after each inspiration. 

At 300 or 400 meters from the summit, there was a moment of hesi- 
tation, of prostration. Although so near, our goal seemed still enor- 
mously far away. The extremely steep grade, the metallic glare of the 
snow, the rarity of the air caused me inexpressible weakness. So I had 
to collect all my energy, appeal to all my reasoning power, and think 
of my responsibility in particular to find strength to go on. 



Mountain Journeys 65 

Finally, thanks to a supreme effort, we reached the edge of the 
crater (5280 meters; temperature — 2° C.) through an opening to which 
I gave the name of Silicco Breach, in honor of the judicious minister 
who had sent us. It was half past one in the afternoon, and the part 
of our ascent which had been made on foot had required no less than 
four hours and a half. 

Within the crater, as soon as we had passed its edge, there was an 
inner slope towards the south, composed of sand and rock fragments. 
We dropped down upon it like inert masses, hardly conscious. My first 
sensation was that of inexpressible comfort. But this comfort lasted only 
a short time. The sand which at first I had found warm soon seemed 
unendurably cold to me. Moreover as the sun was beginning to de- 
scend, a cold little thin wind rose. I was soon shivering. To cheer 
myself, I wanted to eat, to drink a few gulps of an excellent sherry 
wine which our good Indians had brought. But since my throat was 
tight, I could not swallow the food, and the sight of it was distasteful. 
Instead of the strengthening effect expected, the wine produced a very 
different effect; no doubt because of a perversion of taste, I thought 
I had swallowed a stiff brandy, a regular fiery draught which literally 
burned my entrails. At the same time, and in spite of my weariness, 
a strange agitation seized me; it was a feeling of uneasiness, of distress, 
which would not allow me to rest. And yet, when I wanted to move, 
my strength betrayed me and almost refused me service. However, I 
found strength to climb back to the edge of the crater where I eagerly 
seized some snow to quench a little the burning thirst which tormented 
me. 

This agitation nevertheless passed away a little and my strength 
returned for a few hours. But in the evening, and especially during 
the night which we passed huddled against each other under a shelf of 
rock, a feverish condition seized me; my head on fire, piercing cold in 
my limbs, a pulse of 120 to 130, unendurable uneasiness, increased even 
more by the dull mutterings in the abyss beside us. It was a night I 
shall never forget. And therefore the dawn was greeted with joy, and 
after making observations according to our instructions, the signal for 
return was given; we left the volcano at ten o'clock and three hours 
afterwards, we were back at the ranch of Tlacamas, which we had left 
thirty hours before. 

The Scientific Committee GS which accompanied our unfortunate 
Mexican expedition also made this ascent April 23, 1865; the suffer- 
ings were quite endurable: 

The line of perpetual snow begins at a height of about 4300 meters 
above sea level. 

Here everyone dismounts, and climbs over the snow, zigzagging a 
little. . . . When one has ascended about 100 meters, he begins to feel 
great difficulty in breathing, his lungs are oppressed, and every step, 
every movement of his body makes him pant; he has to stop every 
twenty steps to get his breath, and there are certain constitutions which 
cannot endure the discomfort, although it is not very serious. 

The reflection of the sun on the snow is blinding; it is wise to pro- 



66 Historical 

vide oneself with colored glasses and veils so as not to add to fatigue 
and breathlessness the vertigo which would no doubt be caused by 
this immense winding-sheet of snow which surrounds one. 

We could note, moreover, that the physical sufferings attendant 
upon such an ascent have been much exaggerated; none of us had 
hemorrhages of any sort. . . . 

The Indians, used to this ascent, can carry an arroba (11 kilos) 
and they ascend very rapidly. . . . 

We reached the summit of the volcano (the summit reached by the 
travellers is the Espinazo del Diablo (5247 meters), and not the true 
summit, the Pico Mayor (5450 meters). . . . The last steps are rather 
difficult; the rarefaction of the air, becoming greater and g'reater, adds 
still more to the difficulty of the ascent .... 

Hardly had we reached the summit than the difficulty in breathing 
which afflicted us ceased to be felt, and our lungs were not oppressed 
as long as we were resting. However, all of us could observe a certain 
excitement, which increased in some of us to the point of a violent 
headache; this excitement can be compared almost to a slight state of 
intoxication; the blood circulates rapidly, and the pulse rate rises to 
nearly one hundred per minute. (P. 194.) 

Besides Popocatepetl, in Mexico there is only the peak of Ori- 
zaba (5400 meters) the ascent of which can bring on discomforts 
and even symptoms. This happened to Von Muller 1 '"' and his 
companions, September 2, 1856. 

The travellers passed the night at 3000 Spanish feet from the 
summit: 

The consequence of a stay in such rarefied air were soon strongly 
felt by all of us. Our respiration had become much deeper and more 
rapid, a natural result of the diminished quantity of oxygen reaching 
our lungs at each inspiration of this thin air. We all had violent head- 
aches with feverish tendency. These symptoms could not surprise us, 
because we were at an elevation greater than that of Mont Blanc. . . . 
Although we were lying close together, with furs and rugs over us, we 
were all shivering with cold and fever. The temperature was below 
freezing. (P. 278.) 

The next day they wished to complete the ascent: 

The climb was extremely steep, so that in 25 steps, we mounted no 
more than 8 to 10 feet: besides we had to stop after these 25 steps .... 

None of us had nosebleed or such symptoms during the ascent; 
but we had severe congestion of blood in the head so that the whites 
of our eyes were deep red. . . . All had violent headaches, and shook 
terribly with fever. (P. 282.) 

A large company of American, English, and Mexican travellers, 
including artists, engineers, and mere tourists, tried to reach the 
summit of this peak in 1866. They did not succeed either. They 
were much distressed by symptoms of which one of the company in 



Mountain Journeys 67 

the New Orleans Picayune gave a very picturesque and very 
strangely worded account. Although I am quoting it, I do not hesi- 
tate to say that it seems to me greatly exaggerated; I shall add, 
along with the editor of the Alpine Journal, that I am not sure that 
I have always understood what the author meant, 70 in his obscure 
and bombastic style: 

At first they sang and whistled while they climbed; but these 
noisy demonstrations soon ceased. Respiration became difficult. . . . 
Up to about 2000 feet from the summit, the members of the company 
were strung out at a great distance from each other. At that time, 
some became weak and fell. Blood began to issue from their ears and 
noses; their faces were so swollen that old friends knew each other only 
by their garments. A few continued to climb some thousand feet, lay 
down, went to sleep on the snow or the black dust, and awoke panting. 
The artists, laden with their instruments, felt greatly the painful effects 
of the atmosphere; with one accord they turned around and went back 
down to the place where our companions who had no ambition and 
poor endowment of lungs had stopped. . . . The engineers and the others 
lay down; they were stumbling as they walked, incapable of will or 
action, and calling to those who were ahead. Had it not been for the 
continual struggle to cling to life, the distress in breathing, and the con- 
stant loss of blood, one would have thought he was asleep and dream- 
ing in a hollow in the snow or a gorge filled with ashes. We were 
then at an elevation of about 16,000 feet. . . . General S. went on to- 
wards the summit. In spite of the claims of the natives, it is doubtful 
that anyone ever went as far as we did. During the war with Mexico, 
20 years ago at the most, an officer tried to reach the summit; but he 
fell paralyzed, at the height of 15,000 feet. His comrades went no 
further, and at this point planted a standard the staff of which is still 
there. 

Two-thirds of our company were out of sight; only three, besides 
the terrified guides, went on. Blood issued from our ears, nostrils, and 
mouths, and the veins stood out on our foreheads like dark lines; our 
progress was more and more uncertain, the slope steeper and more 
dangerous . . Colonel C. . . completely exhausted, talked incoherently 
like an intoxicated man. 

A stone which broke the shoulder of General S. . . . compelled 
them to retreat, at about 500 feet from the summit. 

North America. As we have seen, North America in many 
places has peaks lofty enough for travellers to experience on them 
the symptoms of mountain sickness. But the hardy explorers of 
the banks of the Colorado, the Oregon (Columbia) , and the upper 
Missouri, gave little heed to scientific and picturesque ascents. On 
the other hand, the engineers and the officers whom the government 
of the United States sent repeatedly to the Far West generally 
were satisfied with making trigonometric abstracts, and journeyed 



68 Historical 

only over the passes, the elevation of which rarely reaches 3000 
meters. 

However, Colonel Fremont, in his account of his expedition to 
the Rocky Mountains of Oregon, gives us an interesting observa- 
tion. 71 

August 13, 1842, in latitude 42° N., the travellers made the ascent 
of a lofty peak, and were suddenly extremely weary. The barome- 
ter stood at 20.522 inches, the altitude was reckoned at about 10,000 
feet (3050 meters) ; the temperature was only 50° F.; they stopped 
to camp: 

I was seized shortly after (says Fremont) by violent headache and 
vomiting which lasted almost all night. These symptoms were probably 
caused by excessive fatigue, the lack of food, and also, to a certain 
degree, by the rarefaction of the air. . . . 

The next day two of our men were sick and lay down upon the 
rock; at that time I was seized by headache and vomiting, as on the day 
before, so that I was unable to go any further; M. Preuss had reached 
his limit, too; the thermometer stood at 50°, the barometer at 19.401 
inches. (P. 67.) 

August 15. . . . The barometer dropped to 18.293 and the thermo- 
meter to 44°; we were at an elevation of 13,570 feet (4130 meters); at 
this great height we saw a solitary bee flying . . . This is probably the 
highest peak of the Rocky Mountains. 

Our careful method of advancing slowly had spared my strength; 
and with the exception of a slight tendency to headache, I felt no signs 
of the discomfort of the day before. (P. 70.) 

The mountain discussed here is marked on the maps by the 
name of Fremont's Peak (4130 meters) , in the State of Wyoming. 

In the following journey, made in 1943-44, the American ex- 
pedition crossed the Sierra Nevada in California at a height of 9300 
feet, February 20 (ibid. p. 235) ; June 18, 1844, it reached the sources 
of the Arkansas, at a height of 11,200 feet (3413 meters) (P. 285) ; 
in neither case does the account indicate physiological symptoms. 

I found a similar account in the immense scientific publication 
of the expedition organized for determining the route of the trans- 
continental railroad. 

September 12, 1853, Captain Gunnison, 72 topographical engineer, 
ascended Mount Creek, near Fork Lake in Colorado: 

The agreeable and inspiring effect of the pure air of the mountains 
at this elevation, a favorite theme for the eloquence of trappers and 
scouts, manifested itself in our men by shouts of noisy joy. But the 
violent physical exercise soon made them breathless; and while climb- 
ing the hills, our animals were soon completely exhausted, if they did 
not stop often to get their breath; but a few moments of rest gave them 
back their strength and vigor. (P. 53.) 



Mountain Journeys 69 

And yet they were only at a height of 8559 feet (2610 meters) ; 
barometer 564 mm., temperature 17.5°. 

September 2, they had passed the highest point of their journey, 
10,032 feet (3056 meters), at the pass of Coochetopa, in Colorado; 
they complained of no symptoms. (P. 47.) 

The Reverend Hines 7: ' made the ascent of Mount Hood in Oregon 
with three companions, July 24, 1866. It was not without trouble, 
as he says energetically: 

We had only about 700 feet to go, but it taxed our sinews for two 
hours to climb them. The sun was shining again, and the sweat was 
dripping from our brows; but as we approached the summit, fatigue 
seemed to disappear, and it was with a feeling of triumph that we 
trod the summit of the highest mountain in North America. (P. 83.) 

Hines was wrong on this last point; Williamson, 74 who climbed 
Mount Hood again in 1867, found its height to be only 3420 meters; 
it is then not the highest of the Cascades, much less of North 
America. 

More recently, a very well-known English mountaineer, M. 
Coleman, ascended mountains as high as or even higher than 
Mount Hood. 

In August, 1868, he climbed Mount Baker (3390 meters). 75 In 
his account he speaks only of sulphurous exhalations from which 
he and his companions suffered; one of them was seized by vomit- 
ing (P. 365). In August, 1870, ascent of Mount Rainier (4400 
meters), 70 on the summit of which he passed the night, warming 
himself at the crevasses of the volcano, but much inconvenienced 
by their exhalations: here too, no physiological trouble. But that 
proves nothing, for we shall see, when we speak of the Alps, that 
professional mountaineers today seem to make it a point of honor 
never to speak of the sufferings of mountain sickness. 

3. Etna. 

In the preliminary chapter, I reminded the reader that the 
ancients had frequently made the ascent of Etna (3313 meters); 
but they have left us no record that might make us think that they 
felt any extraordinary symptoms. The authors of the Middle Ages, 
who followed their steps, and told of their own journeys, are no 
more explicit than the ancients. 

Pietro Bembo, 77 who in 1494 made the ascent with his friend 
Angelo Chabriele, does not even speak of his fatigue in his cele- 
brated dialogue with his son. In 1540 and 1545, Filoteo climbed 
Etna with several of his friends: he says nothing definite. 78 Thomas 



70 Historical 

Fazello 7: ' gives a few more details in the account of his ascent of 
the 6th "of the Kalends of August", 1541; however he mentions 
nothing but an extreme fatigue: 

We had to climb on foot the crest of the mountain; the ascent was 
very arduous; here, the roughness of the soil, there, deep sand delayed 
us, our feet sliding backwards; in fact, the difficulties were so great that 
although the climb was not more than 50 steps, it took us a good two 
hours, and reaching the summit at last, panting and dripping with 
sweat, we lay down on the ground. (Decas I, liber II, caput IV; vol. I, 
P. 116.) 

But a century later, in 1671, the illustrious doctor-mathematician 
Borelli, 8 " whose attention had been aroused by the accounts of 
travellers in South America, notes symptoms which he indicates 
clearly: 

Among the noteworthy observations which I made at the summit 
of Etna in the year 1671, there is an unexpected effect due to the rare- 
faction of the air. There, in fact, moderate movements . . . brought on 
such lassitude, that young and robust men had to rest, to sit down, 
and to regain their strength by breathing frequently. (P. 242.) 

Then he tries to explain these symptoms; we shall see that he 
gave successively two different theories for them. But the sensa- 
tions which he had noted have not been experienced by all travel- 
lers, and we see beginning here a series of apparent contradictions, 
of which we shall mention numerous examples, even from our own 
times. 

In fact, Riedesel, 81 in the account of his journey to Sicily, relates 
his ascent of May 1, 1767, and he adds: 

I did not find, as various travellers say, that the air was so rare- 
fied and thin as to check or at least to hamper the breathing greatly; 
which may depend, besides, upon the conformation and constitution 
of the chest and the lungs of each subject who tries it. (P. 132.) 

Demeunier, 8 - Houel, 83 who made the same ascent at about the 
same time, do not mention observing any symptom. Delon, 84 when 
he reached the summit of Etna, cried out enthusiastically: 

An ethereal air which crushes him, startles his being, and makes 
him realize an existence which warns man that he is out of the region 
to which his organs chain him. He is impressed by his rashness. . . . 

I leave to the reader the task of deciding whether this ranting 
expresses any physiological phenomenon, and omitting other testi- 
mony quite as unimportant, I come to the account of Dolomieu, 83 
who on June 22, 1781, made the ascent of Etna; the celebrated 



Mountain Journeys 71 

mineralogist was very severely affected, and his guide still more 
than he: 

The cold was cutting . . . often breath failed me, and I was forced 
to stop short to get my breath, and to prevent strong palpitations which 
I felt in the pulmonary arteries. . . . My guide constantly called to me 
to walk more slowly, and when I reached the plain, near the Tower of 
the Philosopher,* he told me that he could go no further, that he felt 
very ill, and in fact, a moment afterwards, he fell unconscious, the 
pallor of death on his face, and in a most pitiful state. ... A few drops 
of wine made him revive a little; but he was very weak and like a man 
about to die. (P. 98.) 

Dolomieu continued his journey alone and reached the crater 
without mentioning any real sufferings in his account; he speaks 
only of his fatigue. 

The report left us by Spallanzani of his ascent on September 3, 
1788, is interesting particularly because of the record he gives of 
the remarks of travellers who preceded him: 

The rarefaction of the air on the summit of Etna did not produce 
upon me the same effects as those experienced by some of the travel- 
lers who had preceded me. Chevalier Hamilton (September 26, 1769) 
felt his respiration hampered by the great thinness of the air; Count 
Borch (October 16, 1776) was still more distressed; "the rarefaction of 
the air on this mountain (he says) is very great, so great that the air 
is hardly suited for breathing." Riedesel (1767), on the contrary, felt 
no effects, or hardly any, as we see by this sentence: "I did not per- 
ceive that the air was so rarefied as several travellers state, nor so thin 
as to prevent breathing, or even to hamper respiration very much." 
Brydone (May 27, 1770) does not mention it, and I concluded from his 
silence that the thinness of the air did not tire him much. 

As for me, my servant, and my two guides, the air gave us no 
trouble. The difficulty of climbing . . . made our respiration painful 
and hurried, it is true; but after we had reached the summit, after 
resting a little, we soon regained our strength, and even while walking, 
we had no further difficulty in breathing. (P. 272.) 37 

The illustrious physiologist did not show his usual acuteness 
there; he could not distinguish, as Borelli had done one hundred 
years before, between the effects of walking and those in a resting 
condition, and whatever he says, we can easily see that the air gave 
him real, though slight, disturbances. 

Ferrara, 88 in his description of Etna, goes farther. According to 
him, not only did the ascent cause no distress, but he breathed with 
greater ease in this pure air: 

The lessened density of the air, no less than its extreme purity," 
produced a full and free respiration. . . . We felt none of those symp- 



72 Historical 

toms which certain travellers say they experienced on the summit of 
Etna; those symptoms must have been an effect of their poor physical 
condition. We all felt very well. In his balloon, at the height of 21,482 
feet, Gay-Lussac was in good shape. (P. 21.) 

The French traveller De Gourbillon, 89 who made the ascent 
October 10, 1819, felt no effects himself; but that was not true of his 
travelling companions: 

M. Wilson experienced strange symptoms; his face, naturally ruddy, 
was wan and pale, almost entirely livid. Though younger and more 
nimble, and though he had not suffered as much from the volcanic 
exhalations, which had produced upon the latter and even upon the 
guide an effect like that of seasickness, my other travelling companion 
seemed neither fresher nor less distressed. . . . Lazarus, when he left 
the tomb, was no paler. (P. 436.) 

Likewise, Count de Forbin, 90 who mounted to the crater the 
following year, was in very bad condition: 

I was hardly halfway from the Tower of the Philosopher to the 
summit, and already I was thoroughly disheartened. The rarefaction of 
the air made breathing difficult; later, the oppression became very great, 
it acted so much upon one of our travelling companions that he fainted. 
He was revived, and summoning all our strength, we reached the high- 
est crest of the crater after an hour and a half. 

Never in my life had I felt such fatigue; . . . my first impression 
was that I was like an invalid, prostrated, distressed by the terrors of a 
feverish brain .... Weariness of the senses and excitement of the 
imagination reduced us to a state nearly like delirium. (P. 173.) 

About the same time, A. de Sayve made this ascent. The results 
of it were told in a very interesting manner by H. Cloquet, who 
made use of it to prove the effect of great heights upon the organ- 
ism. He reported it to the Societe Philomathique in the following 
words: 91 

In the month of January, 1820, M. H. Cloquet published some 
details about the medical topography of Mont St. Bernard, and ideas 
about the effect which a stay on the towering crests of lofty mountains 
has upon man . . . 

In spite of these data, a celebrated author of our time, M. Ferrara, 
thought that only persons in poor health were inconvenienced while 
ascending to the summit of Etna, in Sicily. A careful observer, M. 
Auguste de Sayve, visited this famous place in the month of May, 
1821, and disagrees with the learned M. Ferrara in this point. Here 
are the principal results of the observations which he made, and M. 
Cloquet considers that these results support what he has said .... 

At the snow limit is the little plain called Piano del jrumento, at 
the beginning of which are the ruins . . . known by the name of the 
Tower oj the Philosopher . . . Even before reaching this point, M. de 



Mountain Journeys 73 

Sayve felt that he was breathing with difficulty; in spite of the cold, 
he felt very acute thirst; however, a little rest restored his strength. 

But the scene was to be changed .... The route passes by a 
hut of refuge, which is at the foot of the cone, and which is the highest 
building in all Europe (9,200 feet) .... From there up to the summit 
there is only an absolutely bare cone, 1,300 feet high. 

As our traveller climbed this cone of the crater, he felt his 
distress increase, and was obliged to stop at nearly every step. He 
felt extraordinary weakness in all his limbs; he was nauseated, and 
thinking that he had left the element suited to his physical nature, 
he tried, he says, to inhale a little air, but could not succeed at this 
critical moment; and yet he was perfectly healthy when he began his 
ascent; his passage through the region of snow had tired him very 
little; the symptoms he felt can therefore be attributed only to the 
rarefaction of the air. 

M. Aubert-du-Petit-Thouars . . . told the author that he had 
felt similar symptoms, especially a weakness in the stomach, when he 
climbed the mountain in the He de Bourbon, known as the Benard. 

M. Cloquet, moreover, himself experienced symptoms of this sort, 
when he reached a certain height in the Alps .... 

M. de Sayve had with him a companion who was much more 
severely affected; and we know that the unfortunate Dolomieu, in the 
same ascent, was also attacked by symptoms like those which we have 
just mentioned .... 

These different symptoms are quite varied and appear sooner in 
some persons than in others; but they cannot be attributed to fatigue, 
which never has such consequences in mountains of an elevation less 
than 1,000 fathoms. 

Moreover, they appear alike in animals and men. 

I shall not give more quotations. More recent authors show the 
same differences in power of observation, and most of them say 
nothing about physiological disturbances. What I have reported is 
enough to show that Etna is, if I may use this term, a limited 
mountain, in the ascent of which many persons experience no 
painful symptom, whereas others are more or less ill. Since the 
first symptoms of distress are exactly those of excessive fatigue, 
the difficulties of the ascent of the cone are consequently enough 
to explain everything, in the opinion of most of the travellers; 
some think the cause of the oppression is the poisonous exhalations 
coming from the volcano through the innumerable fissures in the 
ground. It is not surprising, then, that before verification of the 
disease peculiar to mountains, in the main range of the Andes, 
nothing unusual was noted in ascents of Etna. 

4. Peak of Teneriffe. 

Discovered again in the fourteenth century by French navi- 
gators, the Canary Islands were conquered in the fifteenth century 



74 Historical 

by the Spaniards. But for a long time no one dared attempt the 
ascent of the volcano, the summit of which seemed all the higher 
because its foot is at sea level. 

The strangest and most exaggerated estimates were made of its 
height. According to Th. Nicols, 92 it was not less than 15 leagues; 
Riccioli and Kircher estimated it at ten Italian miles; in reality, it 
is 3716 meters. 

The first account of its ascent 93 that we have found is that of a 
journey made in 1652 by some "notable merchants and men of great 
esteem"; they were considerably affected by the rarefied air: 

At six o'clock in the morning we began to ascend the Peak . . . 
Some of our company became very weak and sick, and were attacked 
by diarrhea, vomiting, and feverish trembling . . . One of us was 
so ill that he could go no further. (P. 201.) 

The celebrated Robert Boyle ° 4 reported a similar account, in 
which the effect of the expanded air is confused with that of emana- 
tions from the earth, as often happens in ascents of volcanoes: 

One day I asked an intelligent man who had lived for several 
years in Teneriffe whether he had climbed to the summit of the Peak, 
and what sensations he had had. He replied that he had tried, that 
several of his companions had completed the ascent, but that the thin 
air and the sulphurous exhalations had made himself and a few others 
so sick that they halted far below the summit. The effect of these 
vapors was such that his skin became pale yellow, and his hair was 
bleached. (P. 2039.) 

Not all travellers experienced the same effects, and, as usual, 
those who were free from distress were led to deny what their less 
fortunate predecessors reported. 

Edens, 95 who ascended the Peak in 1715, expresses himself as 
follows: 

What has been said about the difficulty of breathing on the summit 

of the Peak seems wrong; we breathed as easily up there as we did 

below; we had our lunch there. (P. 186.) 

Father Feuillee u0 made the ascent of the Peak on July 31, 1724; 
he says nothing of interest to us. 
G. Glas 97 was less fortunate: 

We reached the foot of the cone (he says in fact) . . . Although 
the distance is hardly a half mile, we were forced to stop forty times, 
I think, to get our breath, and when we had reached the summit, it 
was a quarter of an hour before we had recovered. (P. 255.) 

The same thing was true of the scientists whom Labillardiere ,J8 
had taken with him on his journey in search of La Perouse: 



Mountain Journeys 75 

Citizens Riche and Blavier (he says) had undertaken the ascent 
of the Peak one day after us (Labillardiere, who made the ascent 
October 17, 1791, speaks of no painful sensation) ; but these two 
naturalists did not succeed in climbing to the summit; they were 
still far from it when they spat blood, since their lungs could not 
become accustomed to the rarefied air, and they were forced to give up 
their undertaking. (Vol. I, p. 27.) 

It is true that, according to Bory Saint-Vincent," 

Riche was in very poor health and had very weak lungs .... He 
died as a result of his journey, soon after his return to France. (P. 182.) 

Von Humboldt 100 (ascent of June 21, 1799) says absolutely 
nothing of physiological disturbances. 

The celebrated geologist Cordier, 101 who ascended the Peak 
April 16, 1803, discusses these disturbances, but only to deny them, 
or practically so: 

What has been said of the keenness of the cold, . . . and the 
difficulty of breathing on the Peak is not correct. Moreover, I have 
already proved several times that the opinion generally held in this 
respect is more than exaggerated; I assure you that the cold was quite 
endurable . . . that the rarity of the air did not inconvenience us at all, 
although it forced us to halt quite frequently as we approached the 
summit. (P. 61.) 

The illustrious Leopold de Buch, in the accounts of his ascents 
of May 18 and 27, 1815, 102 does not give them a more important 
place: 

The ascent becomes more difficult after the Estancia de los 
Ingleses ... In spite of that, the difficulties are not comparable to 
those of an ascent to the summit of one of the snow covered peaks, 
of the Alps .... When we reached the crater, we suddenly saw 
appearing opposite us Mme. Hammond, a Scotch lady, with her trav- 
elling companions. She was the first woman ever to ascend to the 
summit. (P. 4.) 

May 27 we again ascended the Peak. (P. 5.) 

The account of Dumont d'Urville 10a is very interesting in its 
brevity. He passed the night, in June, 1826, at the Estancia de los 
Ingleses: 

The air was very pure (he says) and I felt none of these violent 
disturbances and these suffocating sensations experienced by different 
travellers. M. Quoy alone had pains in the stomach, and M. Gaimard 
slept all night without any trouble .... The next day, as we 
approached the Pain-de-Sucre, we were obliged to stop frequently 
to get our breath .... We lunched gayly on the crest of the Piton. 
(P. 37.) 



76 Historical 

At the time of his second journey, in October, 1837, the officers 
of the Astrolabe and the Zelee made the ascent of the Peak. 
Dumont d'Urville 104 reports their sensations in these words: 

In agreement with my observations in 1826, MM. Dumoulin and 
Coupvent noted .... the numbness of the extremities of the body. 
During the night, the thermometer dropped to — 0.5°. MM. Dubouzet, 
Dumoulin, and Coupvent, especially the latter, felt severe headaches. 
(P. 32.) 

The surgeon, Le Guillou, 105 reporting the same ascent, says: 

Several of our comrades were afflicted by a strange symptom; 
they had copious nosebleeds, and we were forced to stop a few 
moments. (P. 29.) 

On September 18, 1842, ascent of M. Charles Sainte-Claire De- 
ville; 10G he does not say a word about physiological disturbances. 

Itier, 107 who climbed the Peak December 28, 1843, gives more 
importance than his predecessors to the sufferings he felt: 

We left the Estancia d'Ariba (3104 meters), and mounted on foot 
the sort of path which winds between two flows of obsidian; walking 
is painful among these fragments of pumice stone mingled with ashes 
which give under the foot; besides, the sun began to affect us, and 
the effect of the rarefaction of the air soon added to the fatigue of 
our effort. My heart throbbed violently, and the arteries of my brain 
shared in this distress; the headache it caused forced me to stop 
frequently; my companion, less accustomed to mountains than I, felt 
these effects much more than I did; he stopped every ten steps, 
suffocating, exhausted. (Vol. I, p. 28.) 

I shall quote finally the account reported from the notes of a 
traveller by Madame Elizabeth Murray, an English artist, 108 of an 
ascent of the Peak, made in August, by four Englishmen and an 
American: 

To pass the night, we made our bivouac at the Estancia de los 
Ingleses, at a height of 9933 feet. (Vol. II, p. 20.) .... 

One of us was seized by extreme weakness, shivering, and 
violent headache; we covered him with rugs, lighted a good fire, 
and the heat, added to the effects of a little liquor, partially revived 
him. (P. 121.) 

It was late, and we stretched ourselves on the ground, wrapped 
in our rugs. Shortly after, my companion on the right rose and 
complained bitterly of extreme cold, pains, and distress in his stomach. 
We placed him near the fire, and gave him warm water and brandy. 
He began to be well enough to permit us to sleep when my 
neighbor on the left was attacked, then treated in the same way. 
Both suffered severely from the symptoms well known to ocean 
voyagers; these symptoms are not rare on the Peak; they are some- 
times attributed to sulphurous exhalations, but I think that they are 



Mountain Journeys 77 

caused instead by the rarity of the air. At any rate, we smelled no 
odor of sulphur. 

Of the four of us, my American friend and I were the only ones 
who felt no discomfort. (P. 123.) 

Before arriving at the Rambleta (11,680 feet), many of us suffered 
more or less from difficulty in breathing. One of my companions, in 
particular, could not take more than eight to ten steps without 
stopping, thus forcing us to wait for him. (P. 126.) 

After a great many halts to regain our breath, we reached the 
summit. (P. 128.) 

We went back by the "Mai Pais", the descent of which was as 
disagreeable as the ascent, except that our respiration was much 
freer. (P. 136.) 

In summary, the Peak of Teneriffe is, like Etna, a limited moun- 
tain, in the ascent of which many travellers feel no great effects, 
those who are ill being only slightly affected. 

5. Alps. 

It is not until the end of the last century that ascents were made 
in the Alps to heights sufficient to bring on physiological disturb- 
ances. Until the time of Canon Bourrit and the illustrious De Saus- 
sure, only a few chamois hunters had ventured above the line of 
perpetual snow. The main peak of Mont Blanc, today traversed in 
all directions every year by hundreds of tourists, bore the sig- 
nificant name of the Accursed Mountains; in the seventeenth cen- 
tury, the Bishop of Annecy, Jean d'Aranthon, 100 came to exorcise 
its glaciers, which withdrew submissively after his benediction. Of 
the rival summits of Monte Rosa and the Jungfrau, there was no 
question. The principal passes had been frequented since the days 
of the Romans; many armies had crossed them; the hospice of the 
Grand Saint-Bernard was founded at the end of the tenth century, 
but no one had thought of risking his life in the ascent of one of 
the innumerable summits which tower above the beautiful Alpine 
valleys: in 1740, the first Englishmen arrived at Montanvert! 

However, it was well known that travellers suffered sometimes, 
in crossing the Alps, from pulmonary disturbances. Haller con- 
siders them, as we shall see in the chapter devoted to the discussion 
of theoretical explanations; he even speaks of hemoptyses observed 
by Scheuchzer: "ut in primis in J. Sch. triste exemplum exstat". 110 
I could not secure the work of this German geographer; m but 
according to Meyer-Ahrens, 112 he must have experienced only the 
oppression and threats (Vorboten) of hemorrhage. 

The first traveller who has given us an account of personal dis- 
agreeable sensations, the second to make the ascent, today so com- 



78 Historical 

mon, of Buet (3110 meters) is the Canon Bourrit. 1 i;i At this 
moderate height, he experienced strange symptoms'. 

In 1776, I left Geneva with the purpose of ascending Buet; it 
was the second time that I had climbed this mountain; .... I was 
in good physical condition .... All three of us reached the summit 
feeling very well .... After ten minutes of peaceful halt, I felt a 
numbness in my arms and legs, and soon I had not the strength to 
force myself out of this condition; I was already unconscious when 
my companions removed me; they carried me down to the first rocks 
of the glacier .... 

The next year, .... I went there in very fine weather; .... 
I began to sketch, and told my guide to hold my parasol over me. 
After 15 minutes, I noticed that he was not holding it well; . . . , 
and you can imagine my surprise when I saw this man as white as 
snow .... and his eyes almost motionless; I made the utmost haste to 
get him away from this baneful summit .... Finally, in 1777, .... 
M. Saint-Ours .... witnessed a similar attack on the summit of 
Buet .... (Vol. II, p. 94.) 

Bourrit, however, seems to have been quite subject to syncopes; 
he reports two others, one on the glacier of Buet, while he was 
walking (Vol. Ill, P. 198), the other during his attempt to ascend 
Mont Blanc, September 11, 1784 (Vol. Ill, P. 300 and 304). 

At a still lower elevation, at the monastery of the Grand Saint- 
Bernard (2430 meters) , a traveller of the same period, Laborde, felt 
similar symptoms, although considerably less severe: 

The sky was clear when we reached the monastery of the Grand 
Saint-Bernard (July 30, 1777). 

It would be difficult to express the different sensations which 
one feels at the same time; the first that is noticeable is an attack 
caused by difficulty in breathing; it seemed as if the lungs did not 
have their usual elasticity and lacked the capacity to hold the air 
inspired; the difference between the air one breathes at such a 
height must be very evident to those who are used only to air of the 
plains; it is more rarified and purer because it is less filled with 
vapors (Lecture on the natural history of Switzerland, P. VIII). 

These few quotations bring us to the celebrated accounts of De 
Saussure; the sufferings experienced at elevations which are very 
low compared with Mont Blanc, the ascent of which he dared to 
attempt and carry out, bring out still more the bravery which he 
displayed in this intrepid undertaking. Canon Bourrit, when he 
said, as we shall see in Chapter III, that it would be difficult, if noi 
impossible to live long on the summit of Mont Blanc, only trans- 
lated, in a somewhat modified form, an opinion universally held by 
mountaineers. 

De Saussure, when he ascended Mont Blanc, had prepared for it 



Mountain Journeys 79 

by numerous expeditions made every year on lofty mountains. 
Now at fairly moderate heights he had already felt symptoms, 
which had attracted his attention. In the account of his ascent of 
Buet, made July 13, 1778, in the company of Pictet, he gives l15 a 
very clear indication of it: 

The rarity of the air, as soon as one passes the elevation of 
1300 to 1400 fathoms above sea level, produces very strange effects 
upon the body. 

One of these effects is that muscular strength is exhausted very 
quickly. (Vol. I, p. 482.) .... 

Another effect of this thin air is the drowsiness it produces. As 
soon as one has rested for a few moments at these great heights, 
he feels his strength entirely restored, as I have said; even the 
impression of the former fatigue seems wholly effaced; and yet in 
a few moments one sees all who are not busy, falling asleep, in 
spite of the wind, the cold, and the sun, and often in very uncomfort- 
able positions. Of course fatigue, even on the plains, produces sleep; 
but not so suddenly, especially when it seems to have entirely 
disappeared, as it does on the mountains, as soon as one has rested 
a few moments. 

These effects of the thinness of the air seemed to me quite 
universal; some persons are less subject to it; the dwellers on the 
Alps, for example, who are accustomed to living and working in 
this thin air, seem less affected by it; but they do not entirely escape 
its effect. The guides, who on the lower slopes of the mountains can 
climb for hours at a time without stopping, have to pause to get their 
breath every 100 or 200 steps, as soon as they are at an elevation of 
1400 or 1500 fathoms, and as soon as they have halted for a few 
moments, they too fall asleep with surprising promptness. One of 
our guides, whom we had standing on the top of Buet with a parasol in 
his hand so that the magnetometer might be in the shade while M. 
Trembley observed it, kept falling asleep constantly in spite of the 
efforts which we made and which he made himself to struggle 
against this drowsiness. And on my first trip to Buet, Pierre Simon, 
who had crept into a snow crevasse to shelter himself from a cold 
north wind which distressed us greatly, went sound asleep there. 
But there are constitutions which this rarity of the air affects still 
more severely. One sees men, very sturdy elsewhere, consistently 
attacked at a certain elevation by nausea, vomiting, and even fainting, 
followed by an almost lethargic sleep. And all these symptoms cease 
although fatigue continues as soon as they have reached a denser air 
in the descent. 

Fortunately for the progress of physics, M. Pictet is not so 
seriously affected by the thinness of the air; however, he is more 
affected than the average man, for although he is very strong, very 
nimble, and well trained in climbing mountains, he is always attacked 
by a sort of distress, a. slight nausea, and an absolute loathing of 
food, as soon as he reaches the elevation of 1400 fathoms above sea 
level. As for me, I feel no effect other than being obliged to rest very 



80 Historical 

frequently, when I ascend steep slopes at these great heights. I tested 
this again in my last trip to Buet. While we were climbing the slope 
covered with soft snow which crowns the mountain, I absolutely had 
to stop every fifty steps, and M. Pictet, more sensitive than I to this 
effect of the rarity of the air, counted his steps without telling me, 
and found that he could not take more than forty without getting his 
breath. (P. 483-85.) 

But that was nothing compared to what he was to observe in his 
trip to Mont Blanc. Already several attempts had been made to 
reach the summit of this colossal mountain. De Saussure recorded 
for us the account of these vain attempts, and it is clear that the 
physiological symptoms experienced by those who made these at- 
tempts had much to do with their failure: 

§1103. In 1775, four guides from Chamounix tried to reach the 
summit by the mountain of La Cote .... Everything seemed to 
promise them perfect success; .... but the reflection of the sun upon 
the snow and the stagnation of the air in a great valley of snow 
which seemed to lead them directly to the crest of the mountain 
gave them a feeling of suffocating heat, as they said, and at the same 
time gave them such distaste for the provisions with which they were 
supplied, that, worn out with lack of food and weariness, they 
retraced their steps. (Vol. II, p. 550.) 

§1104. In 1783, three other guides made the same attempt by the 
same route. They passed the night at the top of the mountain 
La Cote, crossed the glacier, and followed the same valley of snow. 
They were already fairly high and were advancing courageously, 
when one of them, the most daring and sturdy of the three, was seized 
almost suddenly by an absolutely unconquerable desire to sleep; he 
wanted the other two to leave him and go on without him; but they 
could not consent to abandon him and leave him sleeping on the snow, 
convinced that he would die of sunstroke; they gave up their attempt 
and returned to Chamounix. For this need of sleep, produced by the 
rarity of the air, ceased, as soon as he was in a denser atmosphere in 
the descent .... The heat gave them all great distress; they had no 
appetite; the wine and the food which they took with them had no 
attraction for them. 

September 13, 1785, De Saussure himself attempted the ascent 
with M. Bourrit and his son. He slept at the hut (1422 fathoms) : 

§1112. M. Bourrit and his son even more than he were a little 
affected by the rarity of the air; they did not digest their dinner well, 
and could eat no supper. As for me, since the thin air inconveniences 
me only when I am exercising violently in it, I passed an excellent 
night there. 

The next day, he mounted to an elevation of 1900 fathoms; the 
snow stopped him. 

But the ascent of Mont Blanc had become a dominating idea in 



Mountain Journeys 81 

him. The next year, he commissioned Pierre Balmat to construct a 
hut at the foot of one of the crests of the needle of Goute, so that he 
might rest there before trying next to mount to the summit of 
Mont Blanc: 

§1963. In executing this project, Pierre Balmat, Marie Coutet, 
and another guide, June 9, 1786, .... reached the summit of the 
needle of Goute, after having all of them been extremely ill from 
fatigue and the rarity of the air. (Vol. IV, p. 138.) 

It was in consequence of this trip that Jacques Balmat, who had 
rejoined his compatriots and who passed the night on the mountain, 
found the route to Mont Blanc by the Corridor: 

§1965. This route had already been tried but had been discarded 
because of a strange prejudice. As it follows a sort of valley between 
eminences, it was imagined that it was too warm and had too little 
air ... . Fatigue and the rarity of the air caused in those who made 
the first attempts this prostration of which I have often spoken; they 
attributed this distress to the heat and the stagnation of the air, and 
tried to reach the crest only by uncovered and isolated ridges. 

The people of Chamounix also believed that sleep at these great 
heights would be fatal; but the test which Jacques Balmat made by 
passing the night there dissipated this fear. (Vol. IV. p. 140.) 

It seems as if the account given by De Saussure of the discovery 
of Jacques Balmat is not exactly correct. The illustrious physicist 
of Geneva seems to have been led astray by his favorite guides, 
who, jealous of Balmat, attributed to chance what was the fruit of 
long and persistent research. The interesting works of M. Ch. 
Durier have cast some light on this point. At any rate, June 10, 
1786, Jacques Balmat, having found the true route, after several 
nights passed on the mountain, descended to Chamounix almost 
dying of fatigue and cold. Being attended by Dr. Paccard, he in- 
formed him of his discovery and proposed to share the glory of it 
with him by making the ascent with him. Paccard accepted, and 
on August 9, 1786, a human foot for the first time trod the summit 
of the highest mountain of Europe. Dr. Paccard had been ex- 
hausted by fatigue and no doubt also by the rarefaction of the air 
so that he stopped on the way and lay down; Balmat ascended 
alone, then returned to seek his companion, half carried him to the 
crest, and took him back down blinded by the snow. 

Unfortunately I have not been able to get an authentic account 
of this memorable ascent. That of Alexandre Dumas (Impressions 
de voyage en Suisse, Chap. X) , much less inexact than one would 
expect, cannot, however, be trusted in physiological matters. But 
what has been said and written about this journey shows that the 



82 Historical 

two companions, especially Dr. Paccard, suffered keenly from the 
rarefaction of the air. 

At the news of the success, De Saussure, who had promised a 
prize to the person who should find the true way, though hoping to 
use it first himself, made haste to organize a new expedition. But 
judging that the season was too advanced, he had to put off until 
the following year the realization of a desire which had interested 
him deeply for so many years. 

August 1, 1787, he left Chamounix, accompanied by a servant 
and eighteen guides. He slept under the tent on the summit of the 
mountain La Cote. 

The evening of the second day of the ascent, he reached the 
little' plateau; the barometer registered 17 inches 10 lines. They 
made preparations to pass the night (1995 fathoms) : 116 

§1962. There (says De Saussure) my guides first began to exam- 
ine the place in which we were to pass the night; but they very 
quickly felt the effect of the rarity of the air. These sturdy men, for 
whom the seven or eight hours of walking which we had just done 
were absolutely nothing, had hardly lifted five or six shovelfuls of 
snow when they found it absolutely impossible to continue; they had 
to relieve each other constantly .... 

I myself, who am so accustomed to the air of the mountains, who 
feel better in this air than in that of the plain, was completely 
exhausted while examining my meteorological instruments. (Vol. 
IV, p. 144.) 

The next day they continued to ascend, and reached "the cliff 
which forms the left shoulder of the crest of Mont Blanc": 

§1985. When I began this ascent, I was already quite out of 
breath from the rarity of the air ... . The kind of fatigue which 
results from the rarity of the air is absolutely unconquerable; when 
it is at its height, the most terrible danger would not make you take 
a single step further. (P. 165.) 

Soon they were no more than 150 fathoms in elevation from the 
summit of Mont Blano: . 

§1988. I therefore hoped to reach the crest in less than three 
quarters of an hour; but the rarity of the air gave me more trouble 
than I could have believed. At last I was obliged to stop for breath 
every fifteen or sixteen steps; I usually did so standing, leaning on 
my alpenstock, but about once out of every three times I had to sit 
down. This need of rest was absolutely unconquerable; if I tried 
to overcome it, my legs refused to move, I felt the beginning of a 
faint, and was seized by dizziness quite independent of the effect of 
light, because the double crape which covered my face protected my 
eyes perfectly. Since it was with keen regret that I saw thus passing 
the time which I hoped to devote to my experiments on the summit, 



Mountain Journeys 83 

I made different tests to shorten this rest; I tried, for example, not 
to continue to the end of my strength, and to stop an instant every 
four or five steps, but I gained nothing; I was obliged, after fifteen 
or sixteen steps, to take a rest as long as if I had made them consec- 
utively; and this was very noteworthy, that the greatest distress 
is not felt until eight or ten seconds after one has stopped walking. 
The only thing that did me any good and increased my strength was 
the cold air of the wind from the north; when as I climbed I had 
my face turned in that direction, and swallowed great mouthfuls of 
the air coming from it, I could take twenty-five or twenty-six steps 
without stopping. (P. 171.) 

At last the highest crest was reached: 

§1991. I now had to make the observations and experiments, 
which alone gave some value to this journey; and I was terribly 
afraid that I should be able to do only a small part of what I had 
planned. For I had already found, even on the plateau where we 
had slept, that every observation made carefully tires one in this 
thin air, and that is because, without realizing it, one holds his breath; 
and since there one must compensate for the rarity of the air by the 
frequency of his breathing, this suspension caused definite distress; I 
was obliged to rest and to pant after observing any instrument as 
after making a steep ascent. (P. 175.) 

What De Saussure had foreseen happened: 

§1965. When I had to get to work to set out the instruments and 
observe them, I was constantly forced to interrupt my work and 
devote myself entirely to breathing .... 

When I remained perfectly quiet, I felt only slight distress, a 
little tendency to nausea. 

But when I took pains, or when I fixed my attention for a few 
moments consecutively, and especially when I compressed my chest 
by stooping, I had to rest and pant for two or three minutes. My 
guides experienced similar sensations. They had no appetite. (P. 147.) 

§2021. Some could not endure all these kinds of sufferings, and 
descended first to reach a milder air. (P. 208.) 

Farther on, De Saussure makes a very accurate statement, which 
explains many exaggerations and many doubts: 

§2021. I observed a rather curious fact, that for some individuals 
there are perfectly - marked limits, where for them the rarity of the 
air becomes absolutely unendurable. I have often taken with me 
peasants, elsewhere very robust, who at a certain height were sud- 
denly so affected that they absolutely could not ascend higher; and 
neither rest, nor cordials, nor the keenest desire to reach the crest 
of the mountain could make them pass this limit. They were attacked, 
some by palpitations, others by vomiting, others by faints, others by 
a violent fever, and all these symptoms, disappeared as soon as they 
breathed a denser air. I have seen persons, but only a few, whom 
these symptoms forced to stop at eight hundred fathoms above sea 



84 Historical 

level; others at twelve hundred, several at fifteen and sixteen hun- 
dred; as for me, like most of the dwellers on the Alps, I do not begin 
to be noticeably affected until at nineteen hundred fathoms; but 
above this limit, the best trained men begin to suffer when they hurry 
a little. (P. 209.) 

Finally they had to descend; from eleven o'clock to half -past 
three, De Saussure remained on the summit, and he was sorry to 
leave, because, he says, and I call the attention of the reader to 
this extremely important remark: 

§2021. Although I had not wasted a single moment, in these 
four hours and a half I could not make all the experiments which I 
had frequently finished in less than three hours at sea level . . . But 
I kept the well founded hope of finishing, on the col du Geant, what 
I had not done, and what probably no one will ever do, on Mont 
Blanc. (P. 210.) 

The descent was accomplished successfully and without great 
fatigue: 

As the movement one makes while descending does not compress 
the diaphragm, it does not hamper respiration, and one does not 
suffer from the rarity of the air. 

The example of the illustrious physicist was soon followed. 
Seven days after his famous ascent, the English colonel Beaufoy 117 
in his turn reached the summit of the giant of the Alps. It was not 
without keen sufferings, as the following extracts from his account 
prove. 

Leaving Chamounix August 8, 1787, he slept with his ten guides 
at the hut built in 1786 by the orders and at the expense of M. de 
Saussure. The first physiological phenomenon which the colonel 
mentions is thirst: 

Our thirst, since we had reached the upper regions of the air, 
had become unendurable. Hardly had I drunk when my mouth was 
dry. Although I was drinking constantly, the quantity of my urine 
was very small; its color was very dark. The guides were similarly 
affected; they did not wish to taste wine .... 

The rarity of the air soon began to give me a violent headache; 
to my great surprise, I also felt a keen sensation of pain just above 
my knees .... 

When we were within .150 fathoms (270 meters) of the summit, 
the harmful effects of the rarity of the air was evident in all of us; 
an almost irresistible desire to sleep possessed us. My energy had 
left me; indifferent to everything, I thought only of lying down on the 
ground; at other times, I regretted this expedition, and when I was 
almost at the summit, I thought of descending, without doing it how- 
ever. Many of my guides were in the most pitiful condition; exhausted 



Mountain Journeys 85 

by excessive vomiting, they seemed to have lost both strength of 
body and strength of mind. But shame came to our assistance. I 
drank the last pint of water and felt refreshed. Yet the pain of my 
knees had so increased, that every 20 or 30 steps I had to stop until 
its acuteness had diminished. My lungs did their duty with difficulty, 
and my heart throbbed with violent palpitations. Finally, however, 
but with a sort of apathy which barred joy, we reached the summit. 
Six of my guides and my servants immediately threw themselves 
down with their faces against the ground and went to sleep. I 
envied their repose. 

The colonel suffered greatly from the reflection of the sun upon 
the snow; he had neither veil nor glasses. 

Some weeks later, De Saussure, in his ascent of Mont Cenis, 
September 28, 1787, again made very interesting remarks from the 
physiological point of view: 

§1280. At our departure from the summit, where we had stayed 
for two hours, I counted by my watch with a second-hand the pulse 
rate of all those who composed our little caravan, and counted it 
again on our arrival at the post-house of Mont Cenis: 

J. B. Borot, guide, above 112, below 100 

B. Boch, guide above 112, below 96 

J. Tour, guide above 80, below 88 

Tetu, my servant, above 104, below 100 

My son above 108, below 108 

Myself above 112, below 100 

Average above 104% below 98% 

It will be noted that Joseph Tour was the only one whose pulse rate 
was higher at the foot of the mountain than at the top; that for my 
son, the number was the same, and that the other four had a more 
rapid rate on the summit, so that the average gives six beats per 
minute more above than below, with a difference of about 4 inches 
2 lines in the height of the barometer. There is this also to be noted 
that after I counted the pulse rate on the mountain after a stay 
amounting to a rest of at least two hours for the guides; whereas on 
the plain, as they wished to leave, I had to count it a few minutes 
after our arrival. 

What is still more remarkable is that when I separate those who 
were nauseated (three of the four guides, whose names De Saussure 
does not give, were nearly sick on the summit) from those who 
remained well, I find that the average difference was 9V3 for the 
first, and only 2% for the second. This observation confirms what 
I have always believed, namely, that this discomfort partly resembles 
a sort of fever, produced by the frequency of the breathing, which 
quickens the circulation of the blood. And as for me, if my pulse 
was a dozen beats more above than below, even though I felt no 
discomfort, that is because I did not rest a single moment; I was at 
work continually during these two hours; if I had rested like those 



86 Historical 

who were ill, I am sure that my pulse rate would have dropped 
several beats. (Vol. Ill, p. 85.) 

The following year, he went with his son to stay on the col du 
Geant (3360 meters) from July 3 to July 19, 1788; this trip, which 
filled the guides with terror, was undertaken with the purpose of 
attempting experiments which, on Mont Blanc, "the shortness of 
the time and the discomfort caused by the rarity of the air pre- 
vented me from carrying out." (Vol. IV, p. 217.) One whole 
very interesting chapter is devoted to Observations Relating to 
Physiology: 

§2105. It was interesting to note what effect upon our bodies 
would be caused by a prolonged stay in an air as rarified as that 
which we were breathing on the Col du Geant. It must be recalled 
that the average height of the barometer was, during our stay, about 
19 inches, that is, 9 inches lower than at sea level, and that therefore 
the density of the air there was nearly one third less. 

M. Odier, a doctor in medicine, very eager for the progress of his 
profession, had given me some questions which were to serve as text 
for my observations. 

§2106. To determine precisely the degree of animal heat. During 
the morning of July 17, at a moment when I was very calm, and 
without having made any violent movement, I placed under my 
tongue a small mercury thermometer keeping my mouth closed, and 
at the same time I observed this thermometer with a magnifying 
glass. It was at 29 Vz, and registered the same degree under the same 
circumstances on the plain. 

To count the number of inspirations and expirations which a man 
in repose and not forewarned makes in a minute, and also the rela- 
tion of this number to that of the pulse rate. Under the same circum- 
stances as those of the preceding paragraph, at first I found 75 heart 
beats for each inspiration and as many for each expiration. But 
another time, taking a larger number, which for that very reason 
deserves greater confidence, I found that I made 10 inspirations and 
expirations in 35 seconds, which amounts to 17 per minute, and that 
my pulse rate was also 79 per minute. 

§2107. To try to inspire deeply enough to stop the pulse in the 
left wrist, supposing that the same individual can do so on the plain. 

July 19, when I arose, seated on my pallet, I succeeded in stop- 
ping the pulse of the left wrist, prolonging the inspiration for ten 
seconds; immediately I repeated the test, and the pulse stopped at 
the fifteenth second; the third time, at the thirty-fifth second the 
pulse was still resisting when I was forced to catch my breath. When 
I made the same test standing, I could not stop my pulse; but it is 
true that I could prolong the inspiration only for 32 seconds. Therefore 
this test appears, at least for me, not susceptible of regular com- 
parison. 

§2108. To count the pulse in a perfectly vertical position; if the 



Mountain Journeys 87 

difference is greater than on the plain, it is a proof that the air of 
lofty mountains increases the irritability of the heart. 

July 18, in the afternoon, having taken a short nap on my pallet 
on the ground, in a horizontal position, my pulse rate in this same 
position was 83 per minute. I then arose, and while standing, my rate 
was 88; but suspecting that the effort which I had made in rising 
might have contributed to this acceleration, I rested a few instants, 
and then my pulse rate was only 82. 

§2109. To determine by comparison whether the inspiration can 
be held as long on the mountain as on the plain. 

In section 2104 I reported the attempts I had made on the moun- 
tain. I then forgot to repeat them on the plain on my return, and 
since then, my constitution has been so much affected by fatigues 
and illnesses, that the comparative tests I might make would give 
no result on which one could reason. 

To determine* if it is possible comparatively, the proportion of 
the urine to the amount drunk. We lacked the necessary facilities to 
make comparisons. 

§2110. To verify particularly whether the effects of the rarified 
air appear suddenly or gradually. 

It appeared to us that the general effects were almost the same 
during our whole stay. When we arrived, we were all more out of 
breath than we should have been after making an ascent equal to 
that on a less lofty mountain on the last day. On the following days, 
the discomfort was far from increasing; our companions, my son, 
and I thought that we were becoming accustomed to this air: how- 
ever, when we gave attention to it, and especially when we made 
efforts for this purpose, we found that if one ran, if he remamed in 
an uncomfortable attitude, and particularly in a position in which 
the chest was compressed, one was much more out of breath than on 
the plain, and in an increasing progression; so that, from moment 
to moment, it became more difficult, and at last even impossible to 
keep up these efforts. 

§2111. As our observations forced us to remain in the open air 
almost all day, I had advised my son and my servant always to keep 
a piece of crape over the face, as I did myself. My servant thought 
that he could do without it, but his whole face, and particularly his 
lips, swelled, which made him hideous, and which was accompanied 
by very painful cracking of the skin. That made my son think that 
perhaps the action of the sun produced a liberation of air which 
caused this swelling. 

To see whether this air would appear outside, he had this same 
young man hold his hands in water in the sun; they were immediately 
covered with little bubbles; he wiped them, then when he put them 
back in the water, more bubbles appeared; he wiped them a second 
time, and dipped them for the third time; but then there were no 
more bubbles to be seen. We concluded from that, that the bubbles 
which we had seen at first were only air adhering to the surface 
of the skin. 

2212. It seemed to us that in general our nerves were more 
irritable, that we were more subject to impatience, and even to 



88 Historical 

impulses of anger; our tempers were noticeably worse; hunger 
appeared more disturbing and more imperious; but on the other hand 
our appetites were more easily satisfied and digestion seemed to take 
place more rapidly than on the plain. Moreover, it seemed to my 
son and me that in our work and our observations relating to 
physics, our minds were noticeably freer, more active and less easily 
tired, I will even say more inventive, than on the plain, and I hope 
our readers will find the proof of it in the report of our occupations 
during these seventeen days. (Vol. IV; p. 315-318.) 

In his trip around Monte Rosa he also describes the distress felt 
by animals. On August 14, 1789, he was on the glacier of Mont 
Cervin (glacier Saint-Theodule) : 

2220. The mules, which were sinking in the snow up to their 
girths, were unloaded; yet it was very hard for them to go on, they 
were panting, obliged to stop for breath, as soon as they had made a 
few steps. However the grade was not very steep, and the three or 
four hours of walking which they had had could not have tired 
them .... but it was the rarity of the air which affected them; they 
experienced all that we had experienced when we ascended Mont 
Blanc .... The breathing of these poor animals was extremely 
painful, and at the very moments when they were stopping for 
breath, they panted with such distress that they uttered a kind of 
plaintive cry which I had never heard, even when they were very 
weary. It is true that I had never travelled with mules at so great 
an elevation .... we were then 1,736 fathoms above sea level. (Vol. 
IV, p. 380.) 

Canon Bourrit, whose vain attempts had preceded the expedition 
of De Saussure, made the ascent of Mont Blanc in 1788, accom- 
panied by Woodley and Camper. I have not found any complete 
description of this trip. But we owe to him a few details of a 
somewhat later expedition, made August 11, 1802, by Forneret and 
Dortheren: 

The rarity of the air (he says) 113 added to the difficulty of walking; 
their chests felt lacerated, and they told me that nothing on earth 
would induce them to undertake such an attempt again. (P. 431.) 

On July 14, 1809, the first ascent of Mont Blanc by a woman, 
Marie Paradis, a maid-servant at Chamounix. She was so ex- 
hausted at about the elevation of 4600 meters, that the guides who 
accompanied her were forced to hold her up and carry her to the 
crest. 

From 1809 to 1816, only one ascent (Rodaz, 1812) about which 
we have no information. 

A German officer, Count de Lusy, left Chamounix September 14, 
1816, to ascend Mont Blanc; he had eight guides with him. From 



Mountain Journeys 89 

the German pamphlet of Hamel, from which I shall quote presently, 
since I was unable to secure the account of Lusy, 119 I borrow the 
references to the serious symptoms which attacked them: 

Near the summit, some of the travellers felt nausea and a strong 
desire to sleep; three bled from the nose and one from the mouth; 
that did not stop Count Lusy. (P. 36.) 

August 4, 1818, Count Malazesky, a Pole, 120 then van Rensselaer 
of New York on July 11, 1819, also undertook this difficult enter- 
prise. The report of the latter, although quite detailed, 121 contains 
no suggestion of any interesting physiological fact; his companions 
and he experienced only a great acceleration of respiration and 
pulse accompanied by loss of appetite. 

Then, in 1820, Dr. Hamel, 122 court counselor of His Majesty the 
Emperor of all the Russias, made the ascent in the company of 
Colonel Anderson. His trip was interrupted near the summit by a 
terrible catastrophe, which took the lives of three guides, dragged 
down in an avalanche. 

He first made on August 3 an unsuccessful attempt: 

We started from Saint-Gervais and passed the night at Pierre- 
Ronde, sheltered by a few rocks. 

The next day at 11:30 we reached the summit of the Dome du 
Goute .... 

It was on this two hour march that for the first time I expe- 
rienced the effect of the rarified air upon my strength. It was abso- 
lutely impossible for me to take more than forty steps without stopping 
about two minutes to get my breath; and when I reached the summit 
of the Dome (2,200 fathoms), I felt so exhausted that I should have 
needed at least a half-hour's rest if I were to be able to go on to the 
crest of Mont Blanc. After I had made my calculations, I found that 
it would be absolutely impossible to go to the summit and come back 
down the needles of the Goute before night; I therefore decided to 
retrace my steps. (P. 306.) 

August 16, he once more began the ascent, this time starting 
from Chamounix. The travellers, accompanied by twelve guides, 
passed the night at the Grands-Mulets. In spite of his guides, who 
were alarmed by the poor condition of the newly' fallen snow, 
Hamel wished to go on the next day; at half -past eight in the 
morning, they were on the last large plateau: 

No one was ill. And yet for some time we had been feeling the 
effect of the rarity of the air; my pulse rate was 128 per minute, 
and I was thirsty all the time. Our guides suggested that we should 
lunch .here, for higher up, they said, no one has any appetite .... 
Each of us ate his half-chicken with pleasure. 123 .... 

We had reached the elevation of 2,300 fathoms .... No one was 



90 Historical 

talking, for at this height even talking fatigues one, and the air 
transmits the sound feebly. I was still the last, and I was taking about 
twelve consecutive steps; then, leaning on my alpenstock, I stopped 
to take fifteen inspirations. I found that in this way I could advance 
without becoming exhausted. Wearing green glasses and with a 
crape veil over my face, my eyes were fixed on my steps, which I 
was counting, when suddenly I felt the snow give way under my 
feet .... 

The whole sheet of snow slid from under the travellers, and 
three of the guides disappeared forever in an immense crevasse. 

After this fatal experience, no one had ventured upon this 
undertaking "dangerous as well as useless", when F. Clissold tried 
again successfully, on August 18, 1822. In his first rather brief 
account, 124 he limits himself to saying that all the guides, except 
one, were "more or less affected by the rarity of the air". 

The detailed account which he published later 125 is much more 
explicit; it even contains very unusual theoretical ideas which we 
shall report in the proper place. 

It is strange to have to state that this stranger who was making 
his first trip to the Alps endured the decreased pressure better 
than the guides, almost all of whom had already ascended to the 
summit of Mont Blanc: 

We were not far from the Grands Mulets (he says) when the man 
who was fastened to my rope untied himself, being absolutely 
exhausted. I then had myself tied between two others; shortly after- 
wards, a second one stayed behind, and finally all, except Favret 
(one of the six guides) and myself, had to stop from weariness and 
a difficulty in breathing which they attributed to the rarity of the air; 
a little rest soon revived them. At two o'clock, we reached the 
Grand Plateau. Marie Coutet, who could hardly breathe (he had 
already ascended Mont Blanc five times) was surprised at my fine 
condition. (P. 146.) 

They slept in a little excavation of the Rocher Rouge (4490 
meters) and suffered greatly from the cold. The next day, at 
dawn, they set out for the summit: 

Favret and I were the only ones who were comfortable, especially 
in breathing. As for the others, some were stretched out flat on the 
snow, others paused standing up, bent forward with their heads 
hanging, finding it easier to breathe in this position. For my part, I 
have felt much more fatigue in other trips and on much less lofty 
mountains than I felt in ascending Mont Blanc; it is true that I was 
walking more quickly then. My pulse rate did rise from 100 to 150 
per minute, but my circulation always quickens to this degree when 
I climb a steep grade, so that all in all I experienced nothing particular 
or new to me. (P. 149.) 



Mountain Journeys 91 

The account of the trip of Dr. Clark and Captain Sherwill 1J " 
contains very interesting details. They ascended Mont Blanc 
August 25, 1825; leaving Chamounix at seven o'clock in the morn- 
ing, they reached the summit the next day at five minutes past 
three: 

When they reached the Grand-Plateau, M. Clark was exhausted, 
Captain Sherwill was greatly nauseated and oppressed .... Simon, 
one of the guides, complained of headache .... 

On the summit of Mont Blanc, M. Clark found breathing difficult, 
even when he refrained entirely from moving. He felt in his chest a 
sensation like that which precedes hemoptysia, a disease to which he 
was quite subject in his youth. However he did not spit blood on the 
summit of Mont Blanc. One of the guides who had accidentally 
received a blow on the nose lost a little blood, which seemed darker 
in color than usual. Both M. Clark and Captain Sherwill suffered 
from violent headache; their faces were pale and drawn. The captain 
spoke of a singular sensation which he had felt near the summit: 
it seemed to him as if his body had an extraordinary elasticity and 
lightness, as if his feet hardly touched the ground. The guides were, 
in general, very tired and complained of headache. 

In 1827, July 24, another ascent by Hawes and Fellowes, 1 - 7 
accompanied by ten guides. The night was passed at the Grands- 
Mulets (—5°). 

During the ascent of the Dome du Goute, they began to feel the 
effects of the great elevation, the headache increased as they 
advanced; the veins swelled, the pulse was strong and rapid .... 

At a thousand feet from the summit, the travellers had nose-bleed, 
and nearly every one spat blood; these symptoms were extraordinarily 
severe in M. Felowes, who was very delicate; but M. Hawes, short, 
sturdy, and robust, resisted better. Their breathing was strangely 
affected; they could not take more than six or eight steps without 
stopping. Two guides, completely worn out, were sick and vomited 
much blood. Moreover, every one had the skin of his face cracked 
and lost blood within. The cold was intense .... 

By resting, though for only a short time, the travellers reached 
the crest of Mont Blanc at 2:20. (P. 267.) 

The same year, a Scotch traveller, Auldjo, made the same 
ascent on August 9. Not having been able to get the original 
account which he published, I am borrowing a summary of it 
from the work of M. Lepileur, whom I shall mention again soon: 

M. Auldjo says that he did not begin to feel the effects of the 
rarefaction of the air until he had reached an elevation of about 
4,200 meters; he was then attacked by oppression and difficulty in 
breathing. His pulse became frequent; he felt thirst and a fullness 
of the veins of his head, but no headache when he was quiet. Most 
of his guides suffered in the same way and to the same degree. As 



92 Historical 

he mounted, he was more exhausted, the oppression increased, a 
violent headache appeared, as did strong 'palpitations, general lassi- 
tude, and a pain in the knee and the muscles of the thigh, which 
made movement of the legs difficult. About the elevation of 4,570 
meters, he had a strong desire to sleep, and was completely exhausted, 
down-hearted, and discouraged; his guides had to force him to leave 
the rocks of the Petits-Mulets. The rest of the ascent was extremely 
painful for him; they had to hoist him by a rope along the last grade. 
As soon as he had begun to feel ill effects, neither he nor his guides, 
took more than fifteen or twenty consecutive steps. While climbing 
the last hundred meters, the most robust and daring guide, he says, 
was exhausted after three or four steps, and forced to stop to get his 
breath. He suffered much from the cold on the side where the sun did 
not strike. Finally, after climbing the last twenty meters with a little 
less discomfort, he reached the crest, where he fell deeply asleep 
immediately. He was awakened after a quarter of an hour; he was 
better, the headache and the pain in the legs had stopped, but he was 
shivering and thirsty;., his pulse was frequent, his breathing difficult, 
although the oppression had lessened. He could not eat; the sight 
and the smell of food nauseated him .... (P. 20.) 

Mountain excursions became numerous; it was not only Mont 
Blanc that the travellers, who had become "tourists", aimed at. 

A German Swiss, Meyer, 128 who published the account of his 
excursions in 1812, gave his attention to physiological symptoms; 
he found that they had been greatly exaggerated: 

All that De Saussure reports on the effects of the atmosphere in 
lofty elevations upon the animal organism has no general foundation; 
there are still a great many things which are hypothetical. For 
instance, at an absolute elevation of 10,000 to 12,000 feet and more 
above sea level, not one of us was drowsy or in a feverish state, or 
vomited or fainted, symptoms about which some travellers who 
reached very lofty summits have said a great deal .... 

Who could deny that when one is climbing, the pulse rate becomes 
almost immediately twice as frequent as it was before? If one walks 
then at a slow pace long enough to recover, the pulse will quickly 
return to the same rate as on the plain or in the valleys .... I had 
the opportunity to note that the fainting of one of our guides near the 
summit of the Jungfrau had been brought on largely by the great 
efforts he made in ascending, and partly also by the fear inspired in 
him by the danger he was running. None of us felt anything of the 
sort when we were descending. (P. 30.) 

Let us note the fainting of the guide, whatever the expla- 
nation given may be. Let us add that at lower elevations than those 
reached by Meyer, Dr. Parrot, a celebrated mountaineer, expe- 
rienced a strange symptom which he attributes, it is true, to the 
heat, but in which the decrease of pressure seems to me to play 



Mountain Journeys 93 

an important part. He reports in the following words this symp- 
tom which happened to him September 18: r2Q 

I had been for two hours on the western edge of the glacier of 
Lesa, at the height of 3436 meters; the heat was such that my eyes 
began to grow red, and I felt a frontal headache with such drowsiness 
and fatigue that I had great trouble in observing my barometer suit- 
ably; I found no relief for this condition except in lying down on the 
ground. (P. 386.) 

The first ascent of Monte Rosa took place August 5, 1819; it 
was made by two men who lived in the neighborhood, Vincent, 
superintendent of the mines of Indren, and Delapierre, inspector 
of forests, better known by the German translation of his name, 
Zumstein. 

In the first journey, no physiological disturbance was men- 
tioned. But the second, which is reported with details in the 
Memoires de l'Academie de Turin (vol. XXV, p. 230-252; 1820), 
furnishes some interesting references. At first, in the night which 
the mountaineers passed at the foot of the last ridges in the hut of 
the Mineurs, which was occupied two months, "the highest in 
Europe" (1681 fathoms), Zumstein "felt a certain oppression in 
his chest which prevented him from closing his eyes all night. 
"Perhaps," he added prudently, "this excitement was caused only 
by the keen impatience for the morrow" (P. 237). When they 
were near the summit, as the daring travellers were crossing a 
dangerous ridge on steps cut in the ice, "the man who was second 
in line grew pale and tottering leaned towards the slope at the 
left (P. 241)"; rubbing him with snow restored him. On the sum- 
mit, after a certain time for rest, the pulse rate of Vincent was 80, 
that of Zumstein 101, that of one of the guides 104, and that of the 
sportsman who was sick 77, which naturally surprised Zumstein. 

At last they reached the top of the Vincent pyramid (4210 
meters) : 

They had little appetite, but a burning thirst. Vincent had already 
felt discomfort while he was ascending, and Zumstein, as he stooped 
to pick up some silvery butterflies which were lying half dead on the 
snow, had an attack of dizziness, which fortunately soon disappeared. 
(Anal, de Briquet, p. 16.) 

On July 31, 1820, they repeated their ascent, in the company 
of the engineer Molinatti, and passed the night almost at the very 
summit of the mountain, at an elevation of 13,128 feet: 

In the middle of the night, Zumstein was awakened by palpi- 
tations which choked him; he got up to seek recovery and was soon 
better. 



94 Historical 

The next morning, they continued to climb: 

M. Molinatti, exhausted by the rarity of the air, was forced to stop 
constantly, whereas MM. Vincent seemed to have wings, eager as they 
were to reach the summit first; Zumstein, about fifty steps behind, 
followed them panting, but soon overtook them. 

Thus they reached the summit of Zumstein's Point (4560 
meters) , and descended without trouble. 

The other ascents of Zumstein, in 1821 and 1822, had no inci- 
dents which would interest us. 130 

We note, therefore, in this ascent, evident physiological disturb- 
ances, although less than those which the travellers to Mont Blanc 
had reported. 

Much less still are those observed by Hugi, 131 who goes so far 
as to deny even the acceleration of the pulse rate on lofty places, 
which seems rather strange. 

The greatest elevation reached by this traveller and his com- 
panions was the Finsteraarhorn (4275 meters) : 

At these elevations I never failed (he says) to observe the pulse 
rate, the respiratory rate, and the temperature of the body. The results 
were constant; that is, in these respects heights and planes show the 
same results, when neither effort, nor fatigue, nor fear are involved. 
I am omitting the table of observations. Wahren alone, who is noted 
for his vigor all through the Oberland, felt a little nausea on the point 
of the Finsteraarhorn. While he was working at the Pyramid, he 
twice lost power of vision, so that he was forced to sit down. (P. 218.) 

On the opposite side, Hipp. Cloquet KJ - states that the symptoms 
of decompression are often felt, even at the low elevation of the 
Grand Saint-Bernard: 

The rarefaction of the air .... causes in the organs of respiration 
an alteration strange enough to be mentioned. Persons with a strong 
constitution and with lungs in perfect condition experience a certain 
pleasure in breathing an air as cool as it is pure and light; on the 
contrary, those who lack these advantages, and especially those who 
are asthmatic, experience a marked distress and an extreme difficulty 
in breathing, when they visit the monastery and its surroundings. 
At the Saint-Bernard travellers have been seen to be asphyxiated, so 
to speak, for want of air, and to fall in a faint, without any other 
known cause, and this happens often to weak and delicate persons. 
At the beginning of the syncope, the pulse rate is very high; but the 
greater the strength of the lungs, the less is this acceleration in the 
pulse rate. 

It is also to the rarity of the air that we should perhaps attribute 
a strange phenomenon presented by the observation of wounds in this 
place. Their cicatrization requires double or even triple the time it 



Mountain Journeys 95 

would take on the plain for its entire completion .... The same thing 
has been observed on all high mountains. (P. 33.) 

The accounts of travellers on Mont Blanc are always most 
characteristic in reference to mountain sickness. After Auldjo, 
an interval of seven years had elapsed, during which only one 
ascent (Wilbraham, August 3, 1830) had taken place. But Sep- 
tember 17, 1834, Dr. Martin Barry 133 made a scientific ascent the 
account of which is very interesting. 

He mentioned physiological disturbances only above the Grand 
Plateau: 

We had then reached an elevation at which I was to verify the 
statements of previous travellers about the exhaustion brought on by 
the slightest effort in a much rarefied atmosphere. I did not expe- 
rence such discomforts before reaching this point, and I did not see 
any in my guides. I could take only a small number of steps at a time, 
and those were short and slow. Two or three deep inspirations were 
enough at each step to revive me; but when I started again, the 
exhaustion returned as before. I felt an indifference which was not 
overcome by the sight of the summit so close at hand. I even had a 
slight fainting fit, and was forced to sit down for a few minutes; but 
a little wine revived me .... 

After a few minutes rest at the summit, the weakness, exhaustion 
and indifference disappeared .... (P. 112.) 

The account of the ascent of Count de Tilly, which took place a 
fortnight after that of Barry, contains so many mistakes and con- 
fusions that we cannot give our time to it. But the following 
year, an Englishman, Atkins, 134 reached the summit with two com- 
panions, Hedringen and Pedwel, without counting the guides, and 
observed interesting data. 

His ascent took place August 23, 1837. He begins by making 
excuses as if for a foolish action. The first symptoms are not re- 
ported by him until on the Grand-Plateau: 

I was forced (he says) to stop every ten steps to get my breath 
and rest my legs. I suffered from thirst and from deathly languor. 
From time to time I swallowed a mouthful of vinegar, to moderate the 
thirst which devoured my entrails, and I often had nosebleed. 

Coutet was not free from distress and Jolliquet could not hold 
his head straight. Some of those who were ahead dragged themselves 
this way and that, others raised themselves, then fell down again. At 
the foot of the wall of La Cote lay a man stretched out at full length 
and motionless. I cannot say whether this was one of the guides, but 
he finally rejoined us ... . 

At last, after a terrible ascent, after having been forced to stop 
every two minutes to breathe, we reached the summit .... It was 7° 
below zero (P. 36.) .... 



96 Historical 

The little dog which accompanied us had to struggle against sleep 
as soon as we had passed the Grand-Plateau, and every time we 
stopped, it tried to lie down at our feet, finding the snow cold. It 
showed more than one sign of surprise, often casting wild eyes around 
it. Sometimes it made an effort to run very fast, and sometimes fell 
down exhausted. As for its appetite, the chicken bones we gave it 
disappeared with astonishing speed, but it did not appear to suffer 
from thirst .... 

Hedringer, wishing to have the glory of being the first to set foot 
on the crest, began to run, but he had hardly taken a few steps, when 
from exhaustion he stretched himself out stiffly on the snow for two 
or three minutes, enduring cruel pains. He felt the consequences of 
his mistaken ardor as long as we remained on the summit (P. 56) ... 

Our breathing became more and more free as we descended, and 
we felt so light that we hardly seemed to touch the ground (P. 59). 

After that time, the ascents of Mont Blanc became more numer- 
ous. From that of Atkins to the celebrated expedition of Bravais, 
Lepileur and Martins, in 1844, there were 17; but I can hardly call 
any of them interesting except that of Mile. d'Angeville (Septem- 
ber 4, 1838), who had to be almost carried to the summit. 

Dr. Rey 1& ~ in the following words reports the symptoms felt 
by this daring woman: 

I learned from Mile. Dangeville that in her usual condition her 
pulse beats 58 to 60 times per minute, very soft and very regular. 
When she left Chamounix for the ascent, it was already 64 and 
increasing, emotion was beginning: at the Grands-Mulets, it was 70 
and irregular, although she felt better, mentally and physically. On 
the grade which is above the Grand-Plateau, where she began to feel 
a little tired and sleepy, she counted 136 beats at unequal intervals, 
that is, much more than double the number in her ordinary condition. 
When she had reached a place called the Mur de la Cote, near the last 
crest, she felt a sort of agony, caused by an excessive need for sleep, 
and she cannot tell how high this extraordinary acceleration rose 
during her severe attack, but five minutes after she reached the 
summit, the pulse of the noble and intrepid French woman had already 
dropped to 108 (p. 341). 

Now let us consider the other mountains. 

The celebrated naturalist Desor, 130 in the report of numerous 
excursions with a prolonged stay in lofty places which he made in 
the company of the illustrious Agassiz, is surprised at feeling 
and observing no physiological disturbance; he is especially struck 
by it at the time of his ascent of the Jungfrau (4170 meters) in 
1841: 

I must confess that while we were on the summit, and also during 
the ascent, we experienced none of those symptoms, such as nausea, 
nosebleed, buzzing in the ears, acceleration of the pulse, and many 



Mountain Journeys 97 

other discomforts, to which most of those who have made the ascent 
of Mont Blanc say that they were prey. Should we attribute it to the 
difference of 500 meters between the height of Mont Blanc and that 
of the Jungfrau? Or should we seek the cause of it in the habit we 
had formed during several weeks of living at an elevation of more 
than 2,590 meters? But we should note that M. Duchatelier, who had 
been in the mountains only a few days, was not ill either. Without 
claiming to decide this question, which belongs more particularly to 
the realm of physiology, I am, however, inclined to think that there is 
a little exaggeration in all that has been told us on this subject. Per- 
haps also a few travellers have been deceived by their imaginations, 
like the students of medicine who every day think themselves attacked 
by the disease the symptoms of which the professor has just set forth 
to them. Some German physiologists, if I am not mistaken, even claim 
to have observed the most extraordinary symptoms on mountains only 
' a few thousand feet high. (P. 409). 

He refers again 137 to this immunity in reference to his ascent 
of the Schreckhorn, or rather the Lauteraarhorn (4030 meters), 
August 8, 1842: 

I should note that no one of us experienced the least discomfort 
either on the summit, or on the ascent, or on the descent, so that in 
this respect I can fully confirm what I said elsewhere about the so- 
called ill effects of lofty regions. 

And yet to this absolute conclusion we can oppose the follow- 
ing fact from Desor's 138 own accounts: 

We had been travelling thus for a quarter of an hour when 
suddenly our friend Nicolet shouted to us that he could do no more. 
He experienced that complete fatigue by which one is attacked some- 
times in the lofty Alps, but which passes very quickly if one rests a 
moment .... "I feel sure," he said, "that I shall never reach Zermatt 
alive" .... (P. 342.) 

The travellers were only at the foot of Mont Cervin. 
Gottlieb Studer 139 ascended the Jungfrau August 13, 1842; he 
felt no discomfort either and gives a strange reason for it: 

We perceived none of the symptoms which at such great heights 
travellers have often attributed to the rarefaction of the air; yet we 
must note that in such a long ascent, for three long hours, the chest 
can rest .... (P. 313). 

On the opposite extreme, another tourist, Spitaler, 140 who with 
several companions made unimportant ascents, certainly exag- 
gerated the sufferings experienced. So, in regard to the "Venetian" 
on Pinzgau, a mountain of 3675 meters, he makes the following 
lamentable picture: 



98 Historical 

We needed to breathe more frequently and all our muscles acted 
painfully; the heart beats and the pulse doubled or even tripled; the 
pulse was soft and weak, difficulty in breathing amounted to anguish, 
and stopped one of us a few hundred steps from the summit; another, 
returning, had a slight pulmonary hemorrhage; the secretion Of the 
kidneys was strangely lessened .... no one was troubled by perspi- 
ration, but thirst was very great. The temperature was -f- 2° to +6° 
R . . . — On the plain we should not have been cold, but at an elevation 
of 9,000 feet a painful sensation of cold seized us; our skin was flabby, 
our faces aged; the strength of the muscles was greatly lessened, and 
out of forty, only twenty-six reached the summit. 

The evidence of the celebrated English physicist, Principal 
Forbes, is much more valuable and much more exact. Forbes 141 
speaks of the symptoms of mountain sickness in reference to his 
expedition to the col du Geant (3360 meters), April 23, 1842, on 
which he noted that one of his guides was slightly affected: 

We were about a thousand feet from the summit, when Couttet felt 
his respiration a little affected, but not severely. That is a very 
common symptom, which depends greatly on the state of the health. 
I hardly felt it from here to the summit. But in 1841, I was definitely 
affected at a lower level, when ascending the Jungfrau. The guides 
say that these variations depend upon the state of the air; and David 
Couttet assured me that on different days, he and his father had at 
the same time felt difficulty in breathing at a very moderate height. 
(P. 224). 

After all these travellers, naturalists or mere tourists, who 
spoke only incidentally of physiological symptoms, we come to a 
scientific expedition which has justly remained famous, the first 
on Mont Blanc since De Saussure, one of the members of which, 
Dr. Lepileur, was especially charged to observe himself and his 
companions from the physiological point of view. And so the 
report 1 4 - which he makes of this ascent deserves to be analyzed 
here at considerable length. 

But before beginning the report itself, M. Lepileur, who was a 
frequenter of mountains, says that in his excursions previous to 
the ascent of Mont Blanc, he experienced or observed a certain 
number of interesting phenomena, particularly because of the 
moderate heights at. which they appeared: 

While I was going from Martigny to the Grand Saint-Bernard, in 
September 1832, I saw my brother and two of my friends display most 
of the symptoms of mountain sickness; one of them, a young man 
twenty-six years old, was seized by general discomfort, fatigue, 
breathlessness, and palpitations, one hour before reaching the monas- 
tery, and soon he could not walk without being supported and without 
making frequent halts at equal intervals. When he reached the 



Mountain Journeys 99 

monastery, he went to bed, without being able to take anything but 
a little tea; he suffered all night from a discomfort which he compared 
to that of fever; the next morning he still felt oppression, and has- 
tened to descend to Martigny. Of the two others, one was thirty years 
old, and my brother seventeen: they had very little discomfort during 
the last half -hour of the ascent; but although they were not very 
tired when they arrived, they had not the slightest appetite, and even 
the sight and the smell of food disgusted them. During the night they 
recovered completely; on the next day, they were able to ascend to 
one of the crests to the south of the monastery, and to go back down 
to Martigny on foot. The fatigue of this day's efforts also took away 
their appetite that evening, as it did that of another of our companions, 
who had felt no effects at the Saint-Bernard; but then it was only 
fatigue, there was no trace of the discomfort which they had felt the 
night before. 

In the month of June, 1835, while I was climbing the slope of 
snow which extends below Chateau Pictet on Buet, at a height of 
about 3,000 meters, I felt my strength fail, it was very hard for me to 
go on. One of my friends who accompanied me had already been 
suffering for nearly a half-hour from fatigue in the legs and knees. 
He made frequent halts. As for me, I could not take more than 160 
consecutive steps. 

A little chocolate which I ate restored me almost completely; 
however I was still obliged to stop from time to time, although I was 
much less exhausted. From Chateau Pictet to the crest of Buet the 
slope is very gentle, and I felt no lassitude while mounting it. 

In the month of July of the same year, I was climbing with a 
guide on the point of rock which towers above the Saint-Theodule 
pass on the north; about sixty meters below the crest, I perceived 
that the guide stopped frequently; soon it was impossible for him' to 
take more than eight to ten steps without stopping for breath. He 
was a robust man and in the prime of life, so that I could not believe 
that the weight of my sack which he was carrying was enough to 
weary him to this extent; seeing him pant, turn pale, and nearly fall 
in a faint, I told him to take a little rest; he would not admit his 
distress at first, but finally was compelled to sit down, a cold sweat 
ran down his face, he was exhausted. I had him eat a little bread 
and chocolate, which, with a ten minute rest, quite restored him. The 
elevation at which we were was hardly one hundred and fifty meters 
above the Saint-Theodule pass, that is, 3,560 meters, but I had noted 
when we left Zermatt about midnight that the guide was drunk,^ and 
that is what had made him so susceptible to the rarefaction of the 
air. 

Two days after, while climbing the Breithorn, at the east-south- 
east of the Saint-Theodule pass, one of my guides found it impos- 
sible to climb higher than the last plateau (about 3,900 meters) ; this 
man was sixty years old and was afflicted by a double inguinal 
hernia. Another guide of the same age panted greatly while climbing 
the terminal cone of the Breithorn (4,100 meters), the grade of which 
is very steep. The other two guides, men of thirty to thirty-five years, 
felt no more distress than I. The next year, making the same excur- 



100 Historical 

sion with one of my friends, I was suddenly seized by unconquerable 
sleepiness as I was crossing the vast plateau south of the Breithorn, 
where a guide had had to stop the year before. I was sleeping as I 
walked, no matter what efforts I made to stay awake; one of the two 
guides had the same experience, the other and my travelling com- 
panion felt nothing of the sort. As we returned to the Saint-Theodule 
pass (3,410 meters), after a light meal taken with good appetite, we 
all slept in the sunshine for about an hour. When he awoke, my 
travelling companion was nauseated and vomited what he had eaten 
an hour before. I must note that the second night before, we had 
slept little and badly, and that after a walk of eight hours, we had 
had only three quarters of an hour of sleep on the night before our 
excursion. Several times, in Paris, I have found myself thus over- 
powered by sleep so that I slept and even dreamed while I was 
walking. Moreover, none of us felt any other discomfort during this 
excursion. 

In July, 1844, while climbing the slope of the Couvercle, at an 
elevation of about 2,500 meters, I felt a distress and a difficulty in 
climbing like that I had experienced in 1835 on Buet. This condition 
lasted about twenty minutes. I was not forced to stop, but I suffered, 
and my strength seemed much lessened; at last, without any percep- 
tible cause, for I continued to ascend, the discomfort suddenly ceased, 
I could climb without trouble the height of about 150 meters, which 
separated the point where I was from the Jardin. When I reached the 
Jardin, I ate with considerable satisfaction; but I was soon satisfied. Dr. 
Noel de Mussy, one of my companions on this walk, who was in the 
mountains for the first time, was only a little out of breath; at the 
Jardin, he ate with a good appetite. And yet, in the evening, while we 
were returning, he was much more tired than I. Another traveller 
who accompanied us felt no distress. 

Finally, in the month of September, M. Camille Bravais, who 
ascended with me to the rock of the Echelle, when we had reached 
an elevation of about 2,300 meters, had to stop every twenty steps 
to get his breath. It is true that M. C. Bravais, affected no doubt by a 
slight hypertrophy of the heart, was never able to climb a steep 
grade without experiencing severe palpitations. (P. 33 et seq. of 
the separate printing.) 

Now let us turn to the ascents of Mont Blanc. In the first 
attempt with MM. Bravais and Martins, July 30, 1844, they exper- 
ienced some effects on the Grand-Plateau (3911 meters), where 
they set up their tents for the night, and beyond which they could 
not go: distaste for food, diarrhea, prostration. M. Lepileur was 
seized by violent shivering, recurring eight or ten times an hour; 
M. Martins had a similar attack. They had helped their guides in 
setting up their tent, and had become much fatigued. 

August 7, all three set out again, and camped at the Grand- 
Plateau: the shivering attacked M. Lepileur there again; M. 
Martins was quite ill, Bravais felt nothing but an irresistible desire 



Mountain Journeys 101 

to sleep at the Grandes-Montt-es (3800 meters). The face of one 
of the guides was cyanosed, which M. Lepileur attributes to the 
cold. On the descent, M. Martins had a slight hematuria. 

August 28, third journey; departure from Chamounix at mid- 
night: 

The ascent went very well up to about 3,100 meters. There, 
Tournier felt ill, lost courage entirely and was forced to descend. 
He was pale, his face was bathed with sweat, and he could hardly 
climb even a few steps, although his burden had been taken from him 
and although we were on a rather gentle slope. He attributed this 
failure of his strength to the fact that the day before, not expecting 
to make the ascent, he had worn himself out at a painful task. His 
distress ceased as soon as he was two or three hundred meters lower. 

At 3,600 meters, I felt no ill effects as long as I walked slowly; 
but when I wanted to ascend quickly, as for example, to rejoin my 
travelling companions, after having paused a moment, I felt discom- 
fort. M. Bravais suffered much from cold feet for several hours. 
Several times he had been obliged to stop, and we had reestablished 
circulation in him by slapping the dorsal side of his toes with our 
hands .... 

At the Petit-Plateau, I ate, at first with repugnance, then with 
pleasure, when a little food had stimulated the stomach. We all 
took a little wine; that was always what helped us most .... 

M. Bravais again, this time like the two others, became very sleepy 
about the elevation of the Petit-Plateau (3,800 meters). 

When we reached the Grand-Plateau, he was a little tired and 
so was I. M. Martins was not. Cachat and Ambroise Couttet were 
exhausted. As soon as they had halted, they lay down on the snow 
in the sunshine, and remained there for three or four hours, without 
being able to help us at all. Ambroise Couttet felt nausea besides 
all afternoon. As soon as he tried to stand up, he was threatened 
with syncope. The others helped us set up the observation instruments 
and clear our tent which the snow had three quarters buried on the 
north-east side. This labor did not tire us at all, and we were no 
more out of breath than the first time at Chamounix, when we had 
set up the tent ourselves for practice and to show the guides how it 
ought to be done. 

None of us had as much appetite as in the valley. M. Bravais had 
very little; M. Martins and I had none at all. However, I felt no 
distaste for the fresh food which we had brought. Three hours after 
our arrival, when I took off my crape mask which hindered me in 
making my observations, I felt , the beginning of a headache which 
stopped as soon as I put my mask back on. When I gave careful 
attention to the observation of some instrument, when, for example, 
I read a thermometer placed on the snow, and in general whenever 
I was in a position in which respiration was hampered, I felt a slight 
sensation of nausea which lasted hardly one or two seconds; the 
instant before and the instant after, I had no discomfort at all. MM. 
Martins and Bravais noticed the same effect in themselves. With that 



102 Historical 

exception, we were very well, gay, and full of confidence. We noted 
this slight discomfort only to be rigorously exact. 

A. Simon almost fainted while I was feeling his pulse. He was 
standing, and just had time to lie down on the snow to avoid a 
complete loss of consciousness. After our arrival, he had been busy 
clearing the tent and setting out our camping equipment without 
feeling any discomfort; however, this time he was not quite as well 
as the others. After some time he recovered and even ate with 
appetite. In the evening, everyone was well; our two invalids had 
recovered from their fatigue; I slept at night, although very uncom- 
fortable because I could not stretch out my legs. I also felt some 
rheumatic pains in my right knee, toward the inner edge of the knee- 
cap, and a little neuralgia on the outer side of the left thigh. M. 
Bravais made observations until midnight. August 29, at four o'clock 
in the morning, I made the first observation. I was rested and felt 
quite strong, but I had no appetite; the only food I cared to eat was a 
few raisins; the provisions, which had been thoroughly frozen for a 
month, and especially the meat, filled me with disgust. About six 
o'clock, M. Bravais and I took a little bread and wine. The first hours 
of the morning were passed in making observations and a few experi- 
ments, during which we were standing, coming and going on the soft 
snow. At ten minutes past ten, we started for the summit. 

The crossing of the Grand-Plateau was painful because of the 
snow into which we sank up to the calf. I did not feel as strong as 
in the morning, but I felt no distress. I perspired abundantly while 
crossing the Grand-Plateau and during the first half-hour of the 
ascent. Our hands and feet were very cold, those of M. Bravais 
particularly. M. Martins lost his breath a little more and a little 
more quickly than we did. Up to the foot of the upper Rochers 
Rouges, about 4,400 meters, I had no discomfort of any sort; we took 
350 or 400 steps consecutively without stopping for breath; but when 
we reached this number, we felt the need of resting for a few 
moments. The grade which we were climbing, measured with a 
geologist's compass, was, at the elevation of 4,300 meters, 42°, and 
the slope of our course was 16°. 

About 4,400 meters, I began to feel after ten or twelve steps a 
little fatigue with pain like that of lumbago in the legs and knees. I 
counted my steps again, we were still taking one hundred between 
halts; but the last twenty were very painful to me. This pain in the 
legs stopped as soon as I halted, and the first steps I took after that 
were very easy. I began to be very anxious that the grade should 
become easier. A quarter of an hour before we reached the top of 
the upper Rochers Rouges it did become less steep. About this height 
(4,500 meters) I perspired a little, but it lasted only a few moments. 
After a short pause, we continued the ascent; a little before the top 
of the upper Rochers Rouges, I had begun to feel an undefinable 
discomfort when I was walking; I had neither headache nor palpi- 
tations, once or twice I felt a few throbs in the carotids, no doubt 
because I had made a few steps more quickly than the others. I was 
not nauseated either, but I felt a general discomfort, a sort of exhaus- 
tion. I was weak and it seemed to me that I had just enough strength 



Mountain Journeys 103 

to carry out the motions of locomotion for a certain time and then 
it would be all over; in a word, I was like a man who, at the end of 
a long day of walking, perfectly exhausted, feels that he can reach a 
point not very far away, but that he must give up going any further. 
I could walk only with my head lowered and my chin nearly touching 
the sternum. This was the attitude of us all, and when we were 
getting our breath, it was also with the neck stretched out and the 
body leaning forward during the first seconds. Clissold had observed 
the same thing. I felt a slight desire to sleep several times and yawned 
occasionally. What added greatly to the discomfort was a rather keen 
thirst or rather a dryness and a sticky condition of the mouth; a little 
snow melted on the tongue while I chewed a raisin quenched the 
thirst for a few moments. This uncomfortable condition developed 
gradually, and it was quite endurable when at about 4,560 meters a 
violent wind from the northwest struck us. At once we felt as if our 
hands, our faces, and the part of our heads which the head covering 
did not protect were freezing. The side of the body which the wind 
blew upon was also very cold, especially in MM. Bravais and Martins, 
whose clothing was rather thin. As we were climbing in a zigzag, 
when we had the wind in our faces during a squall, I experienced 
then in the highest degree the sensation which I described in connec- 
tion with our first ascent to the Grand-Plateau. It was in vain that 
I covered my nose and my mouth with my hand, stooped, turned aside 
my head; I could not breathe any more than if I had been under 
water. I felt the distress of asphyxia, my head whirled, and I felt 
slightly nauseated. When I turned my back to the squall, it seemed 
as if the wind made a vacuum around me, and I had difficulty in 
breathing. I was the only one to feel this effect of the wind, both on 
the first and on the third trip. This increase of discomfort lasted without 
stopping for a quarter of an hour or twenty minutes, I asked myself 
whether I could reach the summit, I felt sure that I should succeed; 
but I had to use all the mental strength I possessed to actuate my 
physical powers. Sometimes too I advanced mechanically, without 
thinking, so to speak. No one talked, everyone, like me, had but one 
thought, that of advancing a few steps more. So the distance one tra- 
verses between the Rochers Rouges and the summit, although it took 
us nearly two hours to cover it, did not leave many details in my 
memory, and returns to me as a vague recollection, rather painful 
and very short, no doubt because of its uniformity. The same thing 
was true for MM. Bravais and Martins, for we were all three surprised 
when we had to admit from our notes that it took us nearly two hours 
to go from the Rochers Rouges to the summit. We remembered only 
two or three incidents of this ascent, which, although painful, was 
however made without interruption and without the excessive fatigue 
and exhaustion experienced by some travellers. It is, I think, to the 
blank left in the memory by this part of the ascent to Mont Blanc 
that we should attribute the mistakes and the confusions so frequent 
in the accounts of travellers when they speak of this passage. 

When we halted, after two or three seconds I was in perfect 
condition; I felt no discomfort except a slight thirst and cold feet 
and hands. We did not find, as De Saussure observed in himself, that 



104 Historical 

the distress caused by walking reached its highest point after the 
first eight or ten seconds of the halt. 

During the last quarter hour of the ascent, the slope was gentler 
and the wind blew less violently. These two causes, added to the joy 
I felt when I saw the summit only a short distance away, lessened 
my distress greatly. M. Bravais suffered only from the cold. We had 
already realized that of the three of us it was he who felt the effects 
of the rarified air least. M. Martins was the one who suffered most 
from it. He was very much out of breath, had palpitations, throbbing 
in the carotids, and a little headache; he felt a general fatigue, and 
took fewer steps than we did. When he reached the summit, he 
thought he was still a half hour away from it, and felt keen joy when 
he found he was there. None of us felt pain or fatigue or anything 
extraordinary in the coxofemoral articulation while we were walking; 
in general, we felt no fatigue in the muscles of the thigh. MM. 
Bravais and Martins had a little in the right anterior muscle only. 

Between the Rochei's Rouges (4,500 meters) and the Petits- 
Mulets (4,660 meters), we first took eighty steps without stopping 
for breath, then this number was lessened to seventy, and finally to 
thirty-five or forty steps between the PetTts-Mulets and the summit. 
However, as we came near the highest point, since the grade was very 
moderate, we made one or two stretches longer than the others. At 
about forty meters from the summit, M. Bravais wanted to see how 
many steps he could take climbing as quickly as possible and in the 
direction of the great slope. He had to stop after thirty-two steps; 
he felt, he said, that when he stopped, he could have taken two or 
three more, perhaps four, but that it would have been quite impos- 
sible for him to go beyond that. 

During the ascent, none of the guides or porters seemed affected; 
two of them were a little more fatigued than the others; they were 
Frasserand, who the day before had been rather fatigued when we 
reached the Grand-Plateau, and A. Couttet, who had been ill there 
all afternoon. Our two guides and the porter Simon seemed able to 
take more steps than we were. Several times they stopped only 
because they were asked to. M. Bravais and I reached the summit at 
the same time; M. Martins joined us there a few minutes afterwards . . 

For eight or ten minutes I had keen pain in my feet, caused by 
the change from intense cold to warmth. I was also rather drowsy 
shortly after we arrived and when the pain in my feet had stopped. 
I lay down on the snow where I remained five minutes, but without 
being able to sleep. Then I got up, the desire for sleep disappeared, 
and during the whole time we spent on the summit I felt absolutely 
no painful sensation, except a little cold the last hour. I had no 
appetite, although the idea of eating caused me no disgust. M. 
Bravais was also very well; only from time to time he felt the slight 
nausea which M. Martins and I had observed in ourselves the day 
before on the Grand-Plateau. He had an appetite and ate some 
biscuits and a few prunes. Shortly after our arrival at the summit, 
he and I each drank about a third of a glass of brandy. This liquor 
seemed to us delicious and very mild, to our great surprise; it did us 
much good, and gave us strength without causing the excitation 



Mountain Journeys 105 

usually produced by alcohol. We also drank a little wine, during the 
first two hours of our stay on the summit. A moment after he reached 
the crest, M. Martins was attacked by nausea, and vomited some seeds 
of raisins which he had eaten an hour before. Vomiting relieved him. 
He compared his illness to seasickness. When he lay down, he had 
no trouble, but moving about and standing brought back the nausea. 
An hour afterwards, he was better; after two hours, the sickness was 
completely gone. He drank a little wine, but did not wish to eat. The 
six men we had with us ate hardly anything, but they drank about 
two bottles of wine and half a bottle of brandy. All were in perfect 
health; only two were evidently fatigued, although they would not 
admit it ... . 

We could walk without any difficulty on an almost horizontal 
plane; but as soon as we had to climb, we were affected by panting 
and general lassitude .... 

There was a white coating on the tongues of all of us, but less 
in the guides than in us, and their appetites were not, like ou^s, 
completely or almost completely wanting. (P. 44-54.) 

After a few hours of observations, they descended to the Grand- 
Plateau; M. Martins was attacked by panting, palpitations, and 
throbbing in the carotids, so that he had to sit down. During the 
night, M. Lepileur felt violent sciatic neuralgia on the left side. 
His appetite did not return until the next day when he reached 
the altitude of 3000 meters while returning to Chamounix; during 
the whole day, he had eaten only a small piece of bread dipped 
in a little wine. He sent fresh provisions to Martins and Bravais, 
who had remained on the Grand-Plateau; they received them with 
great pleasure and made a good meal; however, what five of them 
ate would hardly have equalled the ration of one man in the 
valley. 

The urine of all of them was scanty and dark. 

The work of M. Lepileur is finished by a series of tables indi- 
cating the pulse rate of himself, Martins, and three guides from 
Servoz or Chamounix to the summit of Mont Blanc. He summar- 
izes it as follows: 

The increase of the pulse rate is a constant result, when one is 
ascending, beginning with a certain elevation, .... which may vary 
with the individual .... My pulse was less frequent at Chamounix 
(60) than at Paris (67.25) ; . . . . the contrary was true of M. Martins 
.... The ratio of frequency between Chamounix and the summit is: 
for M. Martins 0.82; for me 0.68; for Muguier 0.67; for Couttet 0.60; 
for Simond 0.61. (P. 77-80.) 

M. Martins 143 much later narrated the same journey; his recol- 
lections agree with those of M. Lepileur: 

On the Grand-Plateau the guides began to clear snow off the tent. 



106 Historical 

This work was painful; each of them had hardly removed a few 
shovelfuls when he stopped to breathe; a hidden distress was revealed 
on every face; appetites were gone. Auguste Simon, the tallest, the 
strongest, the most daring of the guides, collapsed upon the snow, 
and almost fainted while Dr. Lepileur was feeling his pulse; it was 
the effect of the rarefaction of the air added to fatigue and insomnia, 
from which all of us suffered more or less. We were then about 4000 
meters above sea level, and there are few men who are not inconven- 
ienced at 3000 meters. I am not surprised that in this ascent we felt 
the effects of the rarefaction of the air, which we had hardly noticed 
in the two previous ascents. Never had we mounted so quickly from 
Chamounix to the Grand-Plateau; starting from 1040 meters above sea 
level, after ten and a half hours of walking we were at an elevation 
of 3930 meters; that is a difference in level of 2890 meters, traversed 
in less than a half day. All discomfort disappeared when we ceased 
moving. (P. 25 of the separate printing.) 

The next day, they finished the ascent: 

The rarefaction of the air ... . compelled us to walk slowly; 
every twenty steps we stopped breathless .... 

We were reaching the goal, but we were walking slowly, our 
heads lowered, our chests heaving, like a procession of invalids. The 
effect of the rarefaction of the air was felt painfully: the column 
paused constantly. Bravais wishes to find out how long he could 
continue climbing as quickly as possible; he stopped at the thirty- 
second step without being able to take one more. At last at a quarter 
of two we reached the long desired summit. (P. 27.) 

The account of the ascent of July 19, 1859, made by MM. 
Chomel 144 and Crozet, has also given us interesting observations; 
they followed a route different from the usual one, from the beaten 
path, we may say, so frequent have journeys to Mont Blanc 
become: 

There comes at last the cap of Mont Blanc, which, in spite of its 
slight elevation above the Mer de Glace, nevertheless requires two 
more tedious hours of ascent. During this last stretch, the lack of air 
makes every movement of the body painful, and one must make 
superhuman efforts to resist palpitations, sleep, and fainting .... 

Only a few feet now separate us from this long-desired summit. 
Our self-respect spurs us on, and rising from the snow on which we 
were stretched, we cover the rest of the way at a run .... 

And here we are on the summit of the giant of the Alps. The 
first impression .... was, alas! a dizziness and contractions of the 
stomach which made us reel. 

The celebrated English physicist Tyndall 145 is one of the most 
ardent mountaineers in the Alps. Every year sees him planting 
his alpenstock on some new summit. And it is not only with a 
scientific purpose that he runs thus the greatest dangers; it is not 



Mountain Journeys 107 

only the great spectacles of nature which attract him and thrill 
him; he too seems gripped by this passion for climbing for the sake 
of climbing, which, though it had its origin in England, is making 
progress today in our own country. But his evidence has all the 
more value for these different reasons. 

August 12, 1857, Tyndall made his first ascent of Mont Blanc, 
in the company of MM. Hirst and Huxley. The latter had to stop 
at the Grands-Mulets. 

When he reached the Derniers Rochers, Tyndall felt exhausted. 
The guide Simond cried at every halt: "Oh, how my knees hurt!" 
I lay down upon a bed composed of granite and snow, and went 
to sleep immediately. 

But my companion soon awakened me: "You frightened me," he 
said, "I have been listening for several minutes, and I have not heard 
you breathe once." 

We got up then, it was half past two .... To the feeling of fatigue 
we had felt till then was added a new phenomenon, palpitations. We 
were constantly subject to them, and sometimes they became so severe 
as to cause some apprehension. I counted the number of steps that I 
could take without stopping and found it to be fifteen or twenty. At 
each halt my heart beat hard enough to be heard as I was leaning on 
my alpenstock, and its subsiding was the signal for a new advance. 
My breath was short, but easy and unhampered. I tried to find out 
whether the articulation of the thigh was relaxed because of the 
decreased pressure, but I could not be sure .... 

After we had passed the Derniers Rochers, we struggled on with 
the stoical indifference of men who are carrying out a duty without 
bothering about the results. At last a ray of hope began to brighten 
our spirits; the summit was visible, Simond showed more energy .... 
at half past three I clasped hands over the summit. (P. 80.) 

The account of the second ascent, made September 12, 1858, 
merely alludes briefly to the fatigues of the mountains, (p. 189.) 

In 1859, an ascent still more important and very profitable for 
science. Tyndall, Frankland, and nine guides passed a night on the 
summit of Mont Blanc; they stayed there about twenty hours: 14 "' 

We did not suffer from the cold, although we had no fire and the 
snow was at a temperature of — 15°C. But we were all ill. I was sick 
when I left Chamounix .... I had frequently conquered my discom- 
fort on previous occasions, and I hoped for the same thing this time. 
But I was absolutely disappointed; my illness was more deeply rooted 
than usual, and it grew worse during the whole ascent. But the next 
morning I was stronger, whereas the opposite was true for several 
of my companions. (P. 54.) 

The same year, a German, Dr. Pitschner, 147 made a remarkable 
ascent of this same mountain; he was very seriously affected: 



108 Historical 

At six o'clock in the morning, we were in the Corridor (3,990 
meters) ; the thermometer marked — 8°C. We had hardly been there 
five minutes when a strong desire to sleep seized us, and conquered 
me completely. My respiration was very painful; my eyes blinked, 
I had buzzings in my ears, headache, nausea; soon I vomited repeat- 
edly; Balmat was as much affected as I, and his desire to sleep was 
so great that he lay down on the snow, and I immediately let myself 
fall beside him. 

"I cannot go any further without sleeping a half-hour", I said to 
Balmat .... I fell into a lethargic sleep, interrupted by smothering 
spells, which finally seemed dangerous to Balmat; and so he began to 
stir me and shake me, without being able to awaken me. Fifteen 
minutes passed. His shouts awoke me, and he said to me: "You cannot 
stay here any longer, you must go on". Perspiration covered my face; 
I rubbed my face with snow, and after a score of deep breaths, I felt 
better .... 

From my sensations on the glacier, it is evident that the effect of 
mountain air was evidenced in me very definitely; it produces dang- 
erous congestions .... 

On our return, at three o'clock in the afternoon, the same 
symptoms appeared in the same place, but with much less intensity: 
headache, nausea, vomiting. 

The expedition of Dr. Piachaud, 14S July 26, 1864, gave results 
just as interesting. The author gave heed to the physiological 
phenomena experienced by his companions and himself, and "attri- 
buted to the rarity of the air": 

The chief symptom (he says) is the oppression, which hardly 
exists when one is resting, but which appears as soon as one starts 
walking, then stops again when one halts. From it there results the 
necessity of increasing the number of inspirations, and thence such a 
fatigue that one is forced to halt every twenty or twenty-five steps. 
This fatigue, moreover, is not like that one feels as the result of a 
long walk; it is not the legs which are chiefly affected; it takes 
possession of the whole system; there is a sort of general depression 
both mental and physical. I should add that this peculiar condition is 
observed only during the ascent, for once I had reached the summit 
and during the descent, I felt nothing of the sort. Another noteworthy 
effect of the rarity of the air is sleepiness, which I could hardly 
resist; I felt that if I had stretched out on the snow, or if I had been 
alone, I should have gone to sleep immediately. I do not think that 
this drowsiness can be attributed to the cold, for on the summit, where 
the cold was very keen, I was wide awake. 

I also experienced very slight vertigo, but I mention it only to 
omit nothing. As for nausea, vomiting, fainting, hemorrhages, none of 
us was affected by any of them; our guides, of whom I asked infor- 
mation on these different points, told me that they had never observed 
hemorrhages. As to oppression, which is the symptom most frequently 
observed, I should say that it is far from being absolute, for of the 
six of us, I am the only one who felt it very definitely; the guides 



104 ___. 


104 


108 ___. 


104 


108 ___. 


104 


96 ___. 


96 


92 


80 



Mountain Journeys 109 

did not complain of it and M. Loppe could run when he got near 
the summit. (P. 86.) 

Examination of the pulse rate gave the following results: 

Chamounix Grands-Mulets Mont Blanc 
1000 meters 3000 meters 4800 meters 

Carrier, guide 116 

Couttet, guide 96 

Tournier, guide 96 

Payot, guide 92 

Loppe, traveller 88 

I now come to the two ascents of Mont Blanc which were note- 
worthy from the standpoint that interests us because for the first 
time the whole combination of physiological phenomena was 
studied with the precision instruments used in laboratories. Dis- 
turbances of circulation and respiration were thus determined in 
the conditions which the present exactness of physiological re- 
search demands. Besides, these observations serve as a basis for 
an entirely new theory of mountain sickness, which will be 
discussed in its proper place. 

M. Lortet 149 begins with a rapid historical survey of the symp- 
toms felt by the most celebrated travellers. Then, before beginning 
the account of his journey, he lets escape the precious confession 
of an incredulity of which I have often heard Alpine travellers 
boast, even those who had made the most difficult ascents: 

However, in spite of so many data and proofs reported by these 
distinguished men worthy of credence, I had been a little incredulous 
and I could not help believing that imagination played a great part in 
the production of these phenomena. On the main range of Monte 
Rosa I had often ascended heights of more than 4300 meters without 
any difficulty and without the least discomfort, and I could not believe 
that 500 meters more were enough to affect an organism which had 
stood the test very well up to this altitude. Now I am forced to 
admit it, I have been convinced de visu, and even a little at my 
expense, of the very real existence of symptoms which, above this 
altitude, attack anyone who breathes and particularly anyone who 
moves in this rarified air. (P. 11.) 

He then comes to the account of his first ascent with Dr. 
Marcet, August 16, 1869. I copy the important points of his descrip- 
tion, which is remarkable for its exactness and moderation: 

Up to the Grands-Mulets (3050 meters), where we arrived at 3 
o'clock to pass the night, we were well; no one felt the least discom- 
fort; we all had excellent appetites; but already our instruments 
announced serious disturbance of circulation, respiration, and espe- 
cially calorification, (heat production) 



110 Historical 

The night at the Grands-Mulets was horrible .... At half-past 
two we set out. 

At daybreak they reached the Grand-Plateau (3932 meters) : 

We stopped a moment to breathe .... The guides took a little 
nourishment; but it was completely impossible for me to swallow a 
single mouthful, although I still felt quite well. 

We climbed very slowly; we all felt an inclination to sleep which 
was very difficult to struggle against and an intense occipital head- 
ache, thirst and dryness of the throat, only a few palpitations, but a 
wretched pulse which varied between 160 to 172 per minute. 

When we reached the ridge, we were all tired, and it seemed to 
me that it would be completely impossible for me to go further. None 
of us vomited, but almost all of us were nauseated. Like those who are 
attacked by seasickness, I was completely indifferent about myself 
and the others, and I wanted only one thing, to remain motionless. 
The Englishmen who were following us seemed even more affected 
than we were; one of them was obliged to stop and soon retraced his 
steps. 

At last they reached the summit of Mont Blanc: 

I no longer felt any kind of illness, but the breathlessness was 
extreme as soon as I wished to take a few steps rapidly. The least 
movement caused me disagreeable palpitations. One of my com- 
panions, who had felt no ill effect until then, was attacked suddenly, 
as soon as he had reached the summit, by dizziness and almost con- 
stant vomiting which did not cease until he reached the Grand-Plateau 
on the way down. His stomach was empty, so that he vomited only 
glairy and bilious matter with very painful efforts. Nothing succeeded 
in stopping this stomach trouble; only one thing seemed to relieve his 
condition at all, that was small fragments of pure ice which he 
managed to swallow from time to time. His pulse was very uneven, 
very wretched, and the thermometer placed under his tongue hardly 
went above +32°! 

The sun was warm, the atmosphere fairly calm, so it was with 
surprise that I observed that the temperature of the air was — 9°. 

We remained at the summit nearly two hours to make the experi- 
ments of which I shall speak later. While I was resting, I felt quite 
well, although it was impossible for me to take the least nourishment. 
(P. 16.) 

The second ascent went much better. The night at the Grands- 
Mulets was good; magnificent weather made the walking easy: 

We felt almost no discomfort except a leaden sleepiness while we 
were climbing the slope which leads to the Dome. I have never felt any- 
thing like it, and I am sure that I slept while I was walking. But 
when I reached the ridge, the cold air and rubbing my forehead with 
snow removed this congestion. 

I felt much better than on the first ascent. I even had an appetite 
and could eat some morsels with pleasure. However, breathlessness 



Mountain Journeys 111 

at the slightest movement was still intense. One of our companions 
experienced great nausea, complete lack of appetite, but did not vomit. 
(P. 18.) 

After this general description, M. Lortet passes to the analysis 
of the disturbances in the various functions. And at the beginning 
he is careful to say: 

Hardly noticeable while going from Lyons to Chamounix, that is, 
passing from a height of 200 meters to an altitude of 1000 meters, 
their disturbance is, on the contrary, very appreciable from Cham- 
ounix to the Grands-Mulets (from 1050 to 3050 meters), still plainer 
from the Grands-Mulets (3050 meters) to the Grand-Plateau (3932 
meters) ; finally this change becomes very great from the Grand- 
Plateau to the Bosses-du-Dromadaire (4556 meters), and at the 
summit of the Calotte of Mont Blanc (4810 meters). 

We shall therefore review the variations undergone by the respi- 
ration, the circulation, and the inner temperature of the body, taken 
under the tongue at different altitudes, either while walking, or after 
a suitable period of rest. (P. 20.) 

Respiration: From Chamounix to the Grand-Plateau (from 1050 
to 3952 meters) disturbances of respiration are slight in those who 
know how to walk in the mountains, who keep their heads lowered 
to lessen the laryngial orifice, who breathe with their mouths closed, 
being careful to suck an inert object, such as a hazelnut or a little 
piece of quartz, which considerably increases salivation and prevents 
the drying out of the air passages. From Chamounix to the Grand- 
Plateau, the number of respiratory movements is hardly changed; 
while at rest, we find twenty-four per minute, as in Lyons and in 
Chamounix; but from the Grand-Plateau to the Bosses-du-Dromadaire 
and to the summit, we find thirty-six movements per minute. The 
breathing is very short and very difficult, even when one remains 
quiet; it seems as if the muscles are stiffened and the ribs are held 
in a vise. At the summit, the slightest movement brings on panting; 
but after two hours of rest these discomforts disappear little by little. 
Respiration drops to twenty-five per minute, but it still remains 
painful. (P. 20.) 

M. Lortet studied the changes in the amplitude of his respi- 
ration with the anapnograph of Bergeon and Kastus; the two 
tracings below give a very complete idea of them; in both, the area 
GFED represents the inspiration, the area DCBA, the expiration. 

Comparing the tracing of Figure 1, taken at Lyons, with the 
following, taken at the summit of Mont Blanc, after a rest of an 
hour and a half, we see that the quantity of air inspired and 
expired at the summit of Mont Blanc is much less than at Lyons. 

Circulation: During the ascent, although progress is excessively 
slow, the circulation is accelerated extraordinarily. At Lyons', when 
I am resting and fasting, my average pulse rate is sixty-four per 



112 Historical 

minute. While I was climbing from Chamounix to Mont Blanc, it 
increased progressively, following the altitudes, to 80, 108, 116, 128, 
136; and finally, while I was climbing the last ridge which leads from 




Fig. 1— Lortet. Respiratory tracing taken at Lyons (200 m.) 




Fig. 2 — Lortet. Respiratory tracing taken at the top of Mont Blanc (4810 
m.) after an hour's rest. 

the Bosses-du-Dromadaire to the summit, to 160 and sometimes more. 
These ridges, it is true, are very steep, they have a grade of forty-five 
to fifty degrees; but slowness of the walking is very great. One 
generally takes thirty-two steps per minute and often much less when 
steps have to be cut constantly. The pulse is feverish, hasty, and weak. 
It is plain that the artery is almost empty. The slightest pressure 
stops the current in the blood-vessel. The blood must pass very 
rapidly in the lungs, and this rapidity increases still more the insuffi- 
cient oxygenation which has already resulted from the rarefaction of 
the air. It does not have time to receive the oxygen adequately, and 
neither does it have time to give off its carbonic acid entirely. Above 



Mountain Journeys 



113 



the elevation of 4500 meters, the veins of the hands, the forearms, 
and the temples are distended. The face is pale with slight cyanosis, 
and everyone, even the guides acclimated to these lofty regions feel 
a heaviness in the head and a drowsiness which are often very 
painful, due probably to a venous stasis in the brain or to a failure 
of oxygenation of the blood. 

Even after two hours of complete rest at the summit and fasting, 
the pulse always remains between 90 and 108 beats per minute. 
(P. 23.) 

We reproduce as very interesting examples the following 
sphygmographic tracings (Figs. 3, 4, 5) which, made by M. 
Chauveau of Lyons at the time of his ascent in 1866, give all neces- 




Fig. 3 — Cupelain; at Chamounix (1000 m.) 




Fig. 4— Cupelain; at the Grands Mulets (3000 m.) at midnight, one half- 
hour before starting. 




Fig. 5— Cupelain; top of Mont Blanc (4810 m.) 

sary proofs of accuracy. The guide Cupelain, who was the subject, 
is a very vigorous young man, who seems not to suffer from moun- 
tain sickness at all. 

For M. Lortet, who does suffer from it, the changes were still 
more considerable. 

Temperature. We now come to the subject to which M. Lortet 
gave most attention, and which serves as a basis for his theory of 
mountain sickness. I continue to quote verbatim: 

The thermometer was placed under the tongue, the buccal orifice 
being always closed hermetically, and respiration going on only 



114 Historical 

through the nose .... The instrument was always left in place for 
at least fifteen minutes. (P. 31.) 

Fasting, while walking continues, the decrease of the tempera- 
ture is, according to M. Lortet, almost proportional to the altitude 
at which one is. This is shown by the following table. 

Lortet: Temperature 







First 




Second 


Temperature 








Ascent 


Ascent 


of the 


air 


<u 


Places 


<D 




tuO 

3 










gg, 




3 


a; 


'B 


a> 


'x 


First 


Second 


in .fj 




< 


'3 


OS 


'3 




Ascent 


Ascent 


3 « 


Chamounix 


1050 


36.5 


36.3 


37.0 


35.3 


+ 10.1 


+ 12.4 


64 


Cascade du Dard 


1500 


36.4 


35.7 


36.3 


34.3 


+ 11.2 


+13.4 


70 


Chalet de la Para 


1605 


36.6 


34.8 


36.3 


34.2 


+ 11.8 


+ 13.6 


80 


Pierre-Pointue 


2049 


36.5 


33.3 


36.4 


33.4 


+ 13.2 


+ 14.1 


108 


Grands-Mulets 


3050 


36.5 


33.1 


36.3 


33.3 


— 0.3 


— 1.5 


116 


Grand-Plateau 


3932 


35.3 


32.8 


36.7 


32.5 


— 8.2 


— 6.4 


128 


Bosse du Dromadaire 


4556 


36.4 


32.2 


36.7 


32.3 


—10.3 


— 4.2 


136 


Summit of Mont 


















Blanc 


4810 


36.3 


32.0 


36.6 


31.0 


— 9.1 


— 3.4 


172 



So during the muscular efforts of the ascent, the temperature of 
the body may drop four or five degrees, when one mounts from 1050 
to 4810 meters. As soon as one stops for a few minutes, the tempera- 
ture rises quickly to nearly its normal figure .... 

Since my return to Lyons, I have observed that when one ascends 
rapidly one of the numerous stairways that lead to Fourvieres or the 
Croix Rouge, there is regularly a drop in temperature which varies 
almost always from three to seven tenths of a- degree. (P. 32.) 

It is to this drop in temperature of the body that M. Lortet 
attributes all the symptoms of mountain sickness. In Chapter III 
we shall give this theory and the objections it has aroused. 

The same day when MM. Lortet and Marcet suffered so severely 
during the ascent, M. Ch. Durier 150 followed them, walking, so to 
speak, in their footsteps. Strangely enough, neither he nor his 
companions felt any symptoms: 

There were three of us, three companions of very different 
temperament; one was a lad fifteen years old, the youngest traveller — 
at least that I know of — ever to ascend Mont Blanc. Well! None of us 
felt the slightest discomfort, not even breathlessness. (P. 66.) 

Why this difference in impression? M. Durier asks himself. 
And to this question he gives an answer full of acuteness, of which 
we shall make use later. 



Mountain Journeys 115 

I shall end the review of the principal ascents of Mont Blanc 
with that of M. Albert Tissandier; 1M it is particularly interesting 
because its author, being an aeronaut, could compare his sensa- 
tions with those he felt in a balloon; he had no uncomfortable 
sensations: 

At the height of 4400 meters, respiration began to be somewhat 
painful and panting, but I endured the effect of the rarefaction of the 
air without very much trouble. My two guides looked at me at that 
time, and told me that often, at that altitude, travellers have a 
peculiar color; sometimes their vision grows dim and their strength 
fails; then they have to be hoisted up with great difficulty or else 
descend, depending upon the energy the traveller possesses. 

I should have been very sorry to be obliged to descend. In a 
balloon I have reached altitudes almost equal to that of Mont Blanc 
without being inconvenienced; but a mountain ascent, slow and 
painful, is not at all like the ascent one makes so quickly and easily 
in the basket of a balloon. 

The ascent of Mont Blanc, so much feared before the daring 
attempt of Jacques Balmat, and which the sufferings of De Saussure 
and then the accident of Dr. Hamel had invested with a terrifying 
renown, has in our time become frequent, almost common. In 1873, 
sixty travellers ascended to the summit of the giant of the Alps, 
among them seven women and a lad of fourteen, the youngest 
who has ever made the ascent, named Horace de Saussure. Since 
the time of the illustrious ancestor of this brave lad, I have 
counted on the list still incomplete given by M. Besangon, 1 "' 2 which 
goes to the end of 1873, 828 ascents, 27 of which were made by 
women. The last, made by an Englishwoman, Mrs. Straton, shows 
remarkable courage; it took place January 31, 1876; on the summit 
the lady found a temperature of —24 degrees. But the large majority 
of these expeditions offer no scientific interest; they are mere 
tourist excursions, often managed very imprudently. Mont Blanc, 
of which the professional "mountaineers" speak with a certain 
disdain, seems to avenge itself; there have been more serious acci- 
dents upon it than in all the rest of the Alps. One of these disasters, 
the most terrible of all, perhaps has some relation to our subject. 
September 6, 1870, nine guides and three travellers reached the 
summit of Mont Blanc; they could not get down, and died the next 
day in the snow. In the pocket of one of them, M. Beau, 1 " 3 was 
found a paper giving an account of their sufferings: 

We passed the night in a cavern dug in the snow, a very uncom- 
fortable shelter; I was sick all night. 



116 Historical 

Most of those who have made recent ascents of Mont Blanc, 
the accounts of which have been preserved for us by the Alpine 
clubs, say nothing of mountain sickness. They go on at length 
about the preparations for the departure, the petty incidents of the 
journey, the joys of the return, but maintain complete silence 
about the physiological phenomena. And what I say of Mont Blanc 
is true of all the other ascents, even of mountains rivaling it in 
height. I have gone over, page by page, the journals of the English, 
Swiss, Italian, Austrian, and French Alpine clubs; I have patiently 
read hundreds of monotonous accounts, and have found very few 
data relating to our study; I shall mention them chronologically. 

August 13, 1857, M. Hardy ir ' 4 made the ascent of the Finster- 
aarhorn (4275 meters) : 

Wellig (inn-keeper of Eggischhorn), considering himself insulted 
by our jokes, went on ahead to reach the summit first. But hardly 
had he taken a hundred steps, when he fell as if some one had shot 
him. Ellis, who was walking behind him, thought that he was resting, 
and walked quietly up to him; but when I came, I perceived that it 
was more serious. His eyes were turned up, his mouth open, and he 
looked strangely like a fish. I did not know what to do; but Cruz 
adopted a queer mode of treatment .... He raised him to a seated 
posture and shook him so vigorously backward and forward, that after 
a few vibrations he revived from his faint, got up, and went to join 
Fortunatus. (P. 299.) 

Perhaps we may hesitate to attribute this sudden syncope to 
mountain sickness; but in the narrative of Tuckett, 15 "' the doubt is 
not possible. 

The matter in question is an ascent on Grivola (3960 meters), 
made in June 1859; an avalanche threatened to carry away the 
travellers: 

Chabot, one of the guides, complained of painful sensations in 
the chest and stomach, loss of appetite, vertigo, nausea, headache, 
resulting partly from fear and fatigue, and partly also, perhaps, due 
to the rarity of the air, for we had reached the height of 12,028 feet 
(3665 meters). (P. 297.) 

In my opinion, in spite of the complication of a somewhat 
exaggerated consumption of alcoholic beverages, the influence of 
rarified air is incontestable again in the following observation 158 : 

A young Englishman about twenty-four years old, a regular 
picture of health and strength, passed the Weissthor by Macugnagna. 
He was not much accustomed to difficult ascents .... and to give 
himself strength drank brandy and water frequently. The result was 
soon seen. The guides had to pull him along with ropes, in a state of 



Mountain Journeys 117 

complete exhaustion .... In fact, as he told me, he has no notion 
of the way in which he overcame the difficulties and reached the 
summit; he was in an inert stupor the whole time. (P. 349.) 

M. Kennedy, 157 one of the most daring and one of the first men 
to make ascents in the Alps, was himself attacked in one of his 
expeditions, not the first, far from it, nor the most difficult, nor 
the highest; he was climbing the Dent-Blanche (4365 meters) and 
was still far. from the summit: 

An extraordinary weight seemed to be loaded on me, hampering 
my movements. My legs, although I did not feel fatigued, refused to 
act with their usual vigor, and I was left far behind; but the pure and 
rarified air which blew over us and the sight of the peak of the Dent- 
Blanche began to revive me. (P. 36.) 

In certain accounts, it is only incidentally, as if buried in a 
sentence, that we see the symptoms of mountain sickness 
appearing: 

Guides and travellers were exhausted, stopping often for breath 15S 
.... (P. 107.) 

In other cases they are more clearly indicated, even described. 

The snow was hard, it was necessary to cut steps, and more 159 
than once the travellers had to stop to get their breath. (P. 166.) 

In 1864, Craufurd Grove 160 ascended to Studer-joch (3260 
meters) ; too great speed in walking made travellers and guides ill: 

Perru, who was afraid of avalanches, made us walk at a pace 
unusual in the Alps, which quickly produced signs of distress in the 
whole group; .... but the robust son of Zermatt gave no heed, and 
slackened his pace only when the outraged laws of respiration claimed 
their rights and compelled him to stop completely to get his breath . . . 
We reached the summit; but our joy was greatly lessened by the fact 
that we were almost all ill. Some of us who had relaxed beside 
Italian lakes from the hard work of the mountaineer had eaten figs 
and grapes in excess. The result of this diet, while we were walking 
on the ice, was too painful to be described. The guides were in a 
hardly less pitiful condition; they had drunk Grimsel brandy the night 
before. (P. 368.) 

The account of the ascent of Monte Rosa by Visconti,"' 1 in 
August, 1864, is still clearer and more interesting: 

The rarefaction of the air inconvenienced us greatly, either 
because of the difficulty in breathing or because of the decrease of 
atmosphere pressure on the blood-vessels. For these reasons and 
because of the steepness of the grades, our legs and lungs tired 
quickly; but a few moments of rest restored their strength rapidly . . . 



118 Historical 

Just before we reached the summit (4640 meters), we met the 
English travellers coming down. One of them was pale and disturbed; 
he • told me that the rarefaction of the air had caused frequent 
vomiting which had weakened him; in addition, he was dizzy. I merely 
felt a weakness of the stomach with frequent nausea. (P. 160.) 

Last I shall report an observation made by M. Gamard, 1 "-' dur- 
ing his ascent of the Jungfrau (4170 meters), August 24, 1874, 
which we shall discuss later: 

We were buried in the very side of the mountain; air failed us, 
and as we noticed on Monte Rosa and Mont Blanc, it is not at the 
summit that we suffer from this rarefaction, but in spots which the 
wind does not reach. 

At half past nine, we rested again; we were at an altitude of 
about 3750 meters. (P. 216.) 

But, I repeat, observations of this sort are extremely rare. Ball 
does not say a word about mountain sickness in his useful work 
entitled Suggestions for Alpine Travellers, 1 ™ in which he enu- 
merates the dangers of ascents and the principal observations of 
physics and natural history which can be made there. 

Does this mean that everything has changed since the time of 
De Saussure, and that today one can safely make ascents which 
then were painful and difficult? In this hypothesis, however 
strange it may appear at first thought, there is a portion of truth, 
the amount of which we shall discuss later. But to make sure that 
the immunity is anything but general and complete, we need only 
question carefully those who make ascents, even those who in 
their accounts do not mention physiological disturbances, even 
those who deny the existence of such disturbances. Moreover, M. 
Joanne, who has read and seen and heard so much, summarizes 
perfectly in his excellent guidebook to Switzerland 104 all common 
knowledge on this point: 

The lightness and the great rarity of the air in the Alps, and the 
energy with which it speeds up evaporation cause at certain altitudes 
very noticeable physiological phenomena, such as considerable 
decrease or loss of appetite, distaste for food, nausea, drowsiness, 
panting, headache, fainting, etc.; some of these symptoms even compel 
certain individuals to turn back at once, as soon as they have reached 
an altitude of 3000 meters; at about 3400 meters, mules are so out of 
breath that they utter a sort of plaintive cry. However strength returns, 
in such a case, as quickly and apparently as completely as it was 
exhausted. Mere cessation of movement seems, in the short space of 
three or four minutes, to restore it so perfectly that when one starts 
walking again, one no longer feels any fatigue. (P. 93.) 



Mountain Journeys 119 

But if these symptoms are so frequent, why not speak of them, 
or at least why not mention them in accounts which are often so 
prolix and loaded with uninteresting details? 

In the first place, we must confess, their importance and sever- 
ity have been so exaggerated that travellers affected only by 
panting and palpitations are willing to deny even the reality of an 
illness which they dreaded so much in advance. In this connection, 
I found an interesting indication in the account of ascents made in 
August, 1859, of Grivola (3960 meters) by M. Ormsby. 165 He was 
climbing the "chimney" in a very dangerous position when he had 
a very strange dizzy feeling, and he adds: 

I had read so many terrible stories of the strange effects of the 
rarified air on man at great altitudes that I began to be very nervous 
.... It was the moment to be attacked by apoplexy, catalepsy, 
bleeding from the eyes or some other of the terrible symptoms. (P. 
333.) 

In the second place, most of the tourists whose narrations fill 
the Alpine journals have hardly any scientific interests in their 
ascents; they climb for the sake of climbing, or seeing, or often of 
telling that they have climbed and seen. It is generally this last 
feeling which dictates their accounts, and that is why one sees 
them every year seeking some horn, spitze, or joch, hitherto inac- 
cessible or merely forgotten: a virginity often hard to conquer, 
the sterile conquest of which they will dispute. 

Finally, a point of honor has intervened; they are almost as afraid 
of being ridiculed for mountain sickness as they are for seasick- 
ness. Formerly, they sought its symptoms in themselves, they 
liked to boast of having experienced them, as they would have 
boasted of a mysterious danger they had risked; today they refuse 
to observe them, especially to admit them; sometimes they deny 
them. 

One of the travellers of our period who are most experienced 
in mountain climbing, Count Henry Russell, 1 ' expresses himself 
on this point with the greatest clearness and authority: 

I regret to state that some of the most important authorities of the 
Alpine Club have gone so far as to deny completely a thing like the 
painful phenomenon known in all countries by the name of "mountain 
sickness", or they declare it an exception, an effect of fatigue, of 
exhaustion. It is true that very favored lungs can go to very high 
altitudes and continue to breathe comfortably. Likewise, there are 
travellers who are immune to seasickness, and we can therefore deny 
this sickness as well as the other. Mountain sickness is an ailment 
which has been felt all over the earth (even in the tropics), in the 



120 Historical 

Andes, on the Altai, on the Himalayas .... everywhere. No animal 
is immune to it, at a certain height; and as for me, I confess humbly 
that I can hardly breathe on the summit of Mont Blanc; in fact, we 
were all sick, more or less, including the guides. On the Calotte, 
where the slope is very gentle, not one of us could take more than 
thirty-four steps without pausing a long time. And that was not 
fatigue, because in two hours we were descending to the Grands- 
Mulets, in very good health and full of vigor. (P. 243.) 

How few "mountaineers" and "Alpinists" will have courage to 
make a similar confession! 

6. The Pyrenees. 

Since the highest mountains of the Pyrenees do not attain 3500 
meters, the symptoms due to decreased pressure can be felt there 
only under exceptional conditions. So travellers generally do not 
mention this subject, and when they speak of it, it is usually to 
declare that they have had no such experiences. 

The first author to mention physiological phenomena observed 
in the Pyrenees is Robert Boyle, 107 but he gives only second-hand 
information: 

A gentleman of learning had made the ascent of the peak of Midi 
in the month of September. I asked him whether he had found the 
air on the summit as plentiful for breathing as that belew. He said 
no, that he was forced to breathe more frequently and less deeply 
than usual. And as I thought that perhaps that came from the move- 
ment, I asked him whether this difficulty had ceased after his arrival 
at the summit; he answered: "Yes, evidently, for we could not have 
remained several hours on this summit with such difficulty in breath- 
ing." (P. 2039). 

During the eighteenth century, a fairly large number of ascents 
were made, for scientific reasons, on different mountains of the 
Pyrenees, and those not the least lofty. The book of Dralet 1<1S 
gives an interesting summary of the data formerly observed: 

The artists who were employed in 1700 in constructing on Canigou 
a pyramid for determining the meridian felt no symptom. MM. Vidal 
and Reboul passed three days and three nights on the summit of the 
peak of Midi of Bigorre without any inconvenience; I have always 
been immune, and so have my travelling companions, not only on this 
same peak, but also on the loftiest ridges which separate France from 
Spain .... However some travellers have been affected in the 
Pyrenees, even at moderate heights. In 1741, M. Plantade, celebrated 
astronomer of Languedoc, died at the age of 70 beside his quadrant, 
on the Hourquette des Cinq-Ours (1244) fathoms. Count Dolomieu, in 
August, 1782, almost met the same fate; he was attacked by a violent 
fever which kept him from reaching the summit of the peak 10 '; 



Mountain Journeys 121 

M. de Puymaurin and M. Lapeyrouse, his travelling companions, were 
for an instant almost without pulse. M. Dusaulx, before reaching the 
plateau of the peak of Midi, felt dizziness and a sort of weakness, 
without his companions experiencing any such symptoms. These facts 
seem to prove, according to the opinion of M. de Saussure, that nature 
has fixed for the constitution of each person the altitude to which he 
can ascend without discomfort and without danger. But it should be 
noted that certain travellers have been affected at a moderate height, 
although accustomed to climbing very high mountains without any 
trouble. (Vol. I, p. 38.) 

After that time, the traveller and naturalist Ramond made the 
first ascent of Mont Perdu (3350 meters). His very interesting 
account 17 ° gives proof of very uncommon sagacity; at least he does 
not deny what he was fortunate enough not to feel: 

We were breathing without difficulty this light air which was no 
longer sufficient for the respiration of many others. I have seen 
vigorous men forced to stop at much lower elevations . . . Here we 
felt nothing of the sort; only the condition of the pulse indicated a 
change independent of the excitement of the trip: rest did not quiet 
it. As long as we remained on the summit, it was small, dry, difficult, 
and quickened in the ratio of 5 to 4; this fever, which is nervous, 
announced plainly the illness which we should have felt at a greater 
elevation; but at the point where we were affected by it, it produced 
an effect just the opposite of that which a degree more would have 
produced. Far from causing exhaustion, it seemed as if it aided my 
physical powers and raised my spirits. I am convinced that we often 
owe to it this nimbleness of limb, this acuteness of the senses, this 
activity of thought which suddenly dispel the prostration of fatigue 
and the apprehension of danger; perhaps we need not seek elsewhere 
the secret of the enthusiasm which permeates the accounts of all who 
have mounted above ordinary heights. (P. 84.) 

Likewise Arbanere 1T1 declares that on the summit of Mont Perdu 
in 1821 he: 

Experienced no effect of the rarefaction of the air, that distress, 
that anxiety, that nausea which often cause prostration at such a 
height. (Vol. II, p. 85.) 

On Vendemiaire 11, in the year XI, Cordier and Neergaard 
made the ascent of the Maladetta. One of them was seriously 
affected; here is the account the celebrated geologist gives of this 
complication: 172 

Shortly afterwards, the ridge became wholly impassable and we 
had to go out upon the glacier. We were then at a height of about 
3000 meters. M. Neergaard was so distressed by nausea and dizziness, 
caused by the rarity of the air, that it was absolutely impossible for 
him to go any further. I will note, by the way, that mountain sickness 



122 Historical 

almost always attacks the small number of persons whom a natural or 
accidental tendency makes subject to it, at the height of 2600 to 3000 
meters, immediately above the timber line. (P. 266.) 

Cordier and his guide continued on the way and reached the 
summit without seeming to have experienced any unpleasant 
symptoms; at least the account gives no signs of any. 

A traveller of whom we have already spoken, who made 
numerous ascents, particularly in the Pyrenees, Parrot, 173 gave 
special attention to the variations in his pulse at different heights. 
I reproduce his important observations: 

My pulse rate on the summit of Mont Perdu was 110, and a few 
days before, in my first attempt to climb this mountain, it was 100. 
Upon the Maladetta, it was 103, and some days before, at Bagneres de 
Luchon (628 meters), it was only 70. These variations are in a regular 
ratio with those of the height; they agree with the observations which 
I have already made on my pulse on different mountains. So my 
pulse rate, which is 70 at sea level, rises to 75 at a height of 1000 
meters, 82 at 1500 meters, 90 at 2000 meters, 95 at 2500 meters, 100 
at 3000 meters, 105 at 3500 meters, 110 at 4000 meters. (P. 216.) 

After him, I have hardly anything else to quote but the account 
of M. de Franqueville, 174 who was the first to ascend the highest 
peak of the Pyrenees, the peak of Nethou (3400 meters) . 

The ascent took place July 18 and 19, 1842. The travellers 
reached the glacier of Nethou, very near the goal of their ascent: 

We were all expecting to feel some of the symptoms due to the 
rarefaction of the air, which generally add still more to the difficulties 
of great ascents. However this did not occur. But after making a few 
steps on the glacier, M. de Tchihatcheff was attacked by nausea so 
violent that he was forced to stop from time to time and lie down on 
the snow. A few moments of rest revived him completely, and per- 
mitted him to go on. As for the rest of us, neither the guides nor I 
felt anything special. We did not even have to struggle against this 
lassitude, this distress which are so painful and which so often 
accompany, they say, the presence of man in these lofty regions which 
were not made for him. 

Here ends all related to our subject that we have been able to 
find in the narratives of mountaineers in the Pyrenees. A strange 
document shows us that nothing important ever attracted their 
attention. Count Russell-Killough, who knows the Pyrenees so 
marvellously, has published a collection of ascents of the peak of 
Nethou, from the one which we have just mentioned up to 1868. 
In this interval, there were about two hundred, including nearly a 
thousand persons, twenty-two of whom were ladies. 



Mountain Journeys 123 

The book, which contains the personal notes of each tourist, 
shows absolutely nothing, except the general vanity of motives 
which impelled so many persons to this painful ascent. Physio- 
logical symptoms are not even mentioned. Count Russell alone 
(August 24, 1863) says: "no spitting of blood". (P. 50.) 

Finally, I will quote in this section a few observations 17,! made 
in an ascent of Mulahacen, the highest peak of the Sierra Nevada 
of Spain; they contain the outline of a strange theory: 

The effects produced by the rarity of the air upon the lungs and 
the body were not felt as long as we remained on the mules. But 
now that we had to make muscular efforts, a greater shift of energy 
is necessary than in a dense atmosphere. The equilibrium of the air, 
which supports the bones as the water does for fishes, fails, and the 
muscles are forced to lift a greater weight; hence exhaustion. (P. 157). 

7. The Caucasus, Armenia, Persia. 
Caucasus. The ascents of the lofty summits of the Caucasus are 
quite recent. Klaproth, 177 in the account of his journey to Mount 
Caucasus and Georgia, made in 1807-1808, said: 

No one has ascended Elbrouz; and the Caucasians think that no 
one can reach its summit without special permission from God. (Vol. 
I, p. 131). 

A very serious attempt to ascend to the summit of Kasbek or 
Mquinvari (5030 meters) was made September 17, 1812, by 
Engelhard and Parrot. 178 

The two travellers camped at the line of perpetual snow; Parrot 
alone undertook the ascent to the summit. He had to surmount 
the usual mountain difficulties; but, he adds: 

The most annoying thing to me was a strange lassitude which 
forced me to rest every fifty steps; it arose less from oppression 
of the chest than from a complete weakness of the muscles which 
seized me suddenly, and which soon passed when I stopped for only 
a half-minute. It was generally followed by a strange and agreeable 
sensation, as if I were in a new element, to which my body, made for 
the stronger pressure of the lower regions, was superior in strength. 
An inevitable consequence of the extremely rarified air which sur- 
rounded us was the acceleration of the pulse and the respiration; but 
distress and vertigo troubled neither me nor my companions. In 
return, I observed in them and myself a weakening of several sense 
organs; we were obliged to talk very loud to make each other hear; 
we had difficulty in talking, not because respiration failed us, but 
because our tongues had lost their flexibility; even the eye seemed 
less active, and one would have said that an inner cause prevented 
it from seeing distinctly and at a great distance. (P. 302.) 



124 Historical 

Parrot was forced to stop at an elevation of 2168 fathoms; he 
passed the night with his companions, but had to descend the next 
day without having reached the summit, which he estimates has 
a height of 2400 fathoms. 

In 1829, a military and scientific expedition approached Mount 
Elbrouz (5620 meters) ; Kupffer 17; ' and the other scientists who 
were in the party resolved to attempt the ascent of the giant of 
the Caucasus. 

July 22, 1829, they reached the line of perpetual snow upon 
its sides: 

We were forced to stop at nearly every step. The air is so rarified 
that respiration is no longer able to restore the strength that one has 
lost; the blood is in violent movement and causes inflammation in the 
weakest parts .... All my senses were blunted, my head whirled, 
I felt from time to time an indefinable dejection which I could not 
control .... We were then at a height of 14,000 feet above sea level. 
(P. 33.) 

However they had not reached the altitude of Monte Rosa; 
they could go no higher, but one of their guides ascended to the 
summit. 

Sjogrun, 180 who, May 26, 1836, made the ascent of "the highest 
mountain of the Caucasus" (his account is not clear, but I think he 
means Kasbek) , says absolutely nothing of physiological disturb- 
ances. 

But Radde, 181 although his ascent of Elbrouz August 10, 1865, 
was not completed because of bad weather, shows clearly in his 
account the effect of rarefied air: 

Before us rose, all white, the summit of the mountain. A strong 
west wind had risen. We stopped a certain time; weariness and 
dizziness painfully affected my two companions and myself; we like- 
wise experienced a strange weakness of the knees, which soon checked 
all our movements .... 

We stopped more and more often; dizziness and weakness of the 
knees increased; horrible fatigue (entsetzlich) weighed me down. 

We had reached a height of 14,925 feet (4557 meters). (P. 102.) 

In their journey, in 1868, Douglas W. Freshfield, Moore and 
Tucker, 182 accompanied by a guide from Chamounix, Fr. Devouas- 
soud, with whom they had made ascents in the Alps, made the two 
difficult ascents of Kasbek and Elbrouz. 

July 1, ascent of Kasbek; night passed at a height of 3300 
meters; except for the excessive fatigue which forced one of them 
to lie down and nearly prevented another from reaching the 
summit, our travellers notice nothing to interest us. 



Mountain Journeys 125 

July 31, ascent of Elbrouz; they complain only of the cold. 

Gardiner, Grove, Walker and Knubel 183 ascended to the summit 
of Elbrouz July 28, 1874. July 27, they camped at a height of 
11,300 feet, and the next day reached the summit: 

Everyone suffered from the rarity of the air. In 1868, not one 
felt its effects; the peak ascended then was probably that of the east; 
but the difference in height, if there is any, is too slight to explain 
the immunity of the former expedition. 

It is probably the journey of Douglas Freshfield and others that 
is referred to here. 

In the same publication is a second account, by Gardiner, 184 of 
the same ascent: 

After we left the col, no serious difficulty appeared. However 
Grove, Knubel and I suffered more or less in breathing, which forced 
us to stop often; we also had what I have heard a Swiss guide call 
"a blow in the knees". Walker had the nosebleed, but no other 
symptom. (P. 119.) 

Armenia. The plateau of Armenia, which over a vast expanse 
has an average altitude of over 3000 meters, is dominated by the 
double summit of Ararat, which was well known by the ancients 
and of which the books of the Bible speak, as everyone knows. 

But if Noah, according to the legend, could easily descend from 
the summit to which' the waters had carried him— which, if they 
had covered the lofty Ararat, would have left above them only its 
neighbors Elbrouz and Demavend with the highest peaks of the 
Andes and the Himalayas,— the ascent of the holy mountain offers 
quite serious difficulties. However, Pierre Bergeron, a Parisian, in 
his treatise on the Tartars, 185 gives us the following curious infor- 
mation: 

Elmacin, an Arabian historian, relates that when the emperor 
Heraclius was making war in Persia, and passed by the city of 
Themanin, built, they say, by Noah on leaving the Ark, curiosity 
urged him to ascend this mountain (Ararat, which is the Taur, as the 
Scriptures call it, and the Greeks call it Periarde; today, it is 
Chielder), to see whether he could find any remains of this vessel. 
Haiton says also that in his time there were a few pieces left. (P. 66.) 

It is also to Robert Boyle 186 that we owe the first account of 
an ascent of Ararat, with mention of the discomforts produced by 
a stay in so lofty a place: 

Having met an ecclesiastic who had ascended the lofty mountains 
of Armenia (on one of which, because of its great height, the people 
of the country say that the Ark came to rest), I asked him whether 



126 Historical 

he had had any difficulty in breathing on the summits .... He ans- 
wered that he had not been able to reach the tops of these mountains 
because of the snow; that, however, he had noticed that he was obliged 
to breathe more frequently. 

I asked him whether this difficulty seemed to him accidental or 
peculiar to him; but he assured me that it was general on lofty places 
and was commonly observed. 

This same ecclesiastic felt similar respiratory symptoms when 
he made the ascent of a mountain in the Cevennes. (P. 2038.) 

The celebrated botanist Tournefort, who attempted the ascent 
on August 11, 1701, could not go even to the snow line: 

One (he says) complained that he could not breathe; as for me, 
I had never been so afraid that some lymph vessel would burst in 
my body. (Vol. II, P. 316.) 

The first complete ascent of which we have a record is the one 
made in 1829 by Parrot, the learned traveller whom we have 
quoted so often already; he had to make three attempts. 

September 12, 1SS he ascended only to 3850 meters (p. 130) ; 
September 18, he reached 5000 meters (p. 146) . Finally, September 
26, he passed the night at 4300 meters; he complains only of a 
feeling of fatigue and a tendency to sleep (P. 156.) The next day, 
departure for the summit: 

We had to leave one of our peasants sick at camp. Two others, 
over-tired by the ascent of the glaciers, lay down on the ground, then 
went back down. Without letting ourselves be discouraged, we 
continued on our way. (P. 157). 

The rest of their account shows that their fatigue was extreme; 
but no other symptom is noted. At a quarter past three, they 
reached the summit: "My first desire and my first pleasure was 
rest", says Parrot. (P. 159.) 

The difficulties with which popular opinion surrounded an 
ascent which seemed a trifle sacrilegious caused this circumstan- 
tial and credible account of Parrot to be called in question. But 
a few years later other explorers, Avtonomoff, 189 August 5, 1834, 
Behrens, 190 July 20 and August 9, 1835, Abich, 1 " 1 July 29, 1845, 
proved its exactness. I could not get the complete account of these 
ascents, and the reports of them given by the journals of geo- 
graphy do not mention any physiological disturbance. 

But that proves nothing, for they are equally silent when they 
discuss 19 -' the celebrated ascent of the Russian Colonel Chodzko, 
and yet it appears from a communication the learned geodesist 
sent me that these disturbances were anything but negligible. 



Mountain. Journeys 127 

Here is the account as it was given me in a letter written in 
French by General Chodzko: I quote it in full, thanking my emi- 
nent correspondent sincerely for his kindness. The expedition 
included five officers and sixty soldiers: 

The ascent began July 31 (August 11), 1850. From August 4 (16) 
to August 6 (18), we remained in our tents at the foot of the summit 
of Mount Ararat. August 5 (17), during the night, sheltered under 
perpendicular cliffs, we remained from eight to eleven o'clock in the 
evening in the midst of electrically charged clouds. The lightning 
flashes which one sees from below crossing the clouds like mere thin 
ribbons had enormous dimensions; the thunder roared at the very 
instant when the flash appeared; it was like the fire of a volley of 
cannons. After a storm of three hours, a very loud clap of thunder 
detached a part of the cliff, which fell with a crash. 

After the thunder storm was over, hurricanes of snow came on. 
It was a very difficult task for us to unroll and stretch a little higher 
two little canvas tents, under which we remained from the 16th to the 
19th of August. August 18, after reaching the summit, we set up there 
a cross painted black. Two tents were pitched in holes dug in the 
snow. August 19, the observations of the zenithal distances were begun 
(Ararat was observed from 122 trigonometric points); they were 
finished after a fashion on the morning of August 24. We set out at 
noon, and descended rapidly. 

As for physiological symptoms, my head was very heavy; it 
seemed to me as if an iron ring pressed my skull above the ears. 
We had to walk very slowly in order to breathe easily. At night, 
when we were sleeping wrapped up in pelisses, if the cold penetrating 
through them awakened us, the movements we made to pull them 
around us cut off our breathing. The third day my head became 
lighter; but it was still impossible to walk quickly. 

In their journey to Armenia, Radde and Sievers made some 
fairly lofty ascents, among them one of a mountain near the lake 
of Chara-Gol, July 28, 1871: 

At an altitude of about 12,300 feet (says Radde) 1Da I had to stop. 
My respiration was difficult, my knees were absolutely broken. I 
began to be feverish .... Sievers climbed bravely on. I remained 
lying down completely apathetic, for two hours, awaiting his return. 
At the end of about two hours, he returned, as sick as I, completely 
exhausted and broken. (P. 177.) 

Among the numerous travellers who have traversed Asia Minor 
in all directions, I find only one, Hamilton, 194 who made the ascent 
of Argaeus (3840 meters), July 30, 1837. He says absolutely 
nothing of physiological disturbances. 

Persia. But I have found two accounts of ascents of the extinct 
volcano of Demavend (5620 meters), near Teheran. 



128 Historical 

September 8, 1837, Taylor Thomson 195 camped on the mountain 
side at an elevation of 2000 meters. The next morning, he set out: 

I had not been climbing more than an hour, when two of my men 
refused to go any further .... I kept on with the other two, but one 
of them complained so bitterly of headache and palpitations that I 
had to let him go back. By entreaties and threats I kept the other as 
far as the crater: the cold was extreme .... The temperature was 
56 °F., the barometer stood at 15.05 inches .... which corresponds to 
14,700 feet (4480 meters). 

The other ascent was made July 24 and 25, 1858, by members 
of the different European missions to Teheran. The English 
attache, R. F. Thomson, has given a detailed account of it. 196 

On July 24, camp was made for the night at the village of Rina 
(3920 meters); the thermometer registered 0° centigrade. On the 
morning of July 25, they set out early: 

The ascent of this part of the mountain brought on great fatigue 
especially on account of the rarefaction of the air which began to 
affect our lungs .... 

The last part of the ascent of Bamshi Bend was extremely painful 
because of the rarefaction of the air. We felt nausea and violent 
headache and a great difficulty in breathing, even while resting. M. 
de Saint-Questin, of the French mission, and M. Castelli, a Sardinian, 
who accompanied us, were affected like us. When we had rested a 
little and were less tired, we began our observations. They indicated 
the enormous height of 21,520 feet (6560 meters). 587 

We remained at the summit about an hour and a half. (P. 15.) 

8. Central Asia. 

In the last half of the thirteenth century, a famous traveller, 
Marco Polo, 198 was the first European to penetrate into the lofty 
regions of the plateaux of Central Asia. The celebrated Venetian, 
no doubt, as has been proved by the testimony of those who fol- 
lowed his steps five hundred and fifty years afterwards, must 
have felt the phenomena of which we shall soon give many 
descriptions, and must have observed their effects upon his com- 
panions and his beasts of burden; but his account gives no 
suggestion of it: 

Always one rides through mountains, and mounts so high that it 
is said that this is the highest spot in all the world. (P. 130.) . . . . 

No flying fowl is there, because of height and cold. And I tell 
you that fire, through this great cold, is not so bright nor so warm as 
in other places, nor can it cook viands so well. (P. 133.) 

This place, the highest in the world, is, as the English traveller 



Mountain Journeys 129 

Wood showed later, the plateau of Pamir, at an altitude of 4700 
meters. 

Chinese travellers, still earlier, had visited these lofty places. 
For instance, the pilgrim Fa-Hian 189 in the year 399 crossed the 
pass of Karakorum (5690 meters). Also the celebrated Hiouen- 
Thsang 200 coming from China found "a series of mountains and 
valleys and peaks of prodigious height. He crossed black moun- 
tains." (P. 55.) M. Stanislas Julien declares that this means the 
passes of Hindou-Kouch and the plateau of Pamir. But in the very 
brief reports left us there is no mention of physiological obser- 
vations. 

The description "of the provinces Wei and Zzang" of Western 
China, which, published in Chinese in the year 1792, has been 
translated into French by Klaproth - 01 , contains some indications 
which, as we shall see later, evidently refer to the symptoms of 
decompression. 

In mentioning disturbances which affect travellers in these 
lands of lofty mountains, the Chinese author speaks of: 

Heat of the body, headaches, and other diseases peculiar to the 
climate. (P. 23.) 

Later, in an itinerary remarkable for the accuracy in distances 
and the abundance of details, he mentions the influence of poison- 
ous plants, which we shall soon see playing a great part in the 
narratives of travellers; here, it is rhubarb which is blamed: 

Leaving Djedo, one travels from mountains to mountains; they 
extend a long way, but they are not very high. Rhubarb is abundant 
there; it exhales a very strong odor which annoys the traveller very 
much. (P. 188.) 

Finally, after plants, come exhalations from the ground: 

Further to the west of Djaya, one crosses a great snowy mountain; 
the road is very steep. The accumulated snow looks like silvery vapor. 
The mist which the mountain exhales penetrates the body and makes 
the Chinese sick. (P. 210.) .... 

From Lang Thang Keou, one follows the valley, ascending . . . 
The frozen snow makes the road slippery and very dangerous. There 
are also pestilential exhalations there. (P. 217.) 

During the seventeenth and eighteenth centuries, some Euro- 
pean travellers, missionaries, merchants, soldiers, or adventurers, 
visited the lofty regions of Central Asia, either in the Chinese 
Empire, or in that of the Grand Mogul. 

Only in one account, that of the Portuguese Jesuit Antonio 



130 Historical 

d'Andrada, 202 have I found clear indication of symptoms which 
one can attribute to the effect of the air of lofty places. This mis- 
sionary had the courage to cross the Himalayas almost alone on 
his way from Cashmere to Tibet: 

There begins a region of lofty mountains which one cannot cross 
in less than 20 days. There is nothing there but rocks almost always 
covered with snow .... 

Partly from disease and partly from a certain pestilential 
exhalation from the ground, suddenly one feels a violent inward 
revulsion which kills in a quarter of an hour. I attribute these 
sudden deaths to the cessation of natural warmth which is checked by 
the great cold, and especially to poor food. (P. 13.) 

But as for him and his two companions, he complains only of 
the extreme cold, partial freezing, numbness of hands and feet, 
and "loss of appetite" (P. 16), the only symptom which one can 
attribute to decreased pressure. However they had passed through 
very lofty regions, since they "reached the summits of all those 
mountains where lies the lake whence issue the river Ganges and 
another which waters the lands of Tibet" (P. 16). It is evidently 
Lake Manasarowar that d'Andrada means. 

Dr. Bernier, 2 " 3 who in March, 1663, followed the Grand Mogul 
Aureng-Zeb from Lahore to Cashmere, had to cross a lofty moun- 
tain, still covered with snow; but he speaks only of the cold, and 
alludes only to the difficulties of the trip in speaking of the 
journeys of the merchants who go to Kashgar and Tibet across the 
lofty ranges. 

The accounts of Father Verbiest, 204 who in 1683 accompanied 
the Emperor of China into Eastern Tartary, and those of Father 
Gerbillon, 205 from 1688 to 1698, mention no sufferings. 

In October, 1714, Father H. Desideri left Lahore for Cashmere, 
"across the Caucasus", as the Himalayas were called for a long 
time. May 17, 1715, he undertook the terrible journey through 
Tibet, and reached Ladak June 25. Among his discomforts he 
mentions only fatigue, cold, wild winds, and the reflection of the 
sun upon the snow. 200 

In the second half of the eighteenth century the political rela- 
tions of the English with Boutan and Tibet begin. In 1774, Bogle 
was sent to the Grand Lama by the governor of India; J. Stewart, 207 
who has narrated his journey, makes no allusion to the effect of 
the mountains. 

In 1783, Samuel Turner 20S was entrusted with the same mission. 
He crossed the high passes of Boutan, and stayed several months 



Mountain Journeys 131 

in Tibet. He frequently lays stress upon the extraordinary height 
of these regions and upon the cold and parching winds prevalent 
there. The only observation that can be referred to the harmful 
effect of altitude is the following; Turner was then at the foot of 
Chumalari: 

When we had dismounted at Terma, I felt a violent headache, 
which urged me to throw myself upon a rug; .... I was in pain and 
did not wish to talk. (Vol. I, p. 312.) .... 

I attributed this headache, which gave me great pain, to the 
change of climate. (P. 314.) 

Captain Thomas Hardwicke -«"' in 1796 made a journey to 
Srinagar in Little Tibet, during which he seems to have mounted 
to fairly great heights; but he mentions no symptoms that one 
can attribute to mountain sickness. 

But with the celebrated journey of Moorcroft - 1 " who in 1312 
crossed the Himalayas to reach Lake Manasarowar, begins a new 
era, so to speak. After that, all the narratives of travellers will 
contain clearly and often with details evidence of the sufferings 
which altitude added to fatigue and cold. 

He left May 26, but it was not until June 4 that one finds in 
his journal the indication of a special distress: 

Toward the end of this day (he says) I found that my respiration 
quickened proportionately to the difficulties of the ascent, and I was 
often compelled to stop and wait until the beating of my heart grew 
calm. My companion had been suffering from this oppression for three 
days, but I had not felt it at all until then. (P. 397.) 

Moorcroft does not specify the height which he had then 
reached; he only speaks of a village named Niti where he made 
his camp then. After a few days, he wished from there to make 
the ascent of the neighboring mountains: 

On the morning of June 26, I set out. The ascent was very painful 
because of the great difficulty in breathing; of five persons, only one 
was capable of accompanying me .... I could not take more than 
five or six steps without stopping to breathe .... Having suddenly 
turned my back to the wind, I felt a sensation of fullness in my head, 
with vertigo and threats of apoplexy; and so I quickly lay down on 
the ground. Shortly afterwards, my panting slackened, the beating of 
my heart became less violent, and I could rise. But in spite of pre- 
cautions in walking, I was twice attacked by the same symptoms, 
so that it seemed wise to me to give up ascending higher. 

The imperious necessity of stopping to breathe every four or five 
steps was felt only while I was climbing. When the violent action of 
the heart was lessened by rest, the difficulty in breathing disappeared. 
It did not appear during the descent, even when I ran; but several 



132 Historical 

times at our camp, just as I was going to sleep, I was aroused by this 
sensation .... Although I experienced neither excessive cold nor 
heat, my hands, my neck, and my face were red, the skin was sensi- 
tive, and blood oozed from my lips, which had never before happened 
to me. (P. 408.) 

He refers repeatedly to the oppression which precedes sleep: 

June 30, at sun-rise, the thermometer registered 46 °F I 

awoke very early, and at once was seized with difficulty in breathing 
and great oppression in the heart, symptoms which disappeared after 
a few deep inspirations. As I was going to sleep again, the smothering 
reappeared, and respiration became very uneasy; however, as soon as 
the air had grown warm, this distress lessened. (P. 412.) .... 

In the evening, although overcome by need of sleep, it was impos- 
sible for me to fall asleep because of the smothering which came on 
immediately, and which nothing but a few deep breaths could quiet. 
(P. 415.) 

July 3, Moorcroft reached Daba. The rest of his journey did 
not expose him to mountain sickness, on the cause and nature of 
which he did not venture any hypothesis. 

In 1819, Moorcroft, in the company of Trebeck, began a long 
expedition which was to end in 1825 with the death of the two 
travellers. In the publication by Wilson - 11 of the results of this 
journey, I have found nothing relating to mountain sickness. In 
telling of his crossing of the pass of Chang-La, the highest he 
had yet crossed, Moorcroft complained only of terrible cold 
(Vol. I, P. 428). At the pass of Parang-La, the altitude of which 
he estimates as about 19,000 feet, he says only: 

My horse was so unable to walk, before reaching the summit, that 
I had to dismount and leave him to his fate. (Vol. II, p. 54.) 

Three years after the first journey of Moorcroft, Fraser,'-'- 
who accompanied the political agent sent to the army of General 
Martindale, went up the banks of the Jumna in 1815. He crossed 
the mountains from Jumnotree to Gangotree by very lofty passes, 
the height of which he does not give. 

On July 16 for the first time there appear in his narrative 
symptoms which one may attribute to mountain sickness: 

We were much annoyed by the coolies (he says) .... It was 
very difficult to start them moving, and they sat down after a few 
steps, although their burdens had been greatly lightened in prepara- 
tion for the difficulties of the march. They told us that they were 
attacked by the Seran, or poisonous air coming from the flowers 
which covered the ground (primroses, polyanthus, heather) ; and 
although their condition was perhaps partly due to drink and excesses, 



Mountain Journeys 133 

and although something must also be attributed to laziness, their 
general appearance indicated something more. When they stopped, 
they threw their burdens on the ground, and lay down sick; generally 
they went to sleep immediately, and very few thought of eating first; 
they told us that the next day's stage would be still harder. (P. 440.) 

In fact, the next day, the sufferings increased: 

It was exceedingly cold .... Many of the Mewatees and Goorkhas 
were almost unable to go on, each one complaining of the bis, or 
poisoned wind. I thought then that this supposed poison was nothing 
but the effect of the rarefaction of the air due to our great altitude, 
which makes it insufficient for our breathing; it cannot distend our 
lungs; I have been brought to this belief by my own sensations. I 
was obliged to make tremendous efforts to continue, and could hardly 
find strength enough to walk. I experienced great respiratory oppres- 
sion, as if I lacked air. We certainly could not have endured that 
very long .... 

At last we reached the summit of Bumsooroo-ke-Ghat, where 
there was nothing but moss and lichens .... As soon as one of 
those who complained of oppression lay down, he went to sleep, but 
it did not seem wise to let him do so. Eating a few mouthfuls helped 
a little, but nothing did much good, and no one was free from this 
general weakness. This was the highest point of our journey. (P. 442.) 

From there we had to execute a series of ascents and descents . . . 
along a path which was very difficult and painful on account of the 
snow and rolling stones; we were cruelly tormented by difficulty in 
breathing, until we reached Chaiah-ke-Kanta. (P. 444.) 

They were not at the end of their sufferings. The next day, 
they had to make new ascents: 

We were troubled by the difficulty of the terrain, the poor 
condition of the road, and above all, by the artificial fatigue due to 
the oppression which we all felt most severely. (P. 449.) 

When we reached the high gorge of Bamsooroo, no one escaped 
the baneful influence. It was strange to see those who had laughed 
at their companions give themselves up, some to fatigue, others to 
sickness, in spite of their efforts to hide it from the others. I think 
that I escaped longer than anyone else; and yet, after passing this 
gorge, a few steps upward seemed to me an impossible labor, and even 
while I was passing over level places, my knees trembled under me, 
and I experienced stomachic nausea. The symptoms produced are 
quite varied; some persons suffer from violent headaches; others have 
pain in the chest, with oppression; others have nausea and vomiting; 
many are overwhelmed with drowsiness and fall asleep even while 
they are walking. 

But what proved that all of this was the effect of our great altitude 
is that when we descended and reached the region of vegetation, all 
these violent symptoms, all these sufferings diminished and disap- 
peared. (P. 459.) 



134 Historical 

In 1816, 1817, and 1818, Captain Webb made vain attempts to 
cross the Himalayas, and see again the sacred lake of Manasarowar; 
the Tartars stopped him on the way. His observations were pub- 
lished in an interesting article in the Quarterly Review; 213 some 
of them interest us particularly: 

Without raising the least doubt (says the editor who reviews 
Webb's letters) in regard to the difficulty in breathing experienced by 
M. Moorcroft in his ascent of Ghaut, we shall call attention to the 
fact that higher ascents have often been made without any such effect, 
which seems to indicate that these effects depend greatly upon the 
state of the health. Captain Webb, however, confirms these claims, not 
only by the evidence of his own sensations, but by that of the moun- 
taineers themselves, who experience them as much as strangers do, 
and he assures us that neither horses nor yaks are immune to them. 
The natives call this illness Bis-kae-huwa, that is, poisoned air, and 
attribute it to the emanations from certain flowers; it appears when 
one is walking or when one is tired. 

"Everyone", says our traveller, "complained of loss of appetite 
for several days after our arrival at Nitee. As for me, I felt exactly 
the sensations which precede an attack of fever, with great oppression 
and exaggerated action of the heart and viscera. But one of those 
who accompanied me suffered one of those attacks to which the resi- 
dents of Boutan are subject, at the beginning of the season, and which 
they consider as directly produced by the Bis-kee-huwa. He had gone 
down to the river's edge at the close of day, and when he wished to 
climb back up, he lost the use of his legs and even lost consciousness; 
however, he still retained some feeling, but to me he looked like a 
man struck by apoplexy. His extremities were cold, and after vainly 
trying to revive him by friction and by the application of warm stones 
on his hands and on the soles of his feet for several hours, I decided 
to give him an emetic; a great quantity of foam was thrown up, and 
in two or three days he recovered completely. I think that this secre- 
tion of foam is an effect peculiar to the inhalation of toxic vapors. 
(P. 420.)" 

At about this same time the brothers Gerard began the cele- 
brated series of journeys across the Himalayas. 

In 1817 (August 27 to October 14) first journey of Captain 
Alexandre Gerard, from Soobathoo to Rarung and return. He 
was accompanied part of the way by Dr. Govan, of whom we shall 
speak later. His account was published for the first time from 
his travelling notes by Lloyd in 1841 214 (P. 191-267) . There is no 
mention of mountain sickness in it. 

The next year he set out again, this time accompanied by Dr. 
J. G. Gerard, his brother. They went from Soobathoo to Shipke, 
and returned to Soobathoo (September 22-November 22, 1818). 



Mountain Journeys 135 

From the simple notes which they published 2i5 I extract that 
which concerns our subject: 

October 2. Our tent is pitched at an altitude of 15,095 feet; on 
the pass which separates Choara from Koonawur, there is only scanty 
grass and a little moss .... During the night which we pass there we 
all feel violent headaches, probably due to the rarefaction of the air, 
but which the natives attribute to a toxic plant which grows abun- 
dantly at great heights. (P. 366.) 

October 7, crossing of the pass of Toongrung (13,729 feet), no 
effect noted; October 12, the same, at 13,518 feet, at the pass which 
separates Koonawur from Chinese land. October 16, camp at 
14,900 feet, and October 18, ascent of a peak rising to 19,411 feet 
(5915 meters) : 

Violent headaches, hardly permitting us to make any efforts .... 
The natives refused to go on .... To tell the truth, we ourselves 
could no longer walk, so severe were our headaches, with general 
weakness, and keen pains in the ears and chest .... The thermometer 
did not fall below 22°F .... and yet because of the wind, my hands 
were so numb that I had to rub them for a quarter of an hour 
before being able to use them .... 

The travellers who cross the pass of Gangtung consider it 
extremely difficult: they are covered with garments to defend them 
against the excessive cold, and they complain of terrible pains in the 
head and ears; goats, sheep, and men often die there. (P. 377.) 

October 24, the pass of Hungrung (14,837 feet); October 25, 
the pass of Rooming (14,508 feet) ; no indication. November 22, 
return to Soobathoo. 

Alexandre Gerard soon set out on a new journey. This time, 
he intended, if possible, to go up to the sources of the Setlej, one 
of the tributaries of the Indus, which comes from Lake Manasaro- 
war. The narrative of this journey forms the second volume of a 
work published in London in 1840. 216 It had already been pub- 
lished in a shorter form in a scientific journal of Edinburgh, in 
1826 and 1827. 217 Both accounts are extremely chary of descrip- 
tions and particularly of the physiological type. I quote from the 
volume published in London. 

The journey began June 6, 1821; Al. Gerard set out from the 
land of Rol, at an altitude of 9000 to 10,000 feet. At the summit 
of the pass of Shatool, at 15,555 feet (4738 meters) , where we shall 
see that his brother was to suffer so greatly, he merely says: 

June 9. We slept very little, because of headaches and difficulty 
in breathing. (P. 15.) 



136 Historical 

At the pass of Boorendo: 

June 16. As usually happens at these altitudes, we hardly slept 
at all, worn out by headaches and an extreme difficulty in breathing. 
(P. 37.) 

At the pass of Keoobrung, 18,313 feet, he is a little more 
explicit: 

June 24. I felt great difficulty in breathing, and great weakness, 
but no headache, although my followers suffered from the accelera- 
tion of circulation noted by M. Moorcroft: the temperature was 46°. 

August 30, he made the ascent of the pass of Manerung at the 
enormous height of 18,612 feet (5671 meters) . 

We were ascending the mountain very slowly; respiration was 
difficult and we were almost exhausted at every step. The crest of 
the pass was not visible, and we did not know when our troubles 
would end: the road ascended at an angle of 30° 

Our situation was different from anything we had experienced 
before; it cannot be described. Long before we reached the summit, 
our respiration became panting and oppressed, and we were forced 
to sit down after a few steps; even then we could hardly inhale a 
sufficient quantity of air. The slightest movement was accompanied 
by weakness and mental prostration. We suffered thus for two miles; 
the last half-mile was in perpetual snow. At the summit, the barom- 
eter registered 15.300 inches, the thermometer 36 °F 

Several of my followers could not cross the pass on account of 
headaches. The length and the difficulty of the ascent, the rarity of 
the atmosphere, the rigor of the climate, although it was summer, 
make this pass dangerous to the sturdiest persons. (P. 240.) 

September 29, he had reached Kotgurh, the end of the journey. 

In the first volume of the work published by Lloyd, there is a 
letter from Dr. Gerard, narrating his journey to the passes of 
Shatool and Boorendo, with the purpose of determining the line 
of perpetual snow. It is dated from Lake Charamace, at 13,800 
feet, August 18, 1822. 

At the height of 15,000 feet, the same symptoms attacked him 
and his travelling companions: 

I cannot describe the extreme fatigue which the last 500 feet 
caused us. Distressed, sick, we could not use our arms to break off 
a piece of stone with a blow of the hammer. Respiration was free, 
but insufficient, our legs could hardly support us, and our faces were 
drawn as if we were going to have the fever .... 

All my people were in a wretched condition, I suffered from 
headache, and everyone was complaining. (P. 308.) 

It was August 9, they reached the summit of the pass of Boo- 
rendo, at more than 15,500 feet, the thermometer standing at 37°: 



Mountain Journeys 137 

During the descent, I felt again the symptoms of headache, and 
they did not leave me until after noon; I went out to get flowers, but 
I was obliged to return to camp (12,800 feet). I awoke at daybreak, 
unrefreshed by sleep. I had the same feeling of weakness and languor 
as on the ascent, but not so bad. (P. 315) .... 

My visit had removed my doubts on the phenomena of new snow 
in the passes in July and August, and I had hardly any reason to 
doubt the strange tales of the dwellers at the foot of the mountain 
about the symptoms which sometimes attack travellers crossing it. 
They say that the phenomena of drowsiness and weakness are much 
more to be feared in the rainy season .... 

The people who live at the foot of the mountain and who breathe 
in a very much rarified air, or who are accustomed to climbing their 
steep slopes suffer much less than those who inhabit a lower zone 
in a denser atmosphere; but they know these effects very well, and 
describe their sensations with ingenious and very interesting sim- 
plicity .... 

Between Koonawur (where the people seem born to live and die 
in inaccessible regions) and the Indian slope of the mountains, we 
travelled for a long time on the crests of mountains, at a positive 
elevation of 16,000 feet: I met every day a crowd of people laden 
with grain; they were walking slowly, stopping often to get their breath, 
and they seemed to suffer from a uniform oppression. I have not 
ascertained whether they are subject to an illness like the one I 
experienced, and yet it must be so, and it is undeniable that above 
a certain height, the effects of the rarified air upon the functions of 
animal life are permanent and that neither habit nor constitution can 
conquer them. (P. 320.) .... 

Sandy and I, in our excursion to the peak 19,500 feet high, 
although unable to take a dozen steps without being exhausted, and 
finally being hardly able to move at all, nevertheless were better than 
the villagers who accompanied us, and who live at the altitude of 
12,000 feet. In the interior of the country, where the ground is very 
high, the most dangerous symptoms appear while crossing the moun- 
tains. Between Ladak and Yarkand, an intelligent servant of M. 
Moorcroft told me of the fatal consequences of lack of precaution. 
He says that the passage of the highest range should be made fasting, 
and recommends frequent doses of an emetic during the journey. He 
told me the story of a Russian merchant in good health, who was going 
from Ladak to Lee to see M. Moorcroft, and who died while crossing 
one of the passes because he ate a good meal before starting. Death, in 
such a case, should be attributed to the drowsiness brought on by the 
cold and the extreme rarity of the air which predisposes to inactivity 
and leads the traveller to his last sleep. (P. 325.) 

I took a little walk over the cliffs, but the sensation of fullness 
in my head forced me to return. Since I arrived here, I have been 
more or less affected by headaches, particularly violent at night; the 
pain was not like that of ordinary headaches, but as if an over- 
whelming weight (a dead weight) was attached to all sides of the 
head, pushing it in different directions. Tea relieved me, but only for 
a short time. (P. 325.) 



138 Historical 

I suffered greatly at night from headache and from a sort of 
drowsiness, such as occurs in drunkenness. I have never felt such 
evident proof of the existence of an agency dangerous to the principles 
of animal life, and although I suffered much more in the pass of 
Boorendo, in 1818, the illness did not last day after day, as it did here. 
All my servants were also affected, some by nausea, others by head- 
ache; they were not all equally affected, but we could judge that that 
was only a matter of chance; we should merely say that the natural 
conditions of energy and action are not always the same .... 

The extremes of the barometer here were from 17.055 inches to 
17.160 inches; those of the thermometer from 41.5°F. to 53°; which 
gives the pass of Shadool an elevation of 15,500 feet. (P. 326.) 

Captain Al. Gerard, moreover, has left us in a special chapter 
of a posthumous work, 218 a summary of the data which he observed 
in his numerous excursions: 

On lofty mountains, a depression of spirits and a weakness of 
body, accompanied by cruel headaches, fullness in the brain, oppres- 
sion of the chest, difficulty in breathing, with pain in the ears from 
time to time, affect everyone more or less. All these symptoms result 
from the rarefaction of the air, and of this I have had numerous 
proofs, having visited thirty-seven places at different times, between 
14,000 and 19,400 feet, and thirteen times my camp was pitched 
above 15,000 feet. It should be noted that the people of Koonawur 
and the Tartars estimate the altitude of the passes by the difficulty 
in breathing which they experience when they make the ascents of 
them. 

However it should be noted that the difficulty in breathing does 
not affect everyone equally or at the same time; it certainly depends 
largely on the state of health. When I was not well, I suffered 
from headache at 13,000 feet, whereas in good health I felt no effects 
at 16,000 feet. At Boorendo (15,000 feet) I was very cold, and expe- 
rienced, even when resting, a greater suffocation than ever happened 
to me at 19,000 feet, while I was walking. 

Any fatigue, but especially the ascent of hills, increases these 
symptoms: from 17,000 to 19,000 feet, the headaches are constant, 
and no one can take more than a half-dozen steps without resting. 

When one camps above 16,000 feet (4875 meters), the difficulty 
in breathing is really terrible, and often for whole hours I thought 
I was going to suffocate. 

Persons who have not made such journeys can hardly imagine 
how much time it takes to cover a distance of twelve or fourteen 
miles in lofty places. I have gone thirty-four miles on foot in lands 
which would be called mountainous by those who do not know the 
difficult parts of Koonawur, with more ease and in less time than I 
could walk twelve miles in these lofty regions. An ascent of 5000 or 
6000 feet is not rare, and when the elevation is more than 14,000 
feet, every mile, even when the road is good, requires at least twice 
as much time as at the height of 7000 to 8000 feet. The prostration 
of mind and body experienced on lofty mountains affects everyone 



Mountain Journeys 139 

more or less, and one of my friends was more wearied by an ascent 
and a descent of 5000 feet, in a total walk of nine miles on lofty 
ground than in going from Nahun to Soobathoo, which is 45 miles. 
(P. 57-59.) 

The observations of Captain Hodgson who, in 1817, went to the 
sources of the Ganges and one of its principal tributaries, the 
Jumna, deserve to be quoted for the same reason: 219 

We experienced a great difficulty in breathing and that peculiar 
sensation, constant at great elevations where there is no verdure, 
which I have never felt anywhere as severely as on fields of snow, 
even when I ascended higher .... 

The mercury stood at 18.854 inches, at a temperature of 53 °F. so 
that the altitude was 12,914 feet (3935 meters). (P. 111.) 

It was May 30; the travellers had reached the source of the 
Ganges. 

These countries were visited ten years afterwards by Captain 
Johnson, whose account-" gives data identical with those of his 
predecessors. Moreover, the dangerous effect of lofty places is 
well known to the people of the country. 

In fact, July 1 and 2, 1827, Johnson made the ascent of the 
peak of Tazigand or Pendjeoul: 

The natives, learning of M. Johnson's plan, tried in vain to 
persuade him to abandon it by exaggerated accounts of the innumer- 
able difficulties which it presented and of the dangers of the bis or 
poisoned wind which blows over the snow. (P. 160.) 

Moreover, a fact which deserves mention and of which we shall 
subsequently find many examples, the people dwelling in the 
country suffer much more than the Europeans: 

On July 2, Captain Johnson occupied the same ground as that 
where Dr. Gerard had made his barometric calculations at a height 
of 19,411 feet (5915 meters) above sea level .... 

The natives who had guided him there found breathing very 
difficult; they stretched out on the snow, holding their necks in both 
hands, and the Sepoy nassir, who was the only one to reach the 
greatest height, complained a great deal also. It is surprising that 
our compatriots felt no distress. They occasionally experienced diffi- 
culty in breathing; but they had blisters on the hands and feet and 
momentary blindness from the glare on the show. (P. 162.) 

The French traveller Jacquemont seems to disagree with the 
statements of all his predecessors. At least, he declares that he 
felt no symptoms at heights often equal or superior to those at 
which the English travellers suffered so greatly. This difference 



140 Historical 

made such an impression on him that he reported - 1 it to the pro- 
fessors of the Museum of Natural History, and tried to explain it: 

Kurnaul, February 1, 1831 
Several English travellers have crossed the pass of Bouroune 
(about 15,000 feet), and all complain of the headaches and nausea 
they experienced there. I have gone through much higher places, 
because I camped three times above 16,000 feet, and on my way to 
Beckhur, I had to cross passes at an altitude of more than 18,000 
feet. I have never felt any of the painful symptoms of which all 
travellers on lofty mountains complain, and I have never observed 
them in even one of the numerous companions of my excursions. I 
lived seven months in the Himalayas; I have ascended from their feet 
to their summits; at the time of my journey to Beckhur, four times I 
ascended to an altitude of 6000 meters, and for almost two months I 
almost never went below 3000 meters; then I camped at 4000 meters 
after a stay at 5000 meters. When the ascent is so gradual, the lungs 
easily become accustomed to working freely in an atmosphere which 
gradually becomes more rarified. It is a very considerable change of 
level in a short time that affects them and produces the oppression 
mentioned by Saussure and all who ascended Mont Blanc after him, 
long before they reached the summit. (P. 53.) 

The interesting notes he left, which were published after his 
death, 2 - 2 contain very interesting observations on this subject, to 
which he had given particular attention: 

May 16, 1830, I reached an altitude of 3927 meters .... This 
was the first time I had ascended to so great a height; it exceeds that 
at which the effects of the rarefaction of the air begin to be felt 
painfully in the Alps. I did not feel them at all; I was no more out 
of breath than I should have been at the lowest level, if I climbed 
equal grades with the same speed. 

I saw no real symptoms in any of the people who followed me; 
no panting, nor drowsiness, nor nausea. 

It seems to me that in the temperate climates, on parallels like 
those of the Alps and the Pyrenees, one feels them sooner than on 
mountains nearer the equator. If this statement stands out uniformly 
in the testimony of travellers, it is hard to explain. The effect, if it 
depends solely on the atmospheric rarefaction, should be the same at 
the same altitude in all the regions of the earth, or even greater in 
the tropical countries where the temperature rarities the air more 
at the same elevation. (P. 101.) 

Jacquemont refers repeatedly to this harmlessness of the heights 
of the Himalayas compared to the bad effects in the Alps; in the 
following passage he even offers an explanation of it which has 
some foundation: 

I crossed the pass of Rounang, at an elevation of more than 4267 
meters, three times, on horseback. 



Mountain Journeys 111 

This elevation is higher than that at which travellers claim to 
have begun to feel the effects of the rarefaction of the air in the 
Alps and the Pyrenees. I did not feel them at all. Perhaps the breath- 
lessness from which Saussure and his guides and all those who 
followed his steps on Mont Blanc since then suffered was only the 
result of a long and difficult march on exceedingly steep slopes. 
Perhaps if one could be carried from Chamounix to the summit of 
Mont Blanc, one would escape the illness which is generally attributed 
to the rarefaction of the air at its crest. The Gerard brothers, who are 
undeniably the foremost travellers in Alpine regions, constantly com- 
plain of excessive fatigue and violent headaches on all the passes tney 
crossed, between 4572 and 5791 meters; and this painful condition 
continued as long as they remained at these heights, where they 
camped several times. From that fact it would seem that this illness 
was not merely the passing effect of fatigue caused by a long climb, 
but really an effect of the atmospheric condition .... 

The elevation of Mont Blanc is 3780 meters above Chamounix, 
which is only about 1036 meters above sea level. The ascent is made 
in thirty hours. There is an enormous change in atmospheric pressure 
in which one is immersed, and in a very short time. So sudden a 
transition, independent of the fatigue involved in making it, can 
definitely affect the respiratory organs. Here, on the contrary, for 
more than three months, I have been living at an elevation on the 
average 1829 meters above sea level, and for the last month, at 2743 
meters, an altitude at which I feel none of the effects of the rarefaction 
of the air. When I ascend to an absolute elevation of 4572 meters, I 
pass through a vertical difference of only 1829 meters, half of that 
which exists between Mont Blanc and Chamounix, and I have no 
sensation which I can refer to a respiratory disturbance. Finally, the 
proof that the annoying symptoms felt by travellers on the summit 
of the Alps or on the passes of the Himalayas would vanish in time, 
and that their lungs would find enough oxygen in an air which has 
lost half its density, is the existence of the farm of Antisana in the 
Andes, which M. von Humboldt told us about, at an elevation of about 
4114 meters, where a family lives, plows, and works. There is no 
doubt that the lake of Manasarowar exceeds this height by 305 to 457 22;> 
meters, and yet there are dwellings on its banks, and pilgrims 
go round it in a seven day journey. M. Gerard himself proves very 
satisfactorily that a considerable portion of the high country, in 
which the Kanaweri merchants travel in going from Shipki or 
Skialkur to Garou (Gortope), is above 4877 meters in elevation, and 
yet these merchants do not complain there of symptoms by which 
we see them attacked when crossing passes often at a lower altitude; 
whence I conclude that in the latter case it is from the fatigue of 
the journey that they suffer, laden as they are, whereas in the lofty 
plains of Chinese Tartary, they walk empty-handed on an almost 
level road. 

I myself have felt at an elevation of 4000 meters some of the symp- 
toms in question, that is, fatigue and headache. But I have hardly ever 
mounted to this height without being exposed to a furious wind, and 
whatever precaution I took against its cold, I was always chilled, and 



142 - Historical 

this acting first in me upon the digestive tract, caused a disturbance 
in the digestion, of which the headaches were evidently the conse- 
quence. (P. 259.) 

The following observations corroborate the first explanation 
given by Jacquemont: 

August 11, 1830, I reached the altitude of 5486 meters on the pass 
of Gantong; at the summit, I felt absolutely no difficulty in breathing, 
as long as I remained motionless, carried by my horse, but when I 
tried to walk on an almost level road, fatigue and panting appeared 
promptly. And yet I saw my servants, to reach the summit of the 
pass, walk several hundred steps on very moderate slopes of snow, 
without stopping to get their breath; only one was sick. (P. 288.) .... 

August 16, at the pass of Kioubrong (5581 meters), the same 
immunity; I ascended there rapidly over a very gentle slope, and 
walked quickly for more than an hour, without feeling any special 
lassitude caused by the elevation, no pains of the head or ears, no 
tendency to sleepiness, in a word, nothing particular, perhaps, but 
a slight panting; and in fact, after a few minutes rest, my pulse rate 
was 82. (P. 297.) 

The limit of perpetual snow in this region of the Himalayas 
is hardly below 6000 meters, according to Jacquemont. 

Finally, Jacquemont wished to fix clearly the conditions of the 
problem by a personal experience: 

I had ridden on horseback to Kioubrongghauti, and since the 
experiment which I had made there of walking rapidly for an hour 
in a place with an altitude of 5600 meters, after reaching it without 
any fatigue, left me without doubt as to the cause of the strange 
symptoms experienced by travellers who ascend to the summit of 
Mont Blanc, I wished to climb the pass of Gantong on foot, to see 
whether the walk, which was prolonged but prolonged moderately for 
only five hours and very slowly, with numerous intervals of rest, on 
slopes which are really very steep, but whose vertical height did not 
exceed 1000 meters, would reduce me to the state of exhaustion descri- 
bed by M. Gerard as the immediate consequence of the slightest 
movement, as soon as one reaches the absolute elevation of 4572 
meters. That was just the level of my starting point. 

Stimulated at the beginning of my walk by the morning chill, 
sustained beside by the freshness of the wind, preoccupied by interest 
in the objects which I saw at every step, often stopped by them, and 
taking care after walking three hours to eat a light lunch to ward 
off any feeling of hunger, which, I have found, always produces in 
me in lofty places an extreme weakness and headaches, I arrived 
without weariness, and almost without perceiving it, at the summit 
of the pass of Gantong, at an elevation of 5576 meters. (P. 302.) 

But if Victor Jacquemont was almost free from any acute 
symptom, and did not see any appearing in his travelling com- 



Mountain Journeys 143 

panions and his beasts of burden, it is far from being true that 
all travellers have enjoyed the same immunity. 

In fact, in the annals of Berghaus, for March, 1832, we find 
the following quotation, relating to a passage of the Himalayas 
on the border of Sutlej; the name of the traveller is not mentioned: 

At an elevation of 15,000 feet, respiration becomes difficult; the 
traveller feels great lassitude, vertigo, headaches and unquenchable 
thirst. It is impossible to describe the sensations produced by extreme 
rarefaction of the air; one constantly feels as if he were smothering; 
respiration accelerates in a very painful manner, the elasticity of the 
skin diminishes. The highest "* point of the pass is at an elevation 
of 16,500 feet. (P. 547.) 

Moreover, Lieutenant J. Wood, 225 who made a journey to the 
sources of the Oxus in 1836, 1837, and 1838, gives numerous and 
interesting details on this subject. 

February 20, the expedition reached the plateau of Pamir, 
the altitude of which is 15,600 feet, the mountains surrounding it 
rising 3000 or 4000 feet higher; the party was at the sources of the 
Oxus, on the shore of a frozen lake: 

We began to break the ice to sound the depth of the lake. The 
ice was 2V2 feet thick, and because of the great rarity of the air, a 
few strokes with the picks exhausted us so much that we had to lie 
down on the snow to get our breath. (P. 360.) .... 

Fifty steps at full speed set us to panting. In fact, exercise 
brought on pain in the lungs and a general exhaustion which did not 
improve for several hours. 

Some of us suffered from vertigo and headaches, but except for 
these various phenomena, I felt nothing and saw nothing in the others 
which resembled the sufferings experienced by travellers in the 
ascent of Mont Blanc. In the latter case, the transition from dense air 
to rarified air is so sudden that the circulation does not have time to 
adapt itself to the difference in pressure, so its speed increases in some 
of the most sensitive organs of the body. The ascent of Pamir, on the 
contrary, was so gradual that it required "extrinsic" circumstances to 
remind us of the considerable altitude which we had reached. 

The effects of the great elevation had, however, been proved to 
me some time before in a manner for which I had not been prepared. 
One evening, in Badakhshan, as I was sitting reading by the fire, I 
had the idea of feeling my pulse, and its rapid and wild beating 
aroused my attention. I imagined that I had been attacked by a 
violent fever, and I used the precautionary measures which Dr. Lord 
had prescribed when he left. The next day, my pulse was as rapid 
as on the day before, and yet I felt in excellent health. I thought then 
of examining the pulse of my companions, and to my great surprise 
I found that theirs were more rapid than mine. The cause of this 
increase in circulatory activity was evident to me at once; and when 



144 Historical 

we next went toward Wakhan, I counted the pulse of my companions 
every time I recorded the boiling point of water. 

The changes in the pulse thus form a sort of living barometer, 
by means of which a man accustomed to examining himself can, 
at great altitudes, estimate roughly the elevation. 

On Pamir, the pulse rate gave the following figures: 

Myself 110 Scotland fat 

Gholam Hussein, Munshi 124 Jasulmeere fat 

Omer-Allah, muleteer 112 Afghanistan thin 

Gaffer, servant 114 Peshawuree thin 

Dowd, servant 124 Kabul robust 

The elevation of the snow line in this region is above 17,000 feet 
(5180 meters). (P. 352.) 

Lieutenant Wood was accompanied for part of his journey by 
Al. Burnes, an envoy to Caboul. October 19, 1837, two others of 
their companions, Lieutenant Leech and Dr. Lord, went to recon- 
noiter and cross a pass of Hindu-Koush, going to Caboul. The 
pass is about 15,000 feet high; the snows would soon render it 
impassable; the ascent was easy. However, says Burnes:--' 6 

The horses were in a very pitiful condition, and they had to 
dismount and walk. No one had any symptoms, but the natives 
informed them that they themselves were frequently attacked at this 
point by vertigo, faintness, and vomiting. (P. 152.) 

Some years later, a French traveller, who travelled over not 
the Himalayas, but the much less lofty regions of Upper Tartary, 
made a pitiful story of his sufferings. It is true that one must be 
on his guard against the statements of Father Hue,-'- 7 whose credu- 
lous simplicity is almost boundless. Nevertheless, the vivid pic- 
ture which he has left us of the sensations experienced during 
the passage over Bourhan-Bota, a mountain the height of which 
he does not give, and which seems to be situated about longitude 
95° E. and latitude 40° N., deserves to be reproduced here. The 
day of the ascent is not specified, nor is the temperature of the 
air: 

We prepared to cross Bourhan-Bota, a mountain famous for the 
pestilential vapors in which, they say, it is continually enveloped .... 
Soon the horses refuse to carry their riders, and everyone proceeds 
on foot slowly. Gradually all faces grow pale, nausea comes on, and 
legs refuse to function; one lies down on the ground, then gets up 
and makes a few steps more; then one lies down again, and this is 
the miserable fashion in which one climbs this famous Bourhan-Bota. 
Good heavens! What wretchedness! One feels his strength broken, 
his head whirls, all members seem to be disjointed, one feels illness 
exactly like seasickness, and in spite of that, one must save enough 



Mountain Journeys 145 

energy, not only to drag himself along, but also to beat energetically 
the animals which constantly lie down and refuse to go on. A part of 
the group, as a matter of prudence, stopped half-way, in a depression 
where the pestilential vapors were less thick, they said; the rest, also 
out of prudence, exerted all their powers to get through with it and 
not die from asphyxia, in the midst of this air laden with carbonic 
acid. (P. 256.) 

The travellers whose accounts I shall now mention agree 
much better with what the Gerard brothers said than with the 
extreme statements of Jacquemont and Father Hue. 

July 14, 1845, Hoffmeister - L ' 8 reached the highest point of his 
journey, the pass of Lama-Kaga (Thibet) at the elevation of 
15,355 English feet; the temperature was — 50° Reaumur; the snow 
was falling: 

About an hour and a hslf passed before our first coolies arrived 
with our baggage. They were in a very sorry state, and were suffering, 
as well as our interpreter M. Brown, from headaches which they 
described as unbearable. Loss of strength, pains, and nausea are the 
symptoms of this illness which they call here Bies (poison) or Mun- 
dara. It attacks travellers thus at the line of perpetual snow. In the 
coolies it appeared halfway up the pass. As a remedy against it they 
use a sort of paste made of little sour apricots and their seeds. (P. 
242.) 

In the account of Dr. Th. Thomson,-' 2 '' it was not only the coolies, 
but the European traveller himself, who was affected by the 
altitude. 

September 6, 1847, Thomson and his attendants camped at an 
altitude of 14,800 feet, and on the 7th, they ascended to 17,000 
feet (5180 meters): 

The whole day long I had never been free of a violent headache, 
evidently caused by the great elevation. Rest relieved it, but it 
reappeared at the slightest movement. It lasted all evening, as long 
as I was awake, and I still had it on the morning of the 8th, when I 
got up at daybreak to prepare for the journey .... 

The ascent next day was extremely steep and difficult. The act 
of raising one's body was very tiring, and the last few hundred yards 
were covered only after several pauses .... I reached the summit 
of the pass of Parang at a quarter of eight in the morning; I was . 
at an elevation of 18,500 feet (5640 meters) ; the temperature was 28° 
.... the snow was frozen .... the wind blew violently .... We 
descended without fatigue .... (P. 135.) 

After living a year in these lofty regions, Dr. Thomson recon- 
noitered towards the north, as far as the celebrated pass of Kara- 
korum, at a height of 18,604 feet (5670 meters) . There again, his 



146 Historical 

symptoms reappeared, or to speak more exactly, they became so 
intense that he was compelled to make special mention of them: 

August 19, 1848. During these three days of ascent, I suffered 
greatly from the effects of the rarefaction of the air, being constantly 
tormented by a painful headache which the least exercise aggravated 
.... The temperature of the air was 50 °F. 

The botanist Dalton Hooker is still more explicit.- 50 

At the height of 16,000 feet, while ascending the pass of Kang- 

lachem, December 2, 1848, in eastern Nepal, Hooker experienced 

difficulty in breathing, great lassitude, vertigo and headache. (Vol. 

I, p. 247.) 

Some days afterwards, on the mountain of Nango, at a height of 

15,000 feet: 

I found it quite impossible to remain composed because of the 
increase of the pains in my forehead, lassitude, and oppression. 
(P. 252.) 

July 25, 1849, crossing of the pass of Kongra-Lama (15,741 
feet) : 

After two hours, I was chilled and stiff, and was suffering from 
headache and vertigo due to the elevation. (Vol. II, p. 82.) 
September 18, ascent of the pass of Sebolah (17,517 feet) : 

I took the pulse rate of eight persons after a rest of two hours; 
it varied from 80 to 112, mine being 104. As usual at these altitudes, 
everyone was suffering with vertigo and headaches. (P. 142.) 

October 15, night passed at an elevation of 17,000 feet: 

My coolies were in good health; but those of Campbell were in a 
very sad condition of pain and fatigue; their faces were swollen and 
their pulses rapid; some were practically insensible with symptoms of 
weak cerebral pressure; the latter were especially the Ghorkas 
(natives of Nepal). I have never experienced bleeding from the nose, 
ears, lips, or eyes, and have never seen such symptoms in my com- 
panions on such occasions; nor have I met any recent traveller who 
has experienced them. Dr. Thomson has noted this too, and when 
we were together in Switzerland, we learned from A. Balmat, Fr. 
Cartet, and other guides of experience on Mont Blanc that they had 
never witnessed these symptoms, nor the darkening of the skin, so 
frequently mentioned by Alpine travellers. (P. 160.) .... 

October 17. It is quite surprising to see that Turner nowhere 
alludes to difficulty in breathing, and speaks only in one place of 
headache, even at this great elevation. That is probably because he 
was always on horseback. When I was riding, I never felt any dis- 
turbance in my breathing, my head, or my stomach, even at 18,300 
feet (5580 meters). (P. 167.) 

We see that it is while they are crossing passes that travellers 
feel symptoms; ascents, properly so-called, of isolated mountains 



Mountain Journeys 147 

are, in fact, extremely rare. However here is one, in which 
Captain Robertson,'- 31 in October, 1851, reached the summit of 
Sumeru-Parbut, at a height which he estimates as about 20,000 
feet (6100 meters). The preceding night was passed at nearly 
4000 meters: 

The next morning, we left our tent at ten minutes past eight, 
and at thirty-five minutes past one reached a sloping glacier. At this 
point, vision and respiration became very painful for Lieutenant 
Sandilands and several of our guides .... 

Sandilands reached a spot half an hour's distance from the sum- 
mit, where he was so affected by the rarefaction of the air that it was 
physically impossible for him to go any further; he therefore turned 
back, with the only Rajput who had followed him thus far, the others 
having abandoned him long before; my Brahmin, a handsome young 
man of strong constitution, who came with me to the summit, appar- 
ently felt no effects, but when we reached our tent again, he could 
eat nothing. As for me, my eyes were painful, and my respiration 
and my vital force were affected, but yet I had enough energy and 
physical force left to climb still higher. On my return to my tent, 
my appetite was not affected at all, and I ate a hearty supper. 

But the most interesting accounts I have found in my reading 
are certainly those published by Mistress Hervey. And that is 
easy to understand; a simple tourist, not heeding politics or geog- 
raphy, or science, she gives special attention to everything relating 
to her health and the little incidents of her journey, which she 
tells obligingly in all their details. Besides, since she has rather a 
weak constitution, she seems to be easily affected at rather low 
levels. 

So it is to mountain sickness that we must attribute part of the 
following symptoms, although the elevation is very moderate: 

June 25. We halted (after crossing the pass of Rotung (11,000 
feet, 3350 meters) in Lahoul) .... Captain H. came to say good 
evening to me in my tenf about nine o'clock, and noticed that I was 
very pale, and that my face and hands were cold and clammy. I was 
then very sick; I was delirious; I was nauseated, my hands and feet 
were icy cold. Convulsions came on and I frothed at the mouth. I 
stretched myself on the ground, and remained there in great distress; 
they gave me two doses of Luce water, and put my feet in water 
which, though it was boiling hot, could hardly restore the circulation. 
Yesterday I was sick all day and unable to get up; my pulse rate was 
not less than 108. I am better this morning, but my pulse rate is 
still very high, although less irregular. 

Captain H. declares that this sudden illness is due to the rarity 
of the air of the pass .... If I am already affected thus, what will 
happen at 16,000 or 17,000 feet? (Vol. I, p. 117.) 



148 Historical 

But if doubt is possible in this case, it certainly is not in the 
following quotations. July 6, crossing of the pass of Bara-Lacha; 
Mistress Hervey was very ill: 

I had severe pains in my legs, and felt extreme lassitude, long 
before reaching the summit of the pass; but I made a violent effort 
to overcome these sensations, and succeeded in riding to the summit. 
As soon as we dismounted, a terrible, splitting headache attacked me. 
Before reaching Yunnumscutschoo, I had suffered from nausea and 
felt as if my head were going to split. The principal sensations were 
a very painful and very intense throbbing in my temples, violent 
nausea, pains in my legs, and a lassitude amounting to prostration. 
No one else was sick in the camp, except Ghaussie, who had a bad 
headache. 

I could not get to sleep at night before one or two o'clock, and 
was awakened by the throbbing of my heart, so violent that I felt 
serious fears about it. My pulse was galloping, my head was burning 
and my temples throbbed, and I was wretchedly nauseated. We did 
not set out until late the next morning, and if I had not felt better, 
we could not have moved at all. Captain H. told me that he had had 
a bad headache during the night, that he had felt tired and ill, but 
that nevertheless he had not suffered as much this time as the last 
time he had crossed the pass, for then he had had the same sensations 
as I ... . 

The pass of Bara-Lacha is, I think, between 16,000 and 17,000 
feet above sea level, according to Captain Cunningham. (Vol. I, p. 
133.) 

Mistress Hervey then relates that the natives of the country 
attribute all these symptoms to the effect of a poisonous plant; 
but this time, the plant is a kind of moss. We shall quote this 
passage in Chapter III. 

The next day, the road, which still ran along at great heights, 
several times forced the travellers to ascend small hills: 

As we ascended (says Mrs. Hervey) I noticed a great many 
poisonous mosses, two or three species of which were growing on bare 
rocks. 

I had a terrible headache, and was shivering with a return of 
the terrible "pass sickness" or, as the natives say, from being 
"boottee luggeea", that is, affected by the plants. 

Tomorrow we shall ascend the Long-Illachee Joth (or pass), 
and descend it, which promises to me a fine day of boottee. (Vol. I, 
p. 139.) 

And in fact, when she reached Rokchin (Ladak) the next day, 
Mistress Hervey declared that she was so sick and so weak that 
she could not write. July 9, after a night's rest, she could hardly 
write and had to remain lying down. Two of her servants were 



Mountain Journeys 149 

very sick. Captain H. suffered during the night from a violent 
headache. (P. 142.) 

July 11, passage of a place the height of which Mistress Hervey 
estimates at about 17,000 feet: 

I had a worse headache than usual with a terrible oppression of 
the chest. It is true that since the crossing of the pass of Bara-Lacha, 
I have constantly suffered greatly from the effects of the rarity of the 
air; a constant headache, and, especially during the night, a painful 
pulmonary discomfort, and a very annoying acceleration of the move- 
ments of the heart. I had hardly an hour of continuous sleep; I had 
to sit down on my bed, as I could not breathe when I was lying down. 
These lofty regions do not suit my lungs. (P. 152.) 

The following night, camp at 14,800 feet on the banks of Lake 
Choomoreeree: 

I am now afraid of the night, because, far from sleeping, I suffer 
terribly. Yesterday, it was really very painful; besides a cruel head- 
ache, I suffered from great oppression in the chest, and my heart went 
at a railroad pace, when I moved even an inch in my bed. (P. 153.) 

These sufferings were so great that they decided her to change 
her route a little, to avoid great heights (P. 162) . And yet, July 16, 
when she reached the foot of the pass of Tunglund, she wrote: 

We saw much poisonous bootie today on the road. I was wretch- 
edly sick all night. About eleven o'clock in the evening, the 
respiratory oppression and the suffocation became so unendurable that 
I had to sit up on my bed to get my breath a little. (P. 169.) 

The next day, ascent of the pass (between 16,000 and 17,000 
feet) : 

The odious moss of which I have spoken so often covered the 
pass, and long before I reached the summit, I had a most violent 
headache. But I had no nausea, perhaps because the pass is very easy. 
(P. 171.) 

July 19 of the following year, in spite of her continued resi- 
dence in the lofty regions of Little Thibet, Mistress Hervey was 
not acclimated, for, as she crossed the pass of Brarmoorj in Wurd- 
wun (from 15,000 to 16,000 feet), she said: 

I suffered from an absolutely unendurable headache, which kept 
constantly increasing; but I did not have the nausea which I always 
felt on all the passes of Ladak. (Vol. II, p. 298.) 

And August 5, 1851, while crossing the pass of Hannoo (be- 
tween 15,500 and 16,000 feet), in Ladak, a pass of rather easy 
access, she suffered horribly; it is true that she was already ill. 
She said the next day: 



150 Historical 

I have crossed many passes, but until today I had never expe- 
rienced the terrible sensations which almost made me crazy before I 
was halfway and long after I had left the great heights. My sufferings 
might have been aggravated by my illness, but in any case, they were 
crushing. I lay down on the ground at Dora, more dead than alive, 
and my servants made me a tent of blankets. I was in such a state of 
prostration that not only was I unable to rise, but I could not bear 
to be carried in a "dhoolie" .... A violent headache, unbearable 
nausea, hasty palpitations, and the inability to breathe deeply, such 
were the symptoms of the well known bootie, which attacked me more 
severely than ever before I reached the summit of the pass. I am sure 
that if I had stirred about for a quarter of an hour during these 
horrible sensations, some blood vessel would have broken and I should 
have died on the spot. Just speaking was a painful exercise, which 
brought on copious hemoptysis and increased my pulse rate far 
beyond 100 per minute. I was terribly nauseated, and the exhausting 
power of this distress can be compared only with the nausea of sea- 
sickness. I was also very wretched and my sufferings were intense 
yesterday. Even today I cannot breathe without pain, and my heart 
beats violently and irregularly; I have not yet forgotten the rarified 
atmosphere of the pass of Rannoo. 

As they were carrying me yesterday about a half-mile from the 
summit, Ghaussie called my attention to one of my servants, who 
was lying unconscious on the snow. They woke him easily, but he 
refused to move, saying that his head "was going to split in two." 
After a slight struggle between humanity and strongly rooted prej- 
udices, for the sick man was a sweeper, the lowest class of servants, 
I sent him my own pony to carry him; if he had been left there, he 
would certainly have died during the night. 

While I am speaking of the illness on this pass as a case of 
bCwtie, I must confess that I did not see a single plant of the particular 
kind of moss, which, in the passes of Ladak and Lahoul, are considered 
as poisoning the wind and causing the painful illness which I have 
described. 

One of my servants from Cashmere was the only other person 
among my attendants to be affected; distress in high altitudes is 
therefore not a rule without exception. (Vol. II, p. 367-370.) 
And the next day, as she set out from Scheerebookhchun, she 
wrote: 

I shall travel by moonlight, for I have been so sick all day that 
I have had very little desire to move. If I let myself be governed by 
the painful sensations which have tried me so much, I should not 
start now, but that might be impolitic. In my opinion there is 
nothing like exercise to overcome our little bodily and mental troubles. 

I must practice what I preach, and ride horseback this morning, 
sending my dhoolie on ahead. (P. 378.) 
She set out at sunrise, and went on horseback to Kulatsey. 

I was then so sick and so exhausted that, not finding my dhoolie 
there, I lay down on my shawl on the ground for several hours. At 



Mountain Journeys 151 

last, towards evening, another dhoolie was ready, and I could get into it 
.... I have not recovered from the effects of the rarified air on the 
pass of Hannoo. My heart beats violently and irregularly, and when 
I breathe, I have severe pains in my chest. My distaste for nourish- 
ment is so great that I can hardly touch any food all day long. 
(P. 378.) 

August 14, crossing a sort of a pass, near Ghia: 

I have suffered from a very painful headache, but have felt no 
nausea, although I recognized my old enemy, the bootie, the fatal 
moss of Ladak-Oojar. When I walked fifty steps to pluck a flower, 
the throbbing of my heart increased terribly, and repeated doses of 
digitalis have not quieted its hasty and violent beating. I do not 
know any sensation that is more alarming and more painful than this 
exaggerated action of the heart. None of my servants felt any ill 
effects .... 

I reached Zurra at sunrise. I am completely prostrated by my 
splitting headache, although I have escaped nausea, and that is the 
only consolation I have in my sufferings. (P. 397.) 

August 18, camp at Choomoreeree, at a height of 14,794 feet 
(4510 meters) : 

I passed a miserable night, and this morning I am sick and 
exhausted. I had to remain thus half the night, absolutely incapable 
or breathing in a horizontal position; my heart beat violently with 
terrifying palpitations. I was really afraid of dying in the dark .... 

In the evening, we camped at an elevation of nearly 15,000 feet. 
I have the greatest difficulty in breathing, my chest seems loaded with 
an enormous weight which oppresses me painfully. These distressing 
sensations increase at nightfall. (Vol. Ill, p. 13.) 

August 20, camp at the foot of the pass of Parung, at about 
17,000 feet (5180 meters) : 

A terrible height in which to pass the night under a tent, when 
one suffers from the rarity of the air as I do. Oppression in the chest, 
extreme difficulty of respiration, frequent spitting of blood have left 
me no rest during the last sixteen hours .... The cold is intense .... 

At daybreak, I feel better, although I cannot breathe freely, and 
although the slightest movement distresses me .... My head has 
almost recovered, and since my courage has returned, I have decided 
to cross the pass .... To go on horseback is impossible, to walk ?.s 
impossible too; I am riding a yak. (P. 19.) 

Strange thing, that although this pass is the highest our travel- 
ling lady has crossed, she has little trouble there; no nausea, only 
a slight headache (P. 26). Moorcroft estimates it as at 19,000 feet 
(5790 meters), and Mistress Hervey goes to 20,000 feet (6095 
meters). She is naturally amazed at this result: 



152 Historical 

It is curious (she says) to note the different effects of the 
different passes. Although the painful sensations observed undeniably 
result from the rarity of the air, it is certain that the illness is not 
proportional to the elevation. On the passes of Bara Lacha and 
Hannoo, I was wretchedly sick, beyond all description, and on the 
pass of Parung, 3000 or 4000 feet higher, I had no nausea, hardly a 
headache. I had difficulty in breathing, but that seems to me a 
secondary matter. 

I am far from being able to give a satisfactory reason for this 
difference. I have crossed so many passes that I have had many 
opportunities to note how little relation there is between the "pass 
sickness" and the elevation, of course, beyond 13,000 or 14,000 feet. 
The "Bischk-ke-B66ttie", or poisonous plant, covered the ground many 
miles around Tatung. (P. 33.) 

The journeys of Captain Oliver - 33 in the Himalayas also offer 
an account of impressions connected with our topic. In July, 1859, 
he crossed the pass of Roopung, at about 15,500 feet (4720 meters) : 

We camped at the lower line of perpetual snow, at 14,000 feet 
above sea level. It was very cold .... 

We set out the next morning over the snow .... The summit of 
the pass appeared in a wild and desolate scene. But I heeded it little, 
being occupied with myself, for the rarefaction of the air was acting 
upon me. I suffered from a painful shortness of breath, and soon I 
had to stop every two or three steps. The snow was soft, which made 
walking still more difficult .... I finally reached the last slope, a 
bank of snow 50 feet high and very steep .... But at the moment 
I was so completely exhausted that I was quite unable to cross it 
without assistance. However, after a short halt, I made a desperate 
effort, and somehow or other I reached the summit, where I stretched 
myself out on the ground, absolutely exhausted. (P. 84.) .... 

This pass is much frequented by the Tartars who bring borax 
and wool to the Indian markets. They suffer greatly, however, from 
the rarefaction of the air, but attribute its symptoms to a poisonous 
plant, a fabulous plant, which, according to them, grows at great 
elevations. 

They are also subject to violent attacks of colic in the passes .... 
One of my Sikhs was attacked by it; he lay down on the summit, 
groaning, and declaring that he was going to die; thirty drops of 
laudanum restored him. (P. 85.) 

The same year, another traveller, Cheetam,-' 34 took the road 
from Simla to Srinagar; August 17, 1859, he crossed the pass of 
Lunga-Lacha at 16,750 feet (5100 meters) : 

I then had my first experience of the harmful effects which greatly 
rarified air, bad weather, and fatigue produce at great elevations. 

Vertigo, violent headache, and nausea, such are the character- 
istic sensations, to which is agreeably added a feeling of intense 
exhaustion, a profound physical and mental depression. Happily, in 



Mountain Journeys 153 

me this pleasing complication lasted only a few hours, in the middle 
of the day, and again intermittently. I noticed that invariably I was 
better when descending the hills than when ascending them; and that 
there was a sort of connection between the appearances of the sun 
and my lucid intervals. 

The sufferings of my Cashmere servant and the merchants of 
Caubul were evidently much more continual and acute than mine, 
particularly because of a general disturbance of which they had been 
complaining since the day before, at the pass of Bara Lacha. 

It was impossible to destroy their absolute belief that all these 
symptoms were due to the poisonous exhalations from a mysterious 
plant, the "dewaighas" or "medical herb", which they are sure grows 
in these regions, although they have never been able to find any .... 

The man from Cashmere was sick two days. P. 137.) 

A few days after, crossing of a still higher pass, that of Tung- 
lung, which has an altitude of 17,750 feet (5410 meters). The 
night camp was made at Larsa, at 16,400 feet: 

The aacent of the 1350 feet which we had to climb was very 
rugged; the slightest effort in this rarified air made our breathing very 
painful. (P. 141.) 

The account of Semenof 233 is interesting in that it relates to 
the first journeys made in the high regions of the Celestial Moun- 
tains. June 25, 1857, after camping at an altitude of 7500 feet, he 
crossed the pass of Zauku. There thousands of carcasses of camels, 
horses, oxen, and dogs are to be seen: 

The horse of M. Kosharof broke down .... mine slipped, cut 
itself deeply, and died at once; two of the horses of the Cossacks 
were so exhausted that they could not go on ... . The guide assured 
us that it was so difficult to breathe at the summit of the Zauku Pass 
that it would be impossible to live there more than an hour and a 
half. (P. 364.) 

We see, in this statement of the guide, an example of the 
exaggerations usual in all countries where very lofty places are 
the exception. Unfortunately, Semenof does not give the altitude 
of the pass of Zauku. 

But no one could treat this question with more authority than 
the Schlagintweit brothers, whose expeditions in the lofty regions 
of Asia are among the most important journeys of this century, 
and the most fruitful from the point of view of geography, history, 
and the natural sciences. 

They have devoted a section, in the official account of their 
journey, 230 to the history of the symptoms of decompression. In 
it we see that they mounted to the greatest height ever attained by 



154 Historical 

man in mountain ascents, that is, to 6882 meters, on the sides of 
Ibi-Gamin, August 19, 1855. 

Here is the summary of their highest ascents: 

On some very lofty plateaux which serve as pastures, a tempo- 
rary dwelling for a few months was established at an altitude of 
about 16,500 feet (5030 meters); it is at this height, probably the 
highest of the sort in the world, that the shepherds of Thibet pitch 
their tents and even build permanent dwellings. 

From personal experience we can say that for ten or twelve days, 
man can remain considerably above this altitude, perhaps not without 
distress, but positively without any very serious consequences. In our 
explorations of the glacier of Ibi-Gamin, from the 13th to the 23rd of 
August, 1855, we camped for ten full days, in the company of eight 
men who were our attendants, at really extraordinary elevations. 
During this time, our camp was pitched at 16,642 feet (5070 meters) 
at the lowest. The highest point was 19,326 feet (5890 meters); that 
is the highest elevation at which we passed the night. Another time, 
we camped at 19,094 feet, later at 18,300, and the rest of the time, 
between 18,000 and 17,000 feet .... 

One day we crossed a pass at 20,459 feet (6230 meters), and 
three days before, August 19, 1855, we had climbed on the sides of 
Ibi-Gamin to the height of 22,259 feet (6882 meters). So far as we 
know, that is the greatest height to which anyone has ascended in 
the mountains .... 

On the peak of Sassar, August 3, 1856, we reached a height of 
20,120 feet. Before us, the brothers Alexandre and James Gerard 
ascended to 19,411 feet on the peak in Spiti, October 18, 1818 .... 

So far as the symptoms to be considered in acclimatization are 
concerned, we can speak from our personal experience. When we 
crossed passes at an elevation of 17,500 to 18,000 feet for the first 
time, we first felt serious symptoms. A few days after, when we had 
traversed the highest points and passed several nights at these alti- 
tudes, we were almost completely free from these disagreeable 
symptoms, even at the elevation of 19,000 feet. What the consequence 
of a longer stay in these lofty regions would have been, we cannot 
say. But we consider it very likely that a longer residence would have 
had serious effects on the health .... 

The effect of the altitude varies with the individual. A healthy 
man is likely to suffer less. The difference in race is not particularly 
important. Our Hindu servants, who accompanied us to the highest 
points, suffered from the cold more than the* Thibetans, their comrades, 
but they did not feel the effects of the decrease in atmospheric 
pressure more. 

For most people, the influence of the altitude begins to appear 
at 16,500 feet, the elevation of the highest pastures. Our camels and 
our horses were very definitely suffering at about 17,500 feet. 

The symptoms produced by the rarefaction are: headache; diffi- 
culty in breathing; oppression in the chest, which may go so far as to 
bring on the spitting of blood, and very rarely slight nasal hemorr- 



Mountain Journeys 155 

hages; we never saw blood issue from the lips and the ears; loss of 
appetite and often nausea; muscular weakness, with a general pros- 
tration and dejection. All these symptoms disappear almost simul- 
taneously, in a healthy man, upon return to lower elevations. The 
effects mentioned are not perceptibly increased by cold, but wind has 
a very harmful effect on the symptoms experienced. As this was a 
new phenomenon to us, and as it had not been mentioned by our 
predecessors, we observed it carefully, and noted circumstances in 
which fatigue was not a factor. On the plateaux of Karakorum, it 
frequently happened even to those who were asleep under the tent 
in rather sheltered places to be awakened during the night by a feeling 
of oppression which must be attributed to a breeze, even a gentle one. 
which had arisen during the hours of repose. When we were busy 
with observations, we took little or no physical exercise, sometimes for 
thirty-six hours, and our servants even less than we did. And it 
often happened, in elevations which did not exceed 17,000 feet, that 
the afternoon or evening wind made us so ill that we lost all taste for 
food; we did not even think of preparing dinner. In the morning, 
when the wind was not blowing, appetite generally returned, we were 
not as ill in the morning as in the evening; this was evidently partly 
because the strong winds rose usually in the second part of the day. 
The effects of diminished pressure are considerably aggravated 
by fatigue. It is surprising how exhausted one becomes; even the act 
of speaking is a labor, one heeds neither comfort nor danger. Often 
our servants, even those who had served us as guides, let themselves 
fall on the snow, declaring that they would rather die at once than 
take another step. From simple motives of humanity, we were often 
obliged to intervene in their behalf and tear them by force from the 
stupor into which they had fallen, whereas we ourselves were hardly 
in a better condition of energy. (Vol. II, p. 481-485.) 

The observations of more recent travellers agree completely 
with what we have just reported. We must even note that, since 
the existence of discomforts on lofty passes is today well known 
to everyone, travellers often do not speak of them, or merely 
allude to them in a few words. 

So Captain Godwin-Austen, L:;7 who explored the glaciers of 
Karakorum, in 1860 made the ascent of Bianchu (16,000 feet) and 
Gommathaumigo (17,500 feet) without speaking of any symptom. 

In his journey of 1861, he first climbed Boorje-La (15,878 feet) ; 
his pulse rate was 138, and that of one of his men 104, and he 
mentions no other symptom (P. 23.) But while he was ascending 
a peak of 18,342 feet (5590 meters) on August 10 (this is the highest 
ascent he made) he reports that "many men became ill, had violent 
headaches, and lay down on the ground." (P. 34.) 

And in addition, in the account - :!S of the long and important 
journeys made by two young Brahmins, two brothers, whom the 
English government sent to visit regions in which Europeans can 



156 Historical 

hardly set foot without risking their lives, there is no mention of 
the symptoms of decompression. And yet the two "Pundits" cer- 
tainly visited many lofty places, since they crossed the Himalayas 
in Nepal, at the foot of Dhawalaghiri, followed the course of the 
Brahmapoutra from Lhasa to Lake Manasarowar, and pushed on 
as far as Gartokh. But since they were exclusively interested in 
geography and politics, they did not heed phenomena which are 
universally known, or at least they did not think they should give 
space to them in their narrative. 

Since this native expedition gave excellent results, a few years 
afterwards, the Trigonometrical Survey sent an employe, the Mirza, 
whose journey M. Montgomerie 239 has related, across Hindu-Kush 
and Pamir to Turkestan. In this account there are a few details 
which refer to our subject. 

In January, 1869, the Mirza reached Lunghar, in the steppes 
of Pamir: 

The whole company, when they reached Lunghar (12,200 feet), 
suffered greatly from the Dum, as the Mirza calls it, that is, shortness 
of breath, etc., the usual effect of great altitudes. The natives gener- 
ally consider it to be produced by a bad wind; some of the men 
became almost insensible, but soon recovered when the Mirza had 
them eat some dry fruits and sugar. (P. 158.) 

At the pass of Chichik-Dawan (15,000 feet) they suffered 
greatly; all felt extreme difficulty in breathing, which the Mirza 
tried in vain to overcome with his sugar candy and dried fruits. 
(P. 165.) 

At the same time, an English traveller, Hayward,' 40 was also 
making his way towards Kashgar, but through Little Thibet, across 
the enormous chain of Karakorum. He too is extremely chary of 
observations relating to the rarefaction of the air. 

The journey lasted from October, 1868, to June, 1869. Crossing 
of the pass of Masimik, at an altitude of 18,500 feet (5640 meters) : 

It presents no difficulties, is very easy, but loaded horses are 
slightly affected there by the rarefaction of the air. (P. 36.) 

Crossing of the pass of Chang-Lang at 18,839 feet (5740 meters) 
(p. 38) ; ascent of a peak of 19,500 feet (p. 43) , of another of 19,000 
feet (p. 55-58), without any physiological observation; he merely 
says: 

The chief difficulty at the Chang Lang pass is the distress of 
loaded animals, as a result of the elevation and the rarefaction of 
the air. (P. 126.) 



Mountain Journeys 157 

The following year, in 1870, the "Munschi" Faiz Buksh, leaving 
Peshawar in the Upper Punjab, set out for Kashgar, trying, like 
so many other more or less clearly official envoys, to open these 
new ways by which the commerce, the diplomatic influence, and 
perhaps the arms of England strive to penetrate western Turkestan. 

His account - 41 is very rich in details which interest us. He 
lays particular stress on Pamir: 

Pamir has been given the name of Bam-i-Dunya (roof of the 
world) because of its height. Its great elevation is proved by the 
absence of trees and the scarcity of birds; grass grows there only in 
the summer. The air there is greatly rarified, so that breathing is 
difficult for men and beasts. This difficulty is called tunk by the people 
of Badakhshan and Wakhan, and ais by the Mogols. The liver and 
the stomach are irritated. Travellers suffer from headache, and blood 
flows from their noses. In people of weak constitution, the face, hands, 
and feet swell. The colder it is, the more marked these symptoms are. 
The natives use acid, dried apricots, and plums as remedies. At night, 
if one does not have his head two feet higher than his legs, respira- 
tion is hampered during sleep. These symptoms appear whether one 
is afoot or on horseback. 

I am thirty-four years old. On one of the peaks of Pamir, my pulse 
rate was 89 per minute; I had a headache, with irritation of the liver 
and stomach; once I had the nosebleed. One of my servants, named 
Kadir, a native of Peshawur, aged twenty-seven, had an attack of 
fever, with difficulty in breathing, irritation of the liver, and swelling 
of the face and extremities; his pulse rate was 99. Another, named 
Mehra, a native of Ghizni, aged twenty, felt only slight difficulty in 
breathing; his pulse rate was 75. Over-feeding increases the difficulty 
of breathing. (P. 470) .... 

Between Ak Tash and Sarkol is a lofty peak named Shindi Kotal, 
the summit of which is always covered with snow; we felt more 
difficulty in breathing there than on Pamir .... Three days' journey 
after Sarkol is a lofty peak called Yam Bolak, the summit of which is 
always covered with snow; we experienced great difficulty in breath- 
ing there also. (P. 472.) 

The expedition led by Forsyth the same year from Lahore to 
Yarkand, through Ladak, had to cross successively the Himalayas 
and Karakorum. The account which Henderson '-' 42 gives of it 
frequently indicates the observation of symptoms due to the rare- 
faction of the air. 

June 27, 1870, crossing of the Namyika Pass, in Ladak: 

Although the summit of this pass has an elevation of only 12,000 
feet, several of our men had great difficulty in breathing, which con- 
tinued for several hours after we had reached our camp at Karbu, 600 
feet lower; some of our men could not even sleep during the night for 
this reason. (P. 46.) 



3 ulse 


Respiration 


80 


26 


100 


22 


94 




92 




93 




78 





158 Historical 

July 10, crossing of the pass of Chang-La, from the basin of 
the Indus to that of Shyok, one of its tributaries, at 18,000 feet 
(5485 meters); little snow: 

It was the first time that almost everyone in camp suffered from 
the rarity of the air. The following observations, made after a half- 
hour's rest at the summit, may seem interesting: 

Mercury barometer 15.73. Thermometer 61 °F. Water boiling at 
181° F. 

I walked to the summit 

M. Forsyth, who was on horseback 

M. Shaw, who was on horseback 

Mullik Kutub Deen, of Punjab, on horseback 

A Hindu of Punjab, on foot 

A Thibetan, on foot 

Several travellers told me that they and their companions 
had suffered more while crossing this pass than on others which were 
higher. We camped for the night near a little lake of sweet water, at 
300 feet below the summit of the pass. The painful symptoms caused 
by the rarity of the air did not disappear until the next day, when 
we were at a much lower altitude. As for me, even at 19,600 feet, I 
have never felt great discomfort; mine amounted only to a certain 
shortness of breath after any exercise, and awakening during the night 
with a feeling of suffocation which disappeared usually after a few 
deep inspirations. But in several of our men the symptoms were very 
serious, and even alarming sometimes. They consisted of intense 
headaches, with great prostration of body and mind, constant nausea, 
and such an irritation of the stomach that even a spoonful of water 
was not tolerated. A great irritability of disposition was another 
marked symptom; in some cases the lips became blue; in M. Shaw, 
a clinical thermometer showed a temperature which had fallen 1 or 2 
degrees in comparison with that of the preceding days. Having with 
me a certain quantity of chlorate of potash, I gave a strong solution 
of it to the patients, rather to please them than in the hope of relieving 
them. However, it seemed to have a good effect, but why? I should 
not dare to make a guess. I do not doubt that these symptoms of the 
lofty mountains are merely temporary and that custom would end 
them, as it does seasickness. They become much more intense when 
one makes an ascent when he is already at a great height. 

July 11, we camped 500 feet below the pass. There the headaches 
and nausea stopped quickly. (P. 56 et seq.) 

July 20, crossing of the pass of Cayley, a newly discovered 
pass, easy of access, which is about 5900 meters high; through it 
one goes from the basin of the Indus to the plateaux of Yarkand; 
there was no snow. The travellers found several butterflies there. 
They do not speak of any physiological disturbance. 



Mountain Journeys 159 

July 21, camp on high desert plains, at an altitude of 5000 
meters; they suffered much from the wind: 

Travellers are frequently killed by this wind, which is sometimes 
so cold that it checks the vitality very quickly. Men and horses 
suffered much here from the rarity of the air. Several of our men lay 
down on the plain, completely exhausted, and could not reach our camp 
until the next day; some horses which fell were abandoned to their 
unhappy fate. (P. 77.) 

They remained several days on these lofty plateaux, and in 
reference to this, the narrator adds: 

There are a number of observations which I greatly regret not 
having made while we were at these heights, and among them 
changes caused in the pulse, respiration, and body temperature. My 
travelling companions offered to submit to the boredom of having 
their temperature taken and their pulse counted at determined times, 
but I found that I already had too many irons in the fire. The few 
scattered observations which I made had no great value, but they 
prove clearly that, in me at least, altitude has only a slight effect, as 
the following figures show. I should say that numerous observations 
made on my companions gave similar results: 

Temperature 
Pulse Respir. under tongue 

Ordinarily 80 24 98.2 

At Sakte, seated for several hours, 

12,900 feet, July 9 90 25 98.3 

Summit of Chang-La; 18,000 feet 

(5485 meters), July 10, after walk- 
ing to the summit 80 26 

Lak Zung, more than 17,500 feet; 

July 24 (P. 79.) 75 24 97.8 

The second part of the book is devoted to natural history. The 
ornithology is edited by A. O. Hume. I am quoting from it inter- 
esting observations on the habitat of birds at great altitudes: 

One of the points which seemed most striking to me in the 
observations of Dr. Henderson is the ease with which birds seem to 
live at great altitudes. Our friend the Cuckoo swings on the pendent 
branches of the birches, uttering his joyous song at an elevation of 
11,000 feet, while snow covers the ground. The Lapwing seems at 
home at 18,000 feet (5485 meters), the "Kashmir Dipper", which lives 
above 13,000 feet, seeks for insects in half -frozen torrents; the 
"Guldenstadt's Redstart" hops carefree in the snow at 17,800 feet; the 
Montifringilla haematopygia seems to live permanently between 
14,000 and 17,000 feet, and the "Adams' Finch" is common at 13,000 
feet. The long-beaked tufted Lark is in places from 12,000 to 15,000 
feet, while the Mongolian "Dottrel" and the "Ruddy Shieldrake" live 
at 16,000 feet, and the brown-headed "Gull" at 15,000. (P. 163.) 



160 Historical 

I shall end this long series of quotations with an extract from 
the work which Fr. Drew L ' 43 recently devoted to the geography of 
Jumnoo and Cashmere. 

In the description of the lofty valleys of Ladak, Drew begins 
with that of Rupshu, the average elevation of which is from 14,000 
to 15,000 feet (4270 to 4570 meters) ; the line of perpetual snow 
there is at about 20,000 feet. A wretched tribe, of one hundred 
tents, lives there, the Rupshu Champas. In a special section the 
author discussed the influence of the rarified air: 

At great elevations, in addition to the oppression and the short- 
ness of breath, one feels headaches and nausea, as happens at the 
beginning of fever or seasickness, but with no modification in the 
temperature of the body. In some persons, at high levels, vomiting 
occurs, but has no serious consequences, and the patient recovers 
when he descends to lower regions, provided however, that the organs 
are not diseased; rarity of the air generally reveals lesions of the 
lungs or heart. 

The elevation at which these symptoms are observed varies in a 
peculiar way, and it is not easy to find the cause of these inequalities. 
The condition of the health has a great deal to do with it; a man in 
good condition can endure a much higher elevation than a man who 
is not accustomed to exercise. That is evident first when one exerts 
himself a little more than usual, as in running or climbing some hill; 
under these conditions, in persons who live above 6,000 feet the 
symptoms usually appear at 11,000 or 12,000 feet. At 14,000 and 15,000 
feet, there sometimes appears what may be called an attack of short- 
ness of breath, even when one is resting. The first time I visited 
Rupshu, that happened to me during the night, when I had been in 
bed about a half -hour; but after a week, I overcame this tendency, 
and since then I have not felt any difficulty in breathing while I was 
resting, even when I camped 2,000 or 3,000 feet higher. Likewise I 
knew a native of Punjab, unused to muscular labor, it is true, who 
had an attack at 11,000 feet. 

But although one can become accustomed to the rarity of the air 
to a certain extent, and not feel it at all, the slightest effort will bring 
on its effects. At 15,000 feet, climbing the gentlest slope makes one 
more breathless than scrambling up a very steep hill at a lower 
altitude. Talking or walking, even on a level, soon produces breath- 
lessness. When one is at great elevations— and here every thousand 
feet make a great change — climbing a slope is a painful labor. I have 
crossed a pass at an elevation of 19,500 feet which lower would have 
caused no trouble; and yet at every 50 or 60 steps, I was absolutely 
forced to stop, panting, to get my breath; but yet I did not feel any 
headache or other painful symptom; acclimatization to the mountains 
for a month or two permitted me to sleep under these conditions. 
(P. 291.) 



Mountain Journeys 161 

9. Africa. 

Atlas. — Several summits of the Atlas in Morocco, which were 
11,000 to 12,000 feet high, were visited by Dr. Hookes, 244 in 1871; 
he does not mention any symptoms. 

Kamerun Mountains. — The first ascent was made December 22, 
1861, by Burton. In the account 24r> of it which he published 
immediately he mentions some strange discomforts which should 
very probably be explained by the influence of the altitude: 

While I was ascending the volcano, I was so tired that I could not 
keep my eyes open; I felt a distress which seemed to me to be due 
to fever. I was obliged to rest, I slept an hour, and at four o'clock 
I was able to make this ascent. (P. 79.) 

The general account 24G which he published later of his journeys 
to the Kamerun Mountains and Fernando Po is no more definite: 

M. Saker then complained of complete deafness. The burning 
heat removed all sensation. Perhaps it was aided by the rarefaction 
of the air. However we were not surprised at suffering so little in 
the course of our ascent from the discomforts of which so many 
travellers to Mont Blanc and in the Rocky Mountains complain. (Vol. 
II, p. 121.) 

We must note that they were then only at 7000 feet; but the 
next day they finished the ascent of the great Peak: 

As we approached the summit, the difficulties of the ascent in- 
creased. Kharah dropped on the ground, almost fainting under the 
rays of a burning sun, and was forced to remain there. At half-past 
one, I reached the summit of the peak. (P. 155.) 

January 13, 1862, another ascent by MM. Calvo, Saker, and 
Mann (P. 162-181). No symptom noted. 

But in the account of it published by Mann,' 47 he declares that 
"he was sick on the Albert Peak and compelled to descend" (P. 23) . 

Finally, January 29, 1862, ascent of Burton. He camped at 
10,187 feet, and reached the cinder cone of Mount Albert: 

I noted again the complete absence of any suffering due to the 
thinness of the air. The altitude is considerable, but not sufficient, 
it appears, to cause the hemorrhages from the ears and lips expe- 
rienced by von Humboldt in the Andes, or the sufferings of M. Gay- 
Lussac in his balloon. (Abeokuta, Vol. II, p. 198.) 

Kilimandjaro. — May 11, 1844, Rebmann - 48 saw Kilimandjaro 
covered with snow. The mountain is "inaccessible, the natives 
say, because of the evil spirits which had killed a great many of 
those who had attempted to ascend it." (P. 276.) 



1 62 Historical 

So he could not attempt an ascent. 

In 1861, Baron de Decken reached an elevation on the sides of 
the immense mountain which Thornton," 41 ' his companion, esti- 
mated as 22,814 feet (6952 meters). 

November 27, 1862, he was able to ascend high enough to feel 
some discomfort. Dr. Kersten, 250 who accompanied him, reports 
that they stopped at 4223 meters, because of the cold, before 
reaching the snow line: 

The ascent (he says) continued to be fairly difficult, and we were 
often forced to stop short. Anamouri, one of the men whom we had 
hired, was also indisposed. (P. 36.) 

Baron de Decken 250 expresses himself more definitely on the 
effect of the altitude: 

When I had reached a height of 4225 meters about quarter past 
eleven, I stopped, as I was forced to do, since my servants could go 
no further without danger of pains in the chest. Dr. Kersten also felt 
the effects of the rarified air. (P. 49.) 

And last, October 30, 1871, New-' 1 ascended Kilimandjaro to 
the snow line: 

My men abandoned me, complaining of the cold. I continued with 
Tofiki alone. All went well for an hour and a half; but then Tofiki 
collapsed, hardly able to speak. He urged me to go on, telling me that 
he would wait for me, but that he would die if I did not return. 1 
went as far as the ice, broke off some pieces of it, and descended at 
once. 

Yes, snow in Africa, he cried with enthusiasm! What ideas 
this undeniable evidence must have given the learned editor of 
the Nouvelles annates des Voyages who, in 1849, denied that Reb- 
mann could have seen snow on Kilimandjaro. 

10. Volcanoes of the Pacific. 

Borneo.— The highest peak of this vast island appears to be 
Kini-Ballu, the height of which (4175 meters) is almost that of 
Jungfrau. 

The first attempt to ascend was made March 11, 1851, by Low.--" 
He did not get above 2850 meters, and considered that the summit, 
which he estimates at 13,000 or 14,000 feet, is "inaccessible for any 
one without wings." 

And yet, in April, 1858, he reached the summit, accompanied 
by M. Spencer Saint- John. The latter felt the effects of the rari- 
fied air very slightly, as his account shows: 



Mountain Journeys 163 

During the ascent (says Spencer) 2 " I suffered slightly from short- 
ness of breath and felt some sluggishness in moving. But hardly had 
I reached the summit when the symptoms left me, and it seemed to 
me that I was lighter, that I could float in the air. 

The thermometer at the summit registered 62°F. (Vol. I, p. 271.) 

In June, 1858, second ascent of the same traveller. This time, 
he did not say a word about physiological symptoms. 

In another part of the island, another English explorer, 
Brooke,- 54 ascended Tabalau Indu in March, 1858. It is difficult 
not to attribute to the altitude a part of the causes of this ikak 
of which the natives speak and which one of his companions 
experienced: 

The climb was hard; the heat was excessive; every step seemed 
the last one could make .... We reached the summit and rested there 
with satisfaction. Poor X . . . was in great distress and lay down on 
his back, while some of his servants went to seek "the friend of the 
traveller", a very abundant root, from which they squeeze a cool 
liquid with a slight taste of wood. It is a great mistake to drink, for 
one has constant thirst, and is attacked by what the natives call 
"ikak", a painful oppression in the chest, with difficulty in breathing. 
(P. 305.) 

Malacca. — In his ascent of Mount Ophir, Braddel 255 experi- 
enced some discomfort: 

When I was near the summit, I had a violent headache and severe 
throbbing in my temples; I bathed my brow with brandy, which 
relieved me .... But I felt a peculiar fatigue and stretched out on 
the ground. (P. 87.) 

Japan. — The first ascent of Fuji-yama of which I have found 
an account was made in 1860 by Rutherford Alcock. L ' '■ He esti- 
mates at 14,177 feet (4320 meters) the height of this volcano 
which has been extinct since 1707. It took him eight hours to 
reach the summit; and he definitely felt the effect of rarefaction 
of the air: 

The second half of the ascent was much more difficult .... The 
air became very rare and evidently affected respiration .... It took 
more than one hour of struggling, stopping frequently to breathe and 
to rest our legs and our backs, which pained us; when we reached 
the top, we were absolutely at the end of our strength. The temper- 
ature was 54° F. (P. 344.) 

Gubbins, 257 who ascended the volcano August 10, 1872, com- 
plains only of fatigue. But Jeffreys,-"* whose ascent was on May 4, 
1874, mentions clearly real symptoms of decompression, attacking 
even the natives: 



164 Historical 

As we were painfully climbing, a strong desire to sleep seized us, 
and the coolies could not resist it when we stopped. One of them was 
even unable to go on and we had to leave him on the way. We ended 
the ascent with great difficulty, and reached the summit at noon 
exactly. (P. 172.) 

Kamschatka.— The only known ascent of the highest volcano 
of Kamschatka, Klioutchef (4805 meters), was made by Erman r " : ' 
September 10, 1829. He does not mention any physiological 
disturbance. 

Hawaii.— June 15, 1825, for the first time Europeans ascended 
Mauna Kea, the "White Mountain" (4195 meters); they were a 
missionary and some officers of the English vessel Blonde. The 
commander Byron" 00 says in narrating this expedition: 

The lieutenant and the purser were so overcome by sleep that 
they lay down on the bare rocks to rest. 

Lord Byron in his turn ascended June 27; but he speaks of no 
discomfort. 

January 12, 1834, ascent of Mauna Kea by David Douglas,- 61 
and January 29, of Mauna Loa, "the Great Mountain" (4250 
meters) : no mention of physiological disturbances. Same silence 
on the part of Loevenstern,- - who ascended Mauna Loa in Janu- 
ary, 1839. Anyway, his account contains only a few lines. 

The great expedition which the government of the United 
States sent around the world under the command of Wilkes 
made a long stay in Hawaii. From December 21, 1840, to January 
13, 1841, Wilkes and several of his officers camped on the side of 
Mauna Loa; several times they reached its highest point. It was 
not with impunity that they lived thus for three weeks at such 
heights; while they were ascending, they suffered severely: 

The thermometer had dropped to 18°, and many of our men were 
severely affected by mountain sickness, with headache and fever, so 
that they were unable to do anything. I myself suffered greatly from 
it, with violent throbbing in my temples, and short, painful, and 
distressing breathing. (P. 149.) 

Officers, sailors, and natives reached with countless difficulties 
the foot of the terminal crater, at 13,440 feet (4095 meters) . The 
next morning, their distress was somewhat abated. The camp 
was kept at this great height for three weeks, and the detailed 
account of the geodetic and physical operations in which they 
were engaged shows that they suffered frequently from mountain 
sickness: 



Mountain Journeys 165 

Everyone experienced it more or less. Dr. Judd remarked that 
in the natives the symptoms were ordinarily colics, vomiting, and 
diarrhea; one or two were affected by the spitting of blood, some had 
fever and chills. Almost all of us had yellowish skin, headache, 
and vertigo, some had asthma and rheumatism .... 

Dr. Judd also found that patients were very hungry without 
being able to eat. During the day, the least exercise increased the 
pulse rate of all of us by 30 to 40. (P. 177.) 

Since that time, I have found in the accounts of the travellers 264 
who have ascended the volcanoes of Hawaii or Maui no mention 
of physiological distress. 



I See Jourdanet, Influence de la pression do I'air sur la vie de I'hommc. Paris, 1875. Vol. 
If P- 212. . , 

-Relation vcridique de la conqnetc du Perou: in Collection de voyages pour servir a 
Vhistoire de la decouvertc dc t'Amaiquc, by Ternaux-Compans, Vol. IV, Paris, 1837. _ 

3 Histoire d,es querres civiles des Es'pagnols dans les Indcs. Translation of Baudoin, p. 
200. Paris, 1650. (The original work was published in Cordova in 1613.) Book II, Chap. XX. 
Vol. I. • 

4 Histoire veritable d'un Voyage curicnx dans VAmeriquc, from 1534 to 1554. In the 
Ternaux-Compans collection, Vol V. 

5 Acosta (Jose de) Historia Natural y Moral de las Indias: en que se trata de cosas 
notables del Ciclo, d.e los elementos, mctalcs, plantas, v animales, etc. (Seville, 1590) 

''■Historia general de los Hcchos do los Castcllanos en las islas y ticrra firme del mar 
Oceano. Madrid, 1615. Decada V. Book X. Chap. V, Vol. Ill, p. 20, I. 

7 New edition, Vol, VI, VII, VIII, IX. Paris, 1781. 

8 Relation du voyage de la mer dit Sud aux coles du Chily ct du Perou, made during 
the years 1712. 1713, and' 1714. Paris, 1716. 

Relation abregce du voyage fait au Perou, par M. M. de I Academic royale des sciences, 
pour mesurer les degres du meridicn aux environs de I'cquateur, et en conclure le figure dc 
la terre. Memoires de VAcademie des sciences de Paris, 1744, p. 249-297. 

10 Journal du voyage fait par Vordre du Roi, a I'cquateur. 2 vol., Paris, 1751. 

II Memoires philosophiques. historiqucs, physiques, concemani la decouverte de VAmeriquc. 
French translation, Vol. I, 1787. 

12 Voyage aux regions equinoxialcs du nouvcau continent, fait en 1700-1804. Paris, 1814. 

13 Leitre de M. Humboldt adrcssce an citoven Delambre. datee de Lima, November 25. 
Ann. du Museum d'histoire naturellc. Vol. II. p. 170-180, year XI (1803). 

14 Extrait de plusicurs lettres dc M. dc Humboldt. Ann. du Museum, Vol. II, p. 322-337, year 
XI (1S03). 

15 Von Humboldt (Alexander), Notice sur deux tentatives d'ascension au Chimborazo. 
Annals of Chemistry; second series: Vol. LXIX, p. 401-434; 1838. Translated by Eyries from 
the Jahrbuch de Schumacher for 1837. 

1(1 I could not find this statement in Zumstein's accounts. 

17 Tableaux de la nature, translated by Eyries. Paris, 1828, Vol. II. 

18 Histoire contemporainc de I'Espagne. 2 vol. Paris, 1869. 

19 Gervinus. Histoire du dix-ncuvicme siecle, Mirssen translation, Vol. VII. Paris, 1865. 
2 " Historia dclla Rcvolucion hispano-amcricana. Madrid, 1830. 

21 Carta descricion dc los viages hcchos en America par la Comision cientifica mandada 
par el Gobicmo Espanol. durante los anos 1862, 1866. Madrid, 1866. 

22 Sketches of Bucnos-Axres. Chile, and Peru. London, 1831. 

23 Travels in Chile and la Plata. 2 vol. London, 1826. 

24 Travels in South America, during the years 1819-20-21. 2 vol. London, 1825. 
* Travels into Chile over the Andes, in the years 1820 and 1821. London, 1824. 

20 Narrative of a journey across the Cordillera of the Andes, in the years 1823 and 1824. 
London, 1824. 

27 Rough notes taken during some rapid journeys across the Pampas and among the 
Andes. London, 1828. 

28 Journal of a passage from the Pacific to the Atlantic. London, 1829. 
^Journal of a voyage to Peru. London. 182S. 

30 Itineraire de Valparaiso a Buenos-Ayres. published in the second volume of the Journal 
de navigation autour du globe, of Bougainville. Paris, 1837. 

31 Travels in various parts of Peru including a year's residence in Potosi. 2 vol. London, 

iaso. 

32 Observations on the geography of southern Peru, including survey of the Province of 
Tarapaca, and route of Chile by the coast of the Desert of Atacama. Journal of the Royal 
Geographical Society. London, vol. XXT. p. 00-130; 1851. 

33 D'Orbigny, Voyaqc dans VAmeriquc meridionale, made during the years 1826-1833, 7 vol. 
Paris, 1835-1847. 

34 Reise in Chile, Peru, und auf dem Amdsonenstrome, wahrend der Jahre 1827-1833, 2 vol. 
Leipzig, 1836. 

35 Ascension au Cliimboraco, made December 16, 1831. Ann. de Mm., second series, vol. 
LVTTT. p. 150-180; 1835. 

" i; Reise urn die Erde. in den Jahren 1830-32. Berlin 1835. vol. II. 

"Narrative of the voyages of Adventure and Bcaqle; 1826-1836, third volume; Journal and 
remarks. London, 1832-1836. 



166 Historical 

38 Narrative of a journey from Lima to Para. London, 1836. 

38 Practical observation on the diseases of Peru, deseribed as thev occur on the Coast and 
in the Sierra. Edinburgh Med. and Surg. Journal, vol. LIV, LVI, LVII, LVIII, 1839. 1841. 
1842, 1843. 

*" Fragment d'un voyage dans Ic Chile el an Cusco. Bull, dc la Soc. de geogr. Second 
series, vol. XIX, p. 15-57; 1843. 

41 Peru, Rciseskizzen aus den Jahrcn J838-1842. 2 vol. Saint-Gallen, 1?46. 

42 Expedition dans les parties centrales de I Amerique du Slid. Hist, du voyage, vol. Ill 
and vol. IV. Paris, 1851. 

43 Voyage a travers V Amerique du Sud, de V Ocean Pacifique a focean Atlantique. Paris. 

44 The U. S. naval astronomical Expedition to the southern Hemisphere during the years 
1819 - 185(?) 2 Chile, Philadelphia, 1859. 

46 Report of a journey across the Andes, between Cochabamba and Chirnore. J. of the 
royal geographical Society, vol. XXIV, p. 259-265; 1854. 

* a Voyage dans le nord de la Bolivie et les parties voisines du Perou. Paris, 1853. 

47 Voyage dans I' Amerique du Sud, Perou et Bolivie. Paris, 1861. 

48 Rclse durch die La Plata-Staatcn. ausgefuhrt in den Jahren 1857-1860. 

49 Travels in Peru and India. London, 1862. 

50 Description geographique et statisiiquc dc la confederation argentine. 3 vol. Paris. 
1860-64. 

51 Mouqueron's translation. Paris, 1863. 

52 Dc la phthisic pulmonaire dans ses rapports avee I' altitude et avee les races au Perou 
el en Bolivie. Du soroche on mal des inoutagncs. Thesis of Paris, 18(32. 

53 The reference is to Castelnau. 

r ' 4 Relatione dclla gita da curico net Chili a sun Raphael nclla Pampa del sur ( febraio 
1866). Parma. 1869. 

55 Rcise iiber die Cordilleren von Arica bis SaniOrCrus. Extrait in Petermann's Mitthcil- 
nngen, Vol. XI; 1865. 

56 Exploration du cratere du Rucii-Pichincha. Nouv. ami. des voyages, Vol. CVII, p. 
106-112; 1845. 

r ' 7 Ascension du Pichincha. Chalons- sur-Marne, 1858. 

58 Remy (Jules) et Brenchley, Ascension du Chimborazo. Nouv. ann. des voyages, Vol. 
CLIII, p. 230-238; 1857. 

50 Voyages au Chimborazo. a i Altar, et ascension au Tunguragua, letter of April 18. 1873. 
Bull, de la Soc. de geogr., sixth series, vol. VII. p. 258-295; 1875. 

'*> Journey of M. Wafer, in which is found the description of the isthmus of America; 
inserted in volume IV of the Voyage aux tcrres Australes, of G. Dampier. Rouen, 1715. 

61 Voyage geographique aux republiques de Guatemala et de San Salvador. Paris, 1868. 

MAufenthalt and Reisen in Mexico in den Jahren 1825 bis 1834. Stuttgart, 1856. 

63 Recherches de Pathologic comparee. Cassel, 1853. 

04 Jourdanet, Prcssion dc Vair, vol. I, p. 212. 

*'"• L. \Y. Glennie, The ascent of Popocatapetl (sic). Proceedings of the geolog. Soc. of 
London, vol. I, n. 7.3; 1834. 

m Gros (baron), Ascension au sommet du Popocatepetl. Letter of May 15, 1834. Nouv. 
ann. des voyages, vol. LXIV, p. 44-68, 1S34. 

67 Ascension du volcan du Popocatepetl (mountain of smoke) in September, 1856. Nouv. 
ann. des voyages, vol. CLIII, p. 304-317; 1857. 

08 Recit d'une ascension du Popocatepetl, by MM. A. Dollfus, de Montserrat and Pavie, 
Archives de la Commission scicntifique du Mexique, vol. II, p. 187-201. Paris, 1866. 

69 Reisen in den Vcreinigtcn Staaten, Canada und Mexico. Leipzig, 1S64. 

70 Attempted ascent of Orizaba. Alpine journal, vol. Ill, p. 210-214. London, 1867. 

71 Report of the exploration to the Rocky Mountains in the year 1842. Washington. 1845. 
10 Reports of explorations and surveys to ascertain the most practicable and economical 

route for a railroad from the Mississippi River to the Pacific Ocean. Vol. II. Washington, 1855. 

73 Ascent of Mount Hood. Extract in Proceed, of the Roy. Geogr. Soc. vol. Ill, p. 81-84; 
1867. 

74 Petermann's Mitthcil., vol. XIV, p. 151; 1868. 

75 Mountaineering on the Pacific. Alpine journal, vol. V, p. 357-367. London, 1872. 

76 Ibid., vol VI, 192-193; 1874. 

77 Opere, vol. 4. Venet, 1729. 

78 Aetnac topographia; in Thesaurus antiq. sicul. Lugd. Bat., 1728. 
70 De Rebus siculis. Catane, 1749. 

80 De motu animalium. Pars altera. Rome, 1681. . 

81 Voyage dans la Sicile et dans la grande Grece, addressed by the author to his friend, 
M. Winckelmann; translated from the German (without author's name). Lausanne, 1773. 

82 Voyage en Sicile et a Malthe, vol. I, p. 225. Amsterdam, 1775. 

83 Voyage pittorcsque des isles de Sicile, de Malthe, et dc Lipari, vol. II, p. 103. Pans. 
1784. 

84 Voyage en Sicile. Paris, 1788. . . 

85 Relation d un voyage fait depuis pen sur ce volcan: in J / oyagc pittorcsque ou description 
du royaumc de Naples et de Sicile, by the abbe Saint-Non. Fourth volume, p. 91-104. Paris, 1785. 

80 Built by Empedocles, according to the legend. (See Fazello, loc. cit., vol. I, p. .) 

87 Voyages dans les deux Sidles, translated by G. Toscan, Vol. I, Paris, year VIII. 

88 Descrisione dell' Etna. Palermo, 1818. 

^Voyage critique a I' Etna, en 1819, vol. I. Paris, 1S20. 

90 Souvenirs de la Sicile. Paris, 1823. 

91 Note sur les effets physiologiques de la rarefaction de Vair a de grandes hauteurs, boc. 
philomatique, p. 120-122; 1822. . . 

92 "In the midst of it is seen a very steep, round mountain which they call Pico de Teithe. 
the topography of which is as follows: its peak is very steep and includes 15 leagues, which 
amount to more than 45 English miles." Description des Canaries, by the Englishman Nicols 
or Midnal; in Traite de la navigation, by Pierre Bergeron, preface to Voyages faits en Asie 
dans les douzicmc, trcizicmc, quatorzicmc at qninziemc siccles, vol. I, p. 119. La Haye, 1735.. 



Mountain Journeys 167 

M A Relation if the Pico Teneriffe received from some considerable merchants and men 
worthy of credit, who went 'to the top of it. History of the Royal Society of London, by Th. 
Sprat, third edition. London, 1722, p. 200-213. 

94 Philos. Transac, Sept. 12, 1670. Vol. XXIX, p. 317-325, 1717. 

95 An account of a journey from the port of Oratava in the Island of Teneriff, to the top 
of the Pic in August 1715. Mem. of the Royal Soc. of London, second edition, vol. VI, p. 1,2-1,7. 
London, 1745. 

M Memoirs of the Academy of Sciences of Paris for 1746, p. 140-142 

97 The History of the Discovery and Conquest of the Canary Islands. London, 1,64. 

9 > Relation d'un vovage a la recherche de la Perouse, made by order of the Constitutional 
Assembly, during the years 1791-1792 and during the first and second years of the French 
Republic. Paris, year VIII. , .,„._., VT 

99 Essais sur les isles Fortunees et I'antique Atlantide. Paris, Germinal, year XI. 

^""Voyage aux regions equinoxiaJes du nouveau continent, vol. I, p. 123-145. Paris, I 814 - 

101 Lettre au citoven Devilliers fils. Journal de phvs., de chim. et d'hist. not., vol. LVII. 
p. 55-63; 1S03. _ . 

^Description physique des iles Canaries, Translated by Boulanger. Paris, 1836. 

103 Voyage de i Astrolabe, made during the years 1826-27-28-29. Histoire du voyage, vol. 
I; Paris. 1830. 

104 Voyage au Pole Slid. vol. I. Paris ,1841. , 

i<>5 Voyage around the world of the Astrolabe and the Zelee, under the command of 
Dumont d'Urville. Paris, 1S42. . 

106 Voyage geologique aux Antilles et aux iles de Teneriffe et de Fogo. Paris, 1S4S; vol. 1, 
p. 65-79. 

'"'Journal d'un voyage en Chine in 1843, 1845, 1846. Paris, 1S48, 3 vol. 

108 Sixteen rears of an artist's life in Morocco, Spain, and the Canary Islands, 2 vol. 
London, 1859. „„_ _ , . Al 

. 109 Vie de Jean d'Aranthon eve que d'Alex, de 1660 a 1695; Lyons, 1,67. Quoted in the 
Guide ■ itineraire du Mont-Blanc, of V. Payot. Geneva, 1S69; p. 161. 

110 Eletnenta physiologiae, vol. Ill, p. 197. Lauzanne, 1761. 

111 Disquisitiones physicae de meteoris aqueis. Pars prima. Tiguri, 1786. 
i ri Die Bergkrankheit. Le.ipzig, 1854, p. 71. 

113 Nouvelle description des glaciercs et glaciers des Alpes, second edition. Geneva, 3 vol.; 
1785. 

114 Tableaux topographiques, etc de la Suisse, vol. I. Paris, 1,80. 

115 Voyages dans les Alpes, 4 vol. Geneva; 1786-1796. 
110 The exact height is 3655 meters. 

"''Narrative of a journey from the village of Chamouni, in Switzerland, to the summit of 
Mount Blanc, undertaken on Aug. 8, 1787. Thomson's Annals of Philosophy, vol. IX, p. 97-103; 
1817. 

118 Letter from M. Bourrit to the editor uf the Bibliothequc britannique. Biblioth. but. 
de Geneve, vol. XX. p. 429-433; 1802. 

ii» Vovage an Mont-Blanc. Vienna, Gerald Company. 

1211 BibHo-thcque universelle de Geneve, vol. IX, p. 84-89, 1818. 

l * Notice sur un voyage au sommct du mont Blanc, ibid., vol. XIV, p. 219-234, 1820. 

vsi Relation de deux tcntatives rccentes pour monter sur le mont Blanc. Bibliotheque 
universelle de Geneve, vol. XIV. \>. 3U1-323; 1820. Hamel has since published a more 
detailed account of his journey, with historical notes, under the title of Beschreibung zweier 
Reisen auf den Mont-Blanc. Vienna, 1821. 

123 Hamel makes a mistake here; he was still about 700 meters from the summit (Lepileur). 

124 Notice sur une nouvelle ascension au mont Blanc. Biblioth. univ. de Geneve, vol. XXI. 
p. 68-75, 1822. 

135 Details dune ascension au sominet du mont Blanc, Ibid, vol. XXIII, p. 137155 and 
237-244, 1823. 

*** D. Clark and Capt. Sherwill, Qitclques details sur leur expedition au mont Blanc. 
Biblioth. univ. de Geneve, vol. XXX, p. 245-246, 1S25. 

,2f Ascension du mont Blanc en 1827. Nouv. ami. des voyages, vol. XL. p. 265-269, 1828. 

12s Reise auf die Eisgebirge des kantons Bern und Ersteigung ihrer hochstergipfel in 
sotnmer 1812. Aarau, 1813. 

129 Dr. Parrot. Ueber die Schneegranse auf dcr mittaglichen scite des Rosagebitrges und 
barometrische Messungen. Schweiggers journal fur chemie und physik, vol. XIX, p. 367-423, 1817. 

i3o They are told verbatim in the Bibliothequc universelle, vol. XXVIII, p. 66-77, 1825. 
Zumstein's notes were published in Vienna in 1S24, by Baron von Welden, in a book entitled: 
Der Monte Rose, which I could not procure. I am borrowing the preceding details from an 
article published by M. Briquet under the title of Ascnsions aux pics du mont Rose. (Bibl. univ.. 
vol. XII. p. 1-47; 1861.) 

131 Naturhistorische Alpenreise. Solothurn, 1830. 

lxl Apercu sur la topographie medicale de V hospice du mont Saint-Bernard. Nouveau jour- 
nal de Med.. Chim.. Pharm. etc. vol. VII, p. 29-37; 1820. 

133 Ascent to the summit of mont Blanc, Sept. 16-18, 1834. Edinburgh new philos. journal, 
vol. XVIII, p. 106-120; 1835. 

134 Ascension au mont Blanc, translated from the English by Jourdan. Geneva, London, 
1838. 

135 Influence on the human body of ascents of high mountains, Revue medicale, 1842; vol. 
IV, p. 321-344. 

130 Excursions et sejours dans les glaciers et les hautes regions des Alpes, of M. Agassiz 
and his travelling companions. Neufchatel, Paris, 1844. 

137 Revue Suisse. Neufchatel, June, 1843. 

138 Journal d'une course faite aux glaciers du mont Rose et du mont Cervin. Biblioth. 
univ. de Geneve, Second series, vol. XXVII, lS4fl. 

139 Ausflug nach dem Aletsch Eismeer und Ersteigung dcr Jungfrau (4167 m.). Quoted in 
extenso in Materiaux pour Vetudc des glaciers, by Dollfus-Ausset. vol. IV. 1864. 

140 Beobachtungen iibcr den Einfluss der verdunnte Lit ft und des stdrken Sonnenlnhtes 
auf holier Gebirgen, etc. Osterreich. med. Johrb. N. Folge, vol. XXXII; 1843. 



168 Historical 

»« Travels through the Alps of Savoy.— Edinburgh, 1843. , . . 

i4a Metn. sur les phenomenes physiologiques, observed on ascending to a certain neiRnt in 

the Alps. Revue medicate, 1845, vol. II. AT . , 

143 Z?<?ifjr ascensions scientifiques an mont Blanc.— Revue des Deux-Mondes, number ot 

*** Ascension dn mont Blanc par la route de Saint-Germain— les Bains.— Nottv. ann. des 
voy., vol. CLXIII, p. 358-36-2, 1859. 

140 Tyndall, The glaciers of the Alps.— London, 1660. 

146 Hours of exercise in the Alps.— Second edition.— London, 1871. 

147 Der mont B/a»c. Darstellung der Besteigung desselben am 31 juh, 1,«. 2 August 1859. 
rlin, 

us TJ 

p. 66-106, 1865. .... , , , 

149 Deux ascensions au mont Blanc en 1S69; Recherches physiologiques stir de vial des 
tagnes {Lyon medical, 1869.) 

150 Histoire du mont Blanc. Paris, 1873. 

151 Ascensioii du mont Blanc. La Nature, Oct. 10, 1874. 

152 Le mont Blanc et Chamounix. Geneva, no date. 

153 Alpine journal, vol. V, p. 189.— London, 1872. 

154 Ascent of the Fihsterraar-hom— Peaks, Passes and Glaciers.— London, 1So9, 

155 A night bivouac on the Grivola.— Peaks, Passes, and Glaciers.— second series, vol. 11.— 
London, 1862. . „ . _ . „, . 

1S0 Schweitzer. The Breithorn (3735) ascension in 1861.— Peaks, Passes, and Glaciers- 
Second series, vol. 1.— London, 1862. • 

157 Ascent o/ tfce Deiif Blanche (June 9, 1862). 77s<? /Jtyme Journal, vol. I.— London, 1864. 

158 Stephen (Leslie), 77ie Jungfrau-joch and Viescher-joch. Alp. joum., vol. L— London. 

159 Reg. Somerled Macdonald, Parage of the Roththal Sattel (August, 1864). Alp. joum., 
vol. II.— London, 1866. 

100 The Studer-Joch. Alp. joum., vol. L— London, 1864. , . . ,. . ,„ 

101 Ascension al monte Rosa nell' agosto 1864. Bulletino del Club alpino italiano. vol. VI. 

P ' l ™ Ascension de la Jungfrau; Annuairc du Club alpin francais, first year, 1674, p. 211-219. 
—Paris, 1875. 

ia Peaks, Passes, and Glaciers, p. 482-509.— London, 1859. 

104 Paris, fifth edition; 1874. . 

105 /4:?c<?h£ of f/ie Grivola.— Peaks, Passes and Glaciers.— Second series, vol. 11.— London. l»bl. 
1,e On Mountains, and on Mountaineering in general. Alpine journal, vol. V, p. 241>-24S, 1872. 
167 Philosophical transactions, Sept. 12, 1670. 

las Description des Pyrenees, 2 vol.— Paris, 1S13. 

urn He even spat blood, according to Gondret (Mem. concernant les effets de la pression 
atm. sur le corps humain; Paris, 1819. (P. 44.) _ 

170 Voyage au sommet du mont Perdu.— Ann. du Museum d'historie naturelle, vol. Ill, 1804. 

171 Tableau des Pyrenees francaises, 2 vol.— Paris, 1828. 

17 - Rapport fait au Counseil des mines sur un voyage a la Maladctta, par la vallee de 
Bagne'res-de-Luchon.— Journal des Mines, Messidor, year XII, vol. XVI, p. 249-282; 1804. 

173 Ueber die Beschleunigung des menschlichen Pulses nach Maaszgabe der Erhohung des 
Standpunkets uber der Meeresfldche.—Frorieps Notizen, vol. X; 1825. 

* 74 Voyage a la Maladctta.— Paris, 1845. 

175 Recueil des ascensions au pic du Nethou, from 1842 (first ascension) to 1868.— Bull, de 
la Societe Ramond, 1872, p. 15-24, 193-198; and 1S73, p. 49-58. 

718 Ford, A Hand-Book for travellers in Spain— London, 1847. 

177 Voyage au mont Caucase et en Georgie— Paris, 1823. 

178 Voyage a la vallee du Terek. N. Ann. des Voyages, vol. LI, p. 273-324; 1S31. 

179 Voyage dans les environs du mont Elbrous dans le Caucase, undertaken in 1829.— Report 
made to the 'imperial Academy of Sciences of St. Petersburg— St. Petersburg, 1630. 

1S0 Voyage dans les rallies centrales du Caucase, fait en 1836 et 1837.— N. Ann. des Voyages, 
vol. CXVIII, p. 276-328, 1848. w , ^ ttt n _ 

181 Reisen und Forschungen im Kaukasus, 1865.— Peterm. Mitth, vol. X11I, 1867 

182 Journey in the Caucasus, and Ascent of Kasbek and Elbrus.— The joum. of the royal 
oeogr. Society, vol. XXXIX, p. 50-76; London, 1869.— Itinerary of a Tour in the Caucasus: 
Alpine Journal, vol. IV, p. 160-166; London, 1870.— The Caucasus, by C. Tucker (Ibid. 421-42f>.) 

»m Itinerary of a Tour in the Caucasus made bv F. Gardiner, F. C. Grove, A. W. Moore 
and A. Walker, with Peter Knubel of St. Niklaus.— Alp. Journal, vol. VII, p. 100-103; London, 18(4. 
1S4 An ascent of Elbrus.— Alpine Journal, vol. VII., p. 113-124; London, 1875. 
"-Voyages faits en Asie, dans les XII, III, XIV, et XV siecles— The Hague, 1735. 

180 Philosophical transactions, Sept. 12, 1670. 

187 Relation d'un voyage du Levant, 2 vol.— Paris, 1717. 
WReise sum Ararat.— Berlin, 1834. 
189 Magasin fur die Litteratur des Auslandes; 1835, no. 34. 

190 Gazette russe de I' Academic ; 1838, nos. 21, 23. 

191 Journal le Caucase; 1846. nos. 1, 5 7. r-vvv 
™* Journal le Caucase; 1850, no. 50.— Translated in Nouv. Ann. des Voyages, vol. CAAA. 

p. 334-349; 1851. _ , 

™ 3 Reisen im Armenischen Hochland in Sommer 1871— Second part: West— Peterman s 
Mittheilungen, 1873. 

194 Notice d'un voyage dans I'Asic-Mincure, faite en 1837.— iV. Ann. des Voyages, vol. 
LXXXI, p. 153-196; 1839. 

1913 An Account of the Ascent of Mount Demavend, near Tehran, in September, 1837.— 
Joum. of the R. geograph. Soc, vol. VIII, p. 109; 1838. 

1M R. F. Thompson and Lord Schomberg H. Kerr, Journey through the Mountainous Dis- 
tricts North of the Elbruz, and Ascent of Demavend, in Persia.— Proceedings of the royal 
geograph. Soc. vol. Ill, p. 2-18; 1859. 

197 Great mistake; the height of Demavend is 5620 meters. 



Mountain Journeys 169 

19S iLe livre de Marco Polo, citoyen de Venise, drawn up in French at his dictation, in 
1(208, by Rusticien de Pise.— Published by Pauthier. Paris, 1865. 

199 Purdon On the Trigonometrical Survey and Physical Configuration of the valley of 
Kashmir.-], of R. Geogr. S., vol. XXXI, p. 14-30; 1S61. . 

200 Memioires stir les contrecs o<ccidentales, translated from the Sanskrit into Chinese, in 
the Year 648, by Hiouen-Thsang, and from the Chinese into French by Stanilas Julien, vol I.— 

1201 Klaproth, Description du Thibet, translated from the Chinese— Paris, 1831. 

202 Voyages an Thibet; translated by Parraud and Billescoq.— Paris, year IV. 

103 Voyages de Fr. Bemicr, vol. II, letter IX— Amsterdam, 1699. 

2<"2*5 Description de la Chine of P. du Halde, vol. IV— Paris, 1735. . 

206 Letter of April 16, 1710. Lettres edifiantes. New edition, vol. VII, p. 430-435— Paris, 1781. 

301 An Account of the Kingdom of Thibet, by J. Stewart— Phil, transactions, vol. LVII. 
p. 465-492; 1777. , _ . 

'-"" Ambassade an Thibet et an Boutan, translated by Castera, 2 vols.— 1 aris, 1800. 

509 A Journcv to Sirinagur .—Asiatic researches, vol. VI, p. 309-3S1; 1801. _ _ 

410 A Journey to Lake Manasarovara in Un-des, a Province of Little Tibet. Asiatic re- 
searches, vol. XII", p. 375-534— Calcutta, 1816. . . 

211 Travels in the Himalayan provinces of Hindustan and the Penjab; in Kunduz and 
Bokhara; 2 vol.— London, 1851. . . 

212 Journal of a Tour through Part of the snowy Range of the Himalaya mountains, and to 
the sources of the Rivers Jumna and Ganges— London, 1820. This journal was published in 
abridged form in the Asiatic researches, vol. XIII, p. 170-249.— Calcutta, 1820. 

213 Vol. XXII, p. 415-430.-London, 1820. 

214 Account of Koonawur. in the Himalaya.— London, 1841'. 

215 First part: journey out. Account of part of a journey through the Himalaya moun- 
tains—The Edinb. Philos. journal, vol. X, p. 295-305; 1824.— Second part, journey back. Journal 
of an Excursion through the Himalaya mountains, from Shipke to the Frontiers of Chinea. 
Tartary.—Thc Edinb. Journal of Science, vol. I, p. 41-51 and p. 215-244; 1824. These two 
articles are reprinted in the Journal of the Asiatic Society of Bengal, vol. XI, p. 363-391; 
1842. My quotation is taken from this publication. 

2115 Lloyd: Narrative of a journey from Caunpoor to the Boorcndo pass, with Capt. Alex. 
Gerard's account of an attempt to penetrate by Bekken to Garoo and the Lake of Manasarowara. 
—London. 2 vol. 1840. . 

217 Al Gerard, Account of a Survey of the valley of the Setlej River, in the Himalaya 
mountains.— The Edinb. Journal of Science, vol. V, p. 270-288, 1826, and vol. VI, p. 28-50, 1827. 

21S Account of Koonawur in the Himalaya. Published after his death by G. Lloyd. 

London, 1841. 

210 Journal of a Survey to the Heads of the Rivers Ganges and J umma. Asiatic researches, 
vol. XIV, p. 60-152.— Calcutta, 1822. 

230 Voyage par les monts Himalaya aux sources du Djcmna et de la au-v frontieres de 
ran fire chiuois ; d'avril en Oct. 1827.— AT. Ann. des Voyages, vol. LXVII, p. 127-188, 1835. 

221 Corresp on dance inedite, vol. II, 1867. — Lettre a MM. les. Professeurs Administrateurs 
du Museum, a Paris, 

222 Voyage dans I'Inde, pendant les annees 1828 d 1852.— Paris, vol. II, 1641. 

223 The lake is at an altitude of 4650 meters. 
324 Bcrghaus Annalen, vol. V.— Berlin, 1832. 

225 A personal narrative of a journey to the source of the River Oxus, in the years 1836, 
1S37, 183S— London, 1840. 

22s Cabool; in the years 1836, 3-8.— London, 1842. 

227 Souvenirs d'un voyage dans la Tartarie, le Thibet et la Chine, en 1844-1846, vol. II. 
Paris, 1850. 

-^ Brief c aus Indien. — Braunschweig, 1847. 

2,29 Western Himalaya and Tibet; a narrative of a journey through the mountains of 
Northern India, during the years 1647-48. — London, 1852. 

230 Himalayan journal; or notes of a Naturalist, 2 vol. — London, 1854. 

231 Ascension du Sumcni-Parbitt (Himalaya).— N. Ann. des Voyages, vol. CLII, p. SOS- 
SCO; 1856. 

232 The adventures of a Lady in Tartary, Thibet, China and Kashmir.— London, 3 vol., 1853. 
M3 Trips in the Himalaya.— Alpine Journal, vol. IV, p. 73-93; London, 1870. 

234 The Tibetan Route from Simla to Srinagar— Alpine Journal, vol. Ill, p. 118-153; 
London, 1867. 

235 First ascent of the Tian-Shan or Celestial mountains, and visit to the Upper Course of 
the Jaxartcs or Sxr-Daria, in 1S57.— The Journal of the roy. geogr. Soc; vol. XXXI, p. 356- 
36.5; lf-61. 

236 Schlagintweit (Hermann, Adolph and Robert de), Results of a scientific mission to 
India and High Asia, 1S54-1S58; 4 vol.— Leipzig and London, 1861-1866. 

237 On the Glaciers of the Mustakh Range.— The Journal of the royal geogr. Society, vol. 
XXXIV, p. 19-55; London, 1864. 

238 Reisen und Aufnahmen ztveier Punditen (gcbildcter Indier) in Tibet; 1865 bis 1866. — 
Petermann's Mittheilungen; vol. XIV, p. 233-243; 276-290, 1868. 

239 Report of "the Mirsa's" Exploration from Caubul to Kashgar. — The Journ. of the roy. 
geogr. Soc, vol. XLI, p. 132-192; 1871. 

'^'Journey from Leh to Yarkand and Kashgar, and Exploration of the sources of the 
Yarkand River.— The Journal of the roy. geogr. Soc, vol. XL, p. 33-166; 1870. 

^ l Journey from Peshazcar to Kashgar and Yarkand in Eastern Turkestan.— The Journ. 
of the roy. geo'gr. Soc, vol. XLII, p. 44S-473; 1872. 

242 Henderson and Hume, Lahore to Yarkand. Incidents of the route and natural history 
of the countries traversed by the Expedition of 1870, under T. D. Forsyth. — London, 1876. 

243 The Jumbo and Kashmir territories, a geographical account. _ London, 1875. 

244 Letters to S. Roderick Murchison giving an account of his Ascent of tlve Atlas. — 
Proceed, of the roy. geogr. Society, vol. XV, p. 212; 1871. 

245 Relation d'une ascension aux monts Cameron (Afrique occidentale). Translated in N. 
Ann. des voyages; vol. Ill, p. 71-107; 1863. 



170 Historical 

-* Abeokuta.— London, 2 vol., 1863. ,„■,-, i vi 

247 Forscliungen an dcr Westkuste von Africa— Petermann s Mtttheilungen, vol. Al, 

' *» Journal dune excursion au Djagga, le pays dcs nciges de l'Afriqu,e orientate.— N. Ann. 
des Vox; vol. CXXII, p. -'.07-307. 1S4'J. 

2iu Notes on a journey to Kilimandjaro, made in company of the Baron von der Uecken. 
-The Journal of the R. geog. Soc; vol. XXXV, p. 15-21; 1865 _ .,»,„., 

**> Ascension du Kilimandjaro, dans I'interieur de I Ajnque oncntale. N. Ann. aes 
Voyaqes; 1864, vol. I, p. 28. 

251 Alpine Journal; vol. Vi, p. 51-52.— London, 1874, issue of April, 1872. 

*^ Notes of an ascent of the mountain Kina—Balozc (The Journal of the Indian Archi- 
pelago. Vol. VI, p. 1-17). — Singapore, 1852. 

253 Life in the forests of the far East. 2 vol.— London, 18S2. 

254 Ten vears in Sarawak.— London, 1866. 

255 Note's of a Trip to the interior from Malacca. The Journal of the Indian Archipelago, 
vol. Vi, p. 73-104.— Singapore, 1853. 

«" Narrative of a joumev in the interior of Japan, in I860— The Joum. of the R. Gcograph. 

Soc., vol. XXXI, p. 321-356; 1861. „ tt m n 

™ Ascent of Fuji-Yama. Proceedings of the Royal Geogr. Soc, vol. XVII, 1873; p. -8- .9. 

** Ascent of Fuji-Yama in the Snow. Proceedings of the Royal Geogr. Soc, March 18.o: 

'"MReise urn die Erde, in die Jahren 1828; 29 und W.—Historique, third vol., p. 363 et seq. 
w I'ovage of H. M. S. Blonde to the Sandwich Islands in the years 1824-1825.— London. 1826. 
261 Extract from a private Letter addressed to Captain Sabine— Journal of the R. Geograph. 
Soc. vol. IV, p. 333-344.— London, 1834. 

282 Apercu dun viyage autour du monde. Bull, de la Soc. de. Geogr., Second Series, vol. 

'*»' Narrative of' the United States Exploring Expedition during the years 1838, 39, 40, 41, 
42, vol. IV.— Philadelphia, 1844. .. ■ 

264 Sawkins, On the I'olcanic Mountain of Hawaii. Joum. of the Roy. Geogr. Soc, vol. 
XXV p 191-194; 1855. Robert Haskell, On a Visit to the Recent Eruption of Manna Loa. 
Hawaii. The American journal of science and arts. Second series, vol. XXVIII; 1859, p. 66-71. 
- Wilmot, Our Journal in the Pacific, London, 1873. 



Chapter II 
BALLOON ASCENSIONS 



At the end of the 18th century, the remarkable discovery of 
the Montgolfier brothers introduced a new element into the ques- 
tion of decompression. In this case, the traveller no longer climbs 
laboriously and slowly to the regions where rarefied aid can act 
upon his organism; he is carried there without fatigue and with 
great speed. 

We are not interested in the montgolfiers, or hot-air balloons, 
since ordinarily they can mount only to very moderate heights. 
We shall simply note that the first aeronauts, Pilatre du Rozier 
and the Marquis d'Arlandes, made an ascent November 21, 1783, 
and crossed Paris in a montgolfler. 

But the history of gas balloons is rich in data applicable to 
our subject. 

The first of December in this same year of 1783, the physicist 
Charles, who had just invented the hydrogen balloon, tested his 
invention under conditions much more stirring and dangerous than 
the two brave aeronauts just mentioned. This ascension, as we 
know, was divided into two periods: Charles, who left the Tuileries 
at 1:45, landed at 3:30 in the plain of Nesles; he let his companion 
Robert get out of the basket; then, lightened, his balloon rose 
again with extraordinary speed. In less than ten minutes he rose 
over 1500 fathoms; the barometer stopped at 18 inches, 10 lines. 

The story 1 of the clever physicist, filled with justifiable en- 
thusiasm, shows ,him as "questioning his sensation, listening to 
himself live, and having no disagreeable feeling in the first mo- 
ment." But soon: 

In the midst of the inexpressible rapture of this contemplative 
ecstasy, I was recalled to myself by a very extraordinary pain in the 
interior of my right ear and in the maxillary glands; I attributed 

171 



172 Historical 

it to the expansion of the air contained in the cellular tissue of the 
organ, as well as to the cold of the surrounding air .... I put on a 
woolen hood which was at my feet; but the pain vanished only when 
I reached the ground. 

This marvellous invention thrilled the whole world; the most 
ardent illusions about the practical utility of balloons were cher- 
ished. Among the strange ideas produced by these experiments 
in which man took possession of the air for the first time, one of 
the most curious is that which, less than a year after the first 
ascent, inspired a thesis sustained in 1784 before the Faculty of 
Medicine of Montpellier. Louis Leullier-Duche, its author, 2 had 
the idea of using balloon ascension as a treatment of diseases. 

"The effect," he said, "will be triple: motion, cold, change of 
air." 

He insists especially upon this last point: 

The essential part of air is for man the dephlogisticated air 
(oxygen). Now in what proportion is it united with the phlogistic in 
the different regions of the atmosphere? Chemists have not deter- 
mined. But as the phlogistic is lighter, there must be more of it at 
a very great height .... The neighborhood of the earth is the proper 
region of the dephlogisticated air. But we cannot doubt that it is 
polluted there by different emanations of volatile bodies. And so, in 
that part of the atmosphere which is the region of dephlogisticated 
air, the latter is purer the further we go from the surface of 
the earth. Moreover, as it is colder, the dephlogisticated air is accu- 
mulated and condensed there. 

Leullier-Duche attributes the strongest curative virtues to oxy- 
gen, and considers that it acts even on generation and death: 

Births at Montpellier coincide with the spring months and deaths 
with the autumn months; during the spring, the atmosphere is more 
laden with dephlogisticated air which the growth of plants produces, 
and during autumn their putrefaction releases a greater quantity of 
inflammable or phlogistic air (he refers to nitrogen by this double 
name). 

Leullier-Duche then proposes to use balloons in the treatment 
of intermittent, pestilential, or nervous fevers, rickets, scurvy, 
hysteria, chlorosis, melancholy, slow healing sores, etc. 

We have seen that the inventor of the hydrogen balloon, in the 
first and only ascent which he made, experienced painful sensations 
when he had risen rapidly to a height of about 3000 meters. It 
was simply a matter of the expansion of the gases of the middle 
ear, gases which on account of the speed of the ascent had not 
had time to escape by the Eustachian tube. More serious symp- 
toms were soon to be observed. 



Balloon Ascensions 173 

On the 12th of Brumaire in the year VII (see the Moniteur, p. 
173), Testu-Brissy, mounted on a horse, rose to a considerable 
height. 

In a little book,' "dedicated to childhood", a curious engraving 
represents him on horseback on a platform supported by a cylin- 
drical balloon. After some details about the ascent of the 
adventurous aeronaut, the author, who says she knew him, 
declares that: 

The purpose of the scientist was attained; he discovered that at 
a degree of elevation where he himself was not at all affected, the 
blood of large quadrupeds, apparently less fluid than that of man, 
was forced out of the arteries and ran out through the nose and ears. 
Satisfied with this observation, he descended from the considerable 
height to which he had risen, and gave account of his expedition to 
the Institute with modest simplicity. (P. 95.) 
One can hardly attach much importance to this tale. 

Two years after the ascent of Charles, Blanchard, an aeronaut 
who died poor and obscure after enjoying prodigious popularity, 
whose statement, it is true, cannot carry much weight, claimed to 
have risen November 20, 1785, from Ghent, to a height of 32,000 
feet (10,400 meters) : 

I rose with a rupture of equilibrium of 35 pounds .... In less 
than two minutes, I was more than 4500 feet from the earth .... 
The expansion of the inflammable air was such .... that I mounted 
to an incredible height, which according to the record of my instru- 
ment was 32,000 feet from the earth .... 

I sailed in the immensity of the air at the mercy of the winds, 
experiencing a cold which no mortal ever felt in the severest climates. 
Nature grew languid, I felt a numbness, prelude of a dangerous sleep, 
when rising in spite of my lack of strength, I called upon my courage, 
entered my balloon, and with the handle of my flag .... I broke 
the lower pole in pieces. (P. 7.) 

The result of this maneuver was a rapid fall, which ended 
happily after a series of curious incidents. 

Blanchard announced his ascent briefly in a letter, 5 addressed 
to the Journal de Paris. It is evident that he mounted very high; 
but his observation or his calculation was certainly wrong. 

The astronomer de Lalande, who also dabbled in aerostatics, 
appeared quite doubtful. He wrote to" the publishers of this 
curious extract to refute the assertions of the vain aeronaut: 



174 Historical 

Paris, December 7, 1785. 
Gentlemen: 

Probably a mistake slipped into the article which you published 
on the fifth of this month in regard to the ascent of M. Blanchard, 
made November 21 near Ghent; it says that he rose to 32,000 feet, 
which would make 5333 fathoms; the greatest height reached hitherto 
is 2434 fathoms, and the great expansion of the air would probably 
make it impossible to rise to or to breathe at a height which is more 
than double that .... At 2430 fathoms height the barometer is at 
only 16 inches. M. de la Condamine observed it at 15 inches 11 lines, 
but no man has seen it lower. If one could rise to 5441 fathoms, the 
barometer would stand at only 8 inches, and it is probable that hem- 
orrhage and death would soon be the result. 

De Lalande. 

There follows a table given by de Lalande, indicating the rela- 
tions between the barometric pressure and the altitude: 



27 


inches 


158 fathoms 


12 inches 
11 inches 
10 inches 


3679 fathoms 
4057 fathoms 
4472 fathoms 


16 


inches 


2430 fathoms 


9 inches 


4929 fathoms 


15 


inches 


2710 fathoms 


8 inches 


5441 fathoms 


14 


inches 


3010 fathoms 


7 inches 


6021 fathoms 


13 


inches 


3332 fathoms 







By the way, Lalande reproduces this table in the Yearbook of 
the Bureau of Longitudes for the year 1805, then he adds: 

The last numbers will probably be eternally useless; human beings 
will never see the barometer at 11 inches, unless, by artificial means, 
they succeed in giving air to the lungs and lessening the pressure of 
the inner air. (P. 94.) 

In the Yearbook of 1806, the remark about the impossibility of 
reaching 11 inches is suppressed. The only statement is: 

The last numbers are probably useless: M. Gay-Lussac went only 
to 3584 fathoms. (P. 99.) 

Prudent correction, for 11 inches correspond according to 
Lalande to 4057 fathoms (7907 meters) , a height far surpassed 
since then, as we shall see, by Glaisher and Coxwell and by Gaston 
Tissandier. 

But let us return to Blanchard; he did not consider himself 
conquered, and replied haughtily in the Journal de Paris: 7 

Gentlemen: 

If I have not replied sooner to the letter written you by M. de 
Lalande about a so-called error in regard to my ascent at Ghent, in 
which I say I rose to the height of 32,000 feet, it is not for want of 
material; I shall not reply even today, intending to discuss his opin- 



Balloon Ascensions 175 

ion at greater length in the collection of journals of my ascents which 
I intend to give the public. The nature of your paper, gentlemen, 
would not permit me so long a discussion. 

M. de la Condamine, says my illustrious antagonist, is the only 
man who has observed the barometer at the lowest level, and he 
observed it, he adds, at 15 inches 11 lines. It would be of no use to 
remind him that I said that I had seen it at 14 inches in my ascent 
from Lille with the Chevalier de l'Epinard, and lower yet in England, 
because, words not being proofs, he would be just as incredulous in 
the matter. Knowing all M. de Lalande's superiority, I shall take 
care to contend with him only with victorious arms; and as facts 
sometimes give the lie to the most careful calculations, I limit myself 
now to inviting him, as I have just done in a personal letter, to do 
me the honor of accompanying me in my next ascent; he will then 
be convinced that the best arguments have no effect against the cer- 
tainty of a fact. Yours, etc. 

Blanchard, 

Citizen of Calais, pensioner of the King. 

We know that de Lalande replied to the challenge. 

One should read in the Journal de Paris, 8 his curious corre- 
spondence with Blanchard on this subject. On the 8th of Thermidor 
in the year VII, they both ascended with the famous flotilla of 
five balloons invented by the celebrated aeronaut. They hoped, by 
making use of currents, to go as far as Gotha "to see with delight" 
said Lalande, "a prince and a princess who, by their learning and 
their zeal for the sciences, give an example to everyone"; but alas! 
one of the balloons burst, and the astronomer and the citizen of 
Calais fell ingloriously into the Bois de Boulogne. 

But let us drop stories lacking precision and perhaps truth. 
We enter the domain of scientific attempts with the remarkable 
ascents of Robertson and, soon after, of Gay-Lussac. 

The most important ascent of the French physicist Robertson 9 
took place at Hamburg, July 18, 1803. He started at 9 o'clock in 
the morning, accompanied by M. Lhoest, his colleague and com- 
patriot; the barometer marked 28 inches, the Reamur thermom- 
eter 16°: 

During the different tests with which we were busied, we felt 
an uneasiness, a general discomfort; the buzzing in the ears from 
which we had for some time been suffering increased still more as 
the barometer dropped below 13 inches. The pain we felt was some- 
thing like that which one feels when he plunges his head below 
water. Our chests seemed expanded and lacked resilience, my pulse 
was hurried; that of M. Lhoest was less so: like mine, his lips were 
swollen, his eyes bloodshot; all the veins were rounded out and stood 
up in relief on my hands. The blood had rushed to my head so much 
that I noticed that my hat seemed too small. The cold increased 



176 Historical 

considerably; the thermometer then dropped quickly to 2°, and stopped 
at 5V2 below freezing, while the barometer stood at 12 and 4/100 
inches. Hardly was I in this atmosphere when the discomfort 
increased; I was in a mental and physical apathy; we could hardly 
ward off the sleep which we feared like death. Distrusting my 
strength, and fearing that my companion would succumb to sleep, I 
had fastened a cord to my thigh and to his; the ends of this cord 
were in our hands. It was in this state, not much adapted to delicate 
experiments, that I had to begin the observations that I was planning. 
(Vol. I, p. 70) ... . 

At this elevation, our state was that of indifference: there, the 
physicist is no longer sensitive to the glory and the passion of dis- 
coveries; the very danger which results from the slightest negligence 
in this journey hardly interests him; it is only by the aid of a little 
fortifying wine that he succeeds in finding intervals of mental clarity 
and power. 

As I wish to omit nothing that can cast light on the functions 
of the animal economy and the operations of nature at this elevation, 
I ought to mention that when the barometer was still at 12 inches, 
my companion offered me bread: I made vain efforts to swallow it, 
but never could succeed. If one considers carefully the state of the 
surrounding atmosphere, the great rarity of which offered only a 
slight resistance to my expanding chest; if one considers the small 
quantity of oxygen contained in the gas in which I was floating, one 
can believe that my stomach, already filled by a denser gas which was 
impoverished by the loss of oxygen, was in no state to receive solid 
food and still less to digest it. I must add that the natural excretions 
were checked in my friend and myself during the five hours of the 
journey, and that they were not resumed until three hours after our 
return to earth .... 

Seventh experiment. I had taken along two birds: at the moment 
of the experiment I found one of them dead, no doubt on account 
of the rarefaction of the air; the other seemed drowsy. After placing 
him on the edge of the basket, I tried to frighten him to make him 
take flight: he beat his wings, but did not leave his place; then I left 
him to himself, and he fell perpendicularly with extreme speed. There 
is no doubt that birds could not support themselves at this elevation. 
(P. 76) ... . 

One can estimate the height of the balloon, taking account of 
all the corrections, at 3679 fathoms (7170 meters). 10 (P. 83.) 

The number of March 16, 1876, of the journal Les Mondes says 
on this subject: 

If, in one passage of his account, Robertson says that he mounted 
to 7170 meters, in another he says only 7075; calculating by the 
present tables of the Yearbook of the Bureau of Longitudes on the 
data of temperature and pressure registered by Robertson, we find 
only 6881 meters for the maximum height. (Ch. Boissay.) 

Robertson sent the account of his ascent and of the experi- 
ments in physics which he performed during it to the Galvanic 



Balloon Ascensions 177 

Society; a report " was made from which we extract the following 
passage: 

We have known for a long time that an animal cannot pass with 
impunity from an atmosphere to which he is accustomed to one much 
denser or much rarer. In the first case, he suffers from the weight of 
the outer air, which has an excessive pressure; in the second case, the 
liquids or elastic fluids which are part of his system, since they are 
undergoing less than the usual pressure, expand and stretch the 
surrounding tissues. In both cases, the effects are almost the same, 
uneasiness, general discomfort, buzzing in the ears, and often hemor- 
rhages; the experiment of the diver's bell long ago indicated to us 
what would happen to aeronauts. Our colleague and his travelling 
companion experienced these effects with great intensity; their lips 
were swollen, their eyes bloodshot; the rounded veins stood out in 
relief on their hands, and — a very astonishing fact — they both dis- 
played a reddish brown complexion which surprised those who had 
seen them before their ascent. 

This distension of the blood vessels, in their farthest ramifications, 
must necessarily produce a hindrance, a constraint in all the muscular 
movements; and it is mainly to this cause that I think we should 
attribute the vain efforts made by our colleague to swallow the bread 
which his companion gave him when they were still at a height 
marked by 12 inches on the barometer. (Mem., Vol. I, page 106.) 

An aeronaut who was celebrated for being the first to descend 
from a balloon in a parachute (October 29, 1797), Jacques Garn- 
erin, tried to take from his rival Robertson the honor of the highest 
ascent. As the following extract from the Journal de Paris 1J 
proves, he claimed to have risen to 4200 fathoms (8186 meters). 

In the interest of the sciences and the arts, which barbarians have 
mutilated, M. Garnerin writes from St. Petersburg to Paris the account 
• of the aerial journey which he undertook at Moscow the third of last 
October, in which he rose exactly to the height of 4200 fathoms, 
without having experienced any symptom other than hemorrhage of 
the nose, and a little discomfort from the cold. Happy opportunity 
to entertain the public with his quarrels with M. Robertson, whom he 
calls "the aeronaut of Hamburg", and whose powers of observation 
and whose truth he questions! "I rose," says M. Garnerin, "521 fathoms 
higher than the aeronaut of Hamburg, and I did not notice that 
matter lost weight, nor did I see the sun without brilliancy, nor the 
sky without azure. I felt neither an extraordinary apathy, nor diffi- 
culty in swallowing, nor a desire to sleep, etc " 

Nothing seems less authentic than the statement of Garnerin; 
the data which we shall presently report show that at the height 
which he says he reached he would have experienced very serious 
physiological disturbances. 



178 Historical 

In this same year, a very dramatic ascent took place at Bologna. 

Count Fr. Zambeccari, of Bologna, Dr. Grasetti, of Rome, and 
Pascal Andreoli, of Ancona, left during the night of the 7th-8th 
of October, 1803. They had spent the day in inflating their balloon, 
which measured 14,000 cubic feet, and intended to start the next 
day; but they had to hurry on account of the rioting and shouts 
of the populace of Bologna. The balloon rose with extreme rapid- 
ity, and they soon reached such a height that Zambeccari and 
Grasetti, overcome by the cold and exhausted by a series of 
vomiting, fell into a sort of torpor accompanied by a profound 
sleep. The brief account, inserted in the Annales de Gilbert, 1 '■ 
tells their sufferings and misfortune as follows: 

Andreoli, who had retained use of his senses, could not read the 
barometer because the candle which they had brought in a lantern 
had gone out. About 2:30 in the morning, the balloon began io 
descend, and Andreoli heard distinctly the noise of waves breaking 
on the coast of Romagna. He awoke his companions .... The basket 
and the balloon fell into the Adriatic Sea with such force that the 
water dashed up around them to the height of a man. The aeronauts, 
covered with water, in great haste threw out a bag of sand, their 
instruments, and all that the basket contained. 

Then the balloon again rushed rapidly into the air. They tra- 
versed three strata of clouds, and their clothes were covered with a 
thick layer of ice; the air was so rarefied that they could hardly hear 
each other. About three o'clock the balloon descended again. 

The melancholy German pamphleteer Kotzebue, 14 during his 
journey to Italy, called on Zambeccari, this man "whose eyes are 
thoughts". The daring aeronaut gave him a detailed account of 
this terrible ascension of October 7-8, in which he nearly perished: 

I rose at midnight .... Suddenly we mounted with inconceivable 
speed. 

We could observe the barometer only by lantern light, and that 
very imperfectly. The unendurable cold which reigns in the region 
to which we had risen, the exhaustion I felt from lack of food for 24 
hours, the grief which overwhelmed my soul, this whole combination 
caused complete torpor and I fell on the bottom of the basket in a 
sort of sleep like death. The same thing happened to my companion 
Grasetti. Andreoli was the only one who remained awake and well, 
no doubt because his stomach was full and he had drunk rum abun- 
dantly. In fact, he too had suffered greatly from the cold, which was 
excessive, and for a long time made vain efforts to awaken me. 
Finally he succeeded in getting me to my feet, but my ideas were 
confused; I asked him, as if I had been dreaming: "What's the news? 
Where are we going? What time is it? What is the direction of the 
wind?" 

It was two o'clock. The compass was ruined, consequently it was 



Balloon Ascensions 179 

useless to us; the candle in our lantern could not burn in an air so 
rarefied, its light grew dimmer and dimmer, and finally went out. 
(Vol. IV, p. 301-303.) 

They then fell into the sea; then having thrown out everything 
in their basket, they rose again: 

With such rapidity, to such a prodigious height, that we could 
hardly hear each other even when we shouted; I was sick and vomited 
considerably. Grasetti had the nose-bleed; we both had short respira- 
tion and an oppression in our chests. As we were wet to the 
bone when the balloon took us into the higher strata, the cold seized 
us rapidly and we were covered in an instant with a layer of ice. I 
cannot explain why the moon, which was in its last quarter, was in 
a line parallel with us, and seemed red as blood. After rushing 
through these immense regions for a half-hour and being carried to 
an immeasurable height, the balloon began to descend slowly, and we 
fell once more into the sea; it was about four o'clock in the morning. 
(Vol. IV, p. 305.) 

The unfortunate aeronauts fell into the Adriatic and remained 
there, the playthings of the winds and the waves, until 8 o'clock, 
when a bark picked them up, not without great difficulties. Their 
feet and hands were frozen, and Zambeccari had to have three 
fingers amputated. 

The following year on June 30, Robertson 15 made a new ascent, 
accompanied by the Russian physicist Sacharoff; but their barom- 
eter went to only 22 inches and they had no special experiences. 

This same year of 1804, two young physicists, Biot and Gay- 
Lussac, 111 were given by the Institut de France a scientific mission 
in the air. They were particularly to investigate variations of 
magnetic power, which de Saussure thought he had observed on 
the col du Geant. 

The two scientists left on the 6th of Fructidor, at ten o'clock 
in the morning, from the garden of the Conservatoire des Arts. 
As they did not rise above 4000 meters in a temperature of +10°, 
they felt no serious physiological disturbances. So they said only a 
few words on this subject: 

We observed the animals which we had taken along; they did 
not seem to suffer from the rarity of the air; however the barometer 
stood at 20 inches 8 lines, which gives a height of 2622 meters. A 
violet bee, which we freed, took flight very quickly and buzzing left 
us ... . 

Our pulses were very fast; that of Gay-Lussac, which is ordi- 
narily 62 per minute, was 80; mine, which is usually 89, was 111. This 
acceleration then was felt by us both in about the same proportion. 



180 Historical 

However, our respiration was not at all affected; we felt no discom- 
fort, and our situation seemed to us extremely agreeable .... 

We observed our animals at all heights; they did not seem to 
suffer at all. As for us, we felt no effect, except this acceleration of 
the pulse rate of which I have already spoken. 

There follows the account of what happened to a greenfinch 
and a pigeon, freed at 3400 meters; the pigeon opened its wings 
and let itself fall describing circles like the large birds of prey. 

Gay-Lussac 17 started alone some days after, and rose much 
higher than the first time. The symptoms of a physiological nature 
were quite endurable; he speaks of them thus: 

When I had reached the highest point of my ascent, 7016 meters 
above sea level, my respiration was noticeably hampered; but I was 
still far from experiencing such severe discomfort as to wish to 
descend. My pulse and respiratory rate were much accelerated; and so, 
breathing very frequently in a very dry air, I was not surprised to 
find my throat so dry that it was painful for me to swallow bread . . . 

These are all the inconveniences I experienced. (P. 89.) 

In regard to this account Robertson made an observation which 
is interesting because it shows what cause he assigns to the 
phenomena which he experienced himself: 

I do not think that there is a professor of physics who has not 
spoken to his hearers of the weight of the column of air which corre- 
sponds to the body surface of a man, and who has not shown that 
this enormous weight is made imperceptible to the body by the 
equilibrium established between the pressure of the outer air and the 
reaction of the elastic fluids which are part of its inner system. There 
is none who has not demonstrated what the effects of the rupture 
of this equilibrium would be. (Mem., vol. I, p. 107.) 

But nothing justified Robertson in drawing from these remarks 
the strange conclusion which follows: 

I do not think that M. Biot has changed all that. No one can 
refuse to conclude that the effects experienced by M. Lhoest and my- 
self, then by M. Sacharoff, are anything but very reasonable; while 
those experienced by MM. Biot and Gay-Lussac are so contrary to 
ours that they need to be explained. Now the only explanation 
possible is that these aeronauts did not rise high enough or that they 
rose so slowly that there was no rupture of equilibrium for them, 
otherwise one cannot see what could have kept them from experi- 
encing the effects which are the inevitable consequences. (Mem., vol. I, 
p. 108.) 

This doubt unnecessarily cast upon the truth of the observa- 
tions of scholars like Biot and Gay-Lussac should have had just 



Balloon Ascensions 181 

reprisals, and it had much to do with the undeserved discredit 
which has since fallen upon the statements of Robertson. 

The ascent of Gay-Lussac had a well deserved fame. But people 
went too far in passing over in complete silence those which had 
preceded it. Robertson complained justly that the role which he 
himself had previously played had not been recognized: 

M. Biot printed in his treatise on physics and repeats in his 
courses in the College de France that M. Gay-Lussac rose to the 
greatest height that man had reached up to that time. This assertion, 
though false, is believed by the youth of today, because I have no one 
who can say every year to some hundreds of auditors that I had risen 
to 3630 fathoms more than a year before the ascent of Gay-Lussac; 
and the time will soon come when no one will know or remember that, 
before the ascent of MM. Biot and Gay-Lussac, I had made one like it, 
and like theirs, in the interest of science, but during which the air of 
those high regions had been less hospitable to me than to those gentle- 
men. (Mem., vol. I, p. 117.) 

A few years after, in August, 1808, Andreoli, one of the com- 
panions of the unfortunate Zambeccari, rose from Padua, and 
reached, if we are to believe him, a height much greater than that 
which his predecessors had attained. The correspondent of the 
Journal de Paris, 18 who tells the story, seems to give little credence 
to the account of the Italian aeronaut, a really very extraordinary 
account, in which we do not know whether to be more astonished 
at the ascent or the descent of the daring and lucky aeronauts: 

Italy. Padua, April 23, 1808. 
M. Andreoli undertook yesterday in this city an aerostatic journey, 
which was not very lucky and the account of which arouses unpleas- 
ant doubts among well-informed people as to the veracity of the 
physicist. According to this really curious story, which people in 
Paris may perhaps ridicule, M. Andreoli, accompanied by M. Brioschi, 
rose at 3:30 in the afternoon, in the presence of a great number of 
spectators. The barometer having dropped to 15 inches (to 15 inches! 
Are they quite sure of what they say, and do they know how prodi- 
giously rarefied the air should be and really is at that height? And in 
that case, how would the two travellers have breathed?) at this eleva- 
tion, Brioschi began to feel extraordinary palpitations, without, however, 
noticing any painful change in his breathing: the barometer dropping 
next to 12, he felt himself overcome by a gentle sleep, which soon 
became a real lethargy (they do not say how M. Andreoli felt, and 
how he resisted the powerful narcotic which overcame his companion). 
The balloon kept rising and when the barometer was at about 9 
inches (that is, a height much greater than that of the highest of the 
Cordilleras) Andreoli perceived that it was completely expanded and 
that he could not move his left hand. The mercury, continuing to 
descend, registered 8V2 inches. Then the balloon exploded with a loud 



182 Historical 

report and began to descend rapidly (I believe it), and then M. 
Brioschi awoke (not without terror). The fall took place at the castle 
of Enganca, not far from the tomb of Petrarch and the city of Acqua, 
12 miles from Padua; and the most marvellous thing about this story, 
which was so marvellous from end to end, is that the travellers, no 
doubt protected by a geni out of the Thousand and One Nights, did 
not experience the slightest harm, not even the least scratch. Surely 
that is a miracle which should disconcert all the calculations of ordi- 
nary physicists. However it may be, the travellers took post horses, 
and reached Padua at 8:30 to receive congratulations which such a 
prodigious success deserved on every score. 

I should note here that the celebrated English aeronaut, M. 
Glaisher, 19 seems disposed to give credence to these extraordinary 
data; he calls attention to the fact that Andreoli, accustomed to 
ascents, suffered much less than his companion. And as to the 
possibility of surviving such a terrible fall, he discusses it with 
authority and admits it without great hesitation. (P. 161.) 

August 29, 1811, two Englishmen, Beaufoy and Sadler,-" made 
an ascent in which they did not rise above 6000 feet, and which 
holds no interest for us except the sensation felt by Beaufoy "of 
a slight pressure in the ears and a little deafness", and especially 
the strange explanation of it which the traveller gives: he attrib- 
utes this effect to "the dampness resulting from not wearing a 
hat during the trip." (P. 296.) 

April 26, 1812, the widow of Blanchard, who was to die so 
miserably July 6, 1819, on a roof in the Rue de Provence, made 
an ascent at Turin in which she claimed to have risen to a very 
great height. The Journal de Paris 21 gave an account of it in the 
following words: 

She had taken a barometer with her .... At 15 inches 6 lines, 
the cold was icy; at 14 inches 1 line, Mme. Blanchard said she had 
experienced a lessening of the cold; at 12 inches 11 lines, she felt a 
palpitation of the artery near the outer angle of the left eye and a 
sort of trembling of the lower lid of the same eye. At 12 inches 3 
lines, she had a severe nosebleed. 

A few minutes later, the barometer marked 10 inches 3 lines, 
which was its lowest point .... This indicates that the highest 
elevation of Mme. Blanchard was 3900 fathoms (7600 meters); at this 
height the cold was unbearable, the Reaumur thermometer was 17° 
below freezing .... 

The color of the sky was almost black .... The sun did not have 
its usual rays and its diameter seemed much smaller than when 
observed from the earth. A moment after these observations, the 
thermometer dropped another degree, and Mme. Blanchard, almost 
stiff with cold, decided to descend. 



Balloon Ascensions 183 

Robertson expressed some doubts about the exactness of Mme. 
Blanchard's barometric readings. The note he sent to the Journal 
de Paris -- contains details about the sufferings which he and 
Lhoest had experienced in their ascent of July 1803, which are not 
included in the account we quoted above: 

The elevation to which you state that Mme. Blanchard rose lately 
at Turin must surprise your readers all the more as it must be 
regarded as the last degree of human temerity .... First I must admit 
that I think it impossible for anyone, with an aerostat of 20 feet 
diameter, which Mme. Blanchard ordinarily uses, to rise high enough 
to make the mercury drop to 10 inches .... 

When one reaches the elevation of 3600 fathoms, one yields grad- 
ually and unconsciously to a lethargic sleep; the mental faculties 
succumb long before the physical faculties. First one has no memory, 
no cares for the present or the future; one forgets to supervise the 
aerostat; soon a soft and gentle sleep, which one cannot resist, lulls 
all the members and holds the aeronaut in a complete asphyxia, which 
no doubt is fatal if it is prolonged .... 

In July, 1803, I made an ascent at Hamburg with M. Lhoest .... 
The barometer dropped to 12 inches and some lines (while we were 
still in possession of our faculties). The sky seemed to us to be brown; 
the sun lacked brilliance; we could gaze at it without being dazzled; 
we had a slight hemorrhage, and experienced all that Mme. Blanchard 
has just mentioned. We succumbed to sleep in this ascent; but the 
lower part of the balloon .... released the gas which was driven 
out by expansion. We roused from this torpor simultaneously and 
suddenly, without being able to tell what had happened, except that 
there had been a break in the continuity of our ideas. 

Eugene Robertson,- 3 one of the sons of the celebrated aeronaut, 
rose on October 16, 1826, from Castle Garden in New York, to 
21,000 feet (6400 meters) ,-* in a balloon of 16,000 cubic feet, 
inflated with hydrogen: 

Respiration was painful and difficult, the faculties were blunted, 
the cold unbearable, especially in the hands. (Therm, at 21 °F.) 

February 12, 1835, this same aeronaut 25 rose from Mexico to a 
height of 5928 meters. He examined from close at hand the crater 
of the former volcano the Chicle and rose "above a nursery of 
mountains." 

The famous English aeronaut Green, who made, according to 
Glaisher, 20 more than fourteen hundred ascents, certainly rose 
several times to great heights; but he seems to have been rather 
careless about exact measurements, and his figures show evidence 
of great exaggeration. 

One of his ascents, which took place in 1821, is curious because 



184 Historical 

of the nature of the gas with which he inflated his balloon; he 
used oxide of carbon which took him to 11,000 feet. JT But this 
does not concern our subject. 

April 20, 1831, Dr. Forster 28 with Green made a balloon trip 
which did not exceed an elevation of 6000 feet, a height at which 
they remained for four hours. Their physiological observations 
referred only to the phenomena of deafness which attack mountain 
travellers and aeronauts. Forster considers them as having very 
different causes in the two cases, due in the first to a feeling of 
fullness in the ears, and in the second to a real weakening of the 
hearing. 

The extravagant exaggeration of Green's statements begins 
to appear in a note of the publisher of Froriep's Notizen, 29 which 
reports naively that Green had made 226 ascents, in which he had 
several times gone above 6000 fathoms, without experiencing diffi- 
culty in breathing. 

The story which Green 30 himself gave of the catastrophe by 
which, September 27, 1836, his companion Cocking lost his life, 
indicates a height which perhaps should not be considered 
accurate. We know that Green played a very sorry role in this 
mad adventure. Cocking had made a parachute wrong side out, 
the absurdity of which no one could doubt; Green consented 
nevertheless to take it along. The unhappy Cocking unfastened 
his parachute just as the balloon reached the height of 5000 feet; 
he fell like a stone. At the same time, the balloon, freed of his 
weight, darted upward to great heights: 

We rose then with such rapidity that we were almost suffocated; 
with great difficulty I controlled my senses enough to observe the ba- 
rometer; but M. Spencer observed that the mercury stopped at 13.20, 
which gives an elevation of 24,384 feet (7430 meters), or about 4*4 
miles. 

But that is nothing beside what he told of an ascent made with 
Rusch; the pathologist Henle u reports this prodigious statement 
as a very simple thing, and without making any comment: 

In his balloon ascents, Green says he never experienced any 
acceleration of the pulse or of the respiration, except when he rose 
rapidly after throwing out ballast. 

In 1838 he rose with Rusch to the height of 27,136 feet (8268 
meters), where he saw the mercury drop to 10.32 inches; he passed 
through the first 11,000 feet (3350 meters) in 7 minutes, without any 
inconvenience except those mentioned above. (P. 386.) 

Tall tales are useless! An Italian aeronaut claimed to have 



Balloon Ascensions 185 

surpassed even the fabulous height that the English balloonist 
said he had reached. We read, in fact, in the Proceedings of the 
Academy of Sciences of Paris: 32 

M. Bonafoux writes that on the occasion of the marriage feast of 
the hereditary Prince of Savoy, M. Comaschi made a balloon ascent 
at Turin, in which, if there was no mistake in the barometer readings, 
M. Comaschi rose to 9474 meters above sea level; but the difference in 
temperature would seem to indicate a lesser height. 

The story of Hobard, if it does not give information of great 
precision, at least appears credible; it is inserted in the Courrier 
francais of October 9, 1835: 

August 17, 1835, an aeronaut, M. Hobard, ran the greatest risks 
in an ascent which he made at Lynchburg, in Virginia; he mounted 
at seven o'clock in the evening, and in less than an hour landed about 
13 leagues from the city. M. Hobard in his account says that a few 
minutes after his departure he lost sight of the earth completely. At 
half past seven he made his last observation and judged that he was 
more than a league high. He saw then two meteors, one in the north 
and the other in the west; the latter seemed to be approaching rapidly, 
but it disappeared suddenly, to the great satisfaction of M. Hobard, 
who feared that it would set his balloon on fire. Shortly after, a 
squall seized the balloon and whirled it aloft to a height which the 
aeronaut estimated as not less than 26,000 feet (7925 meters), judging 
by the difficulty of breathing and the entire loss of hearing. He wished 
to let gas escape by opening the valve; but not being able to hear, 
he could not judge, as usual, the escape of the gas by the noise it 
makes as it issues. He saw nevertheless that the balloon was not 
deflating much, and he feared it would burst; he feared also that some 
of his veins would burst, since the rarefaction of the air had made 
them dilate greatly. The first of his fears was soon realized. Without 
entirely bursting, the balloon split above and rapidly deflating de- 
scended with great speed. Happily for M. Hobard, the fall of the 
balloon was broken by a young fir whose flexible trunk protected 
him from the terrible shock he would have experienced. However he 
was thrown out of the basket and considerably bruised, but what were 
a few contusions in comparison with the cruel death he expected! M. 
Hobard based his estimate that his greatest elevation was 26,000 feet 
on the fact that the rarefied air had affected his organs in a more 
painful way than was experienced by aeronauts who had risen to 
25,000 feet, the maximum height hitherto reached in balloon ascen- 
sions. 

We must refer to the memorable ascent of MM. Barral and 
Bixio, July 27, 1850, to find scientific certainty and precision. But 
from our point of view, this ascent, so useful to meteorology, has 
only moderate interest. In fact, under the influence of a barometric 
pressure of 315 mm., corresponding to a height of 7016 meters, in 



186 Historical 

spite of a temperature of 39° below zero, the two brave travellers 
experienced no physiological symptom which attracted their atten- 
tion: "Our respiration", they merely said, "was not at all 
affected." 13 

Two years later, ascents no less important from the scientific 
point of view were made in England by M. Welsh: 34 

In July, 1852, the Committee of the Kew Observatory decided to 
institute a series of balloon ascensions for the study of the meteor- 
ological and physical phenomena which require the presence of an 
observer in the upper strata of the atmosphere. (P. 311.) 

J. Welsh, who took Nicklin as companion, was charged with 
the scientific part; the control of the balloon was entrusted to the 
celebrated aeronaut Green. The first ascent took place August 17, 
the aeronauts rose to 19,510 feet (5945 meters) ; in the second 
(August 26) , they rose only to 19,100 feet (5820 meters) ; and in 
the third, only to 12,640 feet (3850 meters) . But on November 10, 
in one hour they reached 22,930 feet (6987 meters) and remained 
more than 10 minutes above 20,000 feet; the descent took place 
with extraordinary rapidity: 

At this height, much greater than all the others we had reached 
previously, the effects of lowered pressure began to be felt more. M. 
Green and I experienced very great difficulty in breathing, with 
increased panting and fatigue after the slightest exercise. (P. 320.) 

At much lower elevations still, a celebrated English meteor- 
ologist, M. Glaisher, noted considerable modifications in respir- 
ation and circulation. 

The ascents of M. Glaisher constitute the finest series of aerial 
journeys ever undertaken with a scientific purpose. Some of them 
took him to very great heights, and one will forever remain 
famous, that in which he nearly died from the decompression. I 
am quoting from Voyages acriens 3B the following data which 
have a bearing on our subject. 

The first ascent took place June 30, 1862; Glaisher and his 
balloon engineer Coxwell reached 8000 meters: 

Between the heights of 4700 and 5900 meters, the thermometer 
marks 6° above zero. . . . The palpitations of my heart are beginning 
to become apparent, and my breathing is no less disturbed, my hands 
are growing blue, and my pulse rate, becoming feverish, is 100 beats 
per minute. 

At 6168 meters, we are in a stratum at zero degrees .... my 
pulse is growing still quicker, and I have increasing difficulty in 
reading the instruments; I feel a general discomfort, like seasickness, 



Balloon Ascensions 187 

although the balloon is not rolling or pitching .... The blue of the 
sky has become purer. (P. 47.) 

The English edition of the work quoted above, :!,i which M. 
Glaisher published in 1871, gives quite a different account of the 
symptoms experienced by the learned aeronaut. In the first place, 
the date of this ascent is given as July 17 instead of June 30: 

At the height of 18,844 feet (5740 meters), my pulse beat 100 
times a minute; at 19,435 feet (5920 meters), I noted the beating of 
my heart; the ticking of the chronometer seemed very noisy and my 
respiration began to be affected; my pulse was still faster, and 1 
read the instruments with growing difficulty; the palpitations of tho 
heart were violent. My hands and my lips were a deep bluish color, 
but not my face .... At 21,792 feet (6640 meters) I felt a sort of sea- 
sickness, although the balloon did not roll or pitch; I was so sick 
that I was unable to examine the instruments .... The sky seemed 
a very dark blue. (P. 44.) 

Second Ascent, August 18, 1862. The travellers reached 7100 
meters, the highest point of the ascent: 

I felt the pulse of M. Coxwell," which was only 90 per minute, 
whereas mine was increasing rapidly. From 100 it went to 107 and 
then to 110, without that of my companion changing appreciably .... 
As we descended we heard another clap of thunder roaring in the 
clouds which we were rapidly approaching. Is it the increasing speed 
of our descent that oppresses me? Is it the electric tension whose 
increase disturbs the hidden sources of life? .... I do not know, but 
I experience a sudden distress, a sort of nervous trembling. Happily, 
after a minute of anguish, a wonderful spectacle helps me triumph 
over this fleeting swoon. (Voyages acriens, p. 57.) 

At last came the famous ascent of September 5, 1862; it is the 
third. The ascent from Wolverhampton took place at 1:03 in a 
temperature of +15°. At 1:34, the aeronauts had reached an alti- 
tude of about 5200 meters; the temperature is —9°; there no 
longer is water vapor in the air. The first physiological disturb- 
ances then appear: 

At 1:34, I noticed that M. Coxwell began to be out of breath, 
which is not surprising, because he was constantly occupied with 
managing the balloon .... 

At 1:39, we reached the height of 6437 meters (the altitude of 
Chimborazo) .... We threw out sand .... ten minutes were enough 
for us to rise to the height of Dawalagiri; the temperature had fallen 
to —18.9° .... 

Up to this time I had taken my observations without difficulty, 
whereas M. Coxwell, who was obliged to move about in his duties, 
seemed weary. At 1:51, the barometer marked 11.05 inches. We found 
out later, by comparison with the standard barometer of Lord Wrottes- 



188 Historical 

ley, that we should lessen this figure by a quarter of an inch. About 
1:52, the dry bulb thermometer registered — 5°. Soon I could not see 
the column of mercury in the wet bulb thermometer, or the hands of 
a watch, or the fixed divisions of any of my instruments. I asked M. 
Coxwell to help me get the figures which escaped me, but, because 
of the rotation of the balloon, which had not ceased since we left the 
earth, the cord of the valve was tangled. M. Coxwell had to leave 
the basket and climb on the ring to untangle it. I observed the barom- 
eter; I saw that it registered 10 inches, and that it was falling 
rapidly. Its real height, taking care to subtract the quarter of an inch, 
was 9 and % inches, which indicated a height of 29,000 feet (8838 
meters). Shortly afterwards, I leaned on the table with my right arm, 
which had had its full strength an instant before; but, when I wanted 
to use it, I saw that it was no longer able to render me any service. 
It must have lost its power instantaneously. I tried to use my left 
arm, and found that it too was paralyzed. Then I tried to move my 
body, and succeeded to a certain degree; but it seemed to me that I 
no longer had any limbs; I tried once more to read the barometer, and 
while I was making this attempt, my head fell on my left shoulder. 
I stirred and moved my body again; but I could not succeed in raising 
my arms. I lifted my head but only for an instant; it fell once more. 

My back was leaning on the rim of the basket and my head in one 
of its angles. In this position I had my eyes fixed on M. Coxwell, 
who was in the ring. When I succeeded in sitting up, I was completely 
master of the movements of my spine, and certainly still had great 
control over those of my neck, although I had lost command of my 
arms and my legs; but the paralysis had made new progress. Sud- 
denly I felt incapable of making any movement. I vaguely saw M. 
Coxwell in the ring, and I tried to speak to him, but could not move 
my powerless tongue. In an instant, thick darkness seized upon me; 
the optic nerve had suddenly lost all power. I still was perfectly 
conscious and my brain was as active as while I am writing these 
lines. I thought that I was asphyxiated, that I should make no more 
experiments, and that death would seize me unless we descended 
rapidly. Other thoughts were rushing into my mind when I suddenly 
lost all consciousness, as when one falls asleep. 

My last observation took place at 1:54, at 29,000 feet. I suppose 
that one or two minutes passed, before my eyes ceased to see the little 
divisions of the thermometers, and that about the same time elapsed 
before my faint. Everything leads me to believe that at 1:57 I lapsed 
into a sleep which might have been eternal. I was not able to move 
when I heard the words temperature and observation. I perceived 
that M. Coxwell was speaking to me and that he was trying to awaken 
me; hearing and consciousness had then returned to me. I then heard 
him speak louder, but I could not see him; it was much more impos- 
sible to answer him or make a movement. He was saying to me: 
"Try now, try." Then I vaguely saw the instruments and soon after- 
wards surrounding objects. I rose and looked around me, as if I 
were coming from a feverish sleep, which exhausted instead of resting 
one. "I fainted", I said to M. Coxwell. "Certainly," he answered, 
"and I nearly fainted too." I then pulled up my legs, which were 



Balloon Ascensions 389 

extended straight out, and took up a pencil to continue observations. 
M. Coxwell told me that he had lost the use of his hands, which had 
become black and on which I poured brandy. 

He added that, while he had been in the ring, he had been seized 
by an extreme cold and that icicles hung around the orifice of the 
balloon, like a terrible candelabrum, worthy of the polar seas. When 
he tried to descend from the ring, he could no longer use his hands, 
and was forced to let himself slide on his elbows to get back into the 
basket, where I was stretched out. He thought, seeing me on my 
back, that I was resting, and spoke to me without getting an answer. 
My face was serene and tranquil, without that anxiety which he had 
noticed before climbing into the ring. 

Seeing that my arms and my head were hanging down, M. 
Coxwell understood that I had fainted. He tried to approach me, but 
could not, feeling unconsciousness overcome him too. Then he wanted 
to open the valve, but, having lost the use of his hand, could not 
manage it. He could not have succeeded in controlling our course, if 
he had not had the idea of seizing the cord between his teeth 33 and 
pulling it two or three times by shaking his head violently. 

I resumed my observations at 2:07, and the first figures that I 
registered were 292 mm. for the barometer and 18 degrees for the 
thermometer. I suppose that 3 or 4 minutes passed from the moment 
when I heard the first words of M. Coxwell to the moment when I 
began again to read my chronometer and my other instruments. If 
this is so, I returned to life at 2:04, and was completely unconscious 
for seven minutes. (P. 59-64) .... 

I felt no unpleasant result from my faint .... I walked eight 
or nine miles after we had landed as easily as if nothing had happened 
to me .... 

I made my last observation at 8838 meters. [That is within two 
meters of the height of the highest peak on the surface of the earth, 
the Gaourichnaka of Nepal, at the foot of which the Brahmin pil- 
grims who are seeking Nirvana come to die; 39 one may say that no 
human being ever could drag himself to this height following uneven 
terrestrial surface, and in spite of their courage the brothers Schlag- 
intweit did not aspire to mount there. However, I might have continued 
my observations there, if the continued ascent of the balloon had not 
taken me higher, where life is still more difficult.] When 40 I fainted, 
we were ascending at the enormous speed of 305 meters per minute, 
and when I resumed my observations, we were descending at a speed 
of 610 meters, double our speed of ascent; this circumstance permits 
me to calculate with a certain exactness the height to which we had 
really risen. (Voyages aeriens, p. 65.) 

Calculations based both on the ascensional speed of the balloon 
and on the temperature marked by a minimum thermometer have 
led M. Glaisher to judge that the balloon had reached the height 
of about 11,000 meters. The results of this calculation are, we 
must say, evidently erroneous. We are surprised to see a scientist 
of this caliber suppose that the balloon had a uniform speed in 



190. Historical 

ascending and descending, and solve by equations of the first 
degree a problem which evidently depends on the second. 

Everything leads us to believe that the balloon soon stopped 
and soared for some minutes before descending. 

I should mention a little experiment that is rather interesting: 

We had taken with us six pigeons to toss into the air successively 
at sufficient heights. We threw out the first at 4807 meters; he spread 
out his wings but could not support himself and fell like a leaf of 
paper. 

The second, which was thrown out at 6437 meters, did not let 
itself fall so easily; it whirled about, flying vigorously. Probably it 
turned completely about each time it dived in spite of itself. Perhaps 
by yielding to this strange waltz it found a way to resist the terrible 
suction. 

The third was thrown out before reaching the level of 8048 
meters. It fell like a stone and disappeared rapidly. We kept the three 
pigeons left for the descent, but we found that one of them was dead 
in its cage and another was hardly better. When I took it from its 
cage, it refused to fly away. Only after a quarter of an hour of rest 
did it begin to peck at a bit of pink ribbon which was around its 
neck. It was a carrier pigeon which, when once recovered, flew with 
great rapidity in the direction of Wolverhampton. (P. 67) .... 

Of all the pigeons thrown out during the journey, only one 
returned to Wolverhampton, during Sunday (the fifth of September 
was a Friday). 

M. Glaisher made several more ascents in which he mounted 
above 7000 meters (April 10, 1863, to 7300 meters; 41 June 26, 1863, 
to 7100 meters) ; in his accounts he says nothing at all of physi- 
ological disturbances. 

But he summarizes, in a separate section, the observations of 
this sort which he made in these different ascents; I quote from 
the English edition in which it is much fuller and more interesting 
than in Voyages acriens: 

The number of heart beats per minute increases with the altitude, 
as does the number of inspirations: my pulse was generally 76 before 
starting, about 90 at 10,000 feet, about 100 at 20,000 feet, and 110 at 
greater heights; but the increase in the height is not the only element 
on which the rate depends; the state of health has much to do with 
it, as does the temperament of the different individuals. 

The same thing is true of the color of the face; at 10,000 feet, 
certain persons are of a flaming purplish red, while others are hardly 
affected. At 17,000 feet, my lips were blue; at 19,000 feet, my hands 
and my lips were a deep blue; at a height of four miles, one could 
hear my heart beat and my respiration was much affected; at 29,000 
feet, I became unconscious. From all observations one may conclude 
that the effects of great heights are felt by everyone, but vary in the 
same individual according to circumstances. (P. 92.) 



Balloon Ascensions 191 

M. Glaisher states that one soon becomes accustomed to the 
influence of rarefied air, and cites his own experience in this 
regard. He expresses hopes on this subject that show both keen 
imagination and scientific understanding: 

The diminution of pressure .... should act in a very special way 
on persons who are journeying in the air for the first time. I can 
make this statement from my own personal experience, which cer- 
tainly has some value, for I have not always been able to ascend 
without ill consequences to a height which ordinarily produces great 
distress, and generally brings on discoloration of the hands and face. 
I recall having caused great astonishment in a group of scientists by 
stating that I was accustomed to rising to very lofty altitudes ■ without 
turning blue. I am really convinced that I have become acclimated 
to the effects of the rarefied air found at six kilometers from the 
surface of the earth, and I flatter myself that I can breathe freely in 
these strata high above sea level. I even have no doubt that this 
acclimatization can be sufficiently developed to exercise a considerable 
influence on the scientific use of balloons. At eight or ten kilometers I 
have tested upon M. Coxwell and myself the limits of our ability 
to live in rarefied air. Frequent trials would increase this height, and 
I am certain that it could be extended even more if one used artificial 
means to aid respiration. Certainly human lungs would find up there 
their Columns of Hercules, but I do not hesitate to declare that these 
impassable boundaries are still very far from the regions I have 
reached. (Voyages aeriens, P. 9.) 

The learned meteorologist of Greenwich, in another passage of 
his work, again refers to the future he predicts for ascents to 
great heights; he expresses with unusual vigor his unlimited 
confidence in the fruitful efforts of science. We shall show in the 
rest of this work that these hopes have not been disappointed: 

As I have already explained in the introduction, I do not doubt 
that some one will succeed in making observations in regions which 
I could not attain without fainting. I am persuaded that a day will 
come when aeronauts will surpass me just as I exceeded the height of 
Barral and Bixio, who in their turn reached altitudes higher than 
Sakaroff and Gay-Lussac. I certainly shall not take it upon myself to 
set the limits of human activity and indicate the point, if it exists, 
where nature says to the aeronauts: "You shall go no further." (Voy- 
ages aeriens, p. 67.) 

For about ten years, there has been no ascent to a great height, 
and in the scientific ascents to moderate heights, the aeronauts, 
preoccupied with important problems of meteorology and physics, 
neglected completely the physiological phenomena whose slight 
modifications could not be observed without having great attention 
devoted to them. 



192 Historical 

We must turn to the ascents organized by the Society of Aerial 
Navigation to find facts that interest us. The first among them, 
although it did not pass above 4600 meters, gave Dr. Petard, one 
of the travellers, very interesting physiological observations. He 
begins by listing briefly the temperaments of his travelling com- 
panions: 

M. Croce-Spinelli is blond, of a lymphatic temperament, nervous, 
he is ordinarily inclined to attacks of bronchitis. 

M. Penaud is chestnut-haired, of a lymphatic temperament, and 
he is disposed towards rheumatism. 

M. Jobert is very dark, of an athletic constitution with bilioso- 
sanguine disposition. 

M. Sivel is dark, of a sanguine disposition; he is very strong, and, 
furthermore, not sensitive to aeronautic influences because of the great 
number of ascents he has made. 

Finally, I am dark and of a sanguine disposition. (P. 118.) 

The balloon rose to a height of 4600 meters (429 mm.) , where 
the aeronauts found a temperature of — 7 degrees after having 
passed through a layer at — 20 degrees: 

I could (says M. Petard) observe that the earth below appeared 
like a basin, and this illusion makes the hills seem very low and the 
ravines very shallow. 

The second phenomenon to be observed is the oppression displayed 
by M. Croce-Spinelli, at about 3500 meters. I remind you that M. 
Croce-Spinelli is predisposed to bronchitis. M. Penaud also expe- 
rienced oppression, but to a much less degree than M. Croce-Spinelli. 
The other passengers felt none. 

We next observed the buzzing in the ears which M. Penaud men- 
tioned first at a height of about 2700 meters. 

We were all affected at about the same time and in the same 
way, but with very marked differences in the intensity of the impres- 
sion. For M. Croce-Spinelli it passed to a state of keen pain, and so 
persistent that in the train, during our return, he still complained of 
pains in his ears. 

M. Croce-Spinelli said that in him the buzzing and later the acute- 
ness of the pain appeared only during the rapid descents, that is, 
when the outer pressure exceeded that of the ear. In me, this buzzing 
was perceptible whenever we had a rapid descent or ascent of some 
extent, that is, whenever the equilibrium between the inner and the 
outer pressure in the ear was broken .... Not only did the sounds 
seem weakened, but they also appeared to come from far away. 
(P. 119.) 

The following observations were made above 4000 meters: 

By aid of the buccal thermometer of M. Sainte-Claire Deville and 
that of Celsius, I observed a slight drop in the animal temperature, 
which varied in the experiments made from 35.02° to 35.07°. The 



Balloon Ascensions 193 

acceleration of the respiratory rhythm and of the arterial circulation, 
very noticeable in all, was in very different proportions in the different 
subjects. M. Jobert, whose respiratory rate is normally only 10, had a 
rise to 20; his pulse, normal at 100, reached a maximum of only 130. 
That of M. Penaud rose from 68 to 104, the respiratory rate from 25 
to 45. M. Croce-Spinelli: normal pulse, 72; maximum pulse, 116, at 
an altitude of 3500 meters. At 500 meters it was only 86. The number 
of inspirations went from 40 to 64. M. Sivel: normal pulse, 80; maxi- 
mum, 108; respiration went from 25 to 40. Dr. Petard: normal pulse, 
87; maximum, 110; normal respiration, 26; maximum, 35. 

These data show that the increase in inspirations reached an 
average of 8/5 of the normal value, but that the increase in pulse rate 
varied according to the temperaments. While this increase was from 
7 to 11 for lymphatic temperaments, it was from 10 to 13 for sanguine 
temperaments. 

I could not observe, by the pneumo-dynamometer, any appre- 
ciable difference in the expansion of the lungs. 

The pulse was generally full and regular; but it was not possible 
to make graphs of it, since we were not able to use sphygmographs 
on account of the drop in temperature, which made exposure of the 
skin painful. (P. 120.) .... 

We felt a sensation of peculiar well-being impossible to -describe, 
although it was expressed by words and mien. 

The two celebrated ascents to great height (7300 meters and 
8600 meters) carried out by my regretted colleagues Croce-Spinelli 
and Sivel, having been undertaken after the first publication of 
the results of my researches, their account will naturally be 
placed in the third part of this book. 

In conclusion, I shall merely quote an account of an English 
aeronaut, Simons, who on July 9, 1874, started from Cremorne 
Garden, in London, taking Groof, the Flying Man, with his compli- 
cated apparatus suspended under the basket. 

The balloon contained 27,000 cubic feet; at 1000 feet, Groof 
disengaged himself, and falling head first, was dashed upon the 
ground. Groof and his machine weighed 130 kilograms: 

I looked over the edge of the basket (says Simons), but I was 
rising so rapidly that I lost consciousness until I was over Victoria 
Park." 

But I hasten to add that we should not have too great confi- 
dence in the ascents of Simons, who certainly deviated from the 
truth in his replies during the inquest on this painful event. 



1 Manuscript preserved in the Library of the Institute, under the title of Second Memoire 
de M. Charles sur V Aerostatique, 1784. See also L' Art de voyager dans les airs ou les ballons. 
specifying the means of making aerostatic spheres, following the method of MM. de Montgolher 
and the procedures of MM. Charles and Robert. Paris, 1784, without an authors name (by 
Piroux, according to the Uictionnaire des Anonymes de Barbier). 

-De Aerostation usu medicinae applicando. Theses de Montpelher, LS4. 



194 Historical 

3 Mme. B***, born de V***, The Olympic Circus, etc. followed by the Aeronautic Horse 

of M. Testu-Brissy, Paris. 1817. oat,, , 

I Relation du seizieme voyage acrien de M. Blanchard, dedicated to S.A.S. Mgr. le prince 
de Ligne; br. in-4 of 17 p. Client, 1786. 

B Journal de Paris, December 5, 1785. 

7 lanuary 5, 1786, p. 18. 

* : Ibid., December 20. 1785; p. lir.fi. 

8 16th and 20th Messidor and 10th Thermidor, in the year VII. _ . 

9 Robertson, Relation adressee aji president de V Acad. imp. de Saint-Petersb., in his 
Memoircs recreatifs, scicntiftques ct anecdotiqucs, 2 vols. Paris, 1810. 

10 It is, therefore, by an error that all authors, without exception, have attributed a 
height of 7470 meters to the ascent of Robertson. 

II By Izarn (See the Moniteur universel, January 25, 1804). 
12 January 20, 1804; year XII, vol. I. o. 73. 

™'4bentcuer des Grafe Z . . . bei einer nachtlichen Luftfahrt. Gilberts Annalen der 
Phvsik, vol. XVI, p. 205-209; 1804. .„-,*■ r v ,„ 

" 14 Souvenirs d'un voyage en Livonic. a Rome ct a Naples, faisant suite aux Souvenirs de 
Pans. Translated from the German. Paris. 4 vol.. 1806. . 

»•• .■'j.vimoiz </<? Robertson ct Sacharoff, T"'ie 30, 1804. Annates de Chxmie, vol. LI I, p. 121 
(Report of Robertson). Philosophical Magazine, 1805; vol. XXI, p. 193 (Report of Sacharort). 

1U Account of an aerostatic journey made bv MM. Gay-Lussac and Biot; read to the class 
of mathematical and physical sciences of the Institut National, the 9th of Fructidor. in the 
year XII Moniteur Universel, of the 12th of Fructidor in the year XII (August 30. 1804.) 

17 Account of a balloon journey made by M. Gay-Lussac the 29th of Fructidor, in the year 
XII. Ann. de Chimie. vol. LII. p. 75-94, year XIII. 

18 September 9, 1S08. , . „ _. ,. „ , 

19 Travels in the Air, by Glaisher, Flammarion. W. de Fonvielle and G. Tissandier. 2nd 
edition. London, 1871. 

-" Piblioth. britann., vol. LVII, p. 286-300; 1814. 

31 May 8, 1812. 

-'Mav 16, 1812. 

nSilliman's American Journal, vol. XII, p. 161-108; 1827. . 

-♦The work of Roch (Essai stir les Voyages aeriens d'Eug. Robertson; Paris, 1831), says 
3533 fathoms (6886 meters). „ , ... • • r. • 

26 Relation du premier voyage aerostatique execute dans la Reepubliquc mexicaine. I aris. 
1835. 

-'" I.es Voyages aeriens. Paris, 1870, p. 27. . 

-'• Einigcs iiber die Luftreize des H. Green in London am Kronuugstage des Komgs. 
Froriep's Notizen, vol. I, p. 71; 1822. See also: Ibid, vol. V, p. 202.) 

^ Bericht iiber cine I.uftschiffarht. Ibid, vol. XXXII, p. 49; 1831. 

- 9 Neue Froriep's Notizen, vol. I, p. 8; 1837. 

3,1 Fetter to the "Standard, July, 1837. 

31 Handbuch der rationnellen Pathologic. Vol. II, 2nd. part; 1851. 

3:5 Vol. XIV. p. 921; 1842. ^ , , , , 

33 Tournal d'un voyage aeronautique fait le 27 juillet 1850. Cpt. R. .lead, des sc, vol. 
XXXI," p. 126; 1850. . , 

34 An account of Meteorological Observations in four Balloon Ascents, made under the 
direction of the Few Observatory Committee of the British Association for the advancement 
of science, by Tohn Welch. Philosophical Transactions, Vol. CXLIII, p. 311-347; 1S53. 

35 Glaisher, Flammerion, de Fonvielle, G. Tissandier, Voyages aeriens, Paris, 1870. 

::,: 'Travels in the Air, 2nd ed. London, 1871. . , 

37 Mr. Coxwell was an aeronaut by profession; the ascent of June 30 was Mr. Glaisher s 
first. . . , 

3S The possibility of opening a balloon valve thus, even for a man in full possession ot 
his powers, has been absolutely denied by a professional aeronaut, M. Dute-Poitevin (/ Aeronaute 
of April lsTfi, p. 105). I should call attention to the fact that M. Glaisher never considered 
M. Coxwell a scientific collaborator. . . 

39 In the diagram which accompanies this account, a diagram the original of which, drawn 
by M. Glaisher himself, I have had in my possession, the last certain observation of height 
is" about 8100 meters; the temperature was —20.6°. # 

40 The passage between brackets does not exist in the English text. Can it have been added 
by a fanciful translator? Traduttore, traditove. . 

A1 This is the number in the English edition and diagram. Voyages aeriens gives 7800 
meters. 

45 The journal, the Aeronaut, number of August, 1S74. 



Chapter III 

THEORETICAL EXPLANATIONS AND 
EXPERIMENTS 

In the present chapter, we shall review the manifold explana- 
tions given by different authors, travellers, physicians, and physi- 
ologists of the symptoms the varied descriptions of which we have 
given in the preceding chapters. We shall add the reports of the 
few experiments made in laboratories to throw light on these 
obscure problems. This will be only an exposition of theories; 
criticisms will come in the following chapter. 

We shall follow here a strictly chronological order, since the 
proposed explanations would naturally show the effects of current 
physiological theories. 

The first traveller to describe mountain sickness is, as we have 
seen, the Jesuit Acosta; ' he gave an explanation of it which we 
quote in full, and which is admirable for its shrewdness, the sound- 
ness of its views, and its clearness of expression. On the one 
hand, he specifies the real cause, and on the other, he rejects in 
advance a mistaken hypothesis: 

There is no doubt (he says) that the cause of this distress and 
strange affliction is the wind, or the air current there, because the 
chief and best remedy to be found is to close the nose, the ears and 
the mouth as tightly as possible, and to cover oneself with garments, 
especially the stomach, since the air is so thin and penetrating that 
it pierces the very vitals .... 

By this I am convinced that the element of the air is in this place 
so thin and so delicate that it is not proportioned to human breathing, 
which requires it denser and more temperate .... 

On passes of the Nevada mountains and others of Europe which I 
have seen, no matter how cold the air there may be, nevertheless this 
cold does not take away the appetite to eat; on the contrary, it 
awakens it and does not cause vomiting in the stomach. In the 
Indies .... it happens at the same place even when the sun is warm, 

195 



1 96 Historical 

which makes me think that the distress one feels from it comes from 
the quality of the air one breathes there. (P. 87.) 

When one thinks that these lines were written at the end of 
the sixteenth century, three hundred years before Lavoisier and 
Priestley, by a man whose specialty was not the study of the 
chemical and natural sciences, one is filled with admiration for 
the great astuteness of the learned Jesuit and the unusual accuracy 
of the expressions he uses. Let us remember also that the pneu- 
matic machine had not been invented, and that Torricelli had not 
yet been born, when Acosta said that "the element of the air is 
in this place so thin and so delicate that it is not proportioned 
to human breathing". 

It is interesting to compare the explanations of Acosta with 
what the celebrated Francis Bacon - wrote thirty years later on the 
same subject, in his Novum organum (appeared in 1620). If I am 
not mistaken, the comparison is not to the advantage of the 
learned chancellor of Verulam: 

The rays of the sun produce no heat in what is called the middle 
region of the air; which is explained well enough in the schools by 
saying that this region is not near enough to the sun from which the 
rays emanate, nor to the earth which reflects them. To support this 
explanation, we may cite the summits of mountains (unless their ele- 
vation is not great) where perpetual snows lie. In fact, certain 
travellers have noticed that there is no snow on the summit of the 
Peak of Teneriffe, nor on the Andes of Peru, whereas the sides of 
these mountains are covered with it up to a certain height. It is 
stated, moreover, that at these extreme heights the air is not cold, but 
merely rare and sharp; that is why on the Andes it attacks and injures 
the eyes and the stomach, which cannot keep food down. The ancients 
had already noted that on the summit of Olympus the air was so rare 
that to climb to it one must take with him sponges wet with vinegar 
and water, and often place them on the nostrils and the mouth, since 
the air, because of its rarity, did not suffice for respiration. It is 
added that on this same summit, where neither rain nor snow- fell, 
and where the wind never blew, there reigned such a calm that when 
sacrificers had traced with their fingers characters on the altar of 
Jupiter with ashes of the victims, these impressions remained quite 
intact until the following year. Even today the travellers who ascend 
to the summit of the Peak of Teneriffe make their ascent by night 
and not by day; immediately after sunrise, their guides urge them to 
descend without delay, apparently because of the danger caused by 
breathing an air so rare and asphyxiating. 

In fact, it was not until a half century after Acosta, that 
Torricelli invented the barometer, and Otto de Guericke the 
pneumatic pump. After that, laboratory experiments could go 



Theories and Experiments 197 

on simultaneously with observations made by travellers. But 
strangely enough, for a long time physicists tried exclusively to 
study the effect of a vacuum, that is, the total lack of air. They 
did not inquire what would happen from a sojourn in air which 
was merely rarefied; for them, it seems, only two possibilities 
existed: to have air or to have no air. And yet, by a strange 
contradiction, many of them, trying to find out why animals which 
are kept in closed vessels die, were convinced that it was because 
of "the decrease in the elasticity of the air". Very strange! They 
did not investigate experimentally to see what would happen to 
animals which were subjected to such a decrease from the very 
outset; after the famous experiments of Pascal on the Puy-de- 
Dome (September 22, 1648), they were not surprised to see ani- 
mals continuing to live, which, on the mountains, were subjected 
to a decrease in the elasticity of the air enormously greater than 
that which accompanies asphyxia in closed vessels. 

At any rate, the members of the famous Academy del Cimento 3 
tell us that: 

As soon as Torricelli first advised the experiment with mercury, 
he began to think also how he would imprison different animals in 
a vacuum, so as to observe in them movement, flight, respiration, and 
all the other phenomena which could be observed. But being without 
the instruments necessary for this sort of experiment, he did the best 
he could. For the small and delicate animals were overwhelmed by 
the. mercury, through which they had to climb upward, when next 
the vessel was overturned and they were plunged into the other 
mercury. And they were then quite or almost dead, so" that one 
could not tell whether they were injured more by the mercury which 
suffocated them or by the lack of air. (P. 46.) 

As for them, they tell in their memoirs for the year 1667 the 
numerous experiments they made on animals, using barometric 
tubes, the large chamber of which was closed by a bladder. 

These animals were leeches, snails, insects of different sorts, 
reptiles, and birds. The experiments give with remarkable exact- 
ness the different symptoms displayed by these animals which 
were subjected instantaneously to an almost perfect vacuum. The 
physicists of Florence noticed besides that, in fish placed in the 
vacuum, the "air bladder" deflated and the fish then remained at 
the bottom of the water; in consequence, they performed curious 
experiments, thanks to which they discovered the "little vent-hole" 
through which the air escapes when it is expanded by the effect 
of the diminution of pressure. 

We do not find in this account any very definite theoretical 



198 Historical 

explanation of the effect of the vacuum. It appears, however, that 
for the academicians of the Cimento, a vacuum acts simply by the 
removal of air. Furthermore, their translator and commentator 
van Musschenbroeck explains it very clearly when he says: 

If we wish to know exactly how long a little bird can do without 
air, let him be plunged under water; for then he cannot breathe air, 
and he is immediately in a situation similar to a vacuum. 

These notes of van Musschenbroeck 4 also contain a very curious 
description of the phenomena presented by an animal subjected 
to the action of a vacuum, with an interpretation of the causes of 
death, an extremely interesting interpretation, although it savors 
of the false ideas of the epoch about the pulmonary circulation: 

We shut a rabbit in a glass receiver, and by means of the pneu- 
matic pump drew out all the air; the animal at first was uneasy, 
sought air, swelled up all over; its eyes protruded, it defecated, 
sought a way out all around the vessel, sat up hardly breathing, 
grew weak and fell in convulsions, lay down on its side, and finally 
died; all these things happened in half a minute, after the pump began 
to work and rapidly removed all the air from the vessel: the whole 
body of the animal lost its air and was deflated; then when we opened 
the chest, we found the lungs small, collapsed, solid, heavier than 
water. The whole body of the animal swells in the vacuum because 
the ventricle and the intestines contain much air, which, when it is 
no longer compressed by the outer weight of the atmosphere, expands 
in all directions as a result of its elasticity and distends the abdomen. 
But the blood and the other humors have elastic air mingled with 
their parts, which then, not being compressed, expands, recovers its 
elasticity and distends all the vessels, so that all the body of the 
animal must swell in all parts, especially the eyes, the humors of 
which contain much of this air; experimentation has taught me this, as 
I have tried to prove in my dissertation De aeris existentia in omnibus 
animalium humoribus. 

Moreover, the animal enclosed in a vacuum cannot inhale air into 
its lungs, and although it tries to expand its chest, and often repeats 
this expansion, nevertheless nothing enters from the outer part of the 
lungs into the air vessels or vesicles. That is why the contractile force 
natural to all fibres compresses the vesicles; the lungs collapse, become 
denser, and specifically heavier than water; but whereas the vesicles 
attached to the extremities of the tracheal artery are compressed, the 
circulation of the blood is hampered in the arteries and the veins 
which surround the whole vesicular surface in abundance, and in those 
which are situated in the interstices left around each vesicle. But in 
this adult animal, the blood of the whole body, pumped out by the 
right ventricle of the heart, must pass through the vessels of the lungs 
into the left auricle and ventricle, so that from there it can be 
pumped out into the parts of the body. When the vesicles of the 
lungs are contracted and compressed in the vacuum, the blood vessels 



Theories and Experiments 199 

are also compressed, nothing passes from the right ventricle of the 
heart 'into the left, the blood is not pumped to the brain, the cere- 
bellum, or the other parts of the body, and the circulation of the 
blood, upon which life depended, is ended. But before the circulation 
of the blood ceases entirely in the lungs, the air which is mixed with 
the blood escapes from the interstices, collects, grows rarefied, is 
pumped to the brain, causes obstructions here and there; hence comes 
the disorganized secretion of animal spirits in the brain, and hence 
their irregular influence upon the muscles of the body, which is the 
cause of the convulsions, and delays death. I do not doubt that all 
animals whose heart has two ventricles and is not pierced by an oval 
hole would die in a vacuum with the symptoms which I have re- 
ported . . . 

The animals which have an oval hole opened in the heart live a 
long time in a vacuum, and die only because of thirst, hunger, etc. 
(P. 55.) 

And so, in the opinion of the celebrated professor of Leyden, 
the death of animals subjected to a vacuum occurred as a result of 
a stoppage of the circulation of the blood, a stoppage due to the 
collapse of the lungs from which the vacuum had removed all the 
air; furthermore, the gases which escaped from the blood ob- 
structed the vessels, especially in the brain: 

They say (adds Musschenbroeck) that birds endure rarefied air 
more easily and with less inconvenience than land animals, because 
they are used to breathing a rarer air when they fly high: however, 
they cannot endure an air three-quarters rarefied; that is why they 
can rise only to a certain height in the atmosphere and not to all 
kinds of heights: these animals are uneasy in a rarer air, because this 
air can hardly, by its elasticity, expand the vesicles of the lungs unless 
the chest is expanded by very great force; and this is the cause of the 
uneasiness felt by the men who have climbed to the summits of the 
high mountains of Armenia, Savoy, the Pyrenees, and Teneriffe, where 
the air is much rarer than that which is near the surface of the earth. 
(P. 57.) 

In France, the Academy of Sciences thought at first of making 
experiments with "the machine of M. Guericke of Magdebourg"; 
but the only one which its Memoirs 5 have reported to us dealt 
with a gudgeon which, after the action of the vacuum, fell to the 
bottom of the water, "its bladder being emptied". 

However, in England, one of the most remarkable experiment- 
ing physicists of the seventeenth century, Robert Boyle, 6 had 
undertaken very interesting researches on the life of animals sub- 
jected to a vacuum. He used the pneumatic pump. His experi- 
ments, published in 1670 in the Philosophical Transactions, surely 
antedate this epoch considerably since some of them are quoted in 



200 Historical 

the memoir mentioned above of the Physicists of Florence, printed 
in 1667. 

This noteworthy work is divided into several parts: 

In the First, Boyle questions whether aquatic birds, which can 
remain for some time under water "because of the peculiar struc- 
ture of certain vessels which they have around the heart", could 
sustain better than other animals the lack of air in a pneumatic 
machine. And, after an experiment made on a duck, he replies in 
the negative. 

In the Second and the Third, Boyle reports the results of ex- 
periments made on snakes and frogs, which sustained the vacuum 
for a long time. 

In the Fourth, he says that he experimented on new-born kit- 
tens, and that he was astonished to see that these animals held 
out three times longer than older animals of the same size could 
have done. 

Part V. Experiment to find out the volume of air contained in 
the pores of water. 

Parts VI and VII. On the effect of the vacuum upon oysters, 
crabs, and a gudgeon. 

Part VIII. Experiment on a bird and a frog enclosed in the pneu- 
matic machine, both having the abdomen opened. 

Part IX. Experiment on the heart of an eel. 

Part X. Comparison of the time it takes to kill animals in water 
and in the pneumatic machine. 

In Part XI, Boyle reports the sufferings of which Acosta com- 
plained in his trip over Pariacaca, and he declares that he had 
heard similar reports from travellers who made the ascent of 
Mount Ararat, the Peak of Midi, the Peak of Teneriffe, and even 
the Cevennes. In Chapter I we quoted these different observa- 
tions. He asks himself in this regard 

Whether the difficulty of breathing which certain persons expe- 
rienced on the heights of Pariacaca, and perhaps on some other very 
lofty mountains, comes solely from the lack of elasticity in the air in 
these high places; whether we should not attribute it, at least in part, 
to certain penetrating vapors with which the air may be laden in 
places. (P. 42.) 

Part XII. Effects produced upon an animal by the alternate rare- 
faction and condensation of the same air. 

Part XIII contains the account of a very remarkable experi- 
ment, which Magnus was to repeat, more than a century and a 
half afterwards: 



Theories and Experiments 201 

The blood of a lamb or a sheep was brought me still warm from 
the slaughterhouse, where care had been taken to break the fibers to 
prevent coagulation. This blood I placed in a glass vessel with a wide 
opening, and put the vessel in a receiver; the air was immediately 
pumped out very carefully; but the effect of this operation was not 
so prompt or so apparent, especially at the beginning, as I should have 
expected it to be in so spirituous a liquid; however, after a long delay, 
we saw that the most subtle parts of the blood appeared through the 
more viscous parts, and formed bubbles, some of which were as large 
as big beans or nutmegs; sometimes the expansion was so strong, that 
the blood boiled up out of the glass vessel, of which, however, it 
hardly occupied a quarter at the beginning of the experiment. (P. 46.) 

Robert Boyle drew air in the same way from other organic 
liquids and all the soft parts. And he explains with keen sagacity 
the purpose of these experiments; he wished to find out 

What, joined to the failure of respiration, could contribute to the 
death of animals in the vacuum of the pneumatic machine; as a 
matter of fact, it appears that the bubbles which, when the ambient 
air is removed, form in the blood, the other liquids, and the soft parts 
of the body, can by their number and their expansion in some places 
swell and in others contract the vessels which carry blood and nour- 
ishment into the whole body, especially the smallest of these vessels, 
can choke passages or change their shape, and finally stop or disturb 
circulation in a thousand ways. Add to that the irritation caused in 
the nerves and the membraneous parts by forcible distentions; an 
irritation which produces convulsions and causes death more quickly 
than simple lack of air would have done. This formation of bubbles 
takes place even in the smallest parts of the body, for I have seen a 
very apparent bubble moving from side to side in the aqueous humor 
of the eye of a viper at the time when this animal seemed violently 
distressed in the receiver from which the air had been exhausted. 
(P. 47.) 

In Part XIV there is reported a very fine experiment, by which 
Boyle shows that animals become accustomed to the effect of the 
rarefaction of the air, and suffer less from it in successive experi- 
ments. 

Part XV. Experiment which shows that air can preserve its 
elasticity while ceasing to be suitable for respiration. 

Part XVI. On the use of air for causing the escape of exhalations 
from the body. 

Part XVII. Ability of the slug and the leech to endure lack of 
air. 

Part XVIII. Trial of the vacuum upon certain crawling insects. 

Part XIX. Winged insects enclosed in a vacuum. 

Part XX. On the need of air for motion shown by ants and mites. 

In another work, 7 the celebrated physicist again dwells upon the 
experiment relating to the bubbles of air which escape from 



202 Historical 

organic liquids placed in a vacuum, and he is led to ascribe to 
the escape of these bubbles an important part in the symptoms 
due to decreased pressures: 

When I re.call how our machine (the pneumatic machine) brings 
out air invisibly held in the pores not only of the water, but also of 
the blood, serum, bile, urine, and other liquids of the human body; 
when I reflect that (as I have shown experimentally elsewhere) the 
pressure of the atmosphere and the elasticity of the air act upon 
liquids and upon bodies immersed in these liquids, and upon bodies 
directly exposed to the air, I am inclined to believe that simple 
changes of the atmosphere from the point of view of weight can, in 
some cases, have a perceptible influence even on the state of health 
or sickness of man. When the ambient air, for example, suddenly 
becomes lighter than before or than usual, the spiritual or airy par- 
ticles, which are contained in abundance in the blood, naturally will 
swell this liquid, being able thus to distend the large vessels, and 
change considerably the speed of the circulation of the blood in the 
capillary arteries and the veins. That through this alteration several 
changes can occur in the body will not seem improbable to those who 
know, in general, how important the rhythm of the circulation of the 
blood is, although, as to its special effects, I leave them to the specu- 
lation of the physicians. 

These experiments were repeated, and varied in different ways 
by all the physicists of this time: Stairs, Derham, Huyghens, 
Papin, du Hamel, etc. 

I shall quote an extract of the work written in collaboration 
by Huyghens and Papin; this passage is remarkable for the wholly 
mechanical explanation given in it of the cause of the death of 
animals placed in a vacuum in the pneumatic machine. 

According to Huyghens and Papin, 8 warm-blooded animals 
never revive when they have been placed in a perfect vacuum. 
They then add: 

M. Guide, who has often dissected these animals which we killed 
by a vacuum, has observed among other facts that their lungs sink 
in water, and he maintains that the solidity or density of the lungs 
of animals which have died thus in a vacuum results from the fact 
that the blood, carried into the lungs by the arterial vein, presses 
with such violence upon the bronchi of the tracheal artery, that it 
forces the air out of them and brings together the walls of these col- 
lapsed conduits, as if they had been glued together; but, for my part, I 
do not believe that the blood of the arterial vein can compress the 
bronchi in this way, because the blood has its own vessels which con- 
tain it and prevent it from compressing others. . . . 

It is therefore more probable that if the lungs are compressed, 
it is done by the pleura which can be distended within the chest as 
the skin is distended on the exterior; but the lungs need not be 



Theories and Experiments 203 

compressed in a vacuum to sink in water; for I have several times 
placed in a vacuum pieces of lungs and whole lungs, and they 
remained extremely inflated while in the vacuum; but as soon as air 
was admitted to the receiver, they became flat and red and sank 
when placed in water. (P. 150.) 

Finally, before leaving this fruitful epoch, I think I should 
reproduce here a very curious plan of experiments suggested to 
the English physicist Beale ;| by his celebrated compatriot Boyle: 

It would be, I think, very important to see the effects produced 
on plants placed in Mr. Boyle's air-pump, and likewise on cherry- 
blossoms, etc. 

The distinguished Mr. Boyle suggests that in the approaching 
season I should see: 

1. Whether seeds germinate in the vacuum receiver; 

2. Whether lack of air is harmful to sensitive plants; 

3. Whether grafting pear buds on spina cervina (the only vege- 
table purgative known in England) will give the pears purgative 
qualities. 

4. Whether the eggs of silkworms will hatch in the receiver when 
the season has arrived. 

I should, besides, investigate whether aquatic plants live in water 
from which the air has been removed by the pump .... 

One of these experiments was carried out on lettuce seeds. Those 
which had been planted in open air measured IV2 inches in height 
after a week, the others had not sprouted; but they germinated when 
air was admitted. 

We shall not dwell longer on these attempts which, as we have 
noted, relate almost exclusively to the effect of an almost complete 
vacuum. Except for a few experiments of Boyle and Musschen- 
broek, air that is merely rarified is, in fact, not considered in them 
at all. 

And yet, as we have seen, these physicists tried to find in these 
experiments explanations for the physiological disturbances ex- 
perienced by travellers who ascend high mountains. This interest 
is shown also in a curious passage in the History 10 of the Academy 
of Sciences for 1705; it shows at the same time how many uncer- 
tainties then assailed the minds of the physicists themselves on the 
question of measuring altitudes by the barometer: 

There is some reason to believe that the air expanded in a tube 
is not quite of the same nature as air at the top of a mountain. If 
one puts lukewarm water in the vacuum machine, it boils very hard 
as soon as half of the air has been pumped out, because that which 
was naturally mixed with this water, and which had already been 
warmed a little, when it is freed of half the weight which pressed 



204 Historical 

on it, tends to escape entirely. Hence M. Mariotte has conjectured 
that if one was at an elevation where the weight of the atmosphere 
was diminished by half, the blood, much warmer than lukewarm 
water and still full of air, would boil, so that it could no longer circu- 
late, and we must admit that the conjecture was well founded. How- 
ever, MM. Cassini and Maraldi, who have ascended to altitudes where, 
according to their calculation, the weight of the atmosphere was 
almost a half less, felt no distress caused by the rarefaction of the air. 
Many persons who have been still higher felt no more than they. 

I do not need to go to great lengths to show the mistake of 
the writer in regard to the height of the mountains which Cas- 
sini and Maraldi ascended. A few lines above, he said himself 
that "the barometer hardly drops 5 or 6 inches on the highest 
mountains where observations have been made". 

Later, the Italian physicists once more took up the study of 
these important problems. Veratti, an academician of Bologna, 
made numerous experiments 11 on this subject. He begins by re- 
calling that two very different explanations have been given for 
the death of animals in the vacuum: 

According to the clever Borelli, this death occurs because, when 
the outer air is removed, the air contained in the blood and the humors 
is greatly rarefied and distends the vessels beyond the endurance of 
the animal. According to this idea we must conclude that in the blood 
and the other liquids a sort of effervescence is caused which rarefies 
them and slows their movement, that the nerves are compressed by 
it and the course of the animal spirits checked, which necessarily 
brings on the death of the animal .... 

M. Musschenbroeck . . . thinks that the cause of this phenomenon 
lies in the lungs. He thinks that the pulmonary vesicles, when they 
receive no more outer air, contract more than is natural .... which 
causes the vessels to be cramped and the blood to be stopped in them 
.... (See above the opinion of Musschenbroeck and that of Guideus.) 

Veratti, having placed quails in the vacuum, found that their 
lungs floated after death. The lungs of rats and rabbits floated 
also, but those of kittens a week old did not. He concludes from 
this: 

That Musschenbroeck and Guideus had either used in their experi- 
ment new-born animals, in which the oval hole was not yet closed, 
and whose lungs could not expand sufficiently to become specifically 
lighter than water; .... or that they left the animals in the vacuum 
for too long a time after their death; .... or that the air in the 
receiver was perhaps more rarefied in the experiments of these physi- 
cists .... who were not careful about specifying the degree of 
rarefaction which they used .... As for him, he merely rarefied the 
air to the point necessary to kill the animals .... 

The lungs, he says in conclusion, are heavier than water only in 



Theories and Experiments 205 

case they have been kept in the vacuum for some time after the death 
of the animal. That proves that this death should not be attributed 
to the contraction of the lungs .... Perhaps the lungs do not become 
denser in the vacuum, and seem so when they are withdrawn only 
on account of the pressure of the outer air, which then begins to 
act upon them. Besides, when all the other parts of the body swell in 
the vacuum, it is not clear why the lungs should be the only excep- 
tion. 

We see that Veratti is far from being satisfied with the result 
of the experiments of the Dutch physicists. However, he does not 
take sides definitely, although he is inclined towards the opinion 
of Borelli. 

In another memoir 12 which he devotes to the study of asphyxia 
in closed vessels, he makes an observation, mistaken to be sure, 
which shows how complex these questions seemed to him: 

None of the animals which die in the receivers (confined air) 
have convulsions, as always happen to those which die under the 
receiver of the pneumatic machine; which proves that the cause which 
kills animals in confined air is very different from that which kills 
them in a vacuum. 

We are really much surprised to see, after that, that in the 
explanation of the death of the enclosed animals he gives an im- 
portant role to "the destruction of the elasticity of the air, proved 
by his experiments", that is, to a decrease in pressure of a few 
millimeters of mercury. 

Another Italian, J. Fr. Cigna, 13 shortly after, carried on research 
of the same type on death in closed vessels. But he was the first 
to have the idea of studying what would happen to animals kept 
until death in closed receivers, in air of different degrees of rare- 
faction. 

He used a bottle containing "about 50 pounds of water". In it 
he placed a sparrow, then pumped out the air in two minutes to 
a decompression of 16 inches, 10 lines: 

The animal vomited at the beginning, went through a few con- 
vulsions, then seemed in fairly good condition for a few instants. Its 
respiration at first was shallow and rapid; it became still more so 
afterwards; soon it was rapid and deep, and finally deep and slow; 
then came convulsions which ended its life. The mercury had risen 
little by little in the siphon, so that at the time of the animal's death its 
height had increased about 4V 2 lines. Counting from the moment when 
communication of the tube with the pump had been cut off, the 
sparrow had lived 35 minutes .... 

After washing the bottle, I placed another sparrow in it; I pumped 
out the air so that the mercury rose in the siphon only to 13 inches, 
5 lines, and I cut off the communication of the bottles with the pump. 



206 Historical 

As on the first time, all these operations were carried out within two 
minutes after the sparrow had been inserted. This animal showed the 
same symptoms as the first. It lived 70 minutes; at its death, the 
mercury had risen 7 lines above the point at which it stood at the 
beginning. 

Finally I placed a third sparrow in the bottle, without having 
rarified the air (the height of the mercury was then 27 inches, 6 lines). 
The symptoms were the same with the exception of the convulsions. 
The animal lived three hours and a half. At the time of its death, 
the mercury had risen in the siphon about 1 inch and IV2 lines. 

In these experiments, the quantities of enclosed air were to each 
other as the numbers 128, 169, 330, and consequently almost as 3, 4, 8. 
The duration of life of the sparrows was as the numbers 35, 70, 210, 
and almost as 1, 2, 6; whence it follows first that in airs of different 
density, it does not correspond to the quantity of air, but increases in 
greater proportion than the quantity of air when its density is greater, 
and consequently, that the same quantity of air supports the life of 
the animals longer when it is condensed than when it is rarefied. 
(P. 165.) 

From these experiments Cigna draws the following conclusion: 

A rarefied air is not harmful to the life of animals from its rarity, 
but because it is altered sooner than when it is denser; for in such an 
air, the animals breathe at first without difficulty; their respiration 
becomes labored only by degrees, and in proportion to the' capacity 
of the receiver; in a word, everything goes on just as in an air with 
its natural density. If the air were harmful on account of its rarity, it 
would be equally harmful no matter what the capacity of the receiver 
might be. (P. 166.) 

And to prove it, he performs a double experiment, in which two 
sparrows were subjected to the same very low pressure (from 9 1 /? 
to 714 inches), one in a closed bottle, the other in a receiver in 
which he renewed the air frequently. The first died, whereas the 
second was "full of health" after more than a half-hour: 

I conclude from this experiment (he says) that an air, extremely 
rarefied under the pneumatic receiver, is capable of maintaining respi- 
ration and life, provided it is renewed, and that is why animals 
endure the condensation of enclosed air much better than an equal 
rarefaction; that is also why a flame burns and animals live on the 
highest mountains, although the air there is extremely rarefied, 
whereas they soon die under a receiver in which the air has been 
rarefied to the same degree. (P. 167.) 

But I call particular attention to the remarkable explanation 
which Cigna gives for the harmlessness (which he certainly exag- 
gerates greatly) of air which is rarefied and renewed: 

It is obvious that the air needs only to be dense enough to expand 
the lungs by its pressure; now to expand the lungs, this pressure 



Theories and Experiments 207 

needs only to be able to overcome the resistance which the contractile 
power of these organs opposes to it, for there is no thoracic air to 
increase this resistance, and this pressure hardly exceeds that of two 
inches of mercury; whence it follows that an air, even when extremely 
rarefied, still exerts sufficient pressure for the mechanism of 
respiration. 

So he reaches this opinion that "the suffocation of animals kept 
in closed vessels is the work of vapors". But following him in this 
path would lead us astray from our subject. 

We shall return to travellers who have ascended lofty moun- 
tains; but we should first report the interesting experiments of 
the poet-naturalist Darwin 14 and the curious theoretical conclu- 
sions which he draws from them; we shall return to these explana- 
tions later. 

The author asks himself whether there really exist in the blood 
elastic vapors of some sort or other, which could cause "lunar and 
equinoctial maladies" to be attributed to variations of the atmos- 
pheric pressure: 

The truth of this opinion (he says) seems to be demonstrated by 
the following experiment: Four ounces of blood are drawn from the 
vein of the arm and immediately placed in the reservoir of an airpump: 
when the air is removed, the blood begins to froth and rise in bubbles 
so as to occupy ten times its original volume. 

But that reasoning is mistaken, says Darwin. If, in an animal 
which has just been killed, a certain length of a vessel full of blood 
is isolated between two ligatures, and this fragment is placed in a 
vessel full of water, under the receiver of the pump, it remains at 
the bottom of the water when a vacuum has been made, without 
rising or swelling, as it should do if it really contained air: 

So a great change is produced in the blood drawn from the vein 
by the introduction of atmospheric air .... Therefore a cupping-glass 
applied to a living animal brings out no froth, as happens in a 
vacuum. 

It is, therefore, probable that animals can undergo great variations 
in pressure without inconvenience .... Some persons who have 
ascended lofty mountains report that they have spat blood; but that 
has never been noted in animals placed in the pneumatic machine, 
where the decrease in pressure was greater than occurs on the highest 
mountains. This blood-spitting was therefore an incidental disturb- 
ance, or was the result of the violent exercise of the ascent. 

We have seen, quoted above by Veratti, the explanation at first 
given by Borelli of the symptoms of decompression, which he him- 
self had experienced when he ascended Etna; he thought they were 
the result of a sort "of effervescence which might occur in the 



208 Historical 

blood and the other humors". But Borelli did not continue long 
in this opinion, and, absorbed exclusively by his theory of effort, 
he narrowed the question greatly: 15 

I then perceived that this distress was not produced by the exces- 
sive rarity of the air or by any corruption of its qualities, since, when 
we were sitting down or were on horseback, naturally breathing the 
same air, we felt no more oppression than on the seashore. I have 
given a solution of this problem in my Meteorology 16 of the Fires of 
Etna; but when I reflect upon it, I cannot remain in this opinion, and 
I now come to a more probable explanation of it. (P. 242.) 

Borelli then reminds the reader that he has shown why a fa- 
tiguing labor necessarily brings on panting. He will now show why 
locomotion in rarefied air cannot take place without great fatigue, 
whence comes the difficulty in breathing. (It is his proposition 
CXXIII.) 

A labor can become fatiguing for two reasons: first, if the resist- 
ance increases; second, if the strength lessens . . . 

The air contained in the chest, as I have said, helps the effort of 
the muscles, compressing by its elasticity the air- and blood-vessels. 
Therefore, when the air is very much rarefied, although it is com- 
pressed by the thorax as the dense air was, it acts less upon the vessels, 
and consequently aids the muscles less .... Therefore, in rarefied 
air the same work will require greater effort, since the strength is 
lessened, whence comes the lassitude, which was to be demonstrated. 
(P. 243.) 

Bouguer 1T does not display any greater astuteness; the well- 
known fact that under certain circumstances the symptoms attack 
only those on foot and not horsemen makes him attribute them to 
fatigue; for more serious cases, he resorts to the cold: 

What proves this irrefutably is that one is never exposed to this 
illness when one is on horseback or when he has once reached the 
summit, where the air, however, is even rarer. I do not deny that this 
great rarity hastens lassitude and contributes toward increasing ex- 
haustion, for respiration becomes extremely painful; however little one 
exerts himself, he is all out of breath at the slightest movement; but 
nothing of the sort takes place as long as one remains inactive. . . . 

We passed three weeks (August, 1737) on the summit of Pichincha; 
the cold there was so keen that one of us began to feel some scorbutic 
symptoms, and the Indians and the other servants whom we had en- 
gaged in the country had violent colic: they passed blood, and some 
were forced to descend; but when once we were camped on the edge 
of the cliff, their illness was always the result of the severity of the 
cold to which they were not accustomed, without the rarity of the air 
seeming to be the cause of it, at least, not the immediate or near cause: 
I investigated this the more carefully because I knew that most of the 



Theories and Experiments 209 

travellers had been deceived in this, because they did not distinguish 
sufficiently between the different effects. (P. 262.) 

However, Bouguer gives some importance to the decrease in the 
weight of the air: 

The slight hemorrhages no doubt resulted from the fact that the 
atmosphere, having less weight, was not of enough assistance by its 
compression to help the vessels restrain the blood, which, for its part, 
was still capable of the same action. (P. 261.) 

Ulloa, 18 who in other regions of the Cordillera had seen "riders 
as sick as those on foot", could not assume, as Bouguer had done, 
that fatigue was the principal cause of the symptoms. So he does 
not even mention this hypothesis. But he triumphantly discusses 
that of the cold. 

The idea of the rarity of the air occurred to him, but one cir- 
cumstance puzzled him, which puzzled many others, namely, that 
these symptoms do not appear in the lofty regions near Quito: 

Certainly one cannot attribute this distress to the cold, for if that 
was the only cause, this illness would be common in all cold countries. 
It must therefore come from the properties of the air, either its light- 
ness or some other quality which we do not know. This illness does 
not appear in the lofty regions of Quito, the altitude of which is as 
great as that of Peru, for it is different from the sickness which we 
call paramarse: at least no one has experienced it when the matter 
was being considered, so that no one has spoken of it, whereas it is 
very common in the lands lying before these regions. We should note 
also that those who are likely to vomit at sea are also so inclined on 
the Punas, whereas those on whom the sea makes no impression do not 
experience this distress on these peaks either. Something of the sort is 
felt on the lofty mountains of Europe and other mountain chains; it is 
peculiar to delicate persons, but these symptoms are not so noticeable 
or so serious or even so general as in the regions of America. That 
which is felt in Europe comes only from the rarity of the air and 
from the cold on these heights, two circumstances which might well 
produce some ill effect. (P. 117.) 

Then, in regard to the symptoms noted in beasts of burden, 
Ulloa reports, but only to oppose it, the opinion common in his 
time and even today almost universally accepted in these regions 
of South America, that these symptoms are the result of poisoning 
by metallic emanations from the ground. And yet he cannot keep 
from believing in some foreign substance permeating the air: 

The inhabitants of these regions say that it is because the animals 
are then passing over mines, for they claim that the mountains are full 
of minerals, from which are emitted through the pores of the earth 



210 Historical 

molecules of antimony, sulphur, arsenic, and others, to which they 
attribute these symptoms. 

But the objection may be raised that if this opinion were well 
founded, the men who ride on these animals would experience the 
same distress when they have stopped, which is not the case. We 
must therefore believe that it is due only to the extreme rarity of the 
air, which is filled, moreover, with some foreign body disseminated in 
it, although this foreign substance does not come from the pores of the 
earth. We may also say that it is not probable that there are minerals 
enclosed within all these peaks where the symptoms occur, since we 
see no outer sign revealing them; if it were so, there would be no 
mountain or slope in these chains, covering several hundred leagues, 
in which one would not find some mineral. (P. 116.) 

Ulloa also says a few words about symptoms which are much 
less serious, but which his successors did not always have the 
sagacity to distinguish, as he did, from mountain sickness: 

The dry, rare air causes such dryness that the epidermis, and 
especially the skin covering the lips, chaps and cracks; this causes 
pain, and soon blood issues from them; the hands become rough and 
scaly: this roughness is particularly noticeable on the joints and upper 
part of the fingers, the scales are thicker there than elsewhere, and 
they take on a darkish color which is not removed by lotions. These 
affections are called chugno, a term which the natives use for anything 
that is wrinkled and hardened by the cold. (P. 111.) 

All these data were known to the illustrious Haller, who re- 
views them briefly in the third volume 19 of his immense work, 
and tries to explain them with the data of the physics, chemistry, 
and physiology of his time. The mechanical influence of the pres- 
sure of the air seems to him absolutely predominant. In his dis- 
cussion, he utters this very strange idea, already suggested by 
Cigna, that the air of altitudes would act on the organism in a 
less painful manner than that which was rarefied to the same de- 
gree under the pneumatic bell-jars: 

The air (he says) weighs upon the body of man from all sides 
. . . and different authors estimate this weight at variable amounts 
from 31,144 to 42,340 pounds. Children are more compressed propor- 
tionately than adults, since the surface of their bodies diminishes less 
than the mass. 

All of this varies in the same locality, because the mercury of the 
barometer rises or falls about three inches, and thence come differ- 
ences which have been estimated at from 3062 to 3982 pounds. The 
variation is much greater if we compare the air of the highest moun- 
tains to that of the deepest coal mines ... In this case, it may go 
from 36,292 to 19,281 pounds (according to La Condamine, it would be 
only 17,000 pounds on the top of Chimborazo, which is an inaccessible 
peak anyway). And this difference appears even much greater, if in- 



Theories and Experiments 211 

stead of a man we. consider a fish living in submarine depths as great 
as 400 fathoms ... We should then reach a pressure of 2,272,000 
pounds. 

The English academicians did not doubt that a man can live at 
a depth of 200 fathoms. (P. 191.) . ... 

The effects of this pressure on the human body cannot fail to be 
great; we see that when we place animals under the pneumatic bell. 

The body is subjected to the pressure which presses the blood- 
vessels, the muscles, and the soft parts against the bones. And since 
in the humors of the body, in the air passages, in fact, everywhere, 
there is air kept in a small volume by the pressure, when this pres- 
sure is removed, the animal swells up all over, from the expansion of 
the lungs, the intestines, and the air contained in the vessels and even 
in the cell meshes. (P. 192.) . . . 

But there is a great difference between air rarefied by vapors or 
that rarefied by the removal of a part of itself, and that air which is 
lighter because of the altitude and its distance from the center of the 
earth. In the latter, in fact, although it has lost half its weight, respi- 
ration takes place without difficulty; this I experienced on the moun- 
tains Jugo and Furca. (Haller quotes Cassini, Bouguer, etc.) 

And one can even live a long time at these heights ... I agree 
with Arbuthnot, who teaches that a sudden shift to rarefied air is hard 
to endure at first, but that one can become accustomed to it. Perhaps 
that is the reason why birds endure rarefied air more easily than other 
animals (Derham). It is easy to understand, in fact, that the pressure 
upon our humors and our vessels will increase in proportion as the 
outer air becomes denser, and vice versa. (P. 193.) . . . 

We easily understand the disadvantages of rarefied air; we shall 
see that it cannot inflate the lungs completely. Since 'the pressure no 
longer sustains the vessels of the body, they resist the heart less and 
are more easily ruptured. In a very much rarefied air, the danger is 
increased by the expansion of the air contained in our humors. Light 
air, which does not fully inflate the lungs, makes the passage of the 
blood in these organs more difficult, and allowing less blood to reach 
the left heart in a given time, removes from it the stimulus which 
urges it to contract. (P. 196.) . . . 

In rarefied air, strength is diminished. In our Alps, those who 
have lung ailments die when they are in lofty places, especially if it is 
warm there, for cold moderates the ill effects of rarefied air. The 
sturdy mountaineers of the Alps carry enormous burdens in lofty 
places. 

The fever, prostration, slight hemorrhages and hemoptysis, an 
unfortunate example of which one can find in Scheuchzer, 20- which 
symptoms certain travellers have experienced while passing through 
the mountains, I attribute rather to the fatigue of the ascent and to 
the strain on the respiratory powers. In fact, travellers who are rest- 
ing or are on horseback have no such symptoms. (P. 197.) 

So, according to the celebrated Swiss physiologist, the effect of 
the rarefied air has as its principal causes the lessening of weight 
pressing upon the surface of the body, the dilation of the superficial 



212 Historical 

blood-vessels, and the increased difficulty of the passage of the 
blood through the lungs. We shall return, in. the next chapter, to 
the value of these theories which it would be premature to discuss 
at present. 

According to the account of Haller, we see that travellers in 
the Alps had already experienced painful effects of the decrease 
of barometric pressure. However, no explorers had yet trodden 
the summits of any of the giants of the Alps, Mont Blanc, Monte 
Rosa, nor the Jungfrau, which rise to an elevation of more than 
4000 meters. Below this level, even slight symptoms are rather 
rare. The Genevan physicist de Luc 21 is surprised at that, when 
he considers the great decrease in the weight of the air supported 
by the body; he draws from it a very reasonable conclusion about 
the effect on the health which certain physicians attribute to baro- 
metric changes: 

We were very comfortable near the little rocks to which we had 
descended (the Buet glacier, barometer 19 inches, 6 lines; 9355 feet 
above sea level) . . . We were surprised that we perceived the dif- 
ference in the density of the air only through our instruments, that no 
discomfort or disagreeable sensation warned us that the air we were 
breathing was nearly a third less dense than that of the plain, that 
the weight of the atmosphere upon our bodies was one hundred quin- 
tals less without any disturbance of the inner equilibrium. What a 
marvelous machine this is, which adapts itself to such great variations 
in the very causes of its principal movements, without their ceasing to 
be regular! 

I cannot refrain from saying in this regard how much mistaken 
certain doctors were who attributed to the difference in the weight 
or the density of the air the changes experienced by certain persons 
when the barometer falls, and who undertook to explain them by the 
lack of equilibrium between the inner and the outer air, or by the 
effect which a more or less dense air can produce upon the movements 
of the heart and the lungs. 

If these variations had a perceptible effect upon our organs, what 
would become of those chamois hunters who pass every day from the 
depths of the valleys to the summits of mountains equally high . . . 
Even asthmatic persons are not affected by them; at least I was on the 
mountain of Saleve with one of my friends who feared this effect and 
did not experience it. (P. 328.) 

We have seen that Canon Bourrit, in his ascent of Buet, was 
less fortunate than de Luc; the accounts of de Saussure and Pictet 
show, moreover, that this mountain, in spite of its moderate height, 
is one of those on which travellers are most easily affected in the 
ascent. In this connection, Bourrit - 2 makes a strange remark about 
the difference in density, at an equal altitude, between the air of 



Theories and Experiments 213 

the Alps, which makes one ill, and that of the Cordilleras, "where 
one feels no effect": 

I have noted that these symptoms can be avoided by walking . . . 
a means of renewing the air in the lungs and maintaining their activity. 

I know that it would be difficult, not to say impossible, to live a 
long time on Mont Blanc . . . 

From all these circumstances we must conclude that the air which 
we breathe on the high Alps is much rarer than that of the Cordilleras 
at the same height, because the latter are beneath the equator, and for 
that very reason they are more impregnated with heavy and dense 
vapors. (Vol. II, p. 98.) 

If this idea seems very strange to us today, what shall we say 
about that of d'Arcet,- ■"■ who first denies mountain sickness (he had 
ascended only the peak of Midi) and then asks himself whether 
the air of lofty regions is really rarer than that of the plains! 

As to the difficulty in breathing which it has been thought was 
sometimes felt on lofty mountains, and which we have never experi- 
enced, I think that it may come from the oppression which one feels 
when, heated and weary with the ascent, he reaches a very open and 
very lofty summit. There, he is suddenly struck by a cold and keen 
air . . . 

No matter how tired one is, when one reaches the top of a lofty 
mountain, he is promptly refreshed; he feels nimbler, lighter; the face 
is pale and the flesh less ruddy. In a word, what one feels then has 
nothing in common with, or rather it is the opposite of, the effects pro- 
duced upon living beings by an air which is too expanded and too rare. 
(P. 123.) 

He next discusses the observations of Bouguer and La Conda- 
mine, and says in conclusion: 

I urge physicists who have the opportunity to attempt new experi- 
ments, if it is possible, to ascertain whether at certain heights the air 
really becomes rare and expands to such a degree that animals cannot 
ascend there without suffocating as they do in a vacuum; whether this 
more or less great density is the only cause of the rising and the varia- 
tions of the mercury in the barometer. 

De Saussure,- 4 in the first volume of his great work, after tell- 
ing of his sufferings from mountain sickness during his ascent of 
Buet, tries to find the reason for them. It is strange that he alludes 
to the real explanation, although only to oppose it, which the 
recent discoveries of Priestley and Lavoisier permitted him to 
glimpse: 

559. — We cannot attribute the exhaustion of muscular strength to 
fatigue alone, as M. Bouguer thought. A fatigued man, on the plain 
or on mountains of moderate height, is rarely so exhausted that he 



214 Historical 

absolutely cannot continue; whereas, on a lofty mountain, one is some- 
times so exhausted that, to avoid most imminent danger, he would 
literally not take four steps more, perhaps not even one step. For if 
one persists in making efforts, he is attacked by palpitations and such 
rapid and hard throbbing in all the arteries that he would fall in a 
faint if he increased the palpitations still more by continuing to ascend. 

However, and this forms the second characteristic of this strange 
kind of fatigue, the strength is restored as quickly, and apparently as 
completely, as it was exhausted. Mere cessation of movement, even 
if one does not sit down, and in the short space of three or four min- 
utes, seems to restore the strength so perfectly that when one starts 
walking again, he is convinced that he will ascend even to the summit 
of the mountain all in one breath. Now on the plain, a fatigue as 
great as that of which we have been speaking does not pass away so 
quickly. 

560. — One would be tempted to ascribe these effects to the diffi- 
culty in breathing; it seems natural to believe that this rare and light 
air does not expand the lungs sufficiently, and that the organs of 
respiration are tired by the efforts they make to supply it, or that, 
since the duty of this vital function is not completely carried out, and 
since the blood, according to the theory of M. Priestley, is not suffi- 
ciently supplied with its phlogiston, the whole animal economy is dis- 
turbed by it. 

But what persuades me that this is not the real reason for these 
effects is that one feels fatigued, but not at all oppressed; if the painful 
action of climbing a steep slope makes the respiration shorter and 
more difficult, this inconvenience is felt on low as well as on high 
mountains, and yet does not produce in us, when we climb these low 
mountains, the effect which we experience on those which are very 
lofty; moreover, on the latter, when one is quiet, he breathes with the 
greatest ease. Finally, and this consideration appears to me conclu- 
sive, if it was imperfect respiration which produced this prostration, 
how could a few instants of rest taken while breathing this same air 
seem to restore the strength so completely? 

561. — I am inclined to believe instead that these effects should 
be attributed to the relaxing of the vessels caused by the decrease of 
the compressing power of the air. 

Because we are accustomed to living compressed by the weight of 
the atmosphere, we hardly think of the action of this weight and its 
effect upon the animal economy. However, if one reflects that at sea 
level every part of the surface of our body is laden with the weight 
of a column of mercury 28 inches high, that a single inch of this fluid 
exerts upon a surface one foot square a pressure equivalent to 78 
pounds, 11 ounces, 40 grains, marc weight; that consequently 28 inches 
exert on this same surface the pressure of 2203 pounds, 6 ounces; and 
that therefore, reckoning ten square feet of surface for a man of 
average height, as is usually done, the total mass of weight which 
compresses the body of this man is equivalent to 22,033 pounds, 12 
ounces; if we consider what must result from the action of this 
weight, we shall see that it must compact all parts of our body, that 
it binds them together, so to speak, that it compresses the vessels, that 



Theories and Experiments 215 

it adds to the elastic power of the arteries, that it condenses the walls 
of these same vessels, and resists the transudation of the more subtle 
parts, the nervous fluid, for example, and that for all these reasons 
it must contribute to the muscular strength. 

If then one were suddenly transported from sea level merely to 
the altitude of 1250 fathoms, where the weight of the air lifts only 
about 21 inches of mercury, the action of the atmosphere upon our 
body would be lessened one quarter, or 5508 pounds, 7 ounces; con- 
sequently all the effects of this action would be considerably lessened, 
and the muscular powers would necessarily suffer from it. The ves- 
sels, in particular, would exert very much less pressure upon the fluids 
which they contain; and for that very reason they would interfere less 
with the acceleration which muscular movement tends to give to the 
whole mass of our liquids. 

And so in lofty regions where the vessels are only slightly com- 
pressed by the pressure of the atmosphere, the efforts one makes in 
climbing a steep slope must accelerate the movement of the blood much 
more than in low lands, where the compression of the vessels resists 
this acceleration. From that, no doubt, result the rapid throbbing of 
all the arteries and the palpitations which attack one on lofty moun- 
tains, and which make one fall unconscious if he persists in moving 
with too much speed. 

But also, through an effect of this same relaxing of the vessels, 
since they react weakly upon the blood, as soon as one ceases moving, 
the acceleration which had been produced by this movement ceases of 
itself shortly, whereas if the vessels were greatly strained, their elas- 
ticity would have perpetuated this acceleration, long after its cause 
had ceased to act. That is the characteristic of weak beings, they are 
easily moved, and quieted too; whereas strong beings, hard to set 
in motion, are also harder to quiet. When, therefore, the vessels are 
relaxed by the decrease of the air pressure, a few moments of rest 
are enough to establish order and calmness in the circulation, and by 
the slackening of this circulation to give a feeling of inner coolness, 
which, aided by the coolness of the air which one breathes in these 
lofty regions, brings complete calmness, and persuades one that the 
fatigue has completely vanished. As to the drowsiness, I think that 
it is the effect of the vascular relaxation, and especially that of the 
brain. At least this seems to me the most probable reason for these 
facts: I leave judgment of it to the professional physiologists. (Vol. 
I, p. 482-488.) 

And so to de Saussure it is the decrease of the pressure exerted 
by the air upon the cutaneous vessels which, by lessening their 
resistance to the heart impulses, causes the circulatory acceleration 
and consequently all the symptoms which he observed and experi- 
enced. But, after his celebrated ascent of Mont Blanc, he adds to 
this explanation reflections of a value in much greater harmony 
with the wisdom of his lofty intellect: 

1965. — If we consider after all (he says) that the barometer at 
that height stood at only sixteen inches and one line, and that there- 



216 Historical 

fore the air had hardly more than half of its usual density, we shall 
understand that the lack of density had to be compensated by fre- 
quency of inspirations. Now this frequency accelerated the movement 
of the blood, all the more because the arteries were no longer com- 
pressed from without by a pressure equal to what they usually ex- 
perience; and so we all had fever. (Vol. IV, p. 147.) 

He returns a little later to this explanation and draws conclu- 
sions from it. He likewise refutes the theory of Bouguer: 

2021. — Of all our organs, the one which is most affected by the 
rarity of the air is that of respiration. We know that to maintain 
life, especially that of warm-blooded animals, a specified quantity of 
air must pass through their lungs in a given time. If then the air 
they breathe is twice as rare, their inspirations must be twice as 
frequent, so that the volume may compensate for the rarity. It is 
this forced acceleration of respiration which is the cause of the fatigue 
and the distress which one experiences at these great heights. For at 
the same time that respiration accelerates, the circulation accelerates 
also. I had often noticed this on lofty peaks, but I wished to make 
an exact test of it on Mont Blanc; and so that the effect of the motion 
of walking might not be confused with that of the rarity of the air, 
I did not make my test until we had remained quiet or nearly quiet 
for four hours on the summit of the mountain. Then the pulse rate 
of Pierre Balmat was 98 per minute; that of Tetu, my servant, 112, 
and mine, 100. At Chamounix, also after resting, the same men, in 
the same order, had pulse rates of 49, 60, 72. 

While there, we were all in a state of fever which explains both 
the thirst which tormented us and our aversion to wine, strong liquor, 
and even all kinds of food . . . 

However, when we remained perfectly quiet, we had no definite 
discomfort. And that is the fact which made Bouguer think that the 
symptoms which one experiences in this air come only from fatigue, 
for he agrees with me on all the data . . . 

It seems evident to me that in explaining these data, the learned 
academician made a mistake, confusing the effects of the rarity of the 
air with those of weariness. Weariness does not produce the effects 
of the rarity of the air. Often, in my youth, when I returned from 
some long mountain trip, I felt weary to the point of not being able 
to stand up any longer; in the state which Homer expressed so ener- 
getically by saying that the limbs are dissolved by fatigue, and yet I 
felt no nausea or faintness, and I desired restoratives, far from feeling 
a dislike for them. Moreover, although these academicians often ex- 
perienced great fatigue in the course of their long and painful labors, 
nevertheless, to ascend Pichincha, which is particularly mentioned, 
they started from Quito, which is at an elevation of 1400 or 1500 
fathoms, and they went still higher on horseback. They therefore had 
only 300 or 400 fathoms to make on foot, which could hardly produce 
a fatigue capable of causing the symptoms which Bouguer describes. 
Therefore the same muscular movement which would have produced 
only moderate weariness without any symptoms in a dense air pro- 



Theories and Experiments 217 

duces in a very rare air an acceleration in respiration and circulation, 
from which there results distress which is unendurable to certain tem- 
peraments. (Vol. I, p. 207-209.) 

But the first interpretation accepted by de Saussure, the de- 
crease of the weight sustained, had success much above its deserts, 
whereas the second, which contains, as we shall see, a part of the 
truth, remained much less widely known. 

Some years after him, the physiologist 25 Fodere underlined his 
mistake, so to speak, comparing the hemorrhages from decreased 
pressure to those which follow the application of cupping-glasses: 

The atmospheric pressure keeps the vessels from being too forcibly 
distended by the liquids which they contain and by the elastic force 
of the air abundant there ... If this pressure is removed, or if its 
intensity is merely lessened, the parts undergo considerable swelling 
and hemorrhages; we have common examples of it ... in suction, in 
the operation of cupping-glasses, in the hemorrhages of travellers who 
ascend to the summits of lofty mountains; in the heaviness, distention 
and discomfort which we experience whenever the air is lighter. (P. 
220.) 

Halle and Nysten 2r> share this opinion and express it with the 
greatest clearness. For them, in the first place, the chief effect is 
due to the removal of the weight of the atmosphere: 

Whenever one places an animal under the receiver of the pneu- 
matic machine, or when one mounts rapidly to considerable heights, 
then not only the sudden expansion of the free elastic fluids, propor- 
tional to the rapid decrease of the atmospheric pressure, but also 
the tendency to expansion which exists in the animal liquids them- 
selves, especially in the elastic fluids which they hold in solution, may 
be the cause of several striking results, such as a feeling of general 
discomfort, etc. 

However, after describing the phenomena presented by travel- 
lers and balloonists, the authors seem to relegate their entirely 
mechanical explanation to a secondary place, for they add: 

These effects are easily accounted for. On account of the decrease 
in the density of the air there is a lessened quantity in the same 
volume. This air, therefore, is less adequate for the combinations which 
it must experience in the act of respiration; consequently, so that in 
rarefied air these combinations may take place conformably to the 
purpose of nature, one must breathe proportionately with greater 
rapidity. This is the cause of this hasty and panting respiration and 
consequently of the acceleration of the pulse rate which results from 
it. We even comprehend that at much greater heights the rarefaction 
of the air would be such that acceleration of the respiration would 



218 Historical 

not suffice to bring to the lungs the quantity of air necessary for the 
maintenance of life, and that life would finally be extinguished, as it 
is in asphyxia, for lack of the principal agent of respiration. Death 
in this case might be preceded by various phenomena unrelated to 
respiration, such as emphysema and different hemorrhages due entirely 
to the great expansion of all parts of the body. 

Here again we find, applied to respiration, the explanation 
already given by de Saussure; as to hemorrhages, Halle and Nysten 
persist in attributing them to the decrease of the weight sustained 
by the body. 

The same combination of explanations is expressed with greater 
clearness and moderation in the thesis of Courtois: 27 

Most of these phenomena depend at the same time upon changes 
which occur in the weight of the air and upon the varying quantity of 
oxygen which this fluid contains in the same volume, depending upon 
whether it is condensed or rarefied; thus chemical phenomena compli- 
cate those which depend upon the weight of the air. (P. 17.) 

At the same epoch there appeared a remarkable work, which 
deserved more attention from physiologists, and which nevertheless 
remained almost completely unknown, at least in the part which 
interests us. I must even confess, not without some embarrass- 
ment, that I did not know of its existence until I was doing biblio- 
graphic research necessary for the preparation of the first part of 
this work, after all my experiments had been completed. 

In his researches on animal heat, Legallois 2S was led to compare 
the variations in temperature of warm-blooded animals with the 
quantity of oxygen which they absorb in a given time. Among 
the causes which might act upon this absorption, he considers the 
rarefaction of the air, as a means "of lessening the quantity of 
oxygen contained in the air in which the animal is confined". 
Legallois kept the animals in closed vessels (the manometer, as he 
calls it, measured 41 liters) during the whole experiment; he has 
nowhere specified the degree of decompression to which he had 
subjected them, but it is easy to conclude from his accounts that 
he never reached a half-atmosphere. I summarize in the following 
table the results of his experiments; the comparative test, made for 
each animal at normal pressure, lasted the same time, of course: 



Theories and Experiments 



219 



Change in 

Oxygen Carbonic body 
consumed acid jormed temperature 

1. Rabbit, normal pressure 7.05 6.16 + 0.2° 

Rabbit, rarefied air 6.43 5.02 — 2 '° 

2. Rabbit, normal pressure 6.53 6.56 + 0.3° 

Rabbit, rarefied air 5.97 4.56 — 2.2° 

3. Rabbit, normal pressure 12.08 8.55 — 1.3° 

Rabbit, rarefied air 9.96 7.60 — 1.3° 

4. Cat, normal pressure 9.50 — 0.5° 

Cat, rarefied air 6.93 — 4.2° 

5. Cat, normal pressure 8.52 6.20 — 0.3 

Cat, rarefied air 7.66 6.12 — 7.°^ 

6. Dog, normal pressure 13.26 9.12 — 1.7 

Dog, rarefied air 10.91 9.11 — 4.2° 

7. Dog, normal pressure 13.19 7.65 — 4. 

Dog, rarefied air 10.39 6.63 — 6.2° 

8. Guinea pig, normal pressure 8.49 6.27 — 0.4 

Guinea pig, rarefied air 7.37 6.56 — 2.6° 

9. Guinea pig, normal pressure 11.41 9.10 — 1.3 

Guinea pig, rarefied air 9.58 8.42 — 4.8 

Legallois draws from these experiments, in reference to the 
subject which interests us here, the following conclusion, which 
shows admirable sagacity: 

Since the mere rarefaction of the air, carried far enough to lower 
the barometer less than 30 centimeters, is enough to chill the animal 
which breathes it, the result is that the cold experienced on lofty 
mountains does not depend solely on the coldness of the atmosphere, 
and that it has in addition an inner cause, which acts through respi- 
ration. (P. 59.) 

What a contrast between these clear experiments, these precise 
conclusions and the confused mass of so-called explanations which, 
in that same year, Dralet - n gave both of the discomforts and the 
improved conditions experienced on lofty places! 

The air on mountains of moderate height is more healthful than 
that on the plains ... If we consider, moreover, that the pressure of 
the atmosphere is less as we ascend, we shall not be surprised that 
the dwellers on the plain are in better health on the Pyrenees, eat 
with more appetite, and that the elasticity of their lungs gains new 
strength there. 

But the man who is approaching the region of snow will not find 
an air so favorable to the animal economy; since vegetation, accord- 
ing to the observation of M. Ramond, is practically absent from these 
wild spots, the nitrogen is not absorbed by the organs of plants, and 
lessens the wholesomeness of the air by its abundance. 

MM. Vidal and Reboul have proved that the quantity of vital air in 
the atmosphere at the summit of the peak of Midi in Bigorre was about 



220 Historical 

one-fourth less than in the valley. Moreover, as the weight of the 
atmosphere decreases in proportion to the height of its strata, when 
a man has reached the summit of a lofty mountain, all the parts of 
his body, since they no longer receive sufficient pressure from the 
surrounding air, must yield to the heat which expands them in seek- 
ing its equilibrium in the surrounding bodies. The result is relaxation 
in the fibre, softening in the solid parts, and excess of fluidity in the 
liquids. 

So persons who travel on lofty mountains are subject to hemor- 
rhages, vomiting, and fainting; but these symptoms rarely appear un- 
less one ascends to 2000 fathoms above sea level. (Vol. I, p. 36.) 

Gondret 30 was no more fortunate when he tried to give "an ex- 
planation, if not complete, at least satisfactory", of the symptoms 
observed during mountain ascents. This is what he says: 

The decrease of the weight of the column of air and the elasticity 
of our organs explain the turgidness of the body, the expansion of the 
vessels and fluids, and consequently the hemorrhages. 

The lungs, accustomed to 18 or 20 regular inspirations and expira- 
tions per minute, suddenly forced to multiplied movements in order to 
absorb the same quantity of air, are extraordinarily hasty in their 
labor. 

The heart immediately feels the effect of the hasty action of the 
lungs; the result is an accelerated pulse rate and lipothymies. 

When the two effects which the heart and the lungs exert on the 
brain are thus accelerated, we can imagine the changes that take place 
in this organ, and consequently in its functions; it is to these changes 
that we can attribute the vertigo, dizziness, syncope, and all the dis- 
orders which follow. 

The differences noted in different individuals in the intensity of 
the symptoms are the result of idiosyncrasy. (P. 40.) 

However, we must admit that he was the first to have the idea 
of applying rarefied air to therapeutics. From the very evident 
effect exerted upon us by changes in the barometric pressure, he 
derives this suggestion: 

Perhaps chambers may be constructed in such a way that, by the 
help of the pneumatic pump, we may introduce into them a more or 
less dense air, according to the requirements of the case. (P. 45.) 

The rest of the volume is devoted exclusively to the study of 
the effect of cupping-glasses, simple or combined with scarification. 

The English travellers who, at the beginning of this century, 
journeyed over the lofty regions of India, introduced a new ele- 
ment into the explanation of mountain sickness. According to their 
stories, the natives of these countries attribute the disturbances 
which attack strangers and the natives themselves to the effect of 



Theories and Experiments 221 

a poisoned wind; generally, the emanations of certain plants are 
supposed to give these toxic qualities to the air. 

Fraser 31 is the first to give us this curious information; we 
must admit that he makes haste to reject this explanation, and for 
an excellent reason: 

I did not suspect that the altitude could affect the strength and 
the lungs so severely, and yet it was the only cause, no matter how 
difficult the ascent; for in that respect we had had days before that 
were at least as bad; and although we were told that the air was 
poisoned by the odor of flowers, and although there were indeed a 
profusion of them during the first part of our journey, most of them 
had no odor, and we could not perceive any in the air. More than 
that, we were particularly distressed when we reached the lofty gorge 
of Bamsooroo, where there was no vegetation, and consequently no 
perfume of flowers. (P. 449.) 

Dr. Govan, 3 - who accompanied Captain Al. Gerard on his first 
journey in 1817, reports the same tradition, without giving it any 
more credence. But much astonished by the lack of proportion 
already noted by travellers between the altitude and the intensity 
of the symptoms, he has the peculiar idea of having electricity play 
an active part in these phenomena: 

On the highest peaks of the mountains of Choor there first appear 
the juniper-tree, the alpine rhododendron, and the tall aconite, the 
toxic effects of which, when it is used internally, are well known, and 
seem to have given rise to the belief common among the natives that 
it poisons the surrounding air; I can find no basis for this opinion, 
except that in the lofty places in which this beautiful plant grows, 
travellers often, but not always, experience disagreeable symptoms, 
usually attributed to the expansion of the air. 

If the symptoms considered by eminent naturalists as resulting 
from this expansion should really be ascribed to it, why are they not 
proportional to the elevation and the rarefaction, and why do these 
symptoms not invariably appear when the elevation and rarefaction 
reach a certain degree? 

On two occasions I passed the night at elevations more than 
14,000 feet above the line of perpetual snow; I crossed the Rol-Pass 
(much above 15,000 feet), accompanied by 40 native soldiers, without 
anyone of us experiencing these painful symptoms. Now, in the same 
places, and even at lower elevations, they have been observed in other 
ascents and predicted in advance by the natives. 

All of this seems to indicate that these symptoms result from less 
general atmospheric circumstances, such as the electric force, which, 
in the case of such lofty conductors, must be in a state of constant 
fluctuation. (P. 282.) 

Captain Al. Gerard, 13 in the account of his journey of 1818, also 
mentions poisonous plants: 



222 Historical 

I should note that the inhabitants of Koonawur estimate the height 
of mountains by the difficulty in breathing during the ascent of them, 
which difficulty they attribute to a poisonous plant; but in spite of 
our search in each village, we found no one who ever knew this 
plant, and judging by our experience, we are inclined to attribute 
these effects to the rarefaction of the atmosphere, for we have ex- 
perienced them at elevations where there was no more vegetation. 
(P. 49.) 

He alludes again to this hypothesis in his book on the country 
of Koonawur, 34 but always to reject it: 

Travellers crossing these ranges attribute these painful effects to 
the influence of poisonous plants; but better informed persons, who 
customarily pass over these heights where there is no vegetation, 
know very well that they are produced entirely by the altitude. (P. 
37.) 

But in narrating his expedition and his stay at the pass of 
Shatool (4830 meters), Dr. Gerard 3 " does not give any heed to 
the explanation of the natives. He suffered greatly, as the account 
which we reported above proves, and naturally sought the cause of 
his distress, but without success; but in the meantime, he opposed 
the skepticism of those who for some reason experienced no symp- 
toms: 

There I had a lesson which I shall never forget, and I am sure 
that a man of a more plethoric constitution would have died from 
apoplectic suffocation. The blood left my extremities, and the pres- 
sure on the surface of the body was so diminished in that rarefied 
air that the blood rushed to the head and produced vertigo. (P. 308.) 

The cause of the symptoms is not very easily seen, and these 
extraordinary indications of loss of strength, distress, and mental 
weakness are not satisfactorily explained, and although we cannot 
hesitate to attribute the principal and immediate cause of them to 
the rarity of the air, or, more exactly, to the diminished pressure, 
by which the balance of the circulation is destroyed, nevertheless, the 
effects are so capricious and irregular that they can hardly agree with 
the idea of a constant cause. This leads travellers even to deny the 
existence of the symptoms, and those who have by chance resisted 
this effect while crossing the mountains remain firm in their convic- 
tion; but I know that you will believe my reports, although you had 
only a headache on Boorendo. I too passed the night here without 
any symptom, except weakness. (P. 320.) . . . 

As respiration cannot take place in a vacuum, we must consider 
that, at the elevation of 18,480 feet (5630 meters), the air is nearly 
half exhausted, and as the whole can have only the sum of the effects 
of its parts, the progressive action here becomes an arithmetical series, 
reducible to an experiment in physics, in which the piston strokes of 
a pneumatic pump seem to draw the hand placed over the opening 



Theories and Experiments 223 

more and more, until the greater pressure is so much more than the 
lower pressure as to be unendurable to the experimenter. At 18,480 
feet, the barometer stands on the average, at 15 inches, so that we then 
breathe an air only half as dense as that at sea level; who could be 
surprised at the effects observed? (P. 323.) 

Captain Hodgson, 36 who in his turn reports the statements of 
the natives, seems not far from believing them himself: 

The mountaineers, who know nothing of the rarefaction of the 
air, attribute their weakness to the exhalations of harmful plants, and 
I think that they are right, for a sort of unwholesome effluvium was 
exhaled by them here as Well as on the heights below the snowy 
peaks which I crossed last year on Setlej; although, on the highest 
snow, the complaint was not of weakness, but of the impossibility of 
walking for some time without stopping to breathe. (P. 111.) 

We shall see later, by the testimony of recent travellers, that 
this idea of wind poisoned by plants is today quite popular in 
Upper Asia. 

If now we return to our Alps, about this same time we find 
Hipp. Cloquet 37 republishing the mechanical explanation: 

The pressure of the air, which weighs constantly upon us from 
all sides . . . seems necessary to the maintenance of the equilibrium 
between the living solids and the humors which circulate or float 
within them; it counterbalances the elastic force of the fluids of our 
bodies; and since this pressure is considerably diminished here, it is 
not surprising that the equilibrium is ruptured. (P. 36.) 

Dr. Hamel, 38 when he undertook the fatal expedition on Mont 
Blanc in 1820, had planned to make experiments there; one of his 
plans gives evidence of a remarkable sagacity and shows very 
definite and very scientific hypothetical views about the cause and 
the effects of rarefied air: 

I had prepared a flask of lime water to see whether, at the sum- 
mit, the expired air was laden with carbon in the same proportion as 
in the regions where at every inspiration about one-third more oxygen 
enters with the same volume of atmospheric air. I also planned to 
extract, on the summit, the blood of some animal, to see by its color 
whether it had been sufficiently decarbonated in the lungs. 

The account of the ascent of Mont Blanc carried out by Clis- 
sold 3n in 1882 brings us to an explanation which had not appeared 
up to that time, and which might serve as type for that physiology 
of probabilities which has done such harm to science. 

In the first place, Clissold attributes the symptoms observed to 
the smaller quantity of oxygen contained in the same volume of 
air, which compels respiration to be deep and hasty. 



224 Historical 

On the other hand, since muscular energy in general is dimin- 
ished, the lungs expand less, and compensation must be made by 
greater frequency of inspirations. Then the editor of the Biblio- 
thcque universelle adds: 

Clissold here suggests, without developing it, one of the causes to 
which we should be tempted to attribute the greatest influence upon 
one of the effects noted; we mean the expansion undergone by the air 
enclosed in the abdominal cavity, as one rises in the atmosphere; this 
expansion, by raising the diaphragm, lessens by so much the capacity 
of the thoracic cavity, and does not permit the lungs to expand as 
much as usual, until, by certain slow communications with the ex- 
terior, equilibrium between the abdominal and thoracic cavities is 
established again, and the latter regains its ordinary capacity. 

The French naturalist Roulin, 40 who spent several years fn Bo- 
livia, in 1826 sent to Magendie a letter containing observations on 
the pulse rate, made on the same persons at Guaduas (average 
pressure 718 mm.) and at Santa-Fe-de-Bogota (560 mm.; 2643 
meters above sea level) . They show a slight increase in the pulse 
rate in the latter place. The difference is rather slight, and M. 
Roulin concludes from this: 

According to that, we may assume that the effects felt when one 
ascends lofty mountains and attributed entirely to the decrease of 
pressure, when they are not due to cold or the fatigue of the ascent, 
must be considered chiefly as nervous phenomena. 

And yet, a few pages farther on, the author adds: 

The difficulty in breathing which I felt on the plateau of Bogota 
was at first attributed to the state of my health; but I observed that 
several persons, who had recently arrived on the plateau, also com- 
plained of this difficulty. 

It is evidently rather because of the name of their author than 
because of their own importance that I have quoted these observa- 
tions; they are anything but conclusive. 

It is also from the standpoint of curiosity that I report here 
the conclusions from a work of John Davy 41 upon the gases of the 
liquids and the solids of the body; it is a real step backward from 
what Robert Boyle and Darwin had taught us. But the reader may 
judge from that the hesitations between which the minds of physi- 
ologists drifted. 

J. Davy carried out numerous experiments with the purpose of 
finding out whether the liquids or the solids contain gases which 
the pneumatic pump can extract. The results obtained were always 
negative, and he concluded from that that there are no free gases 



Theories and Experiments 225 

in the blood, which, moreover, would be "unchemical" and incom- 
patible with life, for at the slightest increase in temperature or 
decrease in pressure, nothing could prevent the escape of these 
gases. 

It is curious to see, a few years afterwards, a celebrated French 
physician, Rostan, 42 appeal to the very influence of these gases, 
though vaguely, it is true, to explain the symptoms of decompres- 
sion. He mingles with his discussion the mistaken ideas, which we 
have already met and which we shall often find again, about the 
part played by the decrease of the weight sustained by the body: 

If one places a living animal in a vacuum, the air within, having 
nothing to resist it, expands, the animal swells up and dies ... It is 
the pressure of the air which keeps the fluids in the vessels of animals 
and prevents them from escaping. When the barometer drops a few 
degrees, the fluids press towards the periphery; there is difficulty in 
breathing, disturbance of the circulation, and congestion towards the 
head. (P. 340.) 

About this same time there appeared an English memoir which 
at least had the merit of originality, in the sense of oddness. Cun- 
ningham, 43 as Govan had already done, makes electricity play a 
principal part, thus explaining the unknown by the unknown; but 
he adds a strange idea; that there is a radical difference between 
the effects of the ascent of mountains in the two hemispheres: 

Apoplectic symptoms characterize the distress of travellers on 
Mont Blanc, whereas in the southern hemisphere the threatening 
symptoms are all those which accompany syncope . . . 

The first have been attributed to the great rarefaction of the air 
which permits the soft parts of the human body to expand as a result 
of the reduction in the pressure exerted upon them; but since a similar 
elevation in the Andes produces effects of an opposite nature, we 
should seek to explain the latter by other causes than the rarefaction 
of the air. 

This cause the author finds in electricity, 

Which occupies, in the northern hemisphere, the upper part of the 
body, and, in the southern hemisphere, the lower part, and thus tends 
to draw the blood towards the head in the former, and towards the 
feet in the second . . . which also explains why the distress is re- 
lieved by the horizontal position. 

We think it useless to continue any farther, and we shall also 
report without comment the few lines which Burdach, 44 in his im- 
mense encyclopedia, devotes to the effects of a decrease in pressure 
upon the organism; we see clearly by what he says that he 



226 Historical 

attributes them to the lack of the support of the air upon the 
blood vessels: 

The pressure of the atmosphere (he says) upon the human body 
is equal to a weight of 30,000 to 36,000 pounds; it keeps the mechanical 
arrangements of the organism in their normal state, and gives con- 
siderable help to the circulation, restraining the flow of the blood 
towards the surface . . . Symptoms caused by congestions in various 
organs have sometimes been noted on lofty mountains, where the air 
is greatly rarefied. (P. 325.) 

One of the great difficulties always encountered by authors is 
the lack of proportion between the severity of the symptoms and 
the elevation which the travellers have reached, and that not only 
in different hemispheres, but in the same country, on the same 
chain of mountains. 

That is why the German Poeppig, 4 "' who gave such a complete 
description of the mountain sickness of the Andes, cannot make 
up his mind that the cause of it is the decrease of the atmospheric 
pressure: 

The idea that the Puna, the Veta, does not depend upon the rare- 
faction of the air, but upon a change in its composition, finds support 
in the observation that the illness is not always in proportion to the 
elevation of a place above sea level. The cabin of Casacaucha is 
nearly at the same level as Cerro de Pasco, the pass of Viuda is a 
thousand feet higher, and I have never felt the slightest distress there. 
(Vol. II, p. 84.) 

M. Boussingault 46 also was struck by these variations; but bolder 
than Poeppig, he seeks an explanation of them: 

In all the excursions I undertook in the Cordilleras, I always felt, 
at an equal height, an infinitely more painful sensation when I was 
climbing a slope covered with snow than when I was mounting over 
bare rock; we suffered much more in scaling Cotopaxi than in ascend- 
ing Chimborazo. On Cotopaxi we were constantly mounting over 
snow. 

The Indians of Antisana assured us also that they felt stifled 
(ahogo) when they walked for a long time over a snowy plain; and I 
confess that after considering carefully the discomforts to which de 
Saussure and his guides were exposed when they bivouacked on Mont 
Blanc, at the moderate height of 3888 meters, I am disposed to attribute 
them at least in part to the still unknown effect of snow. In fact, their 
bivouac did not even reach the elevation of the cities of Calamarca 
and Potosi. 

In the lofty mountains of Peru, in the Andes of Quito, the travel- 
lers and the mules which carry them sometimes suddenly experience 
a very great difficulty in breathing; we are told that animals have 
been seen to fall in a state very like asphyxia. This phenomenon is 



Theories and Experiments 227 

not invariable, and, in many cases, it seems independent of the effects 
caused by the rarefaction of the air. It is observed particularly when 
abundant snows cover the mountains and the weather is calm. 

Perhaps this is the place to note that de Saussure was relieved 
of the distress he felt on Mont Blanc when a light north wind arose. 
In America, the name soroche is given to this meteorological state of 
the air, which affects the organs of respiration so greatly. Soroche, 
in the language of the American miners, means pyrites; this name 
shows plainly enough that this phenomenon was attributed to sub- 
terranean exhalations. The thing is not impossible, but it is more 
natural to see in the soroche an effect of the snow. 

The suffocation which I felt several times myself while I was 
mounting over snow, when it was struck by rays of the sun, made 
me think that air which was evidently foul might escape from it as 
an effect of the heat. What supported me in this strange idea was a 
former experiment of de Saussure, in which he thought he observed 
that the air which escaped from the pores of the snow contained much 
less oxygen than the atmosphere. The air subjected to examination 
had been collected in the interstices of the snow on the col du Geant. 
Analysis of it was made by Sennebier, by nitrous gas and in compari- 
son with the air of Geneva. (P. 167.) 

M. Boussingault then repeats the experiment of Sennebier with 
the snow which he had taken from Chimborazo. Ordinary analysis 
gave him only 16% of oxygen. But the celebrated chemist him- 
self declares that objection may "strictly" be made to his method; 
since the snow had melted in the bottle, the air, in the presence 
of water only slightly aerated, might have given it part of its 
oxygen. Evidently that depends upon the quantity of air in pro- 
portion to the quantity of water, a proportion which is not given 
in the work from which we quote. 

But later, M. Boussingault, having taken up this question again, 47 
showed that the apparent lack of oxygen in the air contained in 
the pores of the snow results from the fact that the oxygen is dis- 
solved in greater proportion than the nitrogen in the water of 
fusion. There is nothing left then of his first hypothesis. 

These contradictory results, due to the improvement of methods 
of chemical analysis, remind us of the different opinions expressed 
in 1804 and 1837 upon the same subject by the illustrious von Hum- 
boldt. 

In the letters which he wrote to his brother and Delambre, 
immediately after his ascents of Antisana and Chimborazo, von 
Humboldt declared that in his opinion 

The distress, the weakness, and the desire to vomit certainly came 
as much from the lack oi oxygen in these regions as from the rarity 
of the air. He had found only 0.20 of oxygen at 3031 fathoms, on 
Chimborazo. (P. 175.) " 



228 Historical 

And yet, it appears from his letter to his brother 40 that the 
same symptoms attacked him on the summit of Antisana, where, 
however, analysis showed them the normal proportion of 0.218 of 
oxygen in the air. 

But when, in 1837, 50 he refers to the details of his account, he 
no longer speaks of the chemical composition of the air, but only 
of the lessened quantity of oxygen in the same volume; further- 
more, he introduces into science a new explanation of the fatigue 
on mountains, an unsatisfactory explanation, which, however, was 
long accepted without contradiction: 

According to the present state of eudiometry, the air seems as 
rich in oxygen in these lofty regions as in the lower regions; but in 
this rarefied air, since the barometric pressure is less than half what 
we are ordinarily exposed to on the plains, a smaller quantity of 
oxygen is received by the blood at each aspiration, and we understand 
perfectly why a general feeling of weakness would result. This is 
not the place to inquire why this asthenia, on the mountains as in 
vertigo, usually causes uneasiness and a desire to vomit, nor is it the 
place to demonstrate that the issue of blood or bleeding from the lips, 
the gums, and the eyes, not experienced by everyone at such great 
heights, can by no means be explained satisfactorily by the progressive 
removal of a mechanical counterweight which compresses the vascular 
system. It would be better to examine the probability of the effect of 
a lessened air pressure upon weariness when the legs are moving in 
regions where the atmosphere is greatly rarefied; since, according to 
the memorable discovery of two clever scholars, MM. Guillaume and 
Edouard Weber, the leg, attached 51 to the body, is supported when it 
moves, only by the pressure of the atmospheric air. (P. 419.) 

If M. Gay-Lussac, who on September 16, 1804, reached the prodi- 
gious height of 21,600 feet, which consequently was between that of 
Chimborazo and Illimani, did not suffer from bleeding, perhaps that 
should be attributed to the absence of all muscular movement. (P. 
418.) 

About this time, a French physician, Dr. Junod,"' 2 conceived and 
carried out the idea, already glimpsed by Gondret, of lowering the 
pressure artificially in apparatuses large enough to accommodate a 
man. 

M. Junod had been led to make his experiments by the effects 
"he felt from the expanded air in the Alps, in the Pyrenees, and 
on Mount Etna. His apparatus consisted of a copper sphere 1.30 
meters in diameter, in which a man could sit: 

When a person is placed in the interior of the receiver, and the 
natural pressure of the air is lessened one-quarter, this is what one 
observes: 

1. The membrane of the tympanum is distended, which causes a 



Theories and Experiments 229 

rather uncomfortable sensation, which disappears as equilibrium is 
reestablished; 

2. Respiration is hampered: the inspirations are short and fre- 
quent after 15 or 20 minutes. A true dyspnea follows this difficulty 
in breathing; 

3. The pulse is full, easily depressed, frequent; all kinds of super- 
ficial vessels are in a state of manifest turgescence. The eyelids and 
the lips are distended by the superabundance of fluids. Not infre- 
quently hemorrhages occur, with a tendency to syncope. The skin is 
the seat of distressing heat and its functions are increased; 

4. The slackened formation of blood, the expansion, more or less 
great, of the gases which circulate with the blood, and the super- 
abundance of this liquid in the different classes of superficial vessels, 
explain well enough the failure of innervation which is characterized 
by lack of energy and a complete apathy; 

5. The salivary and renal glands secrete their fluids less abun- 
dantly, and this effect seems to extend over the whole glandular 
system; 

6. The weight of the body seems to diminish perceptibly. 

The memoir ends with the description of the large cupping- 
glasses and of some pathological cases treated with them. To the 
application of this method of treatment, to which he has given the 
name of hcmospasie, M. Junod has devoted his efforts since that 
time. 53 It really has no connection with our subject, since it con- 
cerns a rupture of the equilibrium of pressure between different 
points on the body, by the application of a partial vacuum on one 
or several members. Magendie first made this evident in the re- 
port 54 which he was requested to present to the Academy of Sci- 
ences upon the work of M. Junod. 

The celebrated physiologist first reviews the history of cupping- 
glasses, which date from the time of the Egyptians, and passes to 
the barometric chambers of M. Junod by a transition which shows 
that, in spite of himself, he still compares them with these cup- 
ping-glasses: 

These apparatuses (he says, in fact) were constructed with the 
purpose of varying, upward or downward, the pressure which the 
body of man sustains through the extent of its cutaneous and pulmo- 
nary surfaces . . . 

It is by acting upon the two surfaces at the same time that this 
apparatus differs from those which were devised in England by MM. 
Murray and Clanny; these apparatuses last mentioned act exclusively 
upon the skin, the lungs having free communication with the outer air, 
through a separate tube. 65 

Then, to come to the part of M. Junod's work which has some 
interest for us, Magendie quotes the report of the phenomena pre- 



230 Historical 

sen ted by a man subjected to the action of compressed or ex- 
panded air; we have just taken from the original memoir what 
relates to this last point. 

We regret to add that Magendie did not display much fore- 
sight when he said: 

From a medical point of view, these apparatuses as yet do not 
seem to offer any application . . . That is not true, however, of those 
which M. Junod designs to use for rarifying or compressing the air 
around members. 

It is not surprising to note that after these discouraging re- 
marks M. Junod gave up the use of expanded air as a general 
medium, and limited himself to improving 56 the large cupping- 
glasses which bear his name, a very powerful therapeutic agent 
which has very unjustly been neglected by physicians. But through 
a strange confusion, explanations which were very appropriate 
when it was a matter of the local rarefaction by the large cupping- 
glasses continued to be applied to the general action of decreased 
pressure. As an example of this mistake, I shall quote the remarks 
of Dr. H. Favre: 57 

The principles upon which the Junod method rests are very 
simple: 

M. Junod, born in the Alps, had himself felt the difference in 
pressure as one ascends or descends in the mountains. He resumed 
the experiments of de Saussure and Gay-Lussac with the most laud- 
able discernment. 

If one ascends to the summit of Mont Blanc, or rises in a balloon 
to a height of 7000 meters, he feels remarkable effects, resulting solely 
from the lack of pressure exerted at these heights by the more and 
more rarefied atmosphere. 

Artificially, we know how, by making a vacuum, to rarefy the 
air, that is, to lessen the pressure on a circumscribed area. If we are 
dealing with a living body, certain effects produced by an ascent in 
the atmosphere will then appear: such is the purpose of hcmospasie; 
Dr. Junod attains it by the creation of his large cupping-glass. (P. 7.) 

Returning now to mountain travellers, we find again the series 
of mistaken preconceptions and apparent contradictions which we 
have already noted. The difficulty of explaining the facts brings 
many of these travellers to deny them. An example of these 
theoretical protests is furnished us by the editor of the Biblio- 
thcque universelle of Geneva, who reviewed the account of the 
ascent of Mont Blanc by Dr. Barry: 

The circumstances observed by M. Barry are so unimportant that 
they confirm us in the opinion that fatigue plays a greater part than 



Theories and Experiments 231 

the rarity of the air or the supposed influence of snow . . . We can 
assert that these are the same sensations felt by ordinary travellers 
when they approach the summit of any mountain whatsoever. 

I beg the reader to refer to the actual words of Barry, which I 
quoted previously (See page 95) ; he will find, I hope, in them a 
proof of the necessity of verbatim quotations. 

It is interesting to note that M. Martins, 59 who was later to 
become so sick on Mont Blanc as if by a kind of punishment for 
his skepticism, at that time shared these sentiments. Accounts of 
mountain sickness left him very incredulous: 

As for us (he says), occupied night and day with our observa- 
tions, we also tried to test our sensations to find out whether this 
lofty habitation (2680 meters) had any physiological effect upon our 
organs. But it was in vain . . . Since my sojourn there, I have read 
again all the accounts of ascents of Mont Blanc, from de Saussure to 
Mile. d'Angeville, and the sensations felt by these travellers can be 
explained very easily by fatigue . . . 

Of course the air of the mountains is more rarefied, but it is also 
more alive . . . The liveliness of the air, added to its rarity, refreshes 
the traveller and doubles his powers; for the chemical composition is 
the same. (P. 213.) 

I confess that I am surprised that a man with so clear and so 
perspicacious a mind could have used such expressions. What do 
the words "a more alive air" mean.? The Swiss peasants who saw 
the celebrated professor of Montpellier collecting air in balloons 
and sending it to Paris, and who thought that he would make some 
illustrious patient breathe it, shook their heads and said: "Our air 
will be dead when it gets there." We see that essentially they 
thought like M. Martins. 

Dr. Rey, G0 whose work is often quoted, and who, without seem- 
ing ever to have made an ascent, wrote a dogmatic article about 
mountain sickness, reaches the theoretical explanation after an 
enumerative description. He sees, and in this he does not have 
the merit of invention, that rarefied air is the cause of all these 
symptoms: 

It is neither the fatigue which removes the power of breathing, 
nor the difficulty of breathing, nor an incomplete respiration which 
cause the exhaustion, as has sometimes been said; it is the decrease 
in the density of the air . . . 

These effects are due to the relaxation of the fibre caused by the 
decrease of the compressing power of -the air, the explanation of 
which follows. (P. 334.) 

The usual calculation on the difference in the weight sustained 
by the body at different altitudes follows. At the Saint Bernard 



232 Historical 

pass, "the action of the atmosphere is diminished one quarter or 
5500 pounds, which expands the vessels in a similar proportion". 
Then, to the explanations "furnished by science" Rey adds one, 
which I cannot help finding rather queer: 

We can hardly climb to the top of a very lofty tower without 
making frequent pauses on the way, and usually we reach the top only 
with great effort. Certainly that is not because of the rarefaction of 
the air, nor even because of weariness. Is it not because we have had 
to lift our legs many times consecutively, by a law quite different 
from that of walking and much harder to obey? In fact, all the 
muscles of our organs of locomotion, set to work at the same time by 
an ascensional movement to the continuity of which they are not 
accustomed, experience from it a fatigue which forces us to pause 
frequently, which increases as long as we continue ,t° mount, but 
which ceases as soon as we have reached the top and does not return 
while we are taking the same way downward. Well, that which takes 
place in a man climbing a stairway he experiences with greater reason 
on the side of a rugged mountain, because here there is a combination 
of a long walk on trails often requiring violent and unaccustomed use 
of muscular powers and a great rarefaction of the atmospheric air. 
If we could wind around Mont Blanc and reach its crest by a gradual 
slope as we wind around the Saint Gothard or the Simplon pass, it 
would no longer be necessary to make the unnatural movement of 
the legs, members which become heavier to raise in proportion to the 
contraction of the column of the air, and consequently we should no 
longer feel this distress which we mistake for fatigue. (P. 335.) 

Tschudi, 61 the celebrated. German traveller whose complete de- 
scription of the mountain sickness in the Cordillera of the Andes 
we have already quoted, explains the extreme weariness of the 
lower limbs which one experiences in ascending, like von Hum- 
boldt and the Weber brothers: 

Since the head of the femur, according to the researches of Weber, 
is held in its cavity by atmospheric pressure, when this pressure di- 
minishes, a continuous muscular contraction must replace it. (Vol. II, 
p. 66.) 

He then reports, but without seeming to believe it, the explana- 
tion given by the Indians about metallic emanations: 

There are places where it is known that the Veta is more severe 
than elsewhere, and they are sometimes lower than others where it 
is much less evident, so that it does not seem to be caused entirely by 
the rarefied air, but also by some unknown climatic influence. Usually 
these places are rich in minerals, whence comes the general belief of 
the Peruvians that these effects are due to metallic emanations. 

Dr. Archibald Smith G2 does not consider these differences; but 



Theories and Experiments 233 

he gives some very strange information about the symptoms of 
the Veta and their possible causes: 

The inhabitants of the coast, when they climb the chain of the 
Andes, feel their respiration oppressed in places where the Indians 
do not experience this distress, because of the much greater develop- 
ment of their respiratory organs .... 

The pulse accelerates and the lungs act much more rapidly than 
normally. Their free play is hindered, however, by the accumulation 
of blood and a considerable degree of congestion, resulting, in my 
opinion, on the one hand from the lessened atmospheric pressure, 
which causes an expansion of the fluids in circulation, and on the 
other hand from the resistance of the cutaneous and pulmonary 
capillaries enlarged by the cold. 

The result of this is that strangers to these climates are very 
subject to stomach disturbances, dyspnea, apoplexy, or other hemor- 
rhages when they cross the passes of the Cordilleras . . . Cats which 
have been taken to the snow line and have been well-fed are very 
subject to sudden death ... I have heard that at Cerro de Pasco a 
terrier suddenly fell dead, probably from apoplexy, while he was 
jumping with joy and caressing his master. (P. 356.) 

An English traveller, Hill, 03 who was quite sick while crossing 
the Andes, and who saw two children stricken with the soroche 
so violently that they "were almost lifeless in the arms of their 
father", lays stress upon the effect of different temperaments in 
reference to the severity of the illness: 

The illness, in its most serious form, is accompanied by very 
alarming symptoms and is generally fatal; in a traveller of a plethoric 
constitution it is usually very serious; it is characterized then by 
vertigo, weakness of vision and hearing, and very often by a flow of 
blood from the eyes, the nose, and the lips and by violent headaches 
and vomiting.- But in thin travellers, not very strong in constitution, 
it is more likely to cause fits of weakness, accompanied by the spitting 
of blood. In persons who enjoy good health, vomiting is one of the 
most frequent symptoms, and the others generally consist of lassitude 
and difficulty in breathing, such as appeared in my companions and 
myself. (P. 68.) 

Coming to the causes of the symptoms, he repeats, without seem- 
ing to attach real importance to it, the opinion of the natives about 
metallic emanations: 

This illness has been noted to be more common in the provinces 
where metals abound; so the general opinion among the natives is 
that it owes its appearance or its increase of violence to the metallic 
exhalations which are supposed to saturate the atmosphere of those 
regions. This opinion is undeniably based on the fact that the disease 
particularly attacks prospectors for metals, men who are usually not 



234 Historical 

accustomed to the air of the mountains, and who endure great 
fatigue. 

We can hardly doubt that, whatever the form under which it 
presents itself, its appearance is due to the decrease in the weight of 
the air, whose effect everyone feels in very lofty places. (P. 69.) 

Hill does not hesitate to declare that animals can become almost 
completely acclimated to lofty places: 

The effects of the rarefied air are not limited to man; they exert 
equal, if not greater, action upon the other animals of creation. The 
horses and the mules of the plains cannot cover the same distance in 
a given time on the mountains as on the plain; they are not capable 
of carrying as heavy burdens on the Sierra as in the climates in which 
they are accustomed to living. 

However, these animals, when they have been taken to consider- 
able heights and are well cared for, become acclimated, in most cases, 
after a few months, and they become fit to do almost the same work 
as animals born in these lofty regions. (P. 69.) 

The physiologists continued, nevertheless, but without great 
success, to seek for the causes of these symptoms noted, explained, 
or denied by travellers. One of them, M. Maissiat, 64 whom his pro- 
found knowledge of physics has often inspired to better result, tak- 
ing up an explanation which we have already seen mentioned by 
Clissold, in 1822, gives an important part to the abdominal gases, 
expanded by the decrease in pressure: 

Their pressure stimulates the diaphragm and regulates the fre- 
quency of its contractions; therefore, the circulation is linked with 
the production of the intestinal gases. (P. 253.) 

If the pressure enveloping the animal diminishes, there will be 
acceleration of the circulation and respiration and congestion of the 
skin, and if the pressure continues to diminish, delirium or even death 
may result; since the pressure of the abdominal 'gases increases in 
its effects proportional to the decrease in the outer pressure, these 
gases expand and distend the entire abdomen even to the point of 
rupture, if the drop in external pressure is very rapid .... 

The accelerated circulation and respiration tend to speed up the 
abdominal action, and thus to restore equilibrium and quiet regu- 
larity. (P. 254.) 

The German physician, Flechner,* 55 reports an opinion quite con- 
trary to that of Boussingault and von Humboldt upon the compo- 
sition of the air of lofty places; he opposes it, it is true, and pre- 
fers the last idea suggested by de Saussure. I quote from the 
review in Schmidt's Jahrbuch: 

According to the general opinion, the air in the mountains is 
richer in oxygen, from which inflammatory diseases result .... 



Theories and Experiments 235 

Flechner has found that that is not correct .... But if, in lofty 
places, the air is rarer while the composition remains the same, the 
oxygen will weigh less: it will furnish less oxygen to the blood. 
The light of the sun has no effect. 

All the rest of the work is devoted to considerations of the 
diseases which are prevalent in the mountains. 

The professor of Lyons, Brachet, 00 in the special work which he 
devoted to our subject, begins by repeating the common idea of the 
decrease of the weight sustained by the body when the air expands: 

A column of air which raises the barometer only to 13 ¥2 inches 
must exert upon the body and all the surfaces with which it is in 
contact an infinitely smaller pressure, the effects of which we can 
compare to those of the immense cupping-glass of Dr. Junod and which 
we might, consequently, consider as a sort of suction. The capillaries, 
which are less compressed, must therefore react less energetically 
upon the blood and the other liquids which circulate through them; 
they must therefore be distended and congested by a sort of stasis .... 

The rarefaction of the air explains very well the difficulty and 
trouble in breathing, but it does not explain the panting and the 
extreme prostration which the slightest movement causes. 

To explain this new element, Brachet, who has just fallen into 
so strange an error in physics, expresses the most suitable ideas: 

The panting (he says) results from the darker blood which 
reaches the lungs and does not find, in the rarified air which enters 
there, a sufficient quantity of oxygen to revitalize it quickly enough. 
The lassitude results from the fact that the blood, which is therefore 
not well aerated, no longer gives the muscles the normal stimulus 
which they need to contract. 

This view, which is so simple, so clear, and, let us add in ad- 
vance, so true, did not end the controversy, however. 

In fact, a few months afterwards, Castel, G7 a member of the 
Academy of Medicine, discussing the question theoretically, ex- 
presses himself on the subject in the vaguest terms; no doubt, for 
him, the physiological phenomena observed on lofty mountains are 
due to the decrease of atmospheric pressure, but, he adds: 

Not that this pressure is, as certain authors have maintained, the 
immediate agent in the movement of the blood in the most remote 
arterial ramifications and the veins, but it exerts a direct and constant 
influence upon contractility, of which the flow of animal liquids is 
never independent. The contractility is checked to a degree propor- 
tional to the amount of decrease of atmospheric pressure. 

Finally, in this same year, the celebrated German physiologist 
Vierordt os made a certain number of experiments upon the effect 



236 Historical 

of slightly expanded air upon respiration. He gives no informa- 
tion about the manner in which he carried on his experiments, 
which dealt only with pressures included between 340 and 330 lines 
of Paris (767 and 744 mm.) . 

Their chief purpose was to find out whether variations in pres- 
sure have an effect on the exhalation of carbonic acid; their results 
are not very clear, in spite of the profusion of tabelles in which 
they are expressed and the wealth of decimals of doubtful deriva- 
tion which accompany each number. All conclusions based on these 
experiments would seem to me extremely rash. Besides, the slight 
barometric oscillations within the limits of which they are kept 
prevent them from having any interest for us. 

It was also at this same period that M. Lepileur's C9 memoir 
appeared, the interesting narrative of which we have quoted in the 
proper place and in considerable detail (See page 98 et seq.). This 
work is not only rich in precise and shrewd observations, but it also 
contains theoretical views, the importance of which deserves our 
full attention. M. Lepileur first gives credit to the explanations of 
de Saussure and those of Brachet; but they do not satisfy him: 

The phenomena relating to hematosis do not seem to us the only 
causes of the panting and lassitude on lofty mountains .... 

One gradually becomes used to the rarefied air so that he no 
longer feels its effect. If it depended only on the more or less com- 
plete stimulation of the muscles by a blood which is more or less 
arterial, would this fatigue be accompanied by pains of back and 
limbs, and would it be likely to disappear thus through habit in so 
short a time? 

We should be tempted to consider this painful fatigue as resulting 
chiefly from the congestion of blood taking place in the muscles during 
their action, in proportion to their efforts, and the whole group of 
phenomena due to the rarefaction of the air seems to us to agree fairly 
well with this idea. The more active the circulation is, the more easily 
congested the organs are. Now the pulse, without losing strength, 
becomes considerably more rapid when one is ascending a mountain, 
and the tendency to congestions is completely demonstrated by the 
facts which we have given .... When one remains motionless, equi- 
librium is maintained .... but as soon as one begins to move, the 
contracted limbs become the seat of a congestion which occurs with 
a rapidity proportional to the increase in the speed of the circulation. 
(P. 62-64 of the separate printing.) 

Beside the congestion of blood in the muscles, which, according 
to him, explains the lassitude, M. Lepileur places exertion, which 
would explain the nausea, the impending syncope, and the head- 
ache: 



Theories and Experiments 237 

During exertion, there is a stasis of blood in the capillaries and 
congestion in the brain, the lungs, and the muscles. When one makes 
a series of almost uninterrupted efforts, .... when one runs up a 
stairway, .... vision is dimmed, vertigo occurs, a painful fatigue is 
felt in the limbs, and muscular strength fails. But if one stops to get 
his breath before the effects of the cerebral and pulmonary congestion 
have reached this point, the blood then flows back towards the heart, 
the face grows pale, and a well denned sensation of fainting is felt; 
sometimes the syncope occurs even when one has not taken care to 
place himself immediately in a horizontal position .... 

If now we consider the phenomena observed in the organism at 
great heights, we find exactly the same course and the same signs. 
Except that the rarefaction of the air, by making respiration more 
frequent and the panting more rapid, necessarily hastens the rest of 
the ordinary effects of exertion .... 

The slight hemorrhages of the gums, the imminence of hemoptysis, 
and the epistaxis are explained by the congestion, as a result of 
exertion .... 

As to the distress in the stomach, must we not consider the grad- 
ual expansion of the intestinal gases under a constantly decreasing 
pressure of the atmosphere as contributing greatly to this phenomenon 
and to those which accompany it? ... . And yet we have not observed 
any increase in the volume of the abdomen. (P. 65-68.) 

We see that M. Lepileur considers that everything is explained 
by congestions of the muscles and the nervous centers, due to 
exertion and increased by the panting, about the cause of which 
he says absolutely nothing. 

It appeared very difficult, after so complete and detailed an 
observation, to deny the harmful effect of altitude under certain 
circumstances. And so, following the account of his ascent of the 
Wetterhorn (3707 meters), on August 31, 1845, A. Vogt 70 protests 
against denials which are at least unwise; moreover, he tries to 
explain them, but he is not very successful in this attempt: 

We see (he says) in the narratives of travellers who have climbed 
lofty mountains strange contradictions; some mention frequent and 
more or less serious disturbances, others deny them completely. It 
seems to me that three factors act upon the human organism at great 
altitudes: 

1) The decrease of weight of the atmosphere and the consequent 
expansion of the air; 2) the dryness of the air; and 3) the light 
reflected from the stretches of snow. 

Martins, Barry, Agassiz, Desor, Escher von der Linth, etc., who 
felt no symptoms, blame the imagination of their predecessors. I can 
contradict them on one point. During the night which we passed at 
the Aaresattel, I was astonished at the rapidity of my breathing; my 
respiratory rate was twice as great as on the plain, although I did not 
feel the slightest discomfort. 



238 Historical 

It is natural for one to breathe more air in a rarefied atmosphere, 
in order to bring the same quantity of oxygen to the blood, since in a 
given volume of air there is less weight of it than on the plain. If 
there are many mountain climbers who have not noticed this phe- 
nomenon, that is because the diminished atmospheric pressure is a great 
help in the expansion of the thoracic cavity, and thereby makes 
respiration easier. 

Father Hue 71 is not a skeptic, far from it. His well-known 
credulity even robs his accounts of much authority. Nothing is so 
strange as this simplicity which very lightly borrows the language 
and the aid of science. In fact, he adopts absolutely the idea of 
poisonous emanations or vapors; but, more daring than his prede- 
cessors, he even specifies the nature of them, and considers that they 
are formed of carbonic acid: 

The mountain Bourhan-Bota has this very strange peculiarity, 
that the harmful gas exists only on the part that faces east and north; 
on the other side, the air is pure and quite respirable; it seems that 
these poisonous vapors are nothing but carbonic acid gas. The people 
attached to the embassy told us that when it was windy, the vapors 
were hardly noticeable, but that they were very dangerous when the 
weather was calm and serene. Since carbonic acid gas is known to 
be heavier than atmospheric air, it must condense on the surface of 
the ground and remain there until a great agitation of the air sets it 
in motion, scatters it through the atmosphere, and neutralizes its 
effects. When we crossed Bourhan-Bota, the weather was quite calm. 
We noticed that when we were lying down on the ground, we breathed 
with much more difficulty; if, on the contrary, we mounted our horses, 
the influence of the gas was hardly felt. Because of the presence of 
carbonic acid, it was very difficult to light a fire, the argals burned 
without flame, shedding much smoke. However, it is impossible for 
us to tell how this gas was formed and whence it came .... 

A terrible quantity of snow fell during the night; those who, on 
the day before, had not dared to keep on, joined us in the course of 
the morning; they told us that they had finished the ascent of the 
mountain with ease because the snow had dispelled the vapors. 
(P. 265.) 

These regions, so rarely explored, were crossed in 1873 by Cap- 
tain Przevalski. 72 He rejects absolutely the explanation which we 
have just reported: 

The great elevation of northern Thibet causes marked difficulty 
in breathing, especially if one walks quickly; then come vertigo, 
trembling in the legs, and even vomiting. The fuel of the country 
(argal) is hard to burn because of the rarefaction of the air and 
the rarity of the oxygen. 

The missionary Hue explains the same phenomena, which he 
observed on the mountain of Burchan-buda, by emanations of carbonic 



Theories and Experiments 239 

gas; but that is a mistake, for many Mongols from Tsaidam remain 
there during the summer with their cattle, which would not be pos- 
sible if asphyxiating gases escaped there .... Father Hue should not 
be believed when he speaks of the harmful gases of Burchan-buda. 
(P. 174.) 

Dr. Pravaz, 73 a physician of Lyons, a few years before, had 
founded an establishment in which he used a stay in compressed 
air for the treatment of different diseases. The book which he 
devoted in 1850 to the exposition of the data which he had ob- 
served contains, in its first part, interesting remarks on the different 
causes of mountain sickness: 

1. Respiration is mechanically restrained in its extent by the lack 
of elasticity of the atmosphere, which presses upon the interior of the 
lungs and by itself causes their development when the thorax expands 
through the effort of the inspirating muscles. 

2. This function is insufficient for hematosis, because the oxygen, 
or the vivifying principle of the blood, is present in too small an 
absolute quantity in the volume of air introduced by each movement 
of the inspiration, in addition to the fact that the lack of pressure 
makes the quantity of this gas dissolved in the blood less abundant. 

3. The arterial circulation is accelerated as a result of the rapidity 
of the respiratory movements caused by the instinct of self-preserva- 
tion, while the capillary circulation slackens, because the recall of the 
venous blood to the right cavities of the heart has become less ener- 
getic on account of the decrease of the constriction exerted on the 
periphery of the organs. (P. 57.) 

Farther on, while discussing at length these congestions of the 
mucous membranes which have attracted so much attention from 
the observers, he explains them by saying: 

One of the motors of the venous circulation, and consequently of 
the capillary circulation, namely, the atmospheric pressure, decreases 
as one rises above sea level. The greater the altitude, the less active 
will the recall of the blood into the right cavities of the heart be, 
and the greater tendency will the blood have to congest the parts 
where aspiration is ordinarily most effective. We may then compare 
the action of the heart with that of a pump working in a medium 
where the air is very much rarefied, and which can draw water only 
at a depth much less than under the ordinary pressure of the atmos- 
phere .... 

Hence the tendency to hemorrhages and apoplexy on lofty moun- 
tains. 

Mountain sickness presents another symptom which no one has 
tried to explain physiologically. It is evidently produced by a disturb- 
ance of the circulation in the portal vein system; it is characterized, 
in fact, like congestions of the liver and the abdominal viscera, by 
vomiting, cramps in the stomach, and intestinal pains. (P. 82.) 



240 Historical 

As to the differences presented by different individuals with 
reference to the altitude at which mountain sickness attacks them, 
Pravaz finds reason for that in the inequality of "the resistance of 
their tissues and in the vital contractility of their lungs". The 
sudden appearance of symptoms, a suddenness which our 
author exaggerates, is due to the fact that "in an almost indi- 
visible moment, the atmospheric pressure becomes less than the 
reaction of the lung, and ceases to be able to struggle successfully 
against it. . . . The decrease of the quantity of oxygen contained 
in the air breathed would not be great enough to explain this fact, 
for this decrease . . . could bring on dyspnea only gradually". 
(P. 76.) 

Be that as it may in regard to this last restriction, up to that 
time the alternative explanation given by de Saussure had been 
accepted without dispute, an explanation which tends to attribute 
the discomforts of decompression chiefly to the insufficient quan- 
tity of oxygen which the respiratory acts bring into the lungs. But 
in 1851, Pay erne, 74 an engineer who gave much attention to diving- 
bells, raised an objection to this hypothesis, the worth of which 
we shall discuss later: 

Upon the highest summits ever ascended, the pressure is equal at 
least to 32 cm. of mercury. The air there contains still 125 gm. of 
oxygen per cubic meter, or 100 gm. per 800 liters which a man- 
breathes per hour. Now experiments, the accuracy of which no one 
could question, have recently shown that a man while resting con- 
verts only 50 gm. of oxygen into carbonic acid. Assuming that while 
at work he would convert 5 and even 10 gm. more, he will be far 
from lacking it in a place where the barometer stands at 32 centi- 
meters .... 

The weariness and the panting in lofty places therefore do not 
seem to me to come from an insufficiency of oxygen, but from the 
rupture of the equilibrium between the tension of the fluids contained 
in our organs and that of the ambient air, no matter in which direc- 
tion the rupture operates. 

The authors who followed Payerne seemed not to have known 
of his objections. Marchal de Calvi, 75 among others, reproduces 
purely and simply the former explanation; this is shown by the 
extract from his work, published by the Proceedings; this extract 
we quote in full: 

The author thinks that he can conclude from the experiments 
reported in this Note that the variations in the atmospheric pressure 
are far from exerting the influence attributed to them. According to 
him, the mistake comes from the fact that in most cases which have 
been considered, when there is a decrease in pressure on the surface 



Theories and Experiments 241 

of the body, there is at the same time rarefaction of the air entering 
our lungs, and consequently decrease in the quantity of oxygen nec- 
essary for the normal accomplishment of hematosis. 

In 1853, Speer, 76 an English physician, published a special work 
on the nature and causes of mountain sickness. He begins by tell- 
ing that he himself, on the main peak of Mont Blanc, began to feel 
the following symptoms when he had reached 9000 feet: 

Congestion in the head, throbbing of the carotids, palpitations of 
the heart, distaste for food. At 10,000 feet, he felt a constriction of the 
chest, and shortly after, the taste of blood in his mouth, which was 
caused by a slight exudation from the gums. 

He then reviews the different explanations suggested, dwelling 
on that of Brachet, which he finds "too exclusive". To his mind, 
the great fatigue of the muscles is caused by "the congestion of 
blood which follows their repeated contractions", and as for the 
other symptoms of mountain sickness, they are due chiefly to "the 
irregularity of the circulation, with congestion of the brain and 
the abdominal viscera". 

The following conclusions indicate clearly the author's line of 
thought: 

Mountain sickness is characterized by the following symptoms, 
the union of all of which, however, is only rarely seen, if ever, in 
the same person: vertigo, headache, drowsiness, dyspnea, constriction 
of the chest, palpitations, tendency to syncope, oozing of blood from 
the mucous surfaces, increased rapidity of the pulse, anorexia, nausea 
and vomiting, thirst, feverish tongue, muscular pains, sensation of 
extreme weakness in the lower limbs, general prostration. 

These symptoms should be attributed to three causes: gradually 
increasing congestion of the deep portions of the circulatory apparatus; 
increase of venous plethora of the blood; loss of equilibrium between 
. the outer air and that of the gases present in the intestine. 

These determining causes of mountain sickness are themselves the 
result of the considerable and rapid change in the pressure and the 
temperature of the atmosphere. 

The next year, Dr. Conrad Meyer-Ahrens," a physician at 
Zurich, devoted to the study of the symptoms of decompression 
a long work far more important than that of Speer. 

This memoir is composed of two parts; in the first (p. 1-99) 
the narratives of a great many travellers are reported with details; 
the second summarizes the symptomatology (p. 99-123) and indi- 
cates the etiology (p. 123-136), the prophylaxis and treatment (p. 
136-139) of mountain sickness. 

In the preceding chapters, we have given all the data quoted 



242 Historical 

by Meyer-Ahrens and many others besides; since this part of his 
work contains no personal observation, I shall not speak of it. But 
from the part devoted to symptomatology, I extract a very good 
summary of the symptoms from which mountain travellers have 
suffered in different degrees: 

The principal symptoms or at least those which occur oftenest in 
man are: discomfort, distaste for food, especially distaste for wine 
(however, the contrary has sometimes been noted), intense thirst 
(especially for water, which quenches the thirst best), nausea, vomit- 
ing; accelerated and panting respiration; dyspnea, acceleration of the 
pulse, throbbing of the large arteries and the temples; violent palpi- 
tations, oppression, anxiety, asphyxia; vertigo, headache, tendency to 
syncope; unconquerable desire for sleep, though the sleep does not 
refresh but is disturbed by anguish; finally, astonishing and very 
strange muscular fatigue. These symptoms do not always appear all 
together .... Others are observed, although less frequently, such as 
pulmonary, renal, and intestinal hemorrhages (in animals also); 
vomiting of blood; oozing of blood from the mucous membrane of the 
lips and the skin (due merely to the desiccation of these mem- 
branes), blunting of sensory perceptions and the intelligence, impa- 
tience, irritability, .... finally, buzzing in the ears. (Pages 100-101.) 

But the chapter most interesting to us is that on etiology. I 
quote here the principal passages: 

All that we have just said about the etiology of mountain sickness 
shows: 1) that it appears at varying altitudes; 2) that meteor- 
ological conditions, temporary or general personal characteristics, and 
the speed of walking vary the altitude at which one is attacked and 
the severity and number of the symptoms. 

When one sees the appearance of mountain sickness correspond 
to varying altitudes, he asks himself what circumstances depending 
upon the altitude are capable of causing the phenomena which con- 
stitute it. In my opinion, the principal role belongs to the decrease of 
the absolute quantity of oxygen in the rarefied air, the rapidity of 
evaporation, and the intense action of light, direct or reflected from 
the snow, whereas the direct action of the decrease of pressure should 
be placed in the second rank. I find the immediate causes of mountain 
sickness in the changes made in the composition and the formation 
of the blood by the decrease in oxygen and the exaggerated evapora- 
tion, changes to which are added others due to the action of light 
on the cerebral functions, an action which affects the preparation of 
the blood liquid. 

These suppositions permit us to include — if we also take into 
account individual constitutions — all the phenomena of mountain sick- 
ness, without needing to appeal to the -direct action of the decrease 
in the weight of the air. This explains the acceleration of the respira- 
tory movements and the circulation, the congestions, the hemorrhages, 
the functional disturbances of the brain and the extraordinary fatigue 
of which almost all travellers complain. "We see too why mountain 



Theories and Experiments 243 

sickness attacks not only travellers on foot, but also horsemen; why 
the former are stricken much more severely (twice as severely, ac- 
cording to Tschudi); why exertion aggravates it; why it disappears 
when the traveller stops walking for a moment and reappears imme- 
diately when he starts again; why, however, just as horsemen 
themselves feel its painful symptoms, so at very great heights rest 
does not completely free travellers from it (de Saussure, A. Vogt) ; 
why walking on a level at great heights is often accompanied by 
distress which increases when one walks more quickly or begins to 
climb; why aeronauts are not exempt from disturbances of respiration 
and circulation; why patients stricken by the disease of the Puna are 
advised to sit quietly in rooms which are warm and well closed, etc. 
(Pages 131-133.) .... 

Other phenomena can in part be attributed to the immediate 
action of the diminished pressure, as, for example, the strange sensa- 
tion of lightness of which many travellers speak, the violent beating 
of the heart, qualms, nausea, vomiting, and oppression. In fact, the 
lessened pressure of the air, by lowering resistances, aids rapid walk- 
ing, respiratory movements, and the action of the heart, while at the 
same time it tends to increase the volume of gases contained in the 
intestinal canal; so that distention of the stomach and the crowding 
upward of the diaphragm may bring on nausea and oppression. But 
these phenomena of direct action may be relegated to the second 
rank, as I have already said. (P. 134.) 

We know, from the experiments of the Webers, that the great 
lassitude of mountain travellers is due to a direct action of the 
diminished atmospheric pressure; but we must understand that not 
only the large muscles, those that move the large bones and hold 
them in their articulations, become weary, but the same thing is also 
true of the small muscles, like those of the tongue and the larynx 
(Parrot and Hamel) ; a phenomenon which must be general and keep 
increasing, as A. Vogt asserts, if it is the consequence of the decrease 
in pressure, and that really does happen. Here too, we must make 
allowance for individual peculiarities. (P. 135.) 

So, in the eyes of Meyer-Ahrens, the immediate causes of 
mountain sickness are, in the first place, the decrease in the abso- 
lute quantity of oxygen in the rarefied air; then come the rapidity 
of evaporation, the intense action of the light, the increase in vol- 
ume of the intestinal gases, and a weakening of the coxo-femoral 
articulation. 

Dr. Lombard, TS who almost at the same time wrote for the 
Bibliotheque de Geneve excellent articles which he soon afterwards 
collected and published in a brochure, returns purely and simply 
to the two old explanations of de Saussure: diminution of weight 
sustained, diminution of the quantity of oxygen contained in the 
same volume of air; then the theory of the Webers appears again: 



244 Historical 

There is a very important element in mountain climates; it is a 
lessened atmospheric pressure and consequently an air which is less 
dense, as well as a decrease in the quantity of oxygen which is 
necessary to maintain life by means of respiration. To these last two 
circumstances are due in great part the phenomena observed on lofty 
mountains, and to these two I wish to call the attention of my readers 
for a few moments. 

If we question physics, we shall see that the total weight of the 
atmosphere represents as many times one hundred three kilograms 
as there are square decimeters on the surface of our body, so that, 
depending upon the height of different persons, the total weight sus- 
tained by our organs will vary between fifteen and twenty thousand 
kilograms. If then we leave a country more or less near sea level for 
a higher elevation, our bodies will sustain a pressure which will 
diminish in proportion to the increase in altitude. We can understand 
what a shock it must be to our organs when the enormous weight 
to which they are usually subjected is diminished by a sixth, a quar- 
ter, and even a third, as is noted on the Righi, the Saint Bernard, or 
the summit of Mont Blanc. And if we add to this decrease in pressure 
the no less important change which takes place in the density of the 
air, and consequently in the quantity of oxygen, we shall not find it 
difficult to explain the various disturbances which occur in the respi- 
ration, the circulation, the locomotion, and the digestive processes 
of those who climb the lofty peaks of our Alps, or dwell there for a 
time. 

In the appearance of the symptoms of which we are speaking, 
what part is played by a low pressure, and what part by an insufficient 
quantity of oxygen? That question is hard to answer, since both 
respiration and circulation should be equally modified under these 
two influences and should react on the muscular strength; on the 
other hand, now that recent researches have shown that the head of 
the femur is kept in the cotyloid cavity by means of the atmospheric 
pressure, it is clear that a decrease in the weight of the air should 
make movements more difficult; so that we reach the conclusion that 
the phenomena produced in living bodies, transported to great heights, 
are the result of the two meteorological conditions of which we have 
just spoken: a decreased pressure and a smaller quantity of oxygen. 
(P. 273.) 

But shortly after this, M. Giraud-Teulon, a French physician 
who was very competent in matters relating to physics, completely 
exposed the fundamental error upon which M. Lombard, along 
with so many others, was relying. 

Long before this, Valentin, 71 ' calculating the amount of the 
changes in the weight of the atmosphere on the surface of the 
human body at different heights above sea level, and admitting 
that organic matters are compressible to the same degree as water, 
had shown that: 



Theories and Experiments 245 

For one atmosphere of added pressure, the decrease of volume 
would be about 0.2 of a cubic inch, that is, 1/22522 of the total volume 
of the body. 

We see then that the volume of a man who was on the summit 
of Mont Blanc and let himself slide down would contract only seven 
one-hundred-thousandths. (Vol. I, p. 84.) 

However, this clear demonstration of the lack of importance of 
changes in pressure considered from the mechanical point of view 
had not kept a very eminent author, Heusinger, 80 from repeating 
with many details the explanation carelessly approved by so many 
travellers: 

The pressure of the atmosphere upon the body diminishes .... At 
sea level, it has been calculated that an adult man would sustain a 
pressure equal to 33,893 pounds; if he ascends to the height of Mont 
Blanc, the pressure will be only 19,334 pounds .... The bones will 
no longer be held in their articulations with the same strength, the 
muscles will have to exert greater force, fatigue therefore will be 
greater, .... the blood will be held with less force in the vessels, it 
will have a tendency to transude and to form hemorrhages where 
the walls are thin enough, and the blood will accumulate in the less 
contractible organs, where the capillary vessels can be expanded more 
easily, for example, in the mucous membrances, the lungs, and the 
brain; there will be congestion in these organs; the heart, which has 
fewer obstacles to overcome, will contract more often and the pulse 
will become more frequent. (Vol. I, p. 252.) 

We must note that to this erroneous cause a number of others 
are added, which are more or less justified, according to the 
vagaries of the eclectic method. First come evaporation due to 
decreased pressure and dryness, lower temperature, the action of 
the rays of the sun, which is stronger and "penetrates the body 
more deeply, and irritates the eyes, the brain, and the spinal cord", 
then electricity, "probably stronger and less often negative", and 
finally the lessened quantity of oxygen in the rarefied air, which 
"counterbalances the frequency of the respiration and the circu- 
lation". 

To return to the mechanical explanation, it was absolutely 
demolished by the work of M. Giraud-Teulon, and we are surprised 
that after such a thorough refutation, it has appeared again in 
books and even in the academies. 

M. Giraud-Teulon S1 first lays down two principles which have 
been too much forgotten by physicians and physiologists, before 
and after him: 



246 Historical 

1. All pressures exerted by the ambient atmosphere upon the 
human body naturally oppose each other and balance each other 
perfectly. 

2. The force exerted by the weight of the atmosphere is, more- 
over, counterbalanced by the incompressibility of the liquids with 
which all our organs are imbued, and by the tension of the gases and 
vapors in the splanchnic cavities and interstices. Thus the skin is 
placed between two forces which strive in opposite directions and 
cause an equilibrium. 

Then he asks himself: 

Whence comes the difference (a difference, the nature of which 
he unfortunately does not explain) observed between the corpse and 
the living body in the reaction of the two to outer pressure? Should 
we attribute it entirely to the difference in temperatures? But the 
temperature of the human body is not high enough to give a tension 
of more than 3 or 4 centimeters of mercury to the vapors of the 
liquids which it contains. Should it be attributed to the gases dis- 
solved in these liquids? But the experiments of Magnus prove that 
if their quantity, merely for some of them, reaches proportions suffi- 
cient to carry the tension of the liquids containing them to a figure 
which equals or surpasses the atmospheric pressure, their action and 
their reaction, with reference to the atmosphere, would be purely 
physical. Now Magnus has shown, on the contrary, that the gases 
dissolved in the blood are retained there by quite other forces than 
simple pressure. For it is not enough to raise the temperature or to 
lower the outer tension, even to just a few centimeters, to expel the 
gases dissolved in the liquids of the body; it requires the presence of 
other gases for which the blood has a greater affinity than for the 
normal gases which it contains. Where then shall we find the inner 
force which balances the ambient pressure? In the study of the laws 
of circulation and pressure in the great vascular systems. 

The author then shows that, in the living animal, because of 
the circulation of the blood, the tissues are always in a state of 
tension which he estimates at from 8 to 15 millimeters of mercury. 
Since this tension is constant, the result is, he says: 

That the organic system of the living being is never endangered 
by even a great variation, if it is gradual, of the outer pressure and 
that the circulation would continue as it was before the variation. 
And this explains the data collected by M. Poiseuille and by M. Tingu, 
in regard to the continuation of the vital functions, in spite of a 
considerable increase of the ambient pressure. 

The dangerous power of the gases of the blood, freed by the 
decrease of pressure, a hypothesis which Robert Boyle was the 
first to express and which M. Giraud-Teulon strongly opposed, as 
we have just seen, found an able defender in Felix Hoppe. 82 The 
work of this chemist is of a purely experimental type; it was 



Theories and Experiments 247 

undertaken with the purpose of explaining the symptoms which 
attack laborers working in compressed air; and as everyone has 
observed that these symptoms occur at the moment of decom- 
pression, Hoppe hoped to find their cause by studying death in 
rarefied air. Here first is the summary of his experiments: 

A rat was subjected to a rapid decrease of pressure. Convulsions 
occurred at about 50 mm. of mercury .... and death between 40 
and 50 mm. On opening the thorax, .... there could be seen through 
the walls of the vena cava, and the right auricle and ventricle, a 
considerable quantity of gas which could be released by puncture .... 

In a cat ... . which died at about 40 mm., .... I found about 
0.3 cubic centimeters of air in the vena cava and the right cavities 
of the heart; there were a few bubbles of air in the left auricle. The 
veins and the right heart were full of blood, the left heart almost 
empty; the blood was completely liquid, the arteries contracted 
spontaneously, the ventricles only under stimulation; the lungs were 
empty of air and healthy; there was no rupture of vessels; the brain 
was normal .... 

Two swallows died .... at a pressure between 125 and 120 mm.; 
I found a few small bubbles of air in their blood 

In birds as in mammals, the blood of the left heart was bright 
red, and consequently still contained oxygen .... 

Two frogs taken to the point of complete collapse were opened; 
there was no gas in their hearts .... A slow-worm taken to a 
pressure of 22 mm. swelled and remained motionless; then, a few 
minutes after being returned to normal pressure, it seemed as well 
as before. 

Summarizing: 

1. Birds die long before the point of effervescence of their blood; 
mammals die at a pressure hardly above this point; amphibians do 
not die even below this point; 

2. In warm-blooded animals, gas escapes in the interior of the 
vessels as a result of rapid decrease of pressure. This is not true of 
amphibians. 

F. Hoppe then asks himself whether death should be attributed 
to this escape of the gases of the blood, or to the lack of oxygen 
in the blood. It is very difficult to answer this question, he says: 
"For, in the autopsy, the arterial blood is still bright red, and 
very different from the blood of animals dying of asphyxia" (P. 
67) ; an observation which is accurate, but due to an experimental 
error which we shall demonstrate later. At any rate, the sudden 
death seems to him to be certainly due to the obstruction of the 
vessel by the gases liberated: 

The heart exerts upon its contents a pressure of 100 mm.; if the 
air in the large venous trunks has a pressure of only 50 mm., it must 



248 Historical 

be compressed a third of its volume to enter the arteries; the result is 
a great slackening of the circulation. If this slackening, joined to 
the small quantity of oxygen contained in the blood and the unequal 
power of the right and the left heart, can cause death, it can be only 
an instantaneous death. This death can be caused only by the 
obstruction of the capillaries of the lungs by bubbles of air, whence 
comes the stoppage of the circulation. 

He does not limit himself to this theoretical demonstration, and 
tries to prove experimentally that it is not the lack of oxygen, But 
the decrease of the pressure which kills animals placed under the 
bell jar of the pneumatic machine. To make this proof, he uses a 
method which, long before I knew the work of Hoppe, one of the 
last I found in my bibliographical research, I frequently used, and 
from which, as will be seen, I have drawn conclusions diametri- 
cally opposite to his. It will be interesting to discuss the reason 
for these differences; but this is not the place to do so. 

At any rate, Hoppe said to himself: if it is the decrease of pres- 
sure which brings death, and not the lack of oxygen, death will 
necessarily occur at the same pressure, even if pure oxygen is 
used: 

A guinea pig fell in convulsions at 77 mm.; pure oxygen was 
admitted into the b'ell, and it rose at once. When the pressure had 
been lowered again, it experienced the same symptoms at 75 mm.; sec- 
ond admission of oxygen, third lowering of pressure: symptoms at 75 
mm.; another admission of oxygen, collapse at 75 mm. Return to 
normal pressure; the animal survived. (P. 69.) .... 

So the symptoms of sudden asphyxia came at the same pressure, 
whether the animal was in air or in oxygen. 

From this he draws the definite conclusion that the cause of 
death lies in the appearance of free gases; the moment of their 
escape varies with "the pressure, the temperature of the animal, 
the power of absorption and the affinity of the blood for gases, and 
the quantity of blood corpuscles". 

The important researches of M. Fernet 83 this same year brought 
to the question a new element which, during later discussions of 
the cause of mountain sickness, seemed to support mistaken 
theories. 

Ever since the early experiments of Robert Bojde, it had been 
known that gases in considerable quantities are present in the 
blood. More recent chemists, particularly Magnus 81 in 1837, had 
shown that oxygen forms a very large proportion of the gases. 
From these experiments physiologists had been led to conclude 
that respiration is only a simple exchange of gases between the 



Theories and Experiments 249 

carbonic acid of the blood and the oxygen of the air, an exchange 
regulated by the laws of physics. 85 . 

The work of M. Fernet made them change their minds. This 
physicist, by a series of experiments carried on with unusual 
shrewdness, showed that carbonic acid and oxygen are kept in the 
blood chiefly by a chemical affinity. The method of demonstration 
which he used is directly connected with our subject, since he 
utilized the effect of changes in the barometric pressure. 

The method used by M. Fernet involved removing from the 
blood the gases which it contained, agitating it in closed vessels, 
with oxygen or carbonic acid under various pressures, and meas- 
uring the quantity of gas which it absorbed under these different 
conditions. 

He thus showed that: 

The volumes of oxygen chemically absorbed and independent of 
the pressure have a relative value so great that these experiments 
are immediately distinguished thereby from those which relate to 
saline solutions and even to serum. Not only is the progress of the 
phenomenon almost completely freed from the law of simple solution, 
but the volumes absorbed seem from the very first to be independent 
of the pressure, since the volume, when chemically combined, is 
almost five times as great as the volume when dissolved under atmos- 
pheric pressure. (P. 209.) .... 

In respiration, the oxygen of the air exerts a pressure which 
amounts to only one-fifth of the pressure of the atmosphere, so the 
volume dissolved in the blood of the respiratory apparatus must be 
reduced in the same proportion. The volume of oxygen absorbed in 
the state of combination by the corpuscles will then become about 
twenty-five times as great as the volume which actually enters the 
serum in the state of true solution. (P. 211.) 

From this well established fact, in his actual experimental 
conditions, M. Fernet thought he could draw the following con- 
clusion: 

This is the explanation of this result, already verified by a great 
many observations, that the absorption of oxygen is practically the 
same, on the summits of mountain and on the plains, whatever the 
atmospheric pressure; however, observation, here agreeing with 
theory, has already noted slight differences corresponding to differ- 
ences in pressure; but they can be demonstrated only by measuring 
methods capable of great accuracy. (P. 211.) 

We should make reservations about this conclusion, which does 
not seem to us to be included in the experimental premises. But 
we shall see that certain physiologists let themselves be drawn 
far beyond that. In this number is Longet. 



250 Historical 

Longet SG rapidly reviews the observations of mountain trav- 
ellers and aeronauts; he lists the different explanations which they 
have given of the symptoms felt. He agrees that sudden changes 
in the pressure can decrease the oxygenation of the blood, because: 

A certain lapse of time is always necessary for the equilibrium 
between the gases of the blood and the outer gases to be completely 
established, and also for the more active movements of respiration to 
be put in harmony with the new conditions, so that the lungs absorb, 
in a given time, almost the same quantity of oxygen as the normal 
state requires. (First edition, p. 474; third edition, p. 560.) 

But if one stays a long time, a complete equilibrium is estab- 
lished. In fact, he says: 

If, at each breath, the mountain dweller necessarily draws less 
oxygen into his lungs than the plain dweller does, he compensates 
for that by more frequent inspirations, so that, after all, in both of 
them the same quantity of oxygen can be absorbed in the same time. 
(First edition, p. 475; third edition, p. 561.) 

And farther on, speaking of the oxygen of the blood, he writes 
this quite explicit passage: 

We know that the quantity in weight of a gas dissolved in water 
is always proportional to the outer pressure; applying this law to the 
case in question, we would reach this conclusion that the blood of 
dwellers in regions where the atmospheric pressure is hardly 0.380 
meters would contain one-half less oxygen than the blood of dwellers 
by the seashore, where this pressure is 0.760 meters; but no doubt 
the preceding law does not apply here, because some chemical affin- 
ity interferes. (Third edition, p. 592; first edition, p. 493.) 

That was also the opinion of M. Gavarret, ST who, in 1855, 
expressed himself as follows: 

It would be false to say that the absorption of oxygen by venous 
blood is a purely physical fact; everything proves, on the contrary, 
that chemical forces play an important part in this fixation of oxygen. 
If, in fact, its absorption was a simple physical solution, while the 
outer pressure remained the same, the quantity of oxygen absorbed 
should increase in direct ratio to the proportion of this gas in the air 
breathed by the animal; now the experiments of Lavoisier had already 
shown and those of M. Regnault had proved indisputably, that how- 
ever great is its proportion in the artificial atmospheres created 
around the animals, the consumption of oxygen remains the same. 
In the second place, if the composition of the air remains the same, 
the ponderable quantity of oxygen dissolved physically by a liquid 
varies proportionately to the outer pressure. In the hypothesis that 
the phenomenon took place entirely through physical forces, the 
mass of oxygen absorbed by the residents of cities situated on the 



Theories and Experiments 251 

lofty plateaux of the New World would necessarily be reduced to very 
small proportions; the animals which live permanently at the dairy 
farm of Antisana, where the barometer stands at only 47 centimeters, 
would absorb a weight of oxygen less than two-thirds as much as 
they consume at sea level. Such a variation in so important a 
function would certainly cause great changes in their mode of exist- 
ence, which surely would not have escaped observation. If the 
oxygenation of the blood in the pulmonary capillaries was a purely 
physical fact, in birds of lofty flight which pass instantly from the 
surface of the earth to the highest regions of the atmosphere, the 
consumption of oxygen would undergo variations too sudden and too 
extensive not to endanger seriously the lives of these animals. (P. 262.) 

Moreover, in 1868, in his third edition, Longet borrowed this last 
objection from M. Gavarret, and added to the passage which I 
quoted above the following remark: 

How can we admit that observers would not have been struck 
by the profound changes which such variations would not fail to 
produce in the mode of existence of these populations? 

After that, is it not strange to see that when M. Jourdanet, as 
an "observer", noted "these variations in the mode of existence 
of the populations of lofty places", his conclusions were rejected 
by an exception drawn from the fact that by virtue of chemical 
laws oxygen cannot be removed from the blood by decrease of 
pressure? 

In 1858 there appeared the second edition of the book of M. 
Lombard, 88 of which we have already spoken; in announcing it, 
the editor of the Bibliothcque XJniverselle, Dr. Duval, 89 expresses 
himself in these characteristic terms: 

The researches on mountain sickness have been completed and 
better coordinated; perhaps the author made the possible symptoms 
of the digestive functions at an altitude of 1300 to 2000 meters seem 
a little too common. Many tourists will state that at that height they 
feel neither lack of appetite, nor nausea, nor vomiting, but on the 
contrary, an excellent and hearty appetite; some will also deny this 
distaste for wine and alcoholic liquors which would be experienced 
under the same circumstances; but that is only a question of a few 
meters more or less, and the reality of the symptoms described is 
none the less constant at an elevation which varies with the indi- 
vidual. De Saussure, who did not begin to be perceptibly affected 
until he had reached a height of 3800 meters, may pass as an 
exception. 

As for M. Lombard, he thinks much less of the direct effect of 
the diminished weight of the air; he also brings up the objection of 
Payerne, but none the less he gives great importance to the les- 



252 Historical 

sened quantity of oxygen contained in expanded air, of equal 
volume: 

MM. Barral and Bixio, .... in spite of the fact that more than 
9000 kilos were taken from the pressure to which their bodies were 
accustomed, felt no very pronounced sensation .... On the other 
hand, workmen in diving bells endure a double, triple, or even 
quadruple pressure without serious change in the functioning of the 
organs; and by this we are naturally led to consider the differences 
of atmospheric pressure as less important than one would be inclined 
to think from the purely scientific point of view. 

On the other hand, we have recognized that as one ascends 
heights, the air becomes less dense and consequently contains less 
oxygen, so that the respiration must be more frequent and more com- 
plete to bring into the lungs the quantity necessary for the oxygenation 
of the blood. From this physiological necessity there must result a 
considerable difficulty in breathing and consequently in the circulation 
also; and this we see in the dwellers in the lofty regions of our globe. 

Yet we must not believe that the rarefied air of our mountains 
does not contain a sufficient proportion of oxygen to maintain life; 
experiments made on the quantity of oxygen necessary for respira- 
tion have, in fact, shown that a man at rest in one hour converts 50 
grams into carbonic acid, and if we add five or even ten grams for 
the increase produced by movement or work, we shall see that, 
assuming that the stay is in a place where the barometer stands at 
only 315 mm. (7000 meters), the air still contains 100 grams of oxygen 
in the 800 liters that a man breathes per hour. So that we see 
definitely that, even at great heights, the atmosphere can furnish man 
a sufficient quantity of oxygen to sustain breathing. 

Does it follow, nevertheless, that this great decrease in an element 
so essential to life has no effect upon our principal functions? We 
do not think so, quite to the contrary; it is visibly evident that the 
withdrawal of a considerable portion of oxygen must make respiration 
incomplete and react upon the other vital functions which, like the 
circulation, are very intimately associated with respiration. 

But even that is not all; when an incompletely oxygenated blood 
reaches the different organs, such as the brain and the muscular 
system, it is evident that their functions will experience a disturbance 
proportionate to the incompleteness of the oxygenation; so that one 
must attribute to the decrease of oxygen a considerable portion of the 
disturbances which occur in innervation and motility. (P. 47.) 

M. Lombard then admits in part the explanation which the 
Weber brothers had given and which von Humboldt had accepted 
in regard to the role of the pressure on the cotyloid cavities. 

Among the symptoms experienced by travellers attacked by 
mountain sickness, the sensation of extreme cold is neither the 
least strange nor the least painful. M. Ch. Martins,™ who had felt 
it in his ascent of Mont Blanc in the company of Bravais and M. 
Lepileur, made a special study of this physiological cold, an 



Theories and Experiments 253 

expression which indicates, in the mind of the learned professor 
of Montpellier, not a drop in the body temperature, but the sen- 
sation of cold which may be produced by various causes. 

After studying these causes in a man at sea level, M. Martins 
declares that others exist in the mountains. Some act indirectly 
by changing the temperature of the air to which the sun gives less 
heat as a result of its decreased density, and which receives very 
little heat from the much reduced contact surfaces of the ground. 
Let us add that its constant renewal does not give it time to 
become warm, and that the expansion of ascending currents tends 
to chill it. Other causes act directly upon the living body. 

First is the power of radiation, which is twice as great on the 
Grand-Plateau of Mont Blanc as at Chamounix; next, pulmonary 
and cutaneous evaporation, stimulated by the low pressure, by the 
wind which blows almost constantly in lofty regions, and by the 
dryness of the air; finally, on lofty summits, the contact with a 
frozen soil. These are the physical causes which tend to chill the 
body. After explaining them in detail, M. Martins next comes to 
the physiological causes of the chill, which are peculiar to high 
mountains. 

Here we quote verbatim: 

Everyone knows that, at elevations which vary according to the 
individual from 2000 to 4000 meters, one begins to feel painful sensa- 
tions, namely: extreme panting accompanied by headache, desire to 
sleep, nausea, and great lassitude. This is the phenomenon called 
mountain sickness, a complex result of fatigue, abrupt decrease in 
pressure, and especially the rarefaction of the air. Physiologists 
consider that man draws into his lungs in an ordinary inspiration on 
the average a half-liter of air; the oxygen of this half-liter of air 
combines with the blood. At sea level, at a pressure of 760 mm. of 
mercury, a half-liter of air weighs 0.65 gm. and contains in weight 
0.16 gm. of oxygen; at a decreased pressure, 475 mm. for example, to 
which we were subjected for three days at the Grand-Plateau, the 
volume of air inspired is still the same; but its weight differs, for it 
is reduced to 0.40 gm., and the oxygen contained by this half-liter 
of air is only 0.10 gm., and on the summit of Mont Blanc, at a pressure 
of 420 mm., only 0.09 gm 

The oxygen of the blood and consequently the heat production 
are therefore less than at sea level merely because the quantity of 
oxygen drawn into the lungs is much smaller. Respiration is less 
perfect, just as it is in foul air in which the proportion of oxygen is 
lower than in normal air. This entirely physical cause had already 
been pointed out by Halle, Lombard, and Pravaz junior. Like them, 
I attribute to it the symptoms of panting which are noted in rapid 
ascents on lofty mountains. 

The objection that on lofty mountains the number of inspirations 



254 Historical 

compensates for the lessened proportion of oxygen in the air inspired 
is not valid. Anyone who has himself experienced the short and hasty 
inspirations, without proper expansion of the thorax, which accom- 
pany the breathlessness during and immediately after an ascent, 
realizes that these hasty inspirations cannot have the calorific effect 
of regular inspirations. So panting ceases the moment one stops walk- 
ing, and a regular respiration, more frequent than on the plain, partly 
compensates for the lessened quantity of oxygen; I say partly, for to 
make complete compensation, on the Grand-Plateau, for example, the 
number of inspirations would be to the number on the plain as 8 is 
to 5, that is, proportional to the quantities of oxygen inspired. Now 
that is not the case; panting, in a state of rest, certainly does not add 
one-third more. The lessened oxygenation of the blood is therefore 
not counterbalanced by the frequency of the inspirations, and becomes 
a physiological cause of cold which is peculiar to lofty regions, and 
probably the principal one of all those causes which bring on the 
symptoms known under the name of mountain sickness. 

This explanation, we see, is only the one already envisioned by 
de Saussure; we see also that M. Martins is much less optimistic 
than Longet, who asserted that on the mountains one could make 
up for the lessened oxygen content of the inspirations by their 
number. 

The same ideas also occur to the mind of Guilbert, !U when he 
gives an account of the soroche of the Cordilleras: 

Upon the plateau of the Cordilleras, the air contains only 3/5 of 
the quantity of oxygen which it contains at 0.76. When one ascends, 
he reaches colder and colder regions, where man must produce more 
heat, to maintain his normal temperature. To expedite combustion, 
he needs a greater quantity of oxygen, and the air contains less. 
Here are two causes working in the same direction, which are suffi- 
cient to explain the disturbance of the respiration and the circulation. 

The experiments of Magnus have shown the presence of free 
gases in the state of solution in the blood. The tension of these gases 
increases as the pressure diminishes. Then these gases exert a 
pressure against the walls of the vessels in which they circulate with 
the blood, and distend them; hence come compression of the brain, 

and consequently violent pains in the head, etc Perhaps too 

hematosis is incomplete; in this case, it could claim part of the effect 
on the nervous system; the blood, which has lost part of its stimulating 
qualities, could no longer be a sufficient stimulus; hence the tendency 
to syncope, etc 

The decrease of the atmospheric pressure also explains the 
hemorrhages. The free gases of the blood press against the walls of 
the vessels; a moment may come when these walls, unable to resist, 
longer, are ruptured and let the blood escape 

The action of the heart is no longer counterbalanced by the 
atmospheric pressure, and the result is a stasis of blood in the capil- 
laries which are therefore distended. This phenomenon is evident 



Theories and Experiments 255 

in the face and the hands, and especially in the conjunctiva. The 
same thing must take place in the capillaries of the lungs, and the 
exaggerated contraction of the heart also has a share in causing the 
difficulty in breathing. 

Let us note, in addition, that Guilbert adopts the explanation 
of the Weber brothers in regard to the connection between decom- 
pression and the firmness of the articulation of the head of the 
femur. 

Finally I shall report the conclusions of Guilbert with reference 
to pulmonary phthisis. This disease is very common on the Pacific 
coast, except among the Indians. But in the Cordillera, according 
to this physician, one observes: 

1. The absence of phthisis among the natives, without any racial 
distinction; 

2. Curability by a prolonged sojourn, and in such a proportion 
that this curability cannot be considered as the exception; 

3. The constantly delaying effect of the climate upon the progress 
of the disease in those who cannot be definitely cured, and the not 
infrequent remissions. 

In the year 1861 the first book of M. Jourdanet 92 appeared. This 
work had a double merit; first, by actual observation, he recog- 
nized certain signs of harmful effect from prolonged sojourn in 
lofty places, although no one before him had suspected it; second, 
by his explanation, he revived for science the idea glimpsed by 
Pravaz, but rejected through the work of M. Fernet, of a lessened 
solubility of the oxygen in the blood, in consequence of a dimin- 
ished barometric pressure. The true doctrine is completely ex- 
pressed in this volume. In the beginning, M. Jourdanet takes up 
and develops the calculations of M. Martins: 

The barometric pressure of Mexico is 585 mm. Consequently a 
liter of air weighing, at sea level, 13 decigrams, weighs only about 
1 gram in this capital. In both cases, oxygen figures in the proportion 
of 23.01%. That gives us 299 milligrams as the weight of a liter of 
oxygen at sea level, whereas this figure is reduced to 230 milligrams 
for the altitude of Mexico. 

Let us declare then a difference of 69 milligrams per liter to the 
disadvantage of this locality. 

Admitting now as correct the calculation which rated at 16 the 
number of inspirations made by a man per minute, we observe that 
the consumption of air is 8 liters in this interval of time, and 
consequently is 480 liters in an hour. But we have already noted 
for Mexico a loss of oxygen of 69 milligrams per liter. It is 
therefore indisputable that in this capital one loses the benefit of 33 
grams per hour or 794 grams of oxygen per day. (P. 65.) 



256 Historical 

After explaining thus the chief condition of the physico-physio- 
logical problem, M. Jourdanet states that the ardor of the sun on 
the heights of Anahuac must also act to diminish considerably the 
density of the strata of air near the ground, and consequently the 
intrapulmonary gaseous endosmosis. 

When this has been established, he shrewdly compares respira- 
tion in a pure air, but under low pressure, with respiration in air 
with low oxygen content, but at normal pressure. Then answering 
the objection taken from the work of MM. Regnault and Reiset 
by M. Gavarret, an objection which had just found new strength 
in the experiments of M. Fernet, he comments with reason that if 
the chemical combination of the oxygen and the blood was abso- 
lutely independent of pressure, one should live with ease not only 
at the lowest barometric pressures, but also in air with very low 
oxygen content, which no one will admit: 

According to the opinion of M. Gavarret himself, the solubility 
of oxygen in the blood is diminished when the quantity of oxygen 
inspired is lessened. It is therefore indisputable that, however effec- 
tive and necessary the affinity of the corpuscles for oxygen in the 
act of respiratory endosmosis may otherwise be, the mere fact of the 
rarefaction of this gas lessens the absorption of it at high altitudes 
and thus causes real disturbance in the phenomena of respiration. 
(P. 69.) 

M. Jourdanet then adds the following interesting observation: 

If the convictions which we have just expressed were to be shown 
inaccurate in the results, compensation for the rarefaction and the 
lightness of the atmosphere in Mexico would have to be made by 
deep inspirations and by a respiration which in general was more 
active than at sea level. It is commonly believed that this is the case 
and this opinion is based upon the observation furnished by persons 
who make a rapid ascent in the atmosphere or who make only a 
short stay at high altitudes. It is completely erroneous. The truth 
is that those who dwell at great elevations breathe less quickly than 
men whose abode is near sea level. The rarity of the air, as we shall 
see later, produces apathy of the muscular system. The chest also 
feels its effects. I have often surprised the functions in the very act 
by counting the respiratory movements of persons who were unaware 
of it and who were in a state of complete repose. I almost always 
noted a decrease in the number of expansions of the chest. Some- 
times, fairly often, in fact, one forgets to breathe and is forced to 
make up for lost time by taking deep inspirations. (P. 76.) .... 

But this respiration, so calm in absolute repose, easily gains 
amplitude under the influence of movement. (P. 87.) 

The consequences of this decreased absorption of oxygen are 
easily foreseen. The first is a decreased activity in the production 



Theories and Experiments 257 

of animal heat, at the very time when, on account of the altitude, 
this production should be increased. 

In fact, our author says very fittingly: 

Prudent Nature at sea level has established laws which assist, 
through the atmosphere, these variations in the production of human 
heat. For in winter the cold air is denser, and contains a greater 
part of the vivifying principle in a certain volume. The warmth of 
summer, on the contrary, by expanding the atmosphere, gives the 
lungs a proportion of oxygen in keeping with the small amount of 
heat which the body must produce. Thus the source, from which we 
draw the elements of our respiration, itself varies in a certain 
measure, which, at sea level, is a kindness of Providence. 

This is not true at high elevations, where the density of the air, 
lessened by the decrease of the barometric pressure, is no longer 
proportionate to the temperature surrounding us, but to the altitude 
which we have reached. And note particularly this extremely impor- 
tant fact: whereas at sea level the exterior causes which chill us take 
care to give us the means of combatting this drop in temperature, in 
Mexico, on the contrary, the decrease of pressure which produces cold 
in the air alters the source of heat for us by compelling us to breathe 
a rarefied atmosphere. So that, on the one hand, the increased expan- 
sibility of the air and the easier evaporation chill us constantly, while, 
on the other hand, the increased rarity of oxygen refuses us the 
normal means of calorification. 

Upon these data, so clear and so exact, the physiological pecu- 
liarity of altitudes rests entirely. (P. 83.) 

It is, therefore, not surprising to see that: 

Persons in a state of repose chill very easily. Their lower limbs 
are almost never warm. Muscular exercise would stimulate the 
circulation and the respiratory movements; but the blood, deprived of 
oxygen, produces apathy of the muscles and makes one prefer repose. 
Here then appears the result of the experiment made by M. Becquerel 
upon the muscle fiber which loses its contractility and becomes ener- 
vated when it lacks contact with the arterial blood. (P. 86.) 

Here M. Jourdanet meets the phenomenon described by all 
mountain travellers, of exaggerated fatigue, pain in the thighs, and 
heaviness of the lower limbs; he protests energetically against the 
explanation of the Weber brothers, which was accepted by von 
Humboldt and almost all later authors, although this explanation, 
to use his apt expression, "does not bear careful examination": 

In fact, if we estimate in square centimeters the surface on the 
plane of opening of the cotyloid cavity, the diameter of which is 54 
millimeters, we get a result of 22.89 square centimeters, which, multi- 
plied by 1003 grams, a weight equivalent to a square centimeter of 
surface, give us 23,645 grams, to represent the real weight in the 
cavity of the joint. If we remember that many travellers have felt 



258 Historical 

the muscular fatigue which we are discussing when they had hardly 
gone beyond a fourth of the atmospheric pressure, we shall see that 
this phenomenon appeared when the thigh was still supported by a 
weight of 17 kil. 734 gm. We do not understand why a member, 
which may weigh at most 15 pounds, would have so little respect for 
the 21 pounds surplus which it would drag along in its fall. (P. 89.) 
The real reason, according to M. Jourdanet, is expressed thus: 

This phenomenon appears when the blood, incompletely oxygen- 
ated, causes the contractile power of the muscular fiber to be 
considerably diminished. The abdominal member then refuses to carry 
out its normal functions and warns by pain that the task is beyond 
its powers. The same thing would happen to the other muscles of 
the body, if one required of them the exaggerated efforts which ascent 
demands from the muscles of the thigh. (P. 89.) 

Summarizing: 

The symptoms of the famous mountain sickness: vertigo, swoon- 
ing, vomiting, — what do they amount to but cerebral anemia, for 
want of the stimulus of arterial oxygen; congestion of the venous 
system, and especially the portal vein and the liver; but, above all, 
enervation of the muscular fiber for the same reason. 

Always and everywhere: lack of the normal quantity of oxygen 
in the circulation of the arterial blood. (P. 90.) 

Most of the book is devoted, as its title indicates, to the study 
of the diseases of Mexico. Everywhere there M. Jourdanet finds 
predominant the effect of this anemia of a special type, "result of 
an imperfect respiratory endosmosis". It is indeed, as he says 
clearly in his subsequent works, this strange syndrome which, 
awakening his medical shrewdness, caused him to reflect upon the 
conditions harmful to respiration and metabolism presented by a 
prolonged sojourn on the lofty plateaux of Anahuac. 

I shall merely quote the following passage because it offers a 
sort of summary of this remarkable work, and because we find 
in it a part given to the pressure as a mechanical agent, simply 
assisting its chemical action: 

We have already seen the blood, feebly welcomed and lazily 
expelled by the nervous centers, congesting the brain and the spinal 
cord of weak persons, already injured by the climate. We shall 
mention the disturbances of more than one sort of the alimentary 
canal, several of which are due to the circulatory slackening and to 
the capillary congestions of the intestinal venous system. The uterus 
has attracted our attention by phenomena of the same nature. We 
shall take the opportunity to say here that pulmonary congestions 
are frequent in Mexico and too often are fatal. Finally, more 
frequently than all the other organs, the liver imbibes blood and from 
this source draws countless symptoms, the unfortunate consequences 
of which are frequently reckoned among the causes of death. 



Theories and Experiments 259 

And so, beyond any doubt, altitude favors venous stases. When 
they are superficial, one cannot deny that the decrease of the air 
pressure acts in a purely mechanical sense towards this result. The 
superficial capillary networks, deprived of their natural external 
support, expand with an ease in proportion to the decrease in the 
weight. If to this first cause you add a blood not sufficiently stimu- 
lating for the arteries and too abundant in general for the veins, you 
reach the etiological trinity: lessened external adjuvant, organic 
sluggishness, general congestion of the venous system; a trinity the 
effects of which will be directed by turns to different parts of the 
organism, depending upon where the disturbances in innervation have 
previously prepared for them. (P. 254.) 

Two years later, there appeared a long memoir by the same 
author. 93 

The mere title of this second work, The Anemia of Altitudes, 
indicates the idea of M. Jourdanet: in his opinion, "the dwellers 
at great elevations, above 2000 meters, are generally anemic", and 
this condition is particularly evident to the eyes of the practitioner 
by the syndrome. And yet the chemical analysis of the blood 
strangely contradicts what the clinical observation revealed: 

In 1849, while I was in Puebla, I wished to ascertain by 
analytical examination of the blood whether the proportion of 
corpuscles was reduced. I made my first investigation on a young 
man twenty-five years old whom I knew to be suffering from gas- 
tralgias and vertigo. He fell from his horse, and the consequences 
of this fall made bleeding necessary. My analytical tests were made 
on blood obtained in these circumstances. They showed me that the 
proportion of corpuscles was 151/1000. I repeated my experiments 
upon four young women who were bled following accidents. Their 
pallor, their general prostration, and their nervous condition showed 
that they were suffering from chloro-anemia, although auscultation 
revealed no arterial murmur. Their blood furnished the normal 
proportions of corpuscles. (P. 8.) 

What is the explanation of this apparent contradiction? It is 
that: 

The principal duty of the blood corpuscles is to serve as aid to 
the real agent of our life. When their proportion is reduced in the 
blood, it is no doubt correct to say that the sickness is the result 
of the decrease in corpuscles; but we would fix the immediate cause 
-of the symptoms of the disease more accurately if we attributed its 
existence to the decrease in oxygen. I think I am more justified in 
expressing myself in this way because if, in the case of anemia, we 
call attention, as it is natural to do, to the reduced proportion of this 
gas in circulation, we see several causes which may produce this 
circulatory anomaly, without finding it necessary to explain it by a 
decrease in the number of corpuscles. That, exactly, is the case in 
the anemia of altitudes. (P. 10.) 



260 Historical 

M. Jourdanet summarizes his opinion in the following proposi- 
tions: 

1. The corpuscles and the barometric pressure regulate the quan- 
tity of oxygen in the blood; 

2. Disturbances in either of these two forces must necessarily 
affect hematosis; 

3. Since oxygen is the chief vital agent, its decrease for lack of 
corpuscles causes the weakness of anemic patients; its decrease in the 
blood for lack of pressure must produce the same result; 

4. For this reason persons breathing the atmosphere of great 
elevations must have their health affected in the same way as those 
suffering with anemia at lower levels; 

5. The anoxemia of altitudes is therefore analogous to the hypo- 
corpuscular anemia of the sea level. (P. 21.) 

Since plethoric persons have a large proportion of corpuscles 
in their blood, it is not surprising, as M. Jourdanet says, to see 
them often: 

Climbing the rugged sides of Popocateptl and at an altitude of 

17,700 feet imbibing the complete elements of life, whereas their 

travelling companions, of less sturdy constitution, succumbed to 
mountain sickness. (P. 22.) 

Then making a more detailed study of the chief phenomenon, 
the general trend of which he indicated previously, and taking 
into account the experiments of Magnus and M. Fernet and his 
own, M. Jourdanet reaches the remarkable conclusions which we 
give verbatim: 

1. From 76 to 65 centimeters, partial vacuum acts only upon the 
part of the gases of the blood which is held in true solution; 

2. Under the influence of this first barometric decompression, the 
release of carbonic acid is mmh greater than the loss of oxygen, 
the result of which is greater freedom of action for the oxygen; 

3. It is possible then that, since a moderate elevation does not 
noticeably decrease the quantity of the oxygen in the blood, whereas 
it removes a considerable portion of carbonic acid, it may act upon 
man with a tonic and strengthening effect; 

4. As to the portion of oxygen which a weak affinity allows us 
to consider as being held by chemical action, its escape from the 
blood results from lowered barometric pressure only when the pres- 
sure approaches 60 centimeters; 

5. We therefore should consider that the quantity of oxygen in 
the blood is seriously diminished beginning in the neighborhood of 
this limit, and it is then that the anemia of altitudes begins; 

6. We can therefore understand that a moderate altitude may be 
a powerful means of curing anemia, whereas this same disease is a 
natural consequence of sojourn at a considerable altitude. (P. 37.) 



Theories and Experiments 261 

Finally, in 1864, a third 04 work repeats with new develop- 
ments the ideas expressed in the works from which I have just 
taken numerous quotations. However, I cannot refrain from ex- 
tracting from one of his chapters on mountain sickness his clear 
explanation of this syndrome, an explanation in which we need 
to make no important change for the conclusions of the present 
book: 

A man who rapidly ascends to a very lofty point is deprived of 
a certain quantity of oxygen from which he was accustomed to 
receive a stimulating effect necessary for the full exercise of his 
strength. Certainly, what is left him after his ascent is still capable 
of maintaining life and even the regular action of the functions. But 
man cannot endure without temporary symptoms a sudden reduction 
which lessens the resources from which the nervous system is accus- 
tomed to draw its power. The muscular fibers also refuse to perform 
their task when their oxygen supply is decreased. We then see 
appearing those phenomena which hemorrhages have made familiar 
to us. As a result of the loss of blood, the organism, we know, sud- 
denly loses an important part of its normal stimulus; the patient has 
vertigo, his muscles weaken, nausea attacks him, and the more nearly 
vertical his position is, the more quickly he is seized by syncope .... 
The weakness produced by bleeding is evidently the consequence 
of a sudden lack of oxygen through the loss of a certain quantity of 
corpuscles, just as mountain sickness results from a more direct with- 
drawal of the same gas. So that, beyond a doubt, an ascent beyond 
3000 meters amounts to a barometric dis oxygenation oj the blood, 
just as a bleeding is a disoxygenation oj the blood through the lack 
of corpuscles. (P. 92.) 

These works soon stirred up a controversy which was very bit- 
ter. A French expeditionary corps had just been sent to Mexico, 
and the conclusions of M. Jourdanet were anything but encourag- 
ing for those who dreamed of the establishment of a Latin empire 
supported by a French colony established on the lofty plateaux 
of Anahuac. 

Michel Levy, then director of the School of Military Medicine 
and Surgery, was aroused and thought he should open a sort of 
investigation of the accuracy of the data given by M. Jourdanet; 
Dr. L. Coindet, head of the medical service of the second division 
of the French army, agreed to take charge of this investigation. 

The first letter sent by this observer to his hierarchic chief 
censured the statement of M. Jourdanet about the slackening of 
the respiratory movement: 

A statement (said Michel Levy) which contradicts the opinion 
accepted hitherto that, under the influence of reduced atmospheric 
pressure, respiration is accelerated to compensate by the number of 



262 Historical 

inspirations for the diminished quantity of oxygen in the same 
volume of air. 95 

In this document, L. Coindet 96 reports the results of 1500 obser- 
vations made on Mexicans and Frenchmen on the high plateaux, 
in which he counted the number of respiratory movements. I 
give here the summary of his tables: 

Frenchmen Mexicans 

Below 16 inspirations per minute 54 25 

16 inspirations 70 54 

Above 16 inspirations 626 671 

750 750 

General average of inspirations per minute 19.36 20.297 

In the presence of this mass of data (adds our author), doubt is 
no longer possible, and it is certain that those dwelling here do not 
breathe less quickly than men whose dwelling is 2277 meters lower. 
Farther on, Coindet declares: 

That, independently of the greater activity of the respiration, the 
inspirations are generally ample, deep, and profound, and-that all the 
more because they are less numerous. 

He then states, without having made any exact measurement 
of this point, however: 

That thus equilibrium is always established, and that the function 
constantly tends to adapt itself to the rarefaction and lightness of the 
atmosphere. 

Then, in a very sudden decision, which seems to indicate on 
the part of our author a very great desire to be easily convinced, 
Coindet does not hesitate to draw at once this important conclu- 
sion from these observations on the respiratory rhythm: 

That what has been written in regard to the insufficiency of the 
oxygenation of the blood at great altitudes, as a consequence of an 
alleged slowing of the respiration, should be considered unfounded . . . 
It may very well be that the so-called Mexican anemia is merely the 
yellowish complexion characteristic of the natives! 

Next come observations on the pulse rate and the comparative 
measurements of the chest capacity of Frenchmen and Mexicans. 
We shall return to the second of these later. In regard to the 
pulse: 

I have felt it repeatedly (says Coindet) without any prejudice, 

and I have even counted the heartbeats, which agreed with those of 

the arteries. 

In short, he finds as the average pulse rate, 76.216 for French- 
men, and 80.24 for Mexicans. 



Theories and Experiments 263 

The second letter'' 7 treats of "acclimatization on the heights 
of Mexico"; it contains only a summarizing description of the races 
of Mexico and a little meteorological information. However, I 
quote the following passage, which is rather interesting: 

After crossing Cumbre, when we reached an elevation above 2000 
meters, first respiration and circulation, and afterwards absorption, 
exhalation, and metabolism underwent noticeable changes. We per- 
ceived a tendency of the fluids of the body to move towards the 
periphery, the result of which was derangement of the circulation, 
various congestions, cerebral, pulmonary, and nasal hemorrhages, 
several examples of which I have given; difficulty in breathing, which 
made us pant; general discomfort, which made us consider the weather 
heavy, although it was really lighter; difficulty in moving and greater 
fatigue, and these symptoms were particularly marked in the men of 
the 95th of the line, who had not remained long at Orizaba, like us, 
and who had been transferred rather suddenly from sea level to a 
fairly high elevation. Little by little, the organism of everyone, at first 
in conflict with a medium for which it had not been created, adapted 
itself progressively to this medium, and today, after a ten month 
sojourn on Anahuac, it has been so transformed that it resembles that 
of the Indian. (P. 817.) 

The third letter 98 is much more important to us. In it is the 
report of the analyses made in the laboratory of the School of 
Mines of Mexico under the supervision of Professor Murfi, with 
the purpose of measuring the quantity of carbonic acid formed in 
a given time by dwellers on the lofty plateaux. Twenty-five per- 
sons, 10 of whom were French, 10 Indians or half-breeds, and 5 
Mexicans of European origin, were the subjects. The average re- 
sults, for the French, for example, are given in the following table: 

Number of inspirations per minute 19.6 

Pulse rate 78.2 

Quantity of air expired in one minute 5.90 liters 

Average percentage of carbonic acid per minute 4.24 

If we set aside the discussion which Coindet gives about the 
petty differences of details noted among the representatives of the 
different races on whom he experimented, we find that these 
observations inspired the following reflections in him: 

The average quantity of air expired per minute according to M. 
Dumas is 5.3 liters at sea level; here generally we have about 6 liters, 
when once the man is acclimated. This is logical, for since the air 
of altitudes contains in a given volume less oxygen at a barometric 
pressure of 0.58 or 0.59 meters than at 0.76 meters a greater quantity of 
this air must be absorbed to compensate for the difference: this is at- 
tained by a more active respiration; so that the air which is drawn into 



264 Historical 

the lungs and exhaled from them is always about a third of a liter for 
each inspiration and each expiration. 

While the air expired by man at sea level contains from 3 to 5 
parts of carbonic acid per 100, our experiments show that on Anahuac 
the average is just as high, since it is 4.36 for 25 subjects. 

It has been shown by 103 observations made at sea level by MM. 
Brunner and Valentin that the quantity of carbonic acid contained in 
the expired air is 4.267%. M. Vierordt," who made nearly 600 
experiments on this subject, reached nearly the same results. The 
expired air contains on the average 4.336%. 

Our average does not differ from the latter, if we take into 
account the decrease in atmospheric pressure which, as is well known 
(?), increases 'a little the proportion of carbonic acid exhaled. 

We are not surprised, after this long enumeration of data, to 
see Coindet cry out with an accent of triumph: 

Absorption of oxygen, exhalation of carbonic acid constitute two 
connected expressions, from the chemical point of view. On the other 
hand, modification in the qualities of the expired air and the corre- 
sponding changes in the composition of the blood are the two terms 
of the physico-chemical problem of respiration. 

There can be no doubt then about what one should think of the 
alleged insufficiency of the oxygenation of the blood at high elevations. 

The Gazette hebdomadaire contains another series of letters 
addressed by Coindet to Michel Levy, 100 under the general title: 
"Statistical Studies of Mexico", devoted to pathology, meteorology, 
etc.; they only rarely treat questions which are purely physiologi- 
cal. We see that for this physician everything is settled by his 
preceding researches, and that it is quite proved, as he says 
frequently, that at high elevations man compensates exactly, by 
the number and amplitude of the respiratory movements, for the 
loss in oxygen caused by the lessened density of the air; so that 
equilibrium is regularly maintained. I can find to be quoted 
verbatim only the following passage, in which our author's opin- 
ion about the cause of mountain sickness is shown. 

June 5, 1863, (he says) in the company of Dr. Laval, I ascended 
almost to the summit of Iztaccihuatl (4686 meters) .... Our mouths 
and throats were dry; our legs were exhausted; our respiration was 
panting, hasty, deep, often broken; our pulse, which was small, had 
a rate of 128. But we did not yet feel the distress, headache, or 
nausea, which constitutes mountain sickness, in which, by the way, 
acceleration of the circulation no doubt plays a great part by its 
congestive effect. 

M. Jourdanet did not fail to answer the letters which con- 
tradicted his physiological and medical statements on almost all 
points and which gave the impression that there could be nothing 



Theories and Experiments 265 

accurate "in a book", these are the very words of Coindet, "so 
opposed, I am proud to say, to all I have written". Without dis- 
cussing what relates to pathology, we shall go straight to the 
convincing reply which M. Jourdanet 101 made in opposition, not 
to the data reported by Coindet, but to the conclusions which this 
doctor drew from them: 

M. Coindet states that the respiration is not merely accelerated, 
but that it is ample, deep, profound. Now what do this amplitude, 
this depth, and this profundity amount to? We find the definite 
measure of them in the passage of his correspondence in which we 
see that 25 subjects gave an average of 6 liters of air breathed per 
minute, in 20 respirations. That is therefore an average of 30 centi- 
liters of air for each respiratory movement. It is evident that this 
volume of air represents only a very moderate thoracic amplitude . . . 

Our colleague is no more fortunate when he states that, on the 
great elevations of Anahuac, more air passes into the lungs in a given 
time than at sea level; for the 6 liters which he collected in the sub- 
jects of his observations are not above the very ordinary average 
furnished by men from 20 to 30 years old at the pressure of 76 centi- 
meters. And we should also note that, considering the rarefaction of 
the air of Mexico, these 6 liters weigh only 6 grams, instead of 7.8 
grams, the weight of the same volume of air at sea level .... 

So, according to M. Coindet himself, at an altitude of 2277 meters, 
respiration is not ampler, or deeper, or more active than at sea level. 
(P. 150.) 

The reply appears incontrovertible on this phase of the ques- 
tion. The chemical considerations remain. 

Here M. Jourdanet criticizes an obscurity in Coindet's wording, 
which no doubt has already impressed our readers, but which 
makes the reading of the different observations contained in the 
memoir itself quite incomprehensible. In the table reproduced 
above, we have copied verbatim these words: Average percentage 
of carbonic acid per minute: 4.24. What does this information 
mean? Does it refer to a percentage calculated in volume or in 
weight? This question is asked in regard to each of the observa- 
tions. 

We are quite surprised (M. Jourdanet says naturally) at the 
obscurity which reigns in the report of M. Coindet. Let us take, for 
example, the first experiment: 

"H. Staines .... Number of inspirations per minute 22; number 
of liters of air in one minute 6.4; carbonic acid 4.64%." 

Considering these 6.4 liters of air breathed by the subject of the 
experiments, we cannot help thinking that the 4.64% of carbonic acid 
indicates the proportional quantity of this gas in volume also. But 
further on (Gaz., 1864, p. 36, first column), these figures are repeated 
under the heading: Weight per 100 of carbonic acid expired in one 
minute. Evidently the wording is not clear. 



266 Historical 

We repeat with M. Jourdanet: Evidently the wording is not 
clear; but an important circumstance throws complete light on it. 
It is the comparison which Coindet makes between the figure he 
obtained and those of Vierordt, Brunner, and Valentin. These 
physiologists very certainly meant the percentage in volume, and 
Coindet could not have been confused about that, because the 
passage we copied above is the word for word reproduction of a 
new paragraph of the deservedly popular book of M. Beclard, 10 - 
from which only the words "percent in volume" have been left 
out. To M. Coindet, then, the matter concerns a proportion in 
volume, and his own experiments would show, if this were the 
case, a considerable decrease in the intra-organic combustions on 
the Mexican plateau, since, the quantity (in volume) of carbonic 
acid exhaled there being the same as at sea level, the quantity 
in weight would evidently be much lower, in a proportion meas- 
ured by the very decrease of the atmospheric pressure. 

But here is another thing. M. Jourdanet, who was then in 
Mexico, desirous of settling this doubtful question, asked M. Murfi, 
"true author of these analyses", and obtained from him an answer 
showing clearly that: 

The experiments of the College of Mines gave an average of 4 
grams and 51 centigrams of carbonic acid per 100 liters of air expired, 
measured at a temperature of 14 degrees and at a pressure of 58 
centimeters. 

The contradiction is glaring: Coindet specified volumes, M. 
Murfi states that it is a matter of weights, and M. Jourdanet, 
naturally giving more credence to the statements of the Mexican 
chemist, draws from them a really crushing conclusion for his 
adversary: 

It is therefore unquestionable (he says) that the subjects of the 
experiments of the College of Mines produced 4.51 grams of carbonic 
acid per 100 liters of expired air. On the other hand, the report of 
M. Coindet, agreeing in this with the statement of M. Murfi, says that 
the quantity of expired air was on the average 6 liters per minute. 
Who can doubt then that if 4.51 grams of carbonic acid correspond to 
100 liters of air, the 6 liters expired by the subjects of the experiments 
contained 27 centigrams. It is therefore certain that the quite unde- 
niable result of the respiratory proportion of the College of Mines 
was that the subjects from twenty to thirty years old produced 27 
centigrams of carbonic acid per minute, that is, 16 grams and 20 centi- 
grams per hour. 

The conclusions of M. Coindet do not agree with these figures; 
for not only did these alarming figures not authorize him to say that 
respiration in Mexico is identical with that at sea level, but they 



Theories and Experiments 267 

indicate a danger which would justly make one fear sojourn in lofty 
Anahuac; since, according to these experiments, the carbonated respir- 
atory combustions would not be half there what they are at sea 
level. The analyses of the College of Mines therefore leave us in great 
anxiety. I notified my colleagues of the Society of Medicine of Mexico, 
who were sufficiently affected by them to vote new surveys. (P. 151.) 

To this undeniable conclusion, Coindet 10:! tried to reply in his 
turn. Let us set aside the mere assertions and the digressions of 
acrimonious polemics, although they are numerous, and come to 
the root of the matter, the contradiction which we revealed above: 

M. Michel Levy (he says) and the members of the Society of 
Medicine of Mexico know the reply which I made to the statements 
of M. Jourdanet. I proved that the volume 3.90 per 100 of air at a 
temperature of 14 degrees and a pressure of 58, which was given me 
by the weight 4.51 per 100 of air also at a temperature of 14 degrees and 
a pressure of 58, furnished, because of the greater quantity of air 
expired (6 liters instead of 5.3 Dumas), 295.13 grams of carbon con- 
sumed in 24 hours, or 12.30 grams in one hour, and we know the 
averages established at sea level by MM. Dumas, Andral, Gavarret, 
Valentin, Brunner, Vierordt, etc. It is quite certain, I assert, that my 
subjects would not have expired more than 3.3 liters of air at sea 
level. 

I confess for my part that I do not understand this very well, 
and it would have been desirable that Coindet should copy in his 
letter the proofs which he had sent to M. Michel Levy. First, let 
us note that this time the 4.51 are no longer for him a measure 104 of 
volume, as that resulted evidently from the new paragraph which 
we mentioned, but a measure of weight; it is, as M. Murn said, 
the weight of carbonic acid contained in 100 liters of air expired 
at 14° and 58 cm. But from that point, the reasoning and the calcu- 
lation of M. Jourdanet are unassailable. If 6 liters of air per min- 
ute pass through the lungs, that makes 360 liters in an hour, con- 
taining 360 x 4.51 grams = 16.23 grams of carbonic acid. The re- 
searches of Andral and Gavarret 105 give an average, between the 
ages of 20 and 40, of 12.2 grams of carbon consumed, which corre- 
sponds to 44.07 grams of carbonic acid. The difference is enor- 
mous, so enormous that, for my part, I think that there is a funda- 
mental error in the analyses which are the basis of his reasoning. 

Let us see now what Coindet's reasoning is. And first, let us 
note that he takes a strange cross-road: "I have proved", he says, 
"that the volume 3.90 per 100 of air at a temperature of 14 degrees 
and a pressure of 58, which was given me by the weight 4.51 per 
100 of air also at a temperature of 14 degrees and a pressure of 
58 . . ." 



268 Historical 

These are painful and useless calculations; why change a weight 
into volume to find again a quantity in weight? Let us, however, 
make them again, because, if their apparent result is favorable, 
we shall find considerable errors in them. 

A liter of carbonic acid at 0° and 76 cm. of pressure weighs 1.966 

grams. Therefore, 4.51 grams of this gas represent under these 

4.51 
conditions of temperature and pressure liters, and at 58 cm. 

4.51 liters x 76, 4.51 liters x 76 (273 + 14) 

and at 14° = 3.160 liters. 

1.966 x 58 1.966 x 58 x 273 

So the expired air contained in volume 3.16% of carbonic acid, 
and not 3.90 as Coindet said, so that all his subsequent results are 
decidedly wrong. 

Better still: accepting the figure of 3.90% (a proportion, which, 
by the way, does not vary, as Coindet seems to think, with the 
pressure and the temperature) we get final results very different 
from those he records. In fact, the men whom he observed 
breathed per hour 360 liters of air, which consequently contained, 
according to him, 360 x 3.9 liters = 14.04 liters of carbonic acid, 
at 14° and 58 cm., representing at 76 cm. and 0°, 

14.04 liters x 58 x 273 

= 10.19 liters. 

76 (273 + 14) 

Now since 1 liter weighs 1.966 grams, we would have for the 
production per hour only 1.966 grams x 10.19 = 20.03 grams; and 
as there is a weight of 27.68% of carbon in carbonic acid, the 
weight of the carbon consumed per hour would be 

1.966 grams x 10.19 x 27.68 

= 5.54 grams; 

100 * 

which is far from the 12.30 grams announced by Coindet. 

On the contrary, the calculation of M. Jourdanet here finds a 
complete verification by counter-proof. In fact, it results from 
what we have just said that really, according to the experiments 
of Coindet, his men exhaled per hour 

360 liters x 3.16 = 11.376 liters 

of carbonic acid, representing at 76 cm. and 0°, 8.258 liters, which 
weigh 16.23 grams, a number exactly like the one we found before 
according to M. Jourdanet. 



Theories and Experiments 269 

It is for the reader to decide whether, after such a surprising 
argument, one should jeer, as Coindet did, at the "competency" of 
the man who very courteously criticized his mistake. At any rate, 
we can now easily evaluate the following conclusions, which he 
boldly 10 ° formulated: 

4. The average of the carbonic acid expired on Anahuac, with 
diet and conditions equal, is not lower than at sea level. 

6. The quantity of oxygen circulating in the blood is the same at 
high elevations as at sea level; and with similar and equally satis- 
factory hygienic conditions, the efficacy of hematosis is the same also. 

17. Under ordinary conditions, residence in Anahuac does not 
seem to lessen permanently and injuriously the total of the gases 
which circulate in the human body. 

As for me, I do not hesitate to say that in the work of Coindet 
nothing justifies this last conclusion, and everything in it contra- 
dicts the first two. To tell the whole truth, I confess that I can- 
not accept as accurate even the analyses which are the foundation 
of them; there must be some mistake in the experimental method 
or in its application. I shall merely say that the quantity of air 
upon which the analysis was based was much too small; M. Murfi 
had the respiratory movements carried on in his apparatus for a 
half -minute ; Andral and Gavarret had them continued from 8 to 13 
minutes. Furthermore, no one took care to collect the air which 
passed through the nostrils. However disposed I am to think that 
in Anahuac the intensity of the organic combustions is really les- 
sened, I refuse to believe that it is one-half less, as would be 
demonstrated if we considered as accurate the figures furnished 
by the work of Coindet himself. To sum it up, from the point of 
view of the chemical phenomena of respiration, there is absolutely 
nothing left of this work. 

One of the surgeons of the Mexican expedition, M. Cavaroz, 107 
shortly afterwards published a memoir, the observations and con- 
clusions of which are exactly like what M. Jourdanet had already 
said. 

He first made a great many measurements on French soldiers 
and found that at an altitude of 1712 meters the general average 
of respirations was 19% and the pulse rate 65 %•: 

He first draws this conclusion that: on the lofty plateaux of 
Anahuac, there is established in the European a supplementary 
respiration, intended to compensate by the number of respiratory 
movements for the loss of oxygen for hematosis resulting from the 
rarefaction of the atmosphere .... 



270 Historical 

But, he soon adds, we need to know whether this compensation 
is complete, and whether, after all, there is no loss of oxygen, and 
whether the hematosis is as normal and perfect as at sea level. I do 
not think so, for according to the average ratio of 18 respirations for 
67 heartbeats, the number of heartbeats for 19% respirations should 
be 67 V2. It is only 65 x /4; therefore there is a loss of 2V4 heartbeats; 
therefore the circulation is slackening to a certain degree, and the 
physiological condition is disturbed. 

The rest of the work of M. Cavaroz contains observations tend- 
ing to prove that on the lofty plateaux the European loses his 
liveliness and strength, and that if he falls ill, he rapidly passes 
into a state of prostration. So, in his opinion, perfect acclimatiza- 
tion is by no means proved. The resemblance between these ideas 
and those of M. Jourdanet is quite striking. 

However, no one has paid any attention to it, and henceforth 
authors will speak of no one but Coindet, and we must confess 
that without exception they will side with him against M. Jourda- 
net, which proves, among other things, that it is much easier to 
read conclusions than to discuss a memoir. 

So in the article Air which M. A. Tardieu ln " wrote for the Dic- 
tionary of Practical Medicine and Surgery, the learned hygienist 
devotes a page to the study of the physiological effects of rarefied 
air. It is filled by a rapid review of the ideas of M. Jourdanet and 
the works of Coindet; I take from it these characteristic lines: 

After what has just been said, we see what we should think of 
the alleged insufficiency of oxygenation of the blood at high altitudes. 

Moreover, M. Tardieu gives no explanation. 

The article Altitudes which M. Leroy de Mericourt wrote for 
the Dictionnaire Encyclopcdique two years after deserves the same 
reproach. But before discussing it, I must say a few words about 
a very odd book, published in 1863 by Dr. Foley. 109 

When we come to the study of compressed air, we shall have 
to give a lengthy review of it. We shall see that in the opinion 
of this physician, the compression exerted by the air plays the 
principal part: "When one enters the caissons", he says, "he is 
flattened." He naturally brings the same preoccupation of a me- 
chanical type to the study of mountain sickness: 

A traveller climbs a mountain. The higher he ascends, the 
weaker he feels, and the more his subcutaneous veins distend. He 
finally becomes ill. Why? 

The periphery of his body is no longer compressed. A comparative 
vacuum has been formed around it. The blood has accumulated 
there. The brain has therefore failed. The aeronaut has fainted. 
(P. 63.) 



Theories and Experiments 271 

Let us add that farther on M. Foley declares that nausea, 
cramps, etc., are the sign of "insufficient hematosis". 

In his opinion, it is the presence of the air sacs which saves 
the bird from the symptoms of decompression; the shocks* with 
which he would be threatened on his return as workmen are when 
they leave the caissons (see later, Title II, Chapter III) are spared 
him because of the elastic tension of the gases contained in the 
sacs. For that, the bird that is mounting needs only to close 
its beak and its nostrils; but perhaps we may be permitted to 
ask how it can breathe then. 

A distinguished veterinarian, M. Liguistin, 110 who was in com- 
mand of this service during the Mexican expedition, found himself 
confronted with the same problems as the military physicians. He 
seems not to have known of the heated discussion the principal 
points of which we have just summarized: 

"In his opinion, moreover, the effect of the decrease in the density 
of the air is very well known." (Vol. Ill, p. 583.) 

As to symptoms observed in animals, he states that the respira- 
tory disturbances noted by doctors seem not to have attacked 
beasts of burden: 

Would the large solipeds bear more easily than men the effect of 
an air with low oxygen content? Would the lymphatic temperament 
with which they are endowed explain sufficiently the less urgent need 
of a denser air? However we know very well, and have already said 
so, that the atmospheric pressure most favorable to animals Is also 
that found at sea level and in places of moderate elevation, where 
the mercury column registers about 76 centimeters on the barometer; 
that, if we place a living animal in a vacuum, the air within it, no 
longer meeting any resistance, expands, the animal is distended and 
dies; that it is the air pressure which keeps the fluids in the vessels 
of animals and prevents them from escaping. Therefore, when the 
barometer drops a few degrees, the blood must evidently flow towards 
the periphery; then we observe difficulty and acceleration of respira- 
tion, slackening of the circulation, weariness, prostration, and lack 
of interest. If in this situation our animals were endowed with the 
power of speech, they would probably tell us, as men do, that the 
weather is heavy, thus taking the effect for the cause, for we know 
that the rarer the air is, the lighter it is. It is unnecessary to explain 
why the respiration is more hasty. We know well enough that, since 
the air necessary for life is extremely rare, the respiratory acts must 
be more frequent to produce the same result. It is still more unnec- 
essary to add that when the air becomes rarer, one might die of 
asphyxia. In a rarified air, thoracic inflammations and hemorrhages 
must necessarily prevail. And yet we have not observed this, and 
that is why we think that we are authorized to assert that the reduced 
atmospheric pressure on the lofty plateaux of Mexico does not have 



272 Historical 

the peculiar influence upon our animals which we have observed in 
men living in the same medium. We mention the effect of the rare- 
faction of the air only in explaining the exaggerated distention 
accompanying the numerous indigestions observed in our horses and 
mules during the period of the siege. (Vol. Ill, p. 658.) 

In a special work, this same veterinary gives an account of a 
series of very unusual symptoms, observed in the animals of the 
expeditionary corps, in the crossing of Rio-Frio (3300 meters) . 

The animal passes from health to sickness without any preliminary 
symptoms. The system is in a state of general tension, especially the 
muscular system. The eyes are fixed, wild, brilliant, the face con- 
tracted and the pupil dilated. The hind limbs and the whole hind- 
quarters are the seat of spasmodic movements which are very 
definite and easily detectable. The muscles of the stifle and the thigh 
display partial quiverings. 

The mouth is filled with a white, foamy, and very abundant 
saliva. The jaws are in a state of permanent contractility. There is 
certainly an over-stimulation of the salivary glands. There is a mani- 
fest desire to vomit. Frequent efforts with belching are easily 
observed. The belly is not distended. There are a few slight colics 
shown by a little uneasiness, but the animals do not lie down, aroused 
instinctively by the desire to urinate or defecate. The genito-urinary 
system is over-stimulated: there is a stubborn and painful erection 
of the penis. The conjunctiva is in its natural state and shows no 
very perceptible changes; it is moist and very slightly bloodshot. The 
capillary blood system is not visibly changed. The heartbeats are 
strong and tumultuous. One can see at a distance, without resorting 
to auscultation, the hasty movements of diastole and systole, and can 
count the throbs of this organ by looking from behind the knee; . . . 
and yet, strangely enough, the state of the pulse is not appreciably 
modified in its normal rhythm. 

The nostrils are dilated. The expired air is hot; respiration is 
accelerated. The inspiration is shallow and the expiration deep. The 
respiratory muscles are contracted and tense, and the flanks, drawn 
upward, are separated by extremely pronounced projections. They 
rise and fall up to twenty or twenty-five times per minute. 

There is rather general prostration of the nervous system than 
evident over-stimulation of the brain. 

The symptoms which we have just listed continue for several 
hours without increasing and then disappear evidently as the effect 
of suitable measures. (Vol. IV, p. 258.) 

This strange series of symptoms apparently so dangerous, 
which, however, never brought on any serious consequences, sug- 
gested to M. Liguistin the idea of poisoning. Not all of his col- 
leagues shared his opinion; "some explained the symptoms in ques- 
tion by blaming chiefly the rarefaction of the air, slow asphyxia 



Theories and Experiments 273 

M. Liguistin himself realized that this element might have an 
important etiological part: 

Certainly there is no doubt (he says himself) that at the season 
when we crossed Rio-Frio, the period of great heat, that a consider- 
able increase in the temperature, causing evident rarefaction of the 
air, added to an elevation of 3302 meters above sea level, and 
producing by this altitude a decrease of 3 ¥2 kilometers in the height 
of the atmospheric column, had the immediate result of decreasing 
considerably the quantity of respirable air and producing symptoms 
characteristic of such causes. We should have liked to be able to 
prove this physical point by the barometer, during the different 
conditions of the atmosphere; for that alone would have furnished 
the real explanation of the swelling of the abdomen frequently 
appearing in the animals of the expeditionary corps during our 
crossing of Rio-Frio. However, although this rarefaction was not 
demonstrated experimentally, its existence is nevertheless undeniable. 

In Mexico City, observation showed that the atmospheric pressure 
was only 58 degrees. We may therefore estimate it for Rio-Frio at 
approximately 55 or 56, which would cause a decrease of 20 degrees 
from normal atmospheric pressure. Is it illogical to suppose, after 
that, that animals cannot be placed for even an instant in such a 
medium without their organism feeling some effects of it? Evidently 
not; and we were all the distressed, but not surprised, witnesses of 
the harmful effect which so rarefied an atmosphere can produce upon 
the health of large solipeds; I mean this second pathological scene, 
which appeared again more definitely at Rio-Frio, and which brought 
a moment of turmoil and confusion (indigestion with distention). 
(Vol. IV, p. 262.) 

In short, M. Liguistin persists in the idea of poisoning, the 
harmlessness of which he explains by the partial neutralization 
produced by other plants simultaneously ingested. By searching 
in the vicinity, they found a sort of scilla, to which they attributed 
the symptoms. Experiments made with the leaves suspected gave, 
however, only one interesting result: the firm refusal of the horses 
to taste them, even after a fast of 48 hours. As for poisoning 
obtained by aqueous extract, ingested in the animals by force, 
they by no means resemble the symptoms observed during the 
crossing of Rio-Frio. Whence we conclude, in direct opposition 
to our author, that these symptoms were due exclusively to the 
rarefied air. 

I now come to the article of M. Leroy de Mericourt, 111 an article 
to which the name and the special qualifications of its author 
gave much credit, and which is still quoted constantly. 

However, it does not contain any personal observation, and the 
only really original idea in it is due to Professor Gavarret; but 
it gives, in an elegant style, a summary of the data previously 



274 Historical 

observed and the theories put forth. The most interesting part 
consists of a very harsh criticism of the works and opinions of 
M. Jourdanet, whom he considers completely vanquished by Coin- 
det. According to him: 

The proportion of carbonic acid in the air expired, as indicating 
the activity of hematosis on altitudes of more than 2000 meters, 
showed that the average exhalation of this gas is not less than it is at 
sea level. 

We have already shown what one should think of this asser- 
tion, to which the very figures of Coindet would give much too 
complete a contradiction, in our opinion. 

Then, finding the comparison made by M. Jourdanet between 
mountain sickness and bleeding, and expressed in these striking 
and accurate terms: "An ascent above 3000 meters is a baro- 
metric disoxygenation of the blood, just as a bleeding in a cor- 
puscular disoxygenation", M. Leroy de Mericourt finds nothing 
better to say about it than to qualify it as strange: 

Moreover, (he says) a priori, the objection may be raised against 
M. Jourdanet that the absorption of oxygen by the venous blood is 
not a purely physical fact, the result of a simple solution, but that 
chemical forces play an important part in this fixation of oxygen. 

I was very desirous of reporting this opinion because it shows 
well what the sentiment of the most learned and the best authori- 
ties was in 1866. We must, in fact, wait for the theory expressed 
by M. Jourdanet, the accuracy of which I have demonstrated ex- 
perimentally, to be considered soon as a thing so simple and evi- 
dent that everyone will claim to be its originator, or at least will 
refuse it any merit of originality. 

I now come to the passage penned by M. Gavarret. 

After reviewing a few principles of elementary physics, the 
learned professor of the Faculty of Paris continues in these words: 

When he ascends a lofty mountain on joot, man accomplishes a 
quantity of mechanical labor which varies with the weight of his 
body, the height of the ascent, the nature and the disposition of the 
ground on which he walks. To the mechanical force which he thus 
expends there corresponds a consumption of a determined quantity 
of the organic materials of his blood, the combustion of which pro- 
duces no thermic effect. Independently of the quantity of heat 
necessary for the maintenance of his own temperature, the respiratory 
combustions must therefore furnish the calorific equivalent of the 
mechanical force expended during the ascent. To understand thor- 
oughly the consequences of this forced increase of the respiratory 
activity, let us give our attention to a specific example. 



Theories and Experiments 275 

An adult man, of good constitution, weighing 75 kilograms, has 
ascended, on foot, to an altitude of 2000 meters on the side of a 
mountain. He has thus accomplished a useful work of 150,000 kilo- 
grams, representing 353 units of heat, the thermic effect of which is 
zero, since they are transformed entirely into mechanical force, and 
which are furnished by the respiratory combustions. Since eight 
tenths of this transformed heat comes from the combustion of carbon, 
the creation of the mechanical force corresponding to the useful work 
accomplished during the ascent requires the production of 65 liters 
of carbonic acid, above 22 liters of this gas which the man forms per 
hour in his general capillaries to maintain his own temperature. The 
consequences of the production of so great a quantity of carbonic 
acid in the body are apparent. The consumption of the organic 
materials of the blood is excessive, and the powers are rapidly ex- 
hausted. The respiratory and circulatory movements are considerably 
accelerated, on one hand to render possible the absorption of all the 
oxygen necessary for such active combustions, and on the other hand 
to rid the blood of such a proportion of dissolved carbonic acid. When 
the pace is slow, the force expended in a given time is slight, and 
the functional disturbances are not great. 

But if the ascent is rapid, the exhalation of gas, though very much 
activated, is not enough to maintain the normal composition of the 
blood, which remains saturated with carbonic acid; then respiration 
becomes uneasy; the dyspnea is extreme, and is accompanied by head- 
ache, vertigo, and drowsiness .... We easily understand why a halt 
of a few instants is enough to dissipate all these symptoms. 

As soon as the man is resting, the expenditure of energy ceases, 
the activity of the respiratory combustions drops rapidly to the degree 
strictly necessary for the maintenance of his temperature, the utili- 
zation of oxygen is only 22 liters per hour, the blood is very quickly 
freed of the excess of carbonic acid which it contains, and all the 
disturbances of the respiratory and circulatory functions disappear 
at the same time .... 

As a result of these considerations, we think that we are author- 
ized to say that the larger part of the functional disturbances 
characteristic of mountain sickness should be attributed to a true 
intoxication by carbonic acid dissolved in too great proportions in the 
blood. To express our ideas completely, we shall add that an intoxi- 
cation of the same sort, the inevitable result of too great an expendi- 
ture of energy, is one of the principal causes of the serious symptoms 
observed in overdriven animals. 

This interesting and original theory, supported by indisputable 
calculations and the great authority of the learned professor of 
medical physics, should gain great success and be epoch-making in 
science. Henceforth, all will vie with each other in repeating it; 
already Dr. Aug. Dumas 112 has been the first to do so in his inaugu- 
ral thesis. 

But the theory of M. Gavarret does not satisfy him; he ac- 
cepts and supports with well-made calculations the theories of the 



276 Historical 

Weber brothers on the tendency of the head of the femur to sepa- 
rate from the cotyloid cavity in expanded air. The objections of 
M. Jourdanet do not affect him, as we see. That is because he 
does not consider the work of this learned physician very impor- 
tant; in his opinion, Coindet has completely refuted such errone- 
ous statements: 

What becomes then (he cries) of the alleged insufficiency of 
oxygenation of the blood at high altitudes? and what shall we say 
of all the theories which M. Jourdanet has based upon this idea? 

As to the headache, vertigo, and loss of consciousness experi- 
enced by von Humboldt and other travellers, Dumas explains 
them "in a wholly mechanical manner"; to tell the truth, he 
merely copies an explanation already given by Pravaz: 

Barry has shown that at each expiration, the course of the blood 
is slackened in the jugular veins. Therefore it is easy to understand 
that, in a person who has reached the summit of a lofty mountain, 
where his hampered respiration forces his thorax to make hasty 
movements, his venous blood experiences a stasis in the jugular veins 
and even flows backward, possibly causing a congestion of the nervous 
centers and all the symptoms which result from that. 

M. Scoutetten, 111 whose work appeared the next year, is satis- 
fied with copying the principal parts of the article Altitudes, and 
particularly the quotation from M. Gavarret, whose opinion he 
adopts wholly. 

As he seems besides to attach much importance to the varia- 
tions of the weight sustained by the human body under different 
barometric pressures, he took the trouble to draw up a long table 
in which are listed the amounts of this weight in all the mineral 
water spas. 

We learn from this that a man who sustains 15,345 kilograms 
at sea level is relieved of 406 kilograms at Vichy, of 1015 at Saint 
Gervais, of 1905 at Mont Dore, and 2744 at Cauterets, the highest 
of the spas. 

Is it among such ideas that an author takes his stand whose 
Proceedings for 1867 publish a note which is not conspicuous for 
clarity? I do not know and leave the reader the task of decid- 
ing: 114 

M. Kaufmann submits to the judgment of the Academy a memoir 
on the mechanical effect of the air upon certain physiological functions 
in which it does not usually play a part. 

To ascertain, the author says, the mechanical effect exerted upon 
different parts of the organism by the pressure of the air, I began 
experiments to measure the air; some in which I measured the 



Theories and Experiments 277 

changes produced in different physiological or pathological states by 
variations in the weight of the atmosphere; others in which I produced 
these variations artificially. Those whose results I am submitting to 
the Academy today refer to the different periods of generation in 
mammals from conception to the time of delivery. 

In the book which he published at the time of his return to 
France, Coindet lir ' returns to the question of the quantity of car- 
bonic acid formed by men who live on the lofty plateaux. Evi- 
dently he felt ill at ease on this ground, for in a work of two vol- 
umes, containing more than 650 pages, he devotes only 5 to this 
important subject. And yet what could be more convincing in 
favor of his point than to dwell upon this demonstration that the 
intra-organic combustions are as active at high altitudes as at sea 
level? Anoxemia, against which he was battling, would be com- 
pletely disproved. I confess that at first I expected to find new 
experiments in this book; there are none, and the explanation of 
the data is infinitely less complete and detailed in it than in the 
letters addressed to Michel Levy. 

This is soon explained, for first we record a valuable confes- 
sion; "I was mistaken", says Coindet (Vol. II, p. 90), "when I 
formerly wrote weight instead of volume." There is a point 
gained, and, as I had shown when I recalled the passage copied 
by Beclard, the notorious 4.51% in 1864 represented to Coindet a 
proportion in volume, although he said the opposite in his 1865 
letter. But then, if there is 4.51% of carbonic acid in volume in 
the air, since the subjects were breathing at the rate of 6 liters 
per minute, or 360 liters per hour, that makes in one hour 360 
liters x 4.51 — 16.23 liters of carbonic acid expired. 

Since we are working at 14° and at 58 centimeters, this volume 
corresponds., at 0° and 76 cm., to 11.77 liters; and as a liter weighs 
1.966 grams, the production of carbonic acid per hour would be 
23.14 grams, giving 6.40 grams of carbon consumed. Once more 
we are far from the 12.30 grams announced triumphantly by 
Coindet. 

But he thinks better of it: 

We must not lose sight of the fact (he says) that 4.52% in 
volume, the average amount of carbonic acid exhaled in one minute, 
has been removed from an air at a temperature of 14°, and a pres- 
sure of 58 cm., brought to a temperature of 0°, and a pressume of 76 cm. 
... so that 6.125 liters, average amount of air expired in one minute, 
disregarding the Frenchmen who had lately arrived and were not 
acclimated, give us 367.55 liters in one hour . . . 

When the average of 4.52% of carbonic acid exhaled in one min- 
ute is accepted, we can establish the following proportion: 



278 Historical 

100 : 4.52 : : 367.55 : x = 16.62 liters of carbonic acid per hour. 

At sea level, 1.85 liters of carbonic acid contain 1 gram of carbon, 

which gives us 9 grams very approximately consumed in one hour. . . . 

This figure is quite different from the 12.30 grams of the first 
work. And yet how was it obtained? First by taking the quan- 
tity of air expired from 6 liters to 6.125 liters; then by declaring 
that in the calculations the air was reduced to 0° and 76 cm.; but 
Coindet forgets that he said exactly the opposite before: 

I have proved that the volume 3.90% of air at 14° and 58 cm. fur- 
nished me by the weight (let us not forget that now it is the vol- 
ume) 4.51 of air also at 14° and 58 cm 



In another passage, he is no less explicit 



Since the quantity of air expired per minute, as admitted by 
M. Dumas, is 5.3 liters at sea level, in Mexico City . . . we have about 
6 liters. This was logical, for since the air at high altitudes contains 
less oxygen in a given volume, a greater quantity of this air had to 
be absorbed to make up the difference. 

It is not therefore, in our opinion, 9 grams, but 6.40 grams of 
carbon consumed in an hour that are given by the figures of 
Coindet himself. But even with 9 grams, we must realize that 
we are far below the average figure of 12.2 grams found by 
Andral and Gavarret. Coindet cannot conceal it, but he does not 
seem at all disturbed by it: 

Our average of 9 grams (he says calmly), lower than that found 
by some authors, does not cause us, for reasons given above, to con- 
sider the respiratory combustions of carbon as perceptibly lower on 
the lofty plateaux than they are at lower levels. 

What are these reasons then? First, we see, is that 

Our Creoles were students in the School of Mines, on the day 
before their final examination for the year, sitting studying all day 
long, and under these circumstances the expired air has undergone 
little change; 

And second, that 

The Indians had an insufficient diet and used alcohol habitually; 
And third, that 

There were losses through the nostrils! 

I think it would be useless to continue. I can only repeat what 
I said above: from the chemical point of view, there is nothing, 
absolutely nothing, left of the work of Coindet; and as the experi- 
ments which we have just shown to be so unsatisfactory are the 



Theories and Experiments 279 

basis of his whole physiological argument, we see that his position 
is untenable. 

I should certainly not have spent so much time on a work 
which has had far too much publicity, if it was not still quoted 
as an authority by persons who preferred to trust to its peremptory 
conclusions rather than to make the painful analysis through the 
meanderings of which we have led our readers. And the latter 
have had the opportunity to see that even if the a priori asser- 
tions and the statements of conclusions are clear, the experiments 
themselves and the calculations based on them contain only ob- 
scurity, confusion, or error. 

M. Gavarret 116 did not adhere to the theory which we reported 
above, and which he had given in the form of advice to M. Leroy 
de Mericourt. When he wrote the article Atmosphere for the 
Dictionnaire Encyclopcdique, he was led to investigate the effects 
of decreased pressure, without the addition of fatigue, exertion, 
and the production of carbonic acid imposed by mountain ascents. 
Reaching the study of causes, as an experienced physicist, he first 
opposes the opinion that the lessening of the weight sustained by 
the body may have some effect; he properly invokes against this 
error the principle of the incompressibility of liquids, and conse- 
quently of the body. But in giving his attention to this point, 
strangely enough, he returns to the ideas of Robert Boyle: 

The disturbance which accompanies the decrease of the barometric 
column is really the effect of the pressures from within outward 
exerted by the vapors and the gases imprisoned with the body .... 
We must fix our attention upon the gases of the blood which, under 
the effect of a considerable and very rapid drop of the barometric 
column, may cause serious symptoms. The blood, in fact, contains 
oxygen, nitrogen, and carbonic acid in the state of simple solution. 
When the outer pressure diminishes, these gases tend to separate from 
the blood, push the walls of the vessels from within outwards, and 
distend the pulmonary and general capillaries, the walls of which may 
be ruptured because of their thinness and lack of resistance. Such 
is the mechanism of the production of hemorrhages, sometimes slight 
and temporary as their determining cause when they appear on ex- 
ternal surfaces, sometimes serious and even fatal, when they have the 
interior of some vital organ as their seat. (P. 153.) 

But M. Gavarret makes haste to apply a proper restriction to 

this: 

Symptoms of this sort may no doubt be produced in persons who 
are very rapidly moved to great altitudes; but that is not the case 
with travellers who gradually ascend from sea level to the highest 
plateaux on earth. In the latter, the laws of physics governing gases 
and their solubility .... reestablish harmony .... (P. 154.) 



280 Historical 

In other words, the explanation given by the learned professor 
can be applied, according to him, only to laboratory experiments 
performed on animals; mountain climbers and aeronauts are not 
amenable to it. 

The argument brought by M. Gavarret against the part which 
so many authors had given to the decrease of the weight sustained 
by the body seemed to have exposed this error; the important ex- 
periments of Rudolph von Vivenot 117 seemed, on the other hand, 
to give it new authority. In fact, the Viennese physician proved 
very clearly that in rarefied air the depth of the respirations and 
the respiratory capacity diminish considerably. 

These experiments were made at the Johannisberg establish- 
ment, in the apparatuses set up by Dr. Lange; some had as their 
purpose the study of compressed air, and those we shall discuss 
later; the others, of which we shall speak now, related to rarified 
air. 

When we take into account the altitude of Johannisberg, where 
the average height of the barometer is 742 mm., we see that if 
the decompression reached in the apparatus was 318 mm., the 
actual pressure was 424 mm., which corresponds to an altitude of 
4470 meters above sea level. 

Under these conditions, as I said a moment ago, the amplitude 
of the respirations diminished considerably: 

Dr. Lange and Dr. Mittermaier, whose pulmonary capacity shortly 
before at normal pressure had been 3942 cc. and 4237 cc, could only 
with the greatest efforts expire 3448 cc. and 3842 cc, of air which 
was admitted to the receivers of the spirometer. Their respiratory 
capacity therefore had diminished 494 cc. and 394 cc. respectively. 
On an average, we can deduce from the above figures as a normal 
average respiratory capacity 4090 cc, as respiration in rarefied air 
3646 cc, consequently as average decrease of pulmonary capacity 444 
cc, to which we must add that these 3646 cc. of rarefied air represent 
only 2084 cc. of normal air. (P. 7 of the separate printing.) 

The frequency of the respirations has considerably increased, 
working inversely: 

The number of respirations rose in me from 14-15 to 18; in 
M. de G. . . ., from 17 to 21, and at another time, from 17-18 to 19; 
in Dr. Lange, from 15 to 21; in Dr. Mittermaier, from 7.5 to 9.5 per 
minute. As to the consecutive duration of this effect, it could not be 
noted, because no observations were made following the experiments 
in rarefied air. (P. 11.) . . . 

As to the depth and rhythm of respiration in rarefied air, an in- 
crease in the depth of the inspirations is noted. This, then, is the 
first case in which the effect of rarefied air seems to agree with that 



Theories and Experiments 281 

of compressed air, although the causes are opposite. Whereas in com- 
pressed air there is a deeper inspiration spontaneously, as a mechani- 
cal effect of the increase in pressure, it is, on the contrary, the need 
of getting air, which, since it cannot be satisfied in rarefied air by 
normal inspirations, necessarily produces deep and forced inspirations. 
One experiences at the same time a feeling of uneasiness, oppression, 
during which the inspiration is especially difficult, because, even in 
atmospheric air, it requires more energy than the expiration, whereas 
the latter, in rarefied air, is made more easily and more quickly. 
(P. 16.) 

Vivenot also made observations on the pulse rate. It rose from 
78 to 80 in Dr. M., from 73 to 82 in Dr. L., from 61 to 76 in M. de G., 
from 80 to 105 in Vivenot himself. 

A veterinarian of the Royal Corps of English Engineers, Fleme- 
ing, 118 published in 1867 a work in which he reports a fairly large 
number of travellers' observations, and at the head of which he 
expresses his theoretical opinion about the effect of decompres- 
sion: 

If the pressure is reduced artificially, as when one climbs a moun- 
tain or ascends in a balloon, one notes the same phenomena as in 
fish taken from the water. 

The body swells, the inner fluids distend the tissues outwards, 
exerting a vigorous pressure on them, burst the vessels, and often 
cause hemorrhages. 

Rarefied air contains less oxygen in a given volume, so that 
respiration, being incomplete, is accelerated to compensate for this 
deficiency; the inspirations are proportionately more numerous; the 
heart contracts vigorously and more frequently, the blood circulates 
with difficulty, the lungs are congested, the blood vessels are dis- 
tended, and aneurisms are formed. (P. 9.) 

In summary, according to Flemeing, the effect of altitude can 
be produced in several ways: 

1. By the decrease of the atmospheric pressure: the muscles and 
the articulations tend to relax, the blood stops or transudes through 
the walls of the vessels, especially the mucous membrane of the air 
passages, the lungs, and the brain envelopes. 

2. By cutaneous and pulmonary evaporation .... 

3. The frequency of the circulation and the respiration is coun- 
terbalanced, or better, caused by the small quantities of oxygen which 
the inspired air contains. 

4. The lowered temperature .... 

5. The more powerful rays of the sun ... . which cause irrita- 
tion of the eyes, the brain, and the spinal cord. (P. 12.) 

M. Bouchard, in his noteworthy thesis .on the pathogeny of 
hemorrhages, 110 is led to express his opinion about the cause of 
the symptoms, noted both in persons subjected to a considerable 



282 Historical 

decrease of pressure and in workmen who are being decompressed 
when they leave the caissons of bridge piers. In his opinion, as 
we shall see at the proper time, hemorrhages are due partly to 
the escape in the vessels of the carbonic acid of the blood, which 
has been stored up there in exaggerated proportions during the 
compression. 

Decompression by ascent would produce the same effect; and if 
hemorrhages have been noted particularly in mountain climbers, 
the theory which he suggests may explain the difference in these 
effects: 

The man who rises in an aerostat performs practically no work 
except that required by the respiratory movements. The man who 
climbs a lofty mountain, on the contrary, makes a considerable muscu- 
lar expenditure and must load his blood with carbonic acid. Is it not, 
moreover, to this accumulation of carbonic acid in the blood that 
certain authors attribute this peculiar dizzy state called mountain 
sickness? (P. 102.) 

Errors are hardy. It is strange to note that in spite of the 
authoritative answer made by M. Jourdanet to the theory of the 
Weber brothers, it continues to be taught almost universally. 
M. Beclard, 120 in the last edition of a book which should be in 
the hands of all students, says, in fact: 

When man rises in the air, climbing very high mountains on 
foot, as the rarefaction of the air increases, he experiences a very 
peculiar feeling. It seems to him that his limbs are heavier; the 
lower limbs especially soon become the seat of a fatigue which urges 
him to rest. Hardly has he stopped an instant when this fatigue 
disappears to reappear after a short time; and so on. This is what 
happens; the atmospheric pressure is no longer sufficient by itself to 
keep the head of the femur firmly against the cotyloid cavity, and 
thus counterbalance the weight of the lower limb, and muscular effort 
must keep the limb in its articular relations. This unusual muscular 
effort is promptly followed by need of rest for the muscles .... 

This effect is felt even when the differences in pressure of the 
barometric column are not very great. When the barometer falls, 
since the muscles have to move heavier organs, we say that the 
weather is heavy, although in reality the pressure exerted upon the 
surface of the body by the atmospheric column is less. Likewise, 
when the barometer rises, movements are made more easily. (P. 
697.) 

As to the symptoms of decompression other than heaviness of 
the limbs, M. Beclard attributes no importance to them when the 
transitions are made rather slowly: 

At Potosi (4000 meters), at Deba (5000 meters) .... the functions 
of metabolism, respiration, and circulation of the mountain dwellers 



Theories and Experiments 283 

go on as in dwellers on the plains, and they are in just as good 
health .... 

Men and animals therefore can endure very considerable varia- 
tions in pressure without disturbance of the functions of life. It is 
true that, since the density of the air is lessened, the air drawn into 
the lungs contains in each inspiration less oxygen than on the plain 
in the same volume; but the movements of respiration harmonize 
with these new conditions. Moreover, pressure is still exerted in all 
directions, the air penetrates all the open cavities (alimentary canal, 
respiratory passages), the gases of the blood are put in equilibrium 
of tension with the atmospheric air, and the normal conditions of 
gaseous exchange are not altered in the lungs. 

The variations in the pressure of the atmospheric medium in 
mountain ascents or in balloon ascensions are not likely either to 
cause painful symptoms in regard to metabolism. 

But this is not true when the decompression takes place rapidly, 
as happens in aerostatic ascensions: 

Then a certain time is needed for the equilibrium between the 
inner gases and the outer gases to be established. When the ascen- 
sion has been to a considerable altitude, sometimes there appears a 
difficulty in breathing, suffocations (from expansion of the intestinal 
gases which press upon the lungs, crowding the diaphragm upwards) 
and local hemorrhages in the mucous membranes (probably from, sud- 
den expansion of the gases contained in the vessels, and from rupture 
of the capillaries). (P. 696.) 

Beside the ideas of physicians with theories we should place 
the opinion expressed by mountain climbers. After the theories 
and the discussions which we have just reported, it is somewhat 
surprising to see certain travellers almost deny the effect of de- 
compression. 

For instance, Hudson, 1 - 1 who scorning "the easy beaten path 
which usually leads to Mont Blanc," ascended the mountain by a 
new route, starting from Saint Gervais, states that: 

If one is careful to save his strength, he can cross the highest 
summits without experiencing any serious inconvenience. Several 
persons have complained of discomfort experienced at great heights, 
nausea, drowsiness, bleeding from the nose, the eyes and the ears, 
and I do not doubt that such symptoms are possible; but my long 
training in mountain journeys has proved to me that they should be 
attributed only to fatigue, to which no doubt may be added cold 
and the rarity of the air, or rather the unusual precautions required 
by these two circumstances. In fact, there were five of us in the 
group, and thanks solely to care not to get tired, none of us had an 
instant of discomfort; the same thing was true at the time of my 
ascent of Monte Rosa. (P. 85.) 

Dr. Piachaud, 1 - 2 whose interesting observations we have already 



284 Historical 

summarized, made during his ascent of Mont Blanc in 1864, also 
attributes to fatigue alone the disturbances of circulation and 
respiration; according to him, the drowsiness is due to cold, the 
muscular fatigue to the cause indicated by Brachet, and the heavi- 
ness of the lower muscles to the cause specified by Weber and von 
Humboldt. 

But these not very original estimations have hardly any im- 
portance beside the new and very ingenious theory advanced by 
Dr. Lortet. 1 - 3 We have reported at length the observations made 
with all the precision required by modern physiological research 
by this learned physician during his ascent of Mont Blanc. The 
discovery to which he gives most importance is the decrease of 
the body temperature during the act of ascent. In his opinion, 
this is the true cause of the symptoms experienced, and to explain 
it, M. Lortet relies upon the elementary notions of the mechanical 
theory of heat: 

In a state of rest and fasting, man burns the materials of his 
blood, and the heat developed is wholly employed in maintaining his 
temperature constant in the midst of atmospheric variations. On the 
plain and during moderate mechanical work, the intensity of the 
respiratory combustions, as M. Gavarret has shown, increases propor- 
tionately to the expenditure of energy. There is a transformation of 
heat into mechanical energy, but because of the density of the air 
and the quantity of oxygen inspired, there is enough heat formed to 
make up for this expenditure. 

In the mountains, especially at great altitudes and on very steep 
snowy slopes, where the mechanical work of the ascent is great, an 
enormous quantity of heat is needed to be transformed into muscular 
energy. This expenditure of energy uses up more heat than the or- 
ganism can furnish, hence the perceptible chilling of the body and the 
frequent halts which must be made so that one can gain warmth. 
Although the body is burning hot, although it is often covered with 
perspiration, it becomes chilled during the ascent, because it uses up 
too much heat and because the respiratory combustion cannot furnish 
a sufficient quantity of it because the air lacks density; because of the 
rarefaction of the air, at each inspiration less oxygen enters the lungs 
at a great height than on the plain. (P. 33.) 

M. Lortet then shows, by a simple calculation, that while he is 
ascending 1000 meters, a man weighing 75 kilograms would find 
that the temperature of his body would drop 2.3°, if he furnished 
no restorative heat. Hence he draws this conclusion that the drop 
of 4° to 5°, which he noted in ascending to 3800 meters, is quite 
natural and within the limits indicated by his theory: 

Let us take, for example, a human body weighing 75 kilograms, 
and let us assume that during the ascent no combustion repairs the 



Theories and Experiments 285 

loss of heat undergone; let us assume also that all the mechanical 
work is usefully employed, that is, that none of it is lost in slipping, 
false steps, etc. 

When the body has been raised 1000 meters, the quantity of work 
accomplished will be represented by 75 x 1000 or 75,000 kilogram- 
meters. 

As the mechanical equivalent of heat is 425 kilogram-meters for 
each unit of heat, to get the quantity of heat absorbed during this 

75,000 

work of ascent of 1000 meters, we shall have =176 units of 

425 

heat. If we assume that the specific heat of the human body is equal 
to that of water, that is, equal to 1, and if we represent this specific 
heat by C; if we call the drop in body temperature X, we shall have: 
quantity of heat lost by the body 75 (C + X) or 176 = 75 x X, whence 

176 

X = , or X = 2.3 

75 

Therefore the drop in body temperature resulting from the heat 
absorbed by a work of 75,000 kilogram-meters, performed in an ascent 
of 1000 meters, would be 2.3° centigrade, assuming that no combustion 
repaired, at least in part, this loss of heat. But it is evident that in 
reality this combustion exists and that a part of the heat expended 
is restored while it is being absorbed. But we have seen, by the 
study which we have made of the respiratory and circulatory disturb- 
ances, how much this combustion is hampered at a certain altitude, 
and how incomplete it is. 

Furthermore, it is evident also that all the energy expended is far 
from being useful because of false steps and the softness of the snow. 
The quantity of heat used must therefore be enormous, and the drop in 
temperature must be great and hard to meet by respiratory com- 
bustion. 

We see then, when these different elements of the problem are 
well considered, that this drop of four and some tenths degrees centi- 
grade, in the ascent of Mont Blanc, is not at all extraordinary because 
this figure gives one and some tenths degrees centigrade for each thou- 
sand meters of elevation, a quantity which is very near the 2.3° centi- 
grade given us by the physical theory, when we do not take into 
account the respiratory combustions. (P. 36.) 

However, when one is digesting, there is almost no drop in tem- 
perature, probably because of the acceleration of the circulation, either 
general or capillary, and perhaps also because of an extremely rapid 
absorption of alimentary material. This explains the practical habit of 
the guides of giving out food about every two hours. Unfortunately, 
above 4500 meters, distaste for food is so great that it is almost im- 
possible to swallow a few mouthfuls. (P. 37.) 

To this chief cause others are added, which M. Lortet stresses. 
First: 

The rapidity of the circulation is another cause of the drop in 



286 Historical 

temperature, since the blood does not have time to become suitably 
oxygenated in the pulmonary vesicles. (P. 34.) 

In addition, as M. Gavarret has shown: 

The creation of mechanical energy corresponding to useful work, 
accomplished during the ascent, requires the production of 65 liters of 
carbonic acid above the 22 liters of this gas which man forms per hour 
in his capillaries to maintain his temperature. The consequences of 
the production of so great a quantity of carbonic acid in the body are 
apparent. 

At a great height, the respiratory and circulatory movements are 
accelerated not only to make possible the absorption of an adequate 
quantity of oxygen, but also to free the blood of the carbonic acid 
which it holds in solution. But this exhalation of gas, though very 
active, is not sufficient to. maintain the normal composition of the blood, 
which remains supersaturated with carbonic acid; hence the occipital 
headache, the nausea, an irresistible drowsiness, and a still greater 
drop in temperature, from which travellers and guides usually suffer 
above 4000 to 4500 meters. (P. 35.) 

And he concludes by saying: 

The symptoms known by the name of mountain sickness are due 
chiefly to the great chilling of the body, and perhaps also to a cor- 
ruption of the blood by carbonic acid. (P. 37.) 

M. Lortet was accompanied on his ascent by an English physi- 
cian, Dr. W. Marcet, 1 - 4 who made the same experiments, and gave 
an account of them in a special work. 

The observations were made with a thermometer placed in the 
mouth, without pausing in the ascent, because: 

The pause in the progress upward, however short its duration, was 
nevertheless enough to permit the body to produce heat momentarily 
to replace that which had been expended during the act of ascent. 

The results which M. W. Marcet reached are identical with 
those of M. Lortet: 

1. The temperature of the human body in a state of rest does not 
seem usually to be less at great heights than at sea level. 

2. The temperature of the body invariably tends to drop during 
the act of ascent. The amount of this drop depends almost exclusively 
upon the time of the last meal. This drop is due to the muscular 
movements and not to the effect of rarified air .... A rapid ascent of 
only 328 meters was enough to cause a drop of 1.4°. 

3. The general discomfort, particularly the nausea, often experi- 
enced at great elevations, is accompanied by a considerable drop in 
body temperature. It is the result of the fact that the body has be- 
come unable, because of the physiological circumstances in which it is 
placed, to replace the heat which it has expended during the act of 
ascent. 



Theories and Experiments 287 

And so, according to M. Lortet and M. Marcet, who expresses 
himself even more definitely than his travelling companion, there 
is a considerable drop in body temperature, and this drop is due 
"not to an effect of the rarified air", but to the muscular move- 
ment, to the transformation of heat into work. 

But these physiologists found in M. Forel an adversary worthy 
of them. 

The excellent work of the professor of Lausanne is divided into 
three parts published, one in 1871, the last two in 1874. It was 
undertaken first as a criticism of the memoirs of MM. Marcet and 
Lortet. M. Forel 125 begins with very just criticisms of the use of 
the buccal thermometer, as an indicator of the real temperature 
of the body. I copy here his observations, to the complete accuracy 
of which I can testify in many circumstances: 

First, it is very difficult to keep the lips hermetically closed for a 
sufficient time, and only after a rather large number of attempts and 
experiments could I become completely enough accustomed to it so 
that I could be sure that not even one bubble of air was admitted 
during the experiment. What is difficult in a state of repose becomes 
unendurable while one is climbing, when one begins to pant, when all 
the openings together are not enough to admit a sufficient quantity of 
air into our lungs, especially when the rarefaction of the air demands 
imperiously a larger volume than we need on the plain so that our 
system may be supplied with enough oxygen; then it is regular torture 
to close for ten minutes the mouths which we should like to be able 
to enlarge, and the experiment becomes terribly painful. 

Another difficulty is to keep the thermometer exactly under the 
tongue, and as much as possible always in the same place. The tongue 
is very flexible and fairly docile; it can, if need be, surround the bulb 
of the thermometer closely enough not to permit contact with the air 
of the mouth; but the thing is very difficult, as one can convince him- 
self before a mirror, and what is difficult when one is at rest becomes 
almost impossible under the painful conditions of the experiment. 

Now if any portion of the surface of the bulb is in contact with 
the air of the mouth, the results are greatly modified. In fact, the 
buccal cavity is not closed at the back, the opening of the palate per- 
mits a constant mixture of the air contained in the mouth and the air 
which circulates with violent impetuosity in the canal of the pharynx; 
even if there is no current of air in the buccal cavity properly so- 
called, this mixing necessarily takes place, and in proportions which 
are greater, as the current of air in the pharynx is more violent and 
the differences of temperature and humidity between the pharyngeal 
air and the buccal air are greater. In our conditions of experimenta- 
tion on lofty mountains we are as unfavorably placed as possible from 
this point of view. The respiration is panting in a very dry and very 
cold air. The mixing of air must necessarily increase in amount with 
the altitude and with the muscular movements which accelerate the 
respiration. 



288 Historical 

The cold air drawn into the mouth might perhaps be warmed 
quickly enough not to cause very considerable changes in temperature: 
but as this air is very dry, there is evaporation of a certain quantity of 
saliva, and therefore a chilling and a lowering of the temperature. 
(P. 12.) 

Besides this quite general criticism, M. Forel rightly considers 
one of the statements of MM. Lortet and Marcet strange and in- 
explicable, unless we admit a serious mistake in the observation: 

Both say, in fact, that they had to observe the temperature 
while walking, during the very act of ascent, for as soon as they 
stopped, or merely slackened the speed of their progress, the ther- 
mometer, relatively very low during the ascent, rose almost suddenly 
to the normal body temperature .... 

Now the human body cannot grow warm so instantaneously. If 
the temperature is assumed to be 35°, if the body weighs 60 kilograms, 
60 calories must be produced for the temperature to rise to 36° .... 
Helmholtz estimates the production of heat of a man weighing 60 kilo- 
grams at 1.5 calories per minute; it would therefore take 40 minutes to 
produce the 60 calories .... which is very far from the instantaneous- 
ness described by Lortet and Marcet. (P. 15.) 

The first part of M. Forel's work ends with conclusions from 
which I take the two following, which are the most important: 

1. The act of ascent normally produces an increase in body tem- 
perature of some tenths of a degree; 

I reserve my opinion in regard to the effect of ascent upon the 
heat production of the body in the condition known by the name of 
mountain sickness. (P. 28.) 12 " 

These conclusions appear again at the end of the second part, 
in which physicians and physiologists will read with the greatest 
interest experiments investigating very exactly the determination 
of the temperature in different parts of the body (hand, armpit, 
groin, mouth, auditory canal, urine, rectum) . 

The third part is subsequent to the publication in the Annals 
of the Natural Sciences of my Memoir, the results of which M. 
Forel approves. In it is an anecdote which is very interesting 
from the point of view of the theory which I have formulated, 
and the accuracy of which the present work will show, I hope, to 
those who are the hardest to convince; I shall relate it in the third 
part of this work. 

Finally, M. Forel ends with a detailed account of an ascent of 
Monte Rosa in which he experienced mountain sickness, although 
only slightly. On this occasion he makes this remark, — which ex- 
plains both certain exaggerations and certain doubts — namely, that 
attention given to observation of the symptoms one feels dispels 



Theories and Experiments 289 

mental depression and lessens fatigue. This is true of danger as 
well as of scientific interest; no one suffers from mountain sickness 
on dangerous passes. 

On this ascent, M. Forel noted that his temperature was always 
increased by walking, even above 4000 meters; he himself is sur- 
prised at that, considering the very pronounced state of anoxemia 
in which he must have been. But as he was not seriously af- 
fected, he merely states the fact, and, true to his prudent method, 
still reserves the case of ascent during an established state of 
mountain sickness. 

These conclusions were corroborated by the researches of an 
English physiologist who did much research on variations in tem- 
perature of the body in health and in sickness. 

Cliff ord-Allbutt 127 made a series of ascents, one of them on Mont 
Blanc in very bad weather, to study the effects of walking and 
climbing on the temperature of the body. It was measured under 
the tongue during the act of walking, the maximum thermometer 
remaining in place for 15 or 20 minutes. 

From his observations he draws the conclusion that muscular 
exercise tends to raise the temperature. 

I copy one of his tables, the most interesting one, since it re- 
lates to the passage from the Grands-Mulets to Mont Blanc: 

August 18, 1870. 

1:30 in the morning. At the Grands-Mulets, before rising 97.5°F. 

3:30 in the morning. Ascent begun at 3 o'clock 97.7 

5:00 in the morning. On the Grand-Plateau. Terrible weather 98.0 

7:30 in the morning. I began to descend at 7 o'clock 98.5 

8:30 in the morning. Arriving at the Grands-Mulets 98.5 

9:15 in the morning. At the hotel in Chamounix, in bed 97.6 

I should note, however, that the day before, when he reached 
the Grands-Mulets, his temperature suddenly dropped to 95.5°, and 
rose to 98.5° after a 10 minute rest. August 20, at Chamounix, in 
bed, Allbutt's temperature was 95.4°. 

Another English physiologist, C. Handfield Jones, 128 attributed 
the sphygmographic records of M. Lortet to exhaustion from fa- 
tigue. 

The discussions between MM. Lortet and Forel again attracted 
the attention of physicians and physiologists to mountain sickness, 
especially in Switzerland. And so M. Dufour, 129 in his turn, sug- 
gests in regard to this difficult subject a very noteworthy theory, 
which shows thorough acquaintance with the recent advances of 
science. 



290 Historical 

In the session of the Diablerets section of the Swiss Alpine 
Club, on January 27, he expressed the idea 

That the somewhat undefined unhealthy state called mountain sick- 
ness results from the absence in the blood of the ternary elements 
which are used in combustion. (P. 72.) 

M. Dufour is especially struck by the contrast between travel- 
lers and aeronauts, since the latter are in good condition at eleva- 
tions which the former cannot reach without serious symptoms: 

If the mere rarefaction of the air were injurious to health, how 
much more seriously affected Glaisher and Coxwell should have been, 
who in 25 minutes rose from about sea level to the level of the summit 
of Mont Blanc! 

Besides, when aeronauts finally experience pathological symptoms, 
these symptoms do not at all resemble those of mountain sickness. 
M. Glaisher gives a description which resembles a paralysis of sensi- 
tivity and movement extending regularly from the extremities to the 
center. Is this paralysis produced by a stoppage or a slackening of 
the circulation, or is it a direct effect upon innervation? We cannot 
tell. The fact that M. Coxwell's hands were blue for a moment seems 
to support the first hypothesis, whereas the fact that M. Glaisher lost 
the use of the retina, while his mental powers were still intact, would 
rather support the second. 

At any rate, and this is the point which is important to us, the 
pathological symptoms come very late, and when they do come, they 
are not the symptoms of mountain sickness. 

We are therefore led to consider muscular work as the principal 
factor in the production of mountain sickness, and if the rarefaction of 
the air makes some contribution to it, it is through the combustion 
which the work requires. (P. 76.) 

M. Dufour thinks that inanition produced by work is the prin- 
cipal cause of mountain sickness. He says that he experienced the 
symptoms of it on the plain after great muscular efforts: 

M. Dufour experienced several symptoms of mountain sickness, 
including nausea, when he was mounting from the bottom of the 
mines of Freiberg in a shaft and by vertical ladders. He had walked 
in the mine for about three hours, and had eaten nothing; the distress 
attacked him while he was ascending, and was still 50 or 60 meters 
below the surface of the ground. In covering this short vertical dis- 
tance, he had to rest two or three times. 

Likewise in an ascent of Pilate, after too rapid a walk from 
Hergiswyl, he was seized by extreme prostration, throbbing in the 
neck, headache, and dyspnea. At that moment, feeling mechanically 
in the pocket of his coat, he found a morsel of bread which he put 
into his mouth. After taking five minutes to get enough saliva to 
moisten his bread, he swallowed it. A few minutes afterwards, the 
symptoms of distress disappeared as if by magic, and he was able to 
ascend very easily the remaining 100 or 200 meters. (P. 76.) 



Theories and Experiments 291 

Then basing his conclusion on recent physiological data, he con- 
sidered that the work of ascent uses up the reserve of ternary 
materials contained in the blood and the tissues, and results in the 
muscular exhaustion. 

I shall quote this noteworthy passage verbatim: 

It is probable that during the first hours of the ascent, the muscu- 
lar work consumes the non-nitrogenous substances immediately avail- 
able either in the muscular substance or in the blood. 

What replacement can compensate for the effect of so great an 
expenditure? It can take place in only two ways: either the chylif- 
erous vessels bring into the circulatory stream new elements supplied 
by the digestion, or the organism absorbs and draws again into the 
circulation the elements of the subcutaneous adipose tissue. This last 
point is so certain that working hard and eating little is a means of 
getting thin that is well known to everybody. The first of these re- 
placements can be made quite quickly; the second, if we judge by the 
phenomena of absorption which we often witness, can take place only 
much more slowly. 

It is probable that the absorption of the adipose tissue to be used 
as a combustible in the work of ascent is a phenomenon too slow to 
compensate satisfactorily for the expenditure caused by the work of 
someone ascending without stopping. 

Therefore a moment must come whea, if the climber does not eat, 
the available combustible material keeps diminishing and can be only 
partly replaced by absorption. This effect will be produced most 
easily when after work of several hours the climber approaches a steep 
grade which he wishes to climb too quickly, so that there is a still 
greater disproportion between the work performed and the time used 
in performing it. (P. 77.) 

Therefore, according to M. Dufour, it is very easy to explain: 

a. The importance of rest, because during rest there is no ex- 
penditure whereas replacement continues. 

b. The fact that after rest, the quantity of work easily performed 
is obviously proportional to the duration of the rest; for the same 
reason as above. 

c. The fact that, to anyone who has mountain sickness, any new 
effort, such as stooping or using the arms, becomes painful. (See 
H.-B. de Saussure.) 

d. The fact that mountain sickness seems to attack plump persons 
more than thin persons, because the former produce, on an equal 
ascent, a much larger number of kilogram-meters of work. The fact 
that they have in the adipose tissue a deposit of combustible material 
is without importance here, for very thin persons always have a suffi- 
cient adipose membrane to supply the work of ascent as it generally 
appears. 

f. Finally, the fact that a means of avoiding mountain sickness is 
to eat often, that is, to furnish materials not by way of resorption, but 
by way of digestion and absorption. (P. 78.) 



292 Historical 

Then he draws from his theory this logical conclusion: 

We are therefore led to seek a combustible food easy to digest and 
absorb, to avoid mountain sickness. 

M. Dufour thinks that sugar syrup or better, glucose syrup would 
fulfill these conditions. In fact, the fats, which are the best combusti- 
ble material, require a certain time for digestion and may not be 
digested in time to satisfy an immediate need; the feculae must be 
transformed into sugar, glucose syrup then would be the food which 
would reach the circulation most easily. (P. 78.) 

The discussion aroused by the important theory presented by 
M. Dufour brought a very interesting communication from M. 
Javelle, 130 president of the Diablerets section of the Swiss Alpine 
Club. 

The narratives which it contains show, as we have already 
noted, that persons attacked by mountain sickness, even very seri- 
ously, often find that their illness disappears immediately when 
dangers appear or when a very intense application of mind be- 
comes necessary. 

They prove besides that these illnesses are much more frequent 
than is generally supposed, and make a satisfactory reply to cer- 
tain skeptics who did not hesitate to jeer at what they call the 
exaggerations of M. de Saussure. 

Let us note that M. Javelle has had great experience on high 
peaks, and that he has made nearly 200 ascents of 5000 to 15,000 
feet, very often in the company of 10 to 20 young men: 

Mountain sickness very frequently appears in the medium region 
of the Alps, between 5000 and 10,000 feet, that is, at an elevation where 
the air is sufficient for the needs of respiration, and where one can 
hardly consider intoxication from excess carbonic acid as an explana- 
tion for it. At 14,000 or 15,000 feet, the illness experienced by even 
the sturdiest mountaineers differs in several characteristics. 

Mountain sickness affects particularly persons who are unaccus- 
tomed to the mountains, and especially those who lead a sedentary 
life. Those who are anemic rarely escape it. Novices who begin with 
a difficult ascent are very likely to pay tribute to it. (P. 136.) 

This illness appears especially on soft snow, turf, slopes covered 
with landslides where walking is difficult, in small valleys and on long 
slopes, in general, everywhere that walking is both tiresome and 
monotonous. 

It very rarely appears during the climbing of cliffs or on ridges, 
very rarely too on difficult or dangerous expeditions. 

An interesting conversation or merely a careful observation of the 
landscape often wards it off. 

M. Javelle has noted that young men who made the expeditions 
without interest or rivalry and merely to accompany their companions 
were most often affected by it. (P. 13.) 



Theories and Experiments 293 

The editor of the Bulletin summarizes the discussions which 
arose about the etiology of mountain sickness among the members 
of the Swiss Alpine Club in this odd sentence: 

The principal factors are need of food, the intensity and rapidity 
of the work, and the mental characteristics. We cannot remove com- 
pletely from the list of causes the rarefaction of the air and intoxica- 
tion by carbonic acid. The question, which has a certain interest, 
therefore still offers some unknown quantities to be found. (P. 140.) 

Moreover, the following passage, taken from the celebrated 
physicist and daring mountain climber Tyndall, also gives inter- 
esting information on this subject: 

It is not a good idea to begin these ascents without having eaten 
and it is not good to eat heartily. One must eat a little here and 
there, as the need appears. But left to itself, the stomach inevitably 
falls ill, and the energy of the system is rapidly exhausted. If the 
illness brings on distaste for food, vomiting may ensue and the stomach 
be conquered. A little food is enough to restore it. The strongest 
guides and the sturdiest porters are sometimes reduced to this ex- 
tremity. "Sie mussen sich zwingen". The guides attribute these ca- 
prices of the stomach to the great elevation of the air. Perhaps that 
is one of the causes, but I am inclined to think that something is 
likewise due to movement,— the continuous action of the muscles on 
the diaphragm. The conditions under which the journey is made and 
those which have preceded it also deserve much attention. One sleeps 
little or not at all; the morning meal is taken at an unusual hour; 
and if the start is to be made from a cave or a hut instead of a hotel 
bed, there is a serious aggravation of bad conditions. It cannot be the 
slight difference in height between Mont Blanc and Monte Rosa that 
makes the effects of their ascents so different. It is because, for the 
first, one makes his coffee of the melted snow of the Grands-Mulets, 
and has a bare plank for his bed; whereas for the other, he enjoys 
the inn of the Riffel, very comfortable in comparison. Milk and a 
crust of bread are all I need to sustain my strength and ward off 
mountain sickness. (P. 304.) 

These very wise remarks have been made by many travellers. 
The degree of fatigue preceding the ascent is an element the im- 
portance of which is well known today. The same thing is true 
of the habit of walking and of living in the mountains. The fol- 
lowing observations of M. Durier 132 in this regard deserve our 
approval. We have told earlier how, by a strange coincidence, 
M. Durier and his companions, who suffered no ill effects from the 
decompression, ascended Mont Blanc just behind MM. Lortet and 
Marcet, whose symptoms we have given. M. Durier explains this 
difference in the following words: 

In general, the physiologists who have studied the effects of moun- 
tain sickness upon themselves tear themselves from work in their labo- 



294 Historical 

ratory and rush to Chamounix; on the first favorable day, they attempt 
the ascent. Well! I think that they are making their experiment under 
conditions which are not very scientific. The ascent of Mont Blanc is, 
after all, very difficult. It requires previous exercise and training. 
These scholars are likely to confuse the effects of unusual fatigue which 
finds their muscles unprepared, with those of a rarefied atmosphere. 
(P. 63.) .... 

It is under these conditions that MM. Marcet of Geneva and Lortet 
of Lyons made their ascent .... We were in the fourth week of a 
journey on foot, during which, without resting even one day, we had 
crossed some of the highest passes of the Alps. (P. 66.) 

Finally M. Russell Killough, 133 whose very astute replies to the 
skeptics who deny mountain sickness I have mentioned, is less for- 
tunate in regard to theoretical explanations. He revives, without 
the slightest proof to support him, either from experiments or rea- 
soning, the hypothesis of the injurious effect of snow: 

I am ready to agree that altitude is not exclusively the cause of 
these sufferings. I think, and others have thought before me, that snow 
is an important factor in the question, because as soon as one touches 
terra firma, he is relieved. Have we not all observed that on glaciers 
the air has a metallic taste, like water from melted snow, that it seems 
polluted, as if the ice and snow poisoned it with their emanations? 
Why in the tropics, where one walks on grass at an altitude of 18,000 
feet, are nausea and the desire to sleep, this sort of somnambulism, 
felt only at much greater heights than in Europe? 

At any rate, whatever the cause may be, this peculiar sickness 
cannot be denied, and man cannot live at certain altitudes any more 
than in the depths of the ocean. (P. 244.) 

If we pass from the Alps to the Himalayas, we see modern 
travellers giving us in their narratives testimony that even in our 
days the sicknesses of great elevations are attributed by the natives 
to the influence of plants which are supposed to poison the air from 
a distance. 

Mistress Hervey 134 refers to it repeatedly: 

These extraordinary attacks on passes of great altitude are at- 
tributed by the natives to what they call Bischk-Ke-Hawa (Bischk, 
poison; Hawa, wind) or poisoned wind. They believe that the wind 
becomes poisoned because it blows over certain plants of the group 
of mosses, which grow abundantly on the high mountains of Tartary, 
and are found where vegetation ceases. From the summit of Bara 
Lacha to Yunnumscutchoo, I saw thousands of them. They have very 
small yellow flowers, and are of different species. A more scientific 
explanation of this peculiar illness attributes it to the great rarity of 
the air at these extreme altitudes. (Vol. I, p. 133.) 

We even see, in several parts of her narrative, and we have 
quoted some very strange ones in this connection, that she is not 



Theories and Experiments 295 

always very sure of the superiority of ''the more scientific ex- 
planation". 

Henderson 135 also speaks of plants; only it is not a kind of 
moss, but an artemisia: 

Before reaching camp, many of our followers complained of head- 
ache, and I found several of the Thibetan shepherds lying by the road, 
in a state of complete prostration. When I asked them what was the 
matter, they placed one hand on their foreheads, and with the other 
tore up a piece of a strong-smelling artemisia, making signs that this 
plant was the cause of their sufferings. On several of the passes, this 
artemisia has an extremely powerful odor, and all the baggage, the 
horses and the men coming from Yarkand are tainted with it. Even 
mutton has this odor. 

Drew 1:; " does not limit himself to mentioning this prejudice 
and refuting it authoritatively, he looks at the question itself, and 
does not inquire why one is sick, which seems to him very simple, 
but how one can resist the dangerous effect of expanded air: 

In the valleys of Rupsku, water boils at about 187°' F., which 
corresponds to a barometric elevation of 17.8 inches; so that the quan- 
tity of air — and oxygen — drawn into our lungs by an ordinary inspira- 
tion is only 7/12 of the amount that enters at sea level. How do the 
Champas (tribes which occupy the high plains of Rupsku, to the south- 
east) compensate for this loss? I cannot tell exactly; I think, first, 
that there is less wear and tear on the tissues in their bodies than in 
the tribes which live in lower and warmer regions; they take less 
muscular exercise than the peoples of the surrounding lands; it is true 
that they are good walkers, but they think little of this quality and do 
not wish to carry burdens. Watching over flocks is not an occupation 
which causes the muscles to act vigorously. But that cannot explain 
everything; there must be some compensating habit which makes them 
capable of absorbing a large volume of this rarified air; probably, with- 
out realizing it, they breathe more deeply. 

In us, this oxygen compensation tends to take place by a simple 
and direct means. Respiration becomes more rapid and more deep; 
there is an effort to increase both the number of inspirations and the 
capacity of each of them. The intensity of this effect increases every 
time one mounts a little when one is already above the level where 
ordinary respiration is sufficient. (P. 290.) 

The natives commonly attribute these harmful effects of rarified air 
to plants which, in their opinion, have the power of poisoning the air. 
Some of the plants which grow at high altitudes exhale an odor when 
they are crushed, and it is to them that the discomforts are attributed. 
The onion, so much abused, which grows wild at great heights, is often 
blamed. But an easy reply to this error is that the effects are most 
marked at elevations where these plants, and all other vegetation have 
disappeared. (P. 292.) 



296 Historical 

These ideas are far more definite and certain than those of 
Captain Burton 137 about the origin of mountain sickness: 

Some tried to explain our immunity to mountain sickness or the 
puna on the Grand-Pic, by the existence of a wind blowing violently 
and steadily from the east, which brought to our lungs the quantity of 
oxygen necessary for their consumption. I think, however, that this 
sickness must be, like seasickness, a disorder of the liver or the stom- 
ach, often aggravated by stimulants and by violent and sudden exer- 
cise. (Vol. II, p. 121.) 

The celebrated African traveller quotes seriously in this con- 
nection a passage from a work which I could not procure, which 
contains, I think, one of the most comical ideas ever expressed on 
this difficult subject: 

According to Dr. J. Hunt (Acclimatisation of Man) Europeans 
cannot live long at a great elevation in the northern hemisphere; the 
natives of the south can .... "This difference between the north and 
the south hemisphere, he says, is caused by the difference of the attrac- 
tion to the North Pole. In the northern hemisphere the ascent of a 
high mountain causes a rush of blood to the head; in the southern, it 
is attracted to the feet: and hence the cause of the discomforts ex- 
perienced in the ascent of a mountain in the first hemisphere." 

I shall end this long series of quotations by reporting almost 
entirely two very interesting accounts, which we owe to the pens 
of very distinguished physicians, and in which there is a discus- 
sion of the effects of altitudes insufficient to produce mountain 
sickness, but sufficient to cause physiological changes which have 
proved useful to therapeutics. 

The first is by Dr. Jaccoud, 138 and is devoted to the study, from 
the medical standpoint, of the spa of Saint Moritz, in the Upper 
Engadine. 

The greatest variations of the barometer at the baths are in- 
cluded between 599 and 627 millimeters. The altitude of the vil- 
lage of Saint Moritz is 1855 meters above sea level. On the vast 
plateau of the Engadine the climate is much more clement than 
at corresponding elevations in the rest of Switzerland. 

In the adult who is in good health, the first effects of altitude are 
shown by an increase of appetite noticeable the first day, which keeps 
equal with a proportional increase of digestive and assimilative 
power .... 

The parallel superactivity of the digestive functions and of metab- 
olism is shown, on the one hand, by the ease and speed of digestion, 
in spite of the increase of the ingesta; on the other hand, by changes 
in proportion between the adipose tissue and the muscular tissue. . The 
first decreases considerably as a result of a prolonged sojourn in the 



Theories and Experiments 297 

Upper Engadine, whereas the muscles gain a preponderant develop- 
ment shown by increase of strength and motor capacity .... 

The decrease of the atmospheric pressure causes the acceleration 
of the heart beats; in myself, I noted an increase varying from 12 to 
18 in the number of radial pulsations; moreover, the circulation in 
general is considerably modified, in that there is a strong flow of blood 
to the periphery; the cutaneous capillaries are turgescent, and the tegu- 
ments take on a violet red color found in the upper mucous mem- 
branes, especially those of the mouth and tongue; if the sojourn con- 
tinues for several weeks, the predominance of the peripheral circu- 
lation produces a deeper pigmentation of the skin; as this phenomenon 
is more marked in regions usually exposed to the action of the sun, 
one might think that this is merely a pigmentation by solar irradia- 
tion; but the same modification occurs on parts protected by clothing, 
and its real cause is thereby clearly demonstrated. In a few cases, 
rarer than one would suppose a priori, instances of slight epistaxis also 
show the change in the distribution of the blood. 

The constant rush of blood to the periphery keeps the viscera in 
a state of relative anemia, which, in proportion to its degree, is re- 
vealed only by favorable phenomena; the cerebro-spinal functions are 
more active and easy, .the head is free and light, the locomotor power 
is increased, respiration is noticeably eased, although its mode is greatly 
changed, as we shall see in an instant. These organic changes awaken 
in the person who undergoes them the feeling of new strength, which 
he judges by comparison with his usual condition; he feels well and 
gay, he has a vim justified by the real increase of his capacity for 
physical work. (P. 31.) 

The rarefaction of the air at the altitude of Saint Moritz produces 
in the respiratory function two changes which are the point of de- 
parture of important modifications. The frequency of the respiration 
is increased, the average number of my inspirations in Paris, at rest, 
is 15 per minute; it is 19 to 20 in the Engadine; while it is more 
frequent, the respiration is deeper, or rather, more ample; the reason 
is that in this rarified medium a greater capacity and inspiratory ab- 
sorption are needed to maintain in the pulmonary apparatus the quan- 
tity of air necessary for the regular execution of the operations of 
hematosis and metabolism in a state of superactivity. The slight in- 
crease in the number of inspirations could not produce this result; it 
can come only from a greater pulmonary expansion, which puts to 
work certain regions of the lungs which I call lazy, because, under 
ordinary conditions, they take only a very slight part in the inspira- 
tory expansion; these regions are the upper parts of the organs. But 
since the atmospheric pressure is lowered, this more complete partici- 
pation of the lungs in the inspiratory act necessarily involves an in- 
crease in action of the muscular forces which control the expansion of 
the thorax; and this combination of subordinate conditions, all pro- 
duced by the change in pressure of the respirable medium, results 
finally in systematic and constant gymnastics of the respiratory appa- 
ratus, which are kept up without fatigue at the maximum of func- 
tional activity. 

And thus, by active intervention of the organs of respiration, there 



298 Historical 

are produced effects analogous to those which they undergo passively 
under the influence of compressed air; in rarified air, the inspiratory 
absorption becomes complete by means of active use of muscular pow- 
ers; in compressed air, the increased inspiratory absorption is the result 
of an increased pressure, to which the lungs, and the lungs alone, yield 
passively. This comparison, which seems to me interesting, sufficiently 
establishes the superiority of the first condition, in regard to the de- 
velopment and regular exercise of the pulmonary functions. (P. 34.) 

And so increase in the number and amplitude of the respiratory 
movements, with the purpose of compensating for the oxygen defi- 
cit due to the decreased weight of the air, the acceleration of the 
heart beats, and the rush of blood to the periphery of the body 
are, in M. Jaccoud's opinion, the effects on the organism of a 
decompression of 15 to 16 centimeters. 

Dr. Armieux, 139 of whom I still have to speak, examined care- 
fully the soldiers under his medical care at the thermal spa of 
Bareges (1270 meters) . 

He begins by calculating the decrease in the weight of the air 
sustained by a man's body at the elevation of Bareges; it is 
about 220 kilograms; "this decrease," he says, "is very perceptible; 
one is more agile and vigorous (p. 7)". 

Finally, at Bareges, considering the density of the air, there is 
a deficit in the quantity of oxygen admitted to the lungs of 22.56 
grams per hour and 541.44 grams per day. 

But here is the really original part of the work of M. Armieux: 

May 4, 1867, at Toulouse, I measured the chests of 90 hospital 
attendants, who were to be sent to Bareges. The chest circumference, 
taken horizontally at the level of the nipples, gave me an average of 
871 millimeters, at rest, and 905 millimeters in the greatest amplitude 
obtained by a deep inspiration. 

These men reached Bareges May 15, they did not take the thermal 
cure, and the subsequent observations showed only the effect of the 
hygienic medium. 

June 27, that is, after 43 days of residence, their chests measured 
again gave averages of 888 millimeters in circumference at rest and 
917 millimeters in the maximum expansion; the increase of circum- 
ference then was on the average, in the first case, 17 millimeters, in 
the second 12 millimeters. 

September 17, after a sojourn of four months at Bareges, the same 
subjects, given a new measurement, furnished the following average 
results: 900 millimeters at rest and 930 millimeters in maximum ex- 
pansion; there was a new average increase of 12 or 13 millimeters over 
the measurements of the month of June, and a total progressive in- 
crease, after four months, of 25 millimeters in expansion, and 32.9 
millimeters at rest. 

It is therefore indisputable that the chests of these soldiers in- 



Theories and Experiments 



299 



creased in capacity, in four months, in a rather large proportion, as a 
result of their removal to a place the altitude of which is 1100 meters 
higher than that in which they had formerly lived . . . . 

To get a more direct proof, in 1868, we made an experiment which 
confirmed the former one, taking care to get the exact weight of the 
subjects so as to compare their total material gain with the increase 
in volume of the chest. 

We also wished this time to keep an account of the changes made 
in the pulse rate and the respiratory movements by removal to high 
altitudes. 

We subjected fourteen hospital attendants to a close observation, 
before their departure for Bareges and after thirty-five days of resi- 
dence there. 

The following table gives the details and the averages of our 
observations: 







Toulouse 




Bareges 






May 7, 1868 

1 




June 18, 


1868 






Height 


Weight 


. 1 
1 1 




Weight 


1 






Age j meters 


kilos 


Chest |Pulse 


Res. 


kilos 


| Chest 


Pulse 


Res. 


22 


1.620 


62.100 


91c. 


86 


20 


64.5 


98 


85 


19 


23 


1.590 


62 


86 


76 


16 


61 


87 


80 


20 


19 


1.567 


56 


80 


70 


17 


57 


82 j 64 


20 


23 


1.620 


63.100 


85 


80 


18 


65 


88 


70 


22 


31 


1.650 


63 


88 


74 


17 


64 


90 


68 


20 


19 


1.615 


52 


76 


72 


18 


56.5 


81 


75 


21 


23 


1.680 


64 


86 


80 


20 


67 


89 


70 


22 


23 


1.630 


60 


89 82 


21 


61 


89 


80 


22 


23 


1.610 


59.9 


86 J 90 


18 


60 


86 


88 


22 


24 


1.600 


60 


84 1 75 


20 


59.5 


88 


65 


20 


20 


1.610 


57 


85 1 74 


18 


58 


86 


70 


19 


49 


1.640 


59.5 


81 72 


19 


59.7 


83 


68 


20 


23 


1.585 


64 


90 80 


18 


66.5 


91 


80 


20 


36 


1.610 


59 


86 80 


21 


60 

1 


89 


74 


23 


Totals _ 


841.6 


1191 |1091 |261 


859.7 


1227 |io: 


290 


Average 


60.114 | 


85.70|77.92 |18.64 


61.4 


87.64 


74.07 


20.70 


Av. at Bareges 


61.400 


87.64j74.07 |20.70 


| 








Av. at Toulouse 
Inc. at Bareges 


60.114 ] 


85.70|77.92 J18.64 










1.286 | 


1.94 


— | 2.06 


Dec. at Bareges 


— | 


— 


3.85 | — 


1 









We see by this table that the increase in weight is, on the average, 
1 kilogram and 286 grams, varying from 1 to 4 kilograms in 12 of these 
soldiers, and showing a slight decrease in two of them, whereas the 
increase in the volume of the chest is, on the average, nearly two 
centimeters, which is relatively greater; this increase went as high as 
7 centimeters in the first subject; finally, it is general and exists even 
in those who lost weight, which is decisive. 



300 Historical 

For the sake of completeness, I copy here a passage which 
concerns the composition of the gases of the blood, although it 
contains unexplainable mistakes, and although I understand nei- 
ther its purpose nor its results; but it is interesting to show by 
a very recent example how many unknown quantities and obscuri- 
ties these questions contain, even in the minds of the most learned 
physicians: 

Besides the phenomena which we have just reported, there are 
produced as a result of the decrease of atmospheric pressure an expan- 
sion and a greater tension of the gases contained in the blood vessels. 
The venous blood contains per liter: 

Oxygen 11 cubic centimeters 

Nitrogen 15 cubic centimeters 

Carbonic acid 55 cubic centimeters 

Total 81 cubic centimeters 

The arterial blood contains per liter: 

Oxygen 24 cubic centimeters 

Nitrogen 13 cubic centimeters 

Carbonic acid 64 cubic centimeters 

Total 101 cubic centimeters 

For M. Schoeuffele who studied the question at Bareges, these fig- 
ures become at the pressure of 65 centimeters: 94.780 for the venous 
blood and 119.640 for the arterial blood; the increase in volume of the 
intra-vascular gas would therefore be on the average 11.25% at the 
altitude of Bareges. 

M. Armieux ends his work with the following conclusions: 

The experiments which I have just reported show that persons 
who go to Bareges experience, as effects of the altitude: 

1. A considerable increase of the thoracic capacity to compensate 
for the oxygen deficit; 

2. An increase in weight, which shows greater metabolic activity; 

3. An increase of respiratory movements; 

4. A decrease in the pulse rate; 

5. A lack of correlation between the two relations of the respira- 
tion and the circulation; 

6. An expansion of the gases contained physiologically in the 
blood vessels, as a result of decreased atmospheric pressure; 

7. A greater tendency toward diaphoresis for the same reason. 

This considerable increase of the thoracic capacity, observed by 
M. Armieux in soldiers subjected continuously to the influence of 
low barometric pressure recalls what was said long before by 



Theories and Experiments 301 

d'Orbigny, 140 in speaking of a Peruvian tribe, the Quichuas, who 
live in the lofty regions of the Cordillera: 

Their bodies are more bulky in the Quichuas than in the other 
nations of the mountains; we can describe them as characteristic. The 
Quichuas have very broad and square shoulders, their chests are ex- 
tremely capacious, very bulging, and longer than usual, which makes 
the trunk larger; the normal ratio of respective length of the trunk 
with the extremities does not seem to be the same in the Quichuas 
as in our European races, and differs equally from that of the other 
American branches. (Vol. I, p. 226.) 

And the celebrated traveller, struck at the same time by this 
thoracic amplitude, the habitat of this tribe, and its immunity to 
the soroche, tries to determine the anatomical fact and to connect 
it theoretically with the conditions of life of these Indians. 

Let us return to the causes which produce in the Quichuas the 
great volume we have observed: many researches have made us 
attribute it to the influence of the lofty regions in which they live 
and to the modifications resulting from the extreme expansion of the 
air. The plateaux on which they dwell are always included between 
the limits of 7500 to 15,000 feet, or from 2500 to 5000 meters above 
sea level; the air there is so rarified that a greater quantity is re- 
quired than at sea level for man to find the elements of life in it. 
Since the lungs need, because of the great volume necessary and their 
greater expansion during the inspiration, a larger cavity than in the 
lowlands, from infancy and during the whole period of growth, this 
cavity receives a great development, quite independent of that of the 
other parts. 

We wished to ascertain whether, as we should have assumed 
a priori, the lungs themselves had not undergone considerable modi- 
fications, as a result of their greater tension. Living in the city of 
La Paz, which is 3717 meters above sea level, and learning that at 
the hospital there were always Indians from very populous plateaux 
of still greater elevation (3900 to 4400 meters), we took advantage of 
the kindness of our compatriot M. Bernier, physician of this hospital; 
we asked him to permit us to make the autopsy of the cadavers of 
some of these Indians of the higher regions, and, as we expected, 
we found with him that the lungs had extraordinary dimensions, as 
the outer form of the chest indicated. (M. Burnier showed us, be- 
sides, that the lungs seemed to be divided into cells much more num- 
erous than usual. Since this fact seemed to us strange and hard to 
believe, we asked M. Burnier to repeat these observations on a larger 
number of subjects; and when, after a few years, we saw this well 
informed physician again, he confirmed it once more completely.) We 
noted that the cells are larger than those of the lungs which we had 
dissected in France; a condition which was necessary to increase the 
surface in contact with the ambient atmosphere. In summary, we dis- 
covered: 1. that the cells are more expanded; 2. that their expan- 
sion increases considerably the volume of the lungs; 3. that conse- 



302 Historical 

quently the lungs need a larger cavity to contain them; 4. that there- 
fore the chest has a greater capacity than in the normal condition; 
5. that this great development of the chest lengthens the trunk a 
little beyond the ordinary proportions, almost out of harmony with the 
length of the extremities, which have remained as they would have 
been, if the chest had retained its natural dimensions. (Vol. I, p. 267.) 

Thse anatomical observations are so interesting that the Society 
of Anthropology discussed them among the Ethnological and Medi- 
cal Questions Relating to Peru, and suggested in 1861 that travel- 
lers verify them. 

In a scholarly report, M. Gosse senior, 141 states that "up to the 
present, the assertions of d'Orbigny have not been verified by any 
traveller" (p. 107). He even mentions a fact which would seem 
to prove that this is a racial characteristic independent of the 
environment, since: 

The descendants of the mountaineers settled in a colony by the 
Incas on the seashore near Cobija would have retained up to the pres- 
ent, as an effect of heredity, the special physical constitution, said to 
have been acquired in the atmosphere of the lofty plateaux. (P. 108.) 

The same, year, M. Jourdanet, 142 speaking of the Indians of 
Mexico, said: 

The Indian, whom we may consider as positively acclimated, has a 
chest the amplitude of which exceeds the proportions which we should 
expect from his short stature. And so he performs work which might 
well surprise, us in any country .... His vast chest makes him com- 
fortable in the midst of this thin air. (P. 98.) 

On this point also he was contradicted by Coindet. 143 Accord- 
ing to this observer, for a series of Frenchmen whose average 
height was 1.678 meters, the thoracic circumference on the level 
of the nipples was 92.450 centimeters, whereas in the Mexicans, 
in an average height of 1.620 meters, it fell to 89.048 centimeters. 

But the English traveller Forbes confirmed the observations of 
d'Orbigny and M. Jourdanet: 

M. D. Forbes, says M. Darwin, 144 who carefully measured a great 
number of Aymaras, living at an altitude included between 10,000 and 
15,000 feet, told me that they differ very greatly from the men of all 
other races he has seen in the circumference and the length of their 
bodies. 

Finally, in his last book, M. Jourdanet 145 gives specific data, 
saying: 

I have the abstract of a great number of observations which do 
not admit the least doubt. They justify me in stating that with an 
average height of 160 to 165 centimeters, the Indians of Anahuac have 



Theories and Experiments 303 

a sternum 227 mm. long, with a thoracic circumference of 895 mm., 
measured immediately above the nipples. 

On the other hand, my researches permit me to state in a general 
way that to find the same chest dimensions in the Creoles, the height 
had to increase from 168 to 173 centimeters. (Vol. I, p. 317.) 

So the point is really not so much an unusually large thoracic 
capacity as a shorter height, or, to speak more exactly, lower 
limbs which are shorter in proportion to the height of the trunk. 

But let us return to the inquiries of Dr. Gosse. 

M. Gosse follows his shrewd observations on this interesting 
point by a questionnaire on mountain sickness, which I think it 
best to quote here verbatim: 

The study of the influence exerted by the rarefied air of high 
altitudes in the Peruvian Andes upon the physiological constitution of 
their inhabitants naturally leads us to the study of symptoms produced 
by this cause in persons foreign to the plateaux, who are exposed to 
it imprudently or too suddenly, and of the measures which are used 
to combat the symptoms or at least to moderate their effects. 

If the symptoms observed in our European Alps, to which the 
name of mountain sickness has been given, are limited in general to 
extreme breathlessness, accompanied by headache, throbbing of the 
carotids, palpitations, nausea, disturbance of the digestive functions, 
great lassitude and sometimes syncope, the symptoms appearing in the 
Andes of Peru, known by the names of soroche, mareo, or veta, reached 
such violence, they say, that they deserve the attention of physicians 
who are explorers, all the more because sufficient analysis has not yet 
been made, in this connection, of the mechanism of the action, usually 
combined, of the decrease of the oxygen in the air and of the atmos- 
pheric pressure, of the eventual drop in temperature caused by easier 
radiation of heat, of the absence of humidity, and especially of the 
unnatural strain on the muscles, and because, as explanation of the 
anomalies, there has been a tendency to suspect the existence in Peru 
of special unknown causes, which would not be found elsewhere. 

Observations carefully made and new records thoroughly verified 
would end doubts and reconcile opinions. With this purpose we are 
propounding the following questions: 

1. What are the characteristic symptoms of the soroche of the 
Peruvian Andes, with reference to the nervous, circulatory, pulmonary, 
or muscular systems? 

2. What is the normal sequence of these symptoms, in the com- 
monest cases, and which are the predominating ones? 

3. Are there premonitory symptoms of the acute attack, and what 
are they? 

4. Is a tendency to nasal, labial, pulmonary, ocular, cutaneous, 
etc., hemorrhages noted frequently at very great elevations? 

5. Are a congested condition of the cornea and erythema of the 
face observed, in the absence of reflected light from the snow? 

6. Does the skin take on a livid or cyanosed shade at an eleva- 



304 Historical 

tion which cannot be less than 3800 meters, but which, in the latitude 
of Peru, must be the line of perpetual snow? If this phenomenon 
appears, is it only temporary during the ascent, or does it persist after 
the summit has been reached? 

7. When the dwellers on the heights descend to the plains and 
toward sea level, do they experience a disturbance in their functions, 
and of what does this disturbance consist? 

8. Is a mental disturbance corresponding to the physical disturb- 
ance, or discouragement, or irritability of temper often observed? 

9. Are the symptoms of the soroche the same on the eastern and 
western slopes of the Andes, whatever the exposure of the places where 
they are observed? 

10. Do they occur only at the line of eternal snow, as certain 
authors maintain, or do the Peruvian and Bolivian Andes furnish veri- 
fied exceptions to this rule? 

11. Do strangers to the plateaux of the Andes experience the 
soroche when they reach high elevations on the Cordillera on horse- 
back? And when they feel the attacks, did muscular efforts usually 
precede the disturbance of the organs of circulation and respiration? 

12. Do the effects of the soroche differ with age and sex? 

13. Do they vary with idiosyncrasies, and what are the idiosyn- 
crasies which predispose to it or retard it? 

14. What is the effect exerted upon its production or its symptoms 
by the seasons, the prevailing winds, or storms? 

15. What is the effect of the cold in the places where the soroche 
appears? Specify the average temperature of these places and the 
absolute temperature at the time the symptoms appeared. 

16. What is the effect of dryness or humidity? 

17. Is it proved that the absolute altitude in the atmosphere is 
not enough to explain certain local anomalies? And if this is an actual 
fact, seek out the probable causes of these anomalies, either in the 
atmospheric conditions of the time or the locality, or in the telluric 
conditions, especially in the nature of emanations which may rise from 
the ground. Study in this connection the conformation of these lo- 
calities which might favor the continued presence of water and atmos- 
pheric humidity, their nearness to ore-bearing regions, which might 
exhale mineral, harmful, arsenical, or other vapors. Do not neglect 
occasional conditions in which individuals may be placed. 

18. Does the acclimatization of strangers in relation to the soroche 
take place more or less quickly, and what are the conditions which 
favor or delay it? Does this acclimatization have a lasting or merely 
temporary effect? Do the negroes have more difficulty in becoming 
acclimatized than the whites? And if the opportunity offers, it would 
be interesting to make a series of experiments to ascertain the normal 
pulse rate of the inhabitants of the plateaux, Indians, negroes, and 
whites; taking care to repeat them on a great number of healthy per- 
sons of both sexes, adults of verified age, and to make these experi- 
ments at rest, standing and lying down, at a certain distance from 
mealtime, and to note the outer temperature of the season, hot or cold. 

19. If the symptoms of the soroche appear in animals, what are 
their characteristics in the different animals and what are the condi- 



Theories and Experiments 305 

tions which give rise to them? Especially what are the causes which 
give rise to the disease of mules known by the name of trembladera? 
Are the domestic llamas and those used as beasts of burden equally 
subject to this disease? 

20. Is the mortality of certain animals (cats, for example), caused 
by their sojourn in very lofty places, an established fact or not? And 
if the fact is established, what are the symptoms which precede death, 
and what are the probable causes of this mortaltiy? 

21. Are there means of awarding off the soroche, and if there are, 
what are they? Has anyone tried, for example, in Peru, as in Styria 
and the Tyrol, the ingestion of small doses of arsenic to prevent the 
fatigue of the ascent of mountains? Study particularly in this connec- 
tion the effects of the plant known as cuca or coca, either chewed or 
taken in an infusion, which they say has a remarkable prophylactic 
power. 

22. What are the means employed with the greatest success in 
checking or lessening the symptoms produced by the soroche, either in 
man or in the animals? (P. 113-117.) 

As I said at the beginning of this first part of my work, I 
shall not discuss in this historical section any researches which 
rely upon the results of my own investigations or which oppose my 
conclusions. My discussion of them will naturally take place in 
the third part. 

And for this reason I shall say nothing of the book recently 
published by M. Jourdanet, 140 in which he repeats, develops, and 
supports by new proofs taken from the study of altitudes over the 
whole earth the opinions suggested to him by observation of the 
diseases of Upper Mexico. I shall borrow from this immense work 
only the account of an important experiment in which appears 
the first attempt made to study chemically the degree of the 
anoxemia: 

I decided to devote myself to this work of analysis about the end 
of 1864. I found assistance— very worthy of special mention in this 
book — in the laboratory and the cooperation of M. Romuald Zamora, 
a Spanish gentleman, who studied the sciences in his hours of leisure. 
I analyzed the blood of three rabbits by means of carbonic oxide, fol- 
lowing the specifications given by M. Claude Bernard. I found an 
average of oxygen which was very low, but not enough to justify one 
in feeling authorized to make really legitimate general conclusions. I 
also felt hesitant because of a consideration which I thought exceed- 
ingly important; namely, that one could always ask himself whether 
these same animals would not have given this same quantity of oxygen 
at lower levels. In fact, differences in amount found in my previous 
analyses of blood prove that the proportion of this gas is an individual 
peculiarity, at least within certain limits. It seemed to me after that, 
that this interesting point cannot be indisputably decided without a 
double analysis of the blood of the same animal, drawn first at normal 



306 Historical 

pressure, and second, at a more or less pronounced decompression. 
Therefore I again put off till a better time the realization of my wishes. 
(Vol. I, p. 181.) 

These wishes I had the good fortune to realize, thanks to the 
generous assistance of my learned colleague. And we shall see 
that I succeeded in proving how closely his anticipations agreed 
with the truth. But for this demonstration, I refer the reader to 
the second part of my book. 

In the third part he will find the detailed history of the latest 
aeronautic ascensions to great heights, and particularly of the one 
which had so fatal an end. We shall then specify definitely the 
causes of this disaster and draw from it the lessons it contains. 
Limiting ourselves to the subject of the present chapter, we shall 
say that the interpretations, given by the different scientific jour- 
nals and others, of the causes of the death of Sivel and Croce- 
Spinelli are merely those whose discussion fills the preceding 
pages. There is nothing new in them which deserves to be noted 
here, and all these ideas had already been given by authorities of 
greater weight. 

We shall except only the short discussion which arose on this 
subject within the Academy of Medicine. We see that, in the 
opinion of MM. Woillez, Mialhe, and Colin, the diminution of the 
weight sustained by the body again plays the principal part; in 
spite of the elementary principles of physics of which M. Giraud- 
Teulon, M. Gavarret and many others have already reminded 
them, they still harp on the theory of the Universal cupping-glass. 
But M. Colin adds to that a hypothesis which alone would deserve 
the honor of repetition, for it had been only very briefly suggested 
by a few former authors, and M. Maissiat did not go so far as to 
give it such importance. In his opinion, the escape of gases into 
the intestine and the expansion of these gases by the decrease in 
pressure played the chief part in the fatal ending. Here is the 
passage in full: 

M. Larrey: The ingenious experiments of M. Woillez and the new 
researches he has made on the spiroscope would no doubt lead him 
to the physiological study of respiratory phenomena at different alti- 
tudes, and then to the hygienic prophylaxis of the violent disturbances 
of this important function, under other influences. We should also 
decide upon therapeutic measures, when asphyxia, for example, is 
imminent and causes complex symptoms which rapidly become fatal, 
through sudden rarefaction of the air or through the progressive 
diminution of the air pressure. Finally, it would be desirable to 
determine and check the measures by which artificial respiration could 



Theories and Experiments 307 

be established, for instance in the diving bell, comparable, in this 
respect, to the basket of the aerostat. 

The fatal disaster which has just startled the world of science and 
the two victims of which were buried this very day urges me to make 
this suggestion to the Academy, even if it is only a digression useful, 
perhaps, to the interesting communication of M. Woillez. 

M. Woillez: I cannot give an opinion here on so important a mat- 
ter; but it seems to me that it is not only a question of respiration; 
we must particularly take into consideration the decrease in the atmos- 
pheric pressure for which the oxygen they had taken along could give 
no help. 

M. Colin: Since the question of the balloon has been brought up, 
I should like to give my opinion of the causes of the death of the 
aeronauts. Certainly these causes are multiple, especially those con- 
nected with the decrease of pressure; some are already indicated by 
the conditions in which the aeronauts were. 

Two had lunched and they are dead; the other was fasting and he 
survived. The escape of gases into the digestive tract of the first two 
might have played a great part in the progress of asphyxia. We know 
that this escape is very great in ruminants following the eating of 
green fodder, and that it may, at ordinary pressure, produce sudden 
death by asphyxia by immobilizing the diaphragm. No doubt this 
escape is more limited in man: but it increases as a result of illness 
and indigestion, and then, since the expansion of the gases increases 
as the pressure decreases, the diaphragm is soon vigorously crowded 
upward; its movements become very limited and finally become impos- 
sible. We know that at a certain moment, when the traveller is climb- 
ing high mountains, he is seized by lassitude, his arms and legs are 
worn out; the muscles, irrigated by a blood which is imperfectly 
oxygenated, lose their energy. The diaphragm shares in this fatigue, 
and finally becomes inert, especially if it is crowded back by the 
expansion of the gases of the stomach. 

I know very well that aeronauts need to fortify themselves against 
becoming chilled, and that fasting does not warm them, but they can 
arrange their meals in such a way as to complete digestion before 
starting, and replace fermentable food by respiratory food, by liquids 
which stimulate and develop heat. 

Observations made on the victims and the survivor show clearly 
the chief cause of the symptoms. This cause is not, whatever M. Bert 
may say, the lack of oxygen, for in the experiments the animals do 
not die with the proportion of this gas which may be in the air at 
7000 or 8000 meters. It is the decrease of pressure, as M. Woillez has 
just said, which produces the serious symptoms, the hemorrhages in 
the respiratory passages, the circulatory disturbances, etc. 

M. Blot: M. Colin's last words seem to me to contradict what he 
said at the beginning. So he explains death first by the compression 
of the diaphragm and the lungs under the influence of the expansion 
of the intestinal gases, and finally attributes it to the decrease in 
pressure. 

As to the comparison between the herbivores and man, it seems to 
me very debatable. 



308 Historical 

M. Colin: I am surprised that M. Blot sees the slightest contra- 
diction in my words. I said that the symptoms and death in ascen- 
sions are due to several causes, among others the compression of the 
diaphragm by the gases of the digestive tract and the decrease of 
pressure on the tissues and the vessels resulting in pulmonary, nasal, 
and other hemorrhages. Each of these causes has a part in the effect; 
far from excluding each other, they are linked together. 

M. Mialhe: I agree with M. Woillez that the decrease of the 
atmospheric pressure was the principal cause of death, but I cannot 
accept the idea of M. Colin that one should not eat before making 
a balloon ascension. Man is not a ruminant, and things do not go on 
within him just as they do in the herbivores. 

M. Colin: What! Does man then have privileges in regard to diges- 
tion? Does the stomach function otherwise in the abdomen of man 
than in the abdomen of an animal? The dog which has eaten meat 
and bread has in his stomach much gas which one can measure by 
ligating the aesophagus and the pylorus. Why would not these same 
foods also produce gases in the stomach of man? Have not the diges- 
tive process and the fermentations uniform characteristics in species so 
closely related? 

I shall express myself later upon this question of the intestinal 
gases; but now, seeing" the importance which M. Colin seems to 
attribute to it, I cannot refrain from one remark: the desire of 
contradicting must be a very strong passion in some persons, since 
it has led a physiologist of this rank to say such strange things. 

The last document which I shall submit to my readers is 
perhaps still stranger. If there are some among them, as I fear, 
who think that, in giving the history of mountain sickness, I have 
displayed an excessive wealth of quotations and descriptions, they 
will, no doubt, pardon me for this imposition when they consider 
that in 1875, before the Geographical Society, before the Academy 
of Sciences itself, the very existence of mountain sickness was 
denied, a denial which depends upon the strangest of methods, or 
rather which is the very absence of scientific method, because it 
takes into account only the circumstances in which the travellers 
felt no symptoms during their ascents. 

The first communication from M. Virlet d'Aoust on this subject 
is dated May 19, 1875. The official Proceedings 148 of the Geograph- 
ical Society narrates it in the following words: 

M. Virlet d'Aoust, on the occasion of the recent disaster of the 
Zenith, made a communication about the effects of the rarefaction of 
the air in the region of lofty mountains. In an ascent of Popocatepetl, 
at an altitude of 4500 meters, he felt no other discomfort than a fatigue 
more pronounced than on the plains. There are numerous examples 
in the Andes of inhabited places at an altitude of 2000 and 3000 meters. 
Mexico City is at an elevation of 2300 meters. 



Theories and Experiments 309 

A discussion took place in regard to the influence of atmospheric 
pressure on human life. 

MM. Antoine d'Abbadie, Maunoir, de Charencey, and de Puydt took 
part in it. The last mentioned for two years travelled through the 
valleys of the Andes, in Ecuador and Bolivia, living at altitudes of 
4800 meters, always keeping his health and vigor. M. l'abbe Durand 
confirmed this statement, according to M. Stuebel, who made an ascent 
of Chimborazo two years ago. (P. 552.) 

We can see by the account of Stuebel's ascent which we have 
given into what an exaggeration M. l'abbe Durand has fallen. But 
without discussing this for the moment, it is interesting to repro- 
duce at greater length the arguments presented by M. Virlet 
d'Aoust and his learned colleagues, according to an authorized 
journal, the Explorateur: 149 

M. Virlet d'Aoust, on the occasion of the lamentable disaster to 
the Zenith, which cost the lives of two young scientists, MM. Croce- 
Spinelli and Sivel, recalled the circumstances of his ascent of Popoca- 
tepetl, in April 1853, with the purpose of emphasizing the considerable 
differences which exist between ascents of mountains and vertical bal- 
loon ascensions in the atmosphere. 

When one rises in the air by means of a balloon, says M. Virlet 
d'Aoust, he finds himself successively plunged in layers of air, if not 
of different compositions, at least of different densities, in which, how- 
ever, the carbonic acid must diminish in proportion because of its 
greater specific weight. This kind of ascension, moreover, is made too 
rapidly for the organs of human life to have time to undergo sufficient 
changes to make the successive differences in atmospheric pressure 
endurable. 

When one scales a mountain on foot, the layers of air have exactly 
the same composition as on the plain, for these layers, though becom- 
ing thinner, rise in currents from below up to the highest summits. 
The result is that any experiment which has for its sole purpose the 
determination of differences in the composition of the air at different 
heights should be carried out vertically in a balloon and not in a 
mountain ascent. 

The ascent of Popocatepetl (the smoking mountain) by M. Virlet 
d'Aoust involved numerous companions, and was, so to speak, an 
international expedition. The United States, England, Mexico, Ger- 
many, Belgium, Switzerland, Italy, and France were represented. 

Although the plain and the city of Mexico have an elevation of 
about 2300 meters above sea level, life there is very comfortable; public 
health is perfect and free from any endemic disease. The travellers 
halted at the foot of the cone at an elevation of more than 4000 
meters; they had reached this spot on horseback without the least 
inconvenience and without feeling the slightest effect of the rarefac- 
tion of the air. The difficult part was the ascent of the cone, a regular 
sugar loaf, which had to be climbed on foot. That requires four hours 
of very difficult walking, although the descent is made in less than a 
half-hour. Neither M. Virlet dAoust nor his companions experienced 



310 Historical 

any discomfort except that resulting from a somewhat accelerated 
respiration, and a little more heaviness in the limbs .... 

From these experiments M. Virlet d'Aoust has drawn the conclu- 
sion that the so-called mountain sickness is merely great fatigue re- 
sulting principally from heaviness due to the decrease of the layer of 
air which surrounds the traveller and which supports him in the lower 
regions .... 

M. d'Abbadie asked the author whether a distress manifested by 
dizziness and vomiting did not appear on lofty peaks. M. Virlet d'Aoust 
stated that he felt nothing of the sort nor did his travelling com- 
panions. M. de Puydt said that he had crossed the highest peaks of 
the Andes, from the equator to the sixth degree, north latitude; that 
he had reached altitudes of 4800 meters and that he had never felt 
any of these fatigues; and yet he had travelled more than 450 leagues 
in the Andes. M. l'abbe Durand supported this opinion, recalling the 
official ascent of the great volcanoes ordered by the government of 
Ecuador. Finally, M. Maunoir said that the effect of ascents, even in 
the mountains, must vary with the health conditions and the constitu- 
tion of the traveller. (P. 401.) 

M. Virlet d'Aoust 130 returned to this subject in the session of 
July 7; he still followed the same strange method: 

M. Virlet dAoust, resuming the subject studied in a former 
session, that is, the effect of the rarefaction of the air in the higher 
regions of the atmosphere, reported an ascent of the volcano of 
Arequipa or Misti, the altitude of which is 5650 meters, during which 
the travellers were not at all inconvenienced (Reference to the Bulle- 
tin). (P. 107.) 

The Explorateur of July 15, 1875, is much more explicit: 1,1 

Mountain sickness. In support of what he had previously said, on 
the occasion of his ascents of Popocatepetl and Ixtaccihuatl, in refer- 
ence to the so-called mountain sickness, M. Virlet d'Aoust reported 
another ascent, that of the volcano Misti, more often designated by 
the name of the volcano of Arequipa, in Peru, which led to the same 
conclusions. Dr. J. T. Coates, of the United States, who made the 
ascent, left Arequipa September 22, and camped for the night at the 
foot of the mountain, situated 30 miles northeast of this city. The 
next day very early, accompanied by three guides and furnished with 
two aneroid barometers, he undertook the ascent. The little caravan 
could travel on horseback at first; but after an hour, since the grade 
became too steep and the difficulties kept increasing as they advanced, 
they had to continue on foot. 

After ten hours of difficult walking, at half-past six in the even- 
ing,, they finally reached the summit of the volcano, without having 
experienced hemorrhages, or difficulties in breathing, or nausea, or 
headaches, or any other of those painful sensations which, it is 
claimed, should be felt by persons who venture in the mountains to 
altitudes of more than 3000 meters .... 

Finally, M. Virlet d'Aoust thought he should mention another still 



Theories and Experiments 311 

higher ascent which might have taken place in New Guinea. Several 
journals announced recently that the Englishman, Captain Lawson, 
had discovered in this huge isle of the ocean a mountain called Mount 
Hercules, which has an altitude of 10,929 meters above sea level, that 
is, 1262 meters more than Mount Everest, in the Himalayan chain, 
hitherto considered the highest point of the whole world. The 
Explorateur has suggested that the welcome to this alleged discovery 
should be given with certain reservations. At any rate, according to 
his story, when Captain Lawson attempted the ascent of Mount 
Hercules, he could ascend only to the height of 8435 meters, that is, 
an altitude almost equal to that reached by the balloon Zenith in its 
last and fatal ascension; but at this height, blood issued from his eyes 
and ears, and he nearly died as a result of the rarefaction of the air. 
This statement, like the discovery of a mountain claimed to be the 
highest in the world and yet so late in recognition, requires confirm- 
ation. (P. 65.) 

Nothing has confirmed this last account, which no one, unless 
he is exceedingly credulous, could believe. But I will not continue; 
the following chapter will contain the critical discussions. 



I Loc. cit., Chap IX— Sevilla, 1590. 

'Novum organum, Book II, 11. Translation by Lorquet, p. 85. 

3 Relation de divers phenomencs arrives dans le vuide, a dcs animaux qu on y avoit 
cnferm.es. — Collect, acad., foreign part, vol. I, p. 46-61>. 

4 I do not know their exact date. Musschenbroeck lived from 1692 to 1761; the volume 
of the Collection academiquc in which they are included appeared in 1755. 

5 Experience du Vuide— Histoire de I'Acad. dcs sciences de Paris, K6S; vol. I, p. 45.— 
Collect, acad., French part, vol. I, p. '23. .„..,«. i -ir 

8 Boyle, R., Neiv Pncumatical experiments about Respiration. Plulos. Transact., vol. V, 
p 2011-2058, 1670.— Extracted and translated: Collect, acad., foreign part, Vol. VI, p. 23-59; 1761. 

7 A new Experiment concerning an Effect of the varying Weight of the Atmosphere upon 
some Bodies in the Water.— Philosoph. Transact., VII, 1672; p. 5156. 

8 Huyghens and Papin, Some Experiments touching Animals, made in the Air-pump.— 
Philosoph. Transact., X, p. 542-543.— Extracted and translated, Collect, acad., foreign part, vol. 

9 To try the Effects of the Pncumatick Engine exhausted in Plants, Seeds, Eggs of Silk- 
worms. Philosoph. Transact., vol. II, p. 424-425; 1667. . 

in Sur la rarefaction et la condensation de Fair.— Hist, de I'Acad. des sc. de Paris, year 
1705, p. 15; and Collect, acad., French part, vol. II, p. 181. 

II Sur la mort des animaux dans le vuide, Acad, des sc. de Bologne.—Coll. acad., foreign 
part, vol. X. p. 53; 1773. . . 

12 .S'»r la mort de quclques especes d'oiseaux et dc grenouilles dans un air, renferme. 
Acad, des sc. de. Bologne.— Collect. ' acad., foreign part, vol. X, p. 313-321. 

13 Sur la cause de V extinction c la flamme et de la mort des animaux dans un air ferme. 
Soc. roy. des sc. de Turin, vol. II, years 1760-1761; p. 168.— Collect, acad., foreign part, vol. XIII. 

14 Darwin. Experiments on Animal Fluids in the exhausted Receiver. — Philos. Trans., vol. 
LXIV, p. 344-349, 1774. 

15 De Motu Animalium, Pars altera.— Rome. 1681. 

16 I could not procure this book. But probably this solution is the one which Veratti 
quoted and which we have just mentioned. 

17 hoc. cit.: Relation abregee, etc.. 1744. 

^ Loc. cit.: Memoires philosophiques, 1787. 

19 Elementa Physiologiae corporis hutnani. Lausonne, 1761. 

20 De mcteoris aqueis, p. 40. I could not procure this work. 

21 Rechcrchcs sur les Modifications dc V atmosphere, vol. II — Geneva, 1772. 
23 Loc. cit. : Nouvelle description, etc., 1785 

23 Discours en forme de dissertation sur I'etat actuel des montagnes des Pyrenees.— 
Paris, 1776. 

** Voyage dons les Alpes— Geneva, 4 vol. in 4°; 1786 to 1796. 

25 Essai de Physiologic positive appliquee specialcmcnt a la medicine pratique, vol. I,— 
Avignon, 1806. 

28 Art. Air, Diet, des Sc. medi., vol. I, p. 24S; Paris, 1812. 

27 Des effets de la pesanteur de Fair sur 1'homme considere dans I'etat de sante. — Theses dc 
Paris: 1813. . 

28 Deuxicmc Memoir e sur la chaleur animal e ; 1813. Oeuvres de Legallois, avec dcs notes 
de M. Pariset, vol. II— Paris. 1830. 

29 Description des Pyrenees, 2 vol.---Paris, 1813. 

30 Memoirc concernant les effets de la pression atmospherique sur le corps humam, et 
['application de la ventouse dans differents ordres de maladie— Paris, 1819. 



312 Historical 

3 \Loc. cit.: Journal of a Tour, etc.; 1820. 

32 Additional Observations on the Natural History and Physical Geography of the Hima- 
layah .Mountains, between the River-Beds of the Jumna and the Suite]. — The Edinburgh Journal 
of Science, conducted by D. Brewster, vol. II, p. 277-287, 1825. Read before the Royal Society 
of Edinburgh, December 10, 1824. 

33 Loc. cit.: The Ediub. Journal of Science, vol. I; 1824. 

34 Loc. cit.: Account of Koonawur, etc. — London, 1841. 

35 Loc. cit.: Narrative of a journey, etc.; vol. I. — London, 1840. 

30 Loc. cit.: Asiatic Research, vol. XIV; 1822. 

31 Loc. cit.: Nouveau Journal de mede.ine, vol. VII; 1.-20. 

. cit.: Bibl. univ., vol. XIV; 1820. 
30 Loc. cit.: Bibl. univ., vol. XXIII; 1S23. 

40 Observations sur la vitesse du pouls a differents degris de pression atmosph. — Journ. de 
Physiol, de Magendie, vol VI, p. 1-13; 1826. 

41 On the Effects of removing Atmospheric Pressure from the fluids and solids of the 
human Body. Transactions of the Medico-Cliirurgical Society of Edinburgh, vol. Ill, p. 448-458; 
1829. 

42 Dictionnaire de Medecine, article Atmosphere, vol. IV; 1833. 

43 Effects of Mountain Elevation upon the human Body.— London, Med. Gaz., vol. XIV, p. 
207, 520; 1834. 

44 Trait e de Physiologic, Tourdan translation, vol. VI; 1837. 

45 Loc. cit.: Reise in Chile, etc.; 1836. * 

46 Loc. cit.: Ann. de Chimie, Second series, vol. LVIII, 1835. 

47 Sur la composition de I'air qui se trouve dans les pores de la neige. Ann. de Chim. et 
de Phys., Third series, vol. I, p. 351-360; 1841. 

48 Loc. cit.: Lcttre a Delambre. Ann. du Museum; vol. II; 1805. 
40 Loc. cit. : Ibid. 

50 Loc. cit.: Ann. de Chimie, Second series; vol. LXIX; 1838. 

51 The fact that atmospheric pressure is the real cause of the maintenance of articular 
adherences was discovered by the French physiologist Berard, something not generally known. 
Guerard, who bore witness to it, expressed himself as follows: 

"Long before the work of these physiologists was known in France, M. Berard, in a 
competition for the_ Central Board (about 1828 or 1S29), had had printed, according to the practice 
at that time, a series of propositions upon which the argument was based. One of these propo- 
sition was worded as follows: Atmospheric pressure can aid or hamper disjointing, according 
to circumstances. M. Berard quoted an experiment which he had devised, and which consisted 
of removing all the muscles which hold the thigh to the pelvis and of cutting the capsular liga- 
ment. When the leg was pulled, the adherence of the head of the femur to the cotyloid cavity 
under the effect of the weight was sufficient so that the body could be dragged on the ground 
without the two parts of the articulation separating." {Ann. d'hvg. publiquc ct de med. leg. 
Second series, vol. I, 1854, p. 304.) * 

What we really owe to the German physiologists is the mistaken application they have 
made of this truth to the theory of walking. 

52 Rechcrches sur les effets physiologiqucs et therapeutiques de la compression ct de la 
rarefaction de I'air, taut sur le corps que sur les membrcs isoles. Ann. gen. de Med., Second 
series, vol. IX, p. 157-172: 1835. 

53 De I Hemospasic.—Rccucil de Memoires sur les effets therapeutiques de cette mcthodc 
de traitemcnt. — Paris, 1850. * 

54 Rapport sur un Memoire ayant pour litre: De la Condensation et de la Rarefaction de 
I' Air, apSries sur toutc I'habitude du corps on sur les membrcs seiilcmcut, consid recs sous 
leurs rapports therapeutiques. par M. Th. Junod, M. D.—Cpt. R. Acad, des Sc, vol. I, p 60- 
65; 1835. 

50 In fact, that is what Clanny himself says: "It is interesting to note that at the same 
time Sir James Murray of Dublin, Th. Junod of Strassburg, and I invented a similar apparatus, 
for the purpose of lessening the pressure of the atmosphere on the surface of the body, with- 
out anything having been published previously in any journal." {Researches of M. Junod into 
the physiological and therap. effects of compression and rarefaction. The Lancet, 1835-36; vol. 
II, p. 359.) • 

Clanny and Murray had invented only the great cupping-glass. — Apparatus for re- 
moving the Pressure of the Atmosphere from the Body or Limbs. The Lancet, 1831-36; vol. I. 
p. 804-805. 

66 Junod, _ Traite theorique et pratique de I'hemospasie.— Paris, 1875. 

57 Considerations sur les effets therapeutiques de I'hemospasie, d'aprcs les observations re- 
cueillics en Alqerie par T. Junod.— Paris, 1858. 

68 Bibl. univ. de Geneve, Second series, vol. V, p. 151; 1836. 

59 Ascension au Faulhorn. Revue medicate, 1841, vol. IV. 

60 Loc. cit.: Influence, etc.— Revue medicale, 1842, vol. IV. 

61 Loc. cit.: Peru, Reiscskizsen, etc.; 1S46. 

62 Loc. cit.: Practical observations, etc.; vol. LVII, 1812. 

63 Voyages au Perou et a Mexico, vol. I, I am borrowing this quotation from Flemeing, 
Ringuet translation; loc. cit., De V influence, etc.— Perigueux, 1869. 

rA Etudes ilc Physique animale.— Paris, 1843. 

05 Betrachtung der Gcbirgsluft und der Lebenszueise dcr Gebirgsbewohner in Besua ihres 
F.iuflusses auf Bltttbereitung unii auf das Vorkommen gdvisser Kranhhcitsformen. Oesterr, 
Med. Jahrb., vol. XXIIL— Analyse in Schmidt's Jahrb.. vol. XXXIII, p. 298, 1842. 

015 Notes sur les Causes de la lassitude et de lanhelation dans les ascensions sur les men- 
tagnes les plus elevecs.—Rev. Med., 1844, vol. Ill, p. 356-368. 

67 Sur la Cause des plienomenes physiologiques que Von trouve quand on s'elifve d une 
certaine hauteur dans les montagnes.—Cpt. R. Ac. des Sc, vol. XX, p. 1501; 1845. 

68 Physiologic des Atmens — Karlsruhe, 1645, p. 84-89. 
™ Loc. cit., Mem. sur les phen. physio!.; 1845. 

70 Allegemeine Zeitung Misccllcn: Erstcigung des ll'etterhorns, reproduit in extenso dans 
Dolfus-Ausset, loc. cit.. Materiaux, etc., vol. IV, p. 417-429. 

71 Loc. cit.: Souvenirs, etc., vol. II, 1S50. 



Theories and Experiments 313 

72 Esplorazioni Ji N.-M. Przevalski tiella Mongolia orientate e sulle falde N.-E del Tibet 
(187M873). Cosmos di Guido Cora, vol. II, p. 14-19, 164-175 and 261-277.— Turin, 1874. 

73 Essai sur t'Emploi de lair comprime. — Paris-Lyons, 1850. 

74 Observations tcndant a demontrer que, dans les ascensions sur les hautes montagnes, la 
lassitude et t'anhelation eprouv es par la plupart des exvloratcurs n'ont pas pour cause une 
insuffisance d'oxygene dans I' air respire. Cpt. R. Acad, des Sc.„ vol. XXXIII, p. 198; 1851. 

75 Note sur les Effets de la diminution de la pression 'atmospherique sur les animaux. 
Cpt. R. Acad, des Sc, vol. XXXVII, p. 863; 1S53 

76 On the Nature and Causes of the physiological phenomena comprised in the term 
"Mountain Sickness" more especially as experienced among the Higher Alps. — Assoc. Med. 
Journ., 1S53, p. 49 and 80. 

77 Die Bergkrankheit, oder der Emfluss des Ersteigens grosser Hohen auf den thxenscheyi 
Organismus. — Leipzig, 1854; in octavo, 140 p. 

78 Des Climats de montagne consideres an point de vue medical.— Arch des Sc. phys. et not. 
de Geneve, vol. XXXII, p. 265-306; 1856. 

79 Lehrbuch der Physiologie des Menschen. Braunschweig, 1844. 

80 Recherches de Pathologic comparce. Cass el. l€53. 

81 Memoir e sur la pression atmospherique dans ses rapports avee I'organisme vivant. 
Cpt. R. Acad, des Sc, vol. XLIV, p. 233; 1857. 

^Ueber den Einfluss, welchen der Wechsel des Luftdruckes auf das Blut ausubt. Mul- 
ler's Archiv.; 1857, p. 63-73. _ * 

83 Du role des principaux elements du sang dans t'absorption on le degagement des gas de 
la respiration. Ann. des Sc. Natur. Fourth series; Zoo!., vol. VIII, p. 125; K v ~>7. 

84 Ueber die im Blute entlialtenen Gaze : Sauerstiff, Stickstoff und Kohleusaiire. Poggen- 
do-rff's Annalen, 1S37; translated in Ann. des Sc. nal., Zool. Seco nd series, vol. VIII, p. 79; 
1837. 

85 For the development of this view see: Vierordt. Physiologie des Athmens — Karlsruhe. 
1845. 

iG Traite de Physiologic.— Paris, First edition, vol. I, 1857; Third edition, vol. I, 1868. 
87 De la chaleur produite par les Stres viyants, Paris, 1855. 
83 Climats de montagne, etc., Second edition, 1858. 

89 Bibl. univ. de Geneve, Fifth series, vol. II, p. 647, 1S5S. 

90 Du froid thcrmometrique et de ses relations avec le froid physiologique dans les plaines 
et sur les montagnes.— Mem. de I Acad, des Se. de Montpellier, vol. IV, L859. 

01 hoc. cit. De la phthisis, etc., 1862. 

92 Les Altitudes de I'Amerique tropicale eomparccs an niveau des mers, au point de vue 
de la constitution medicate. — Paris, 1861. 

93 De V Anemic des Altitudes et de I'Anemie en general, dans ses rapports apec hi pression 
de V atmosphere.— Paris, 1863. * 

94 Le Mexique et I'Amerique tropicale: climat, hygiene et maladies.— Paris, 1S64. 
05 Gazette hebd. de med et de chir., 1863, p. 777 

rja Gaz. hebd. de med. et de chir., 1863. p. 778-781. 
97 Gaz. hebd., 1863, S17-S21 . 
ai Gaz. hebd., 1864, p. 33-37. 

"The average of the intra-pulmonarv air circulation tor Vierordt was exactly 6 liters, that 
is, equal to that observed by Coindet. 

100 Gaz. hebd., 1864, p. 234, 265, 371. 450, 545, 579, 674. 

101 Gaz. hebd., 1805, p. 145-151. 

102 Traite elementaire de Physiologic, chap. IV, Section 138. 

103 Gaz. hebd., 1865, p. 467-470. 

104 This figure is relative to experiments made on Indians. (Gaz. hebd., 1864, p. 36.) 

105 Recherches sur la quant d'ac carb. exhale par le poumon dans I'espdee humaine. Cpt. 
R. Acad. des. Sc. vol. XVI, p. 113, 1843. 

106 Gazette hebdomadaire, 1865, p. 468. 

107 De la Respiration sur les hauls plateaux de I'Anahuac.—Rec. de Mem. de med. milit,. 
Third series, vol. XIV, p. 512-516, isr.;. 

103 Article Air from the Diction de Med. et de Chir. pratiques— Paris, 1864. 

109 Die Travail dans I'air comprime. — Paris. 1863. 

110 Considerations odncrales sur les maladies principals qui ont regne sur les chevaux et 
mulcts du corps expeditionuaire due Mexique pendant la periode de 1862 a 1863. — Journal de 
medecine veterinaire militairc, vol. Ill, March, April, May, 1865; vol. IV, June, July, August, 
1865. 

111 Article Altitudes from the Dictionnaire encyclopedique des Sciences medicales.—Faris, 
1866. 

112 Etude de quelques-unes des variations que {'altitude fait sentir a 1'air ambiant ct de 
rinftuence de ces variations sur I'homme. These de Paris 1866. 

113 Influence de I'altitude des Heux sur les f auctions physiologiques — Paris, 1867. 
U4 Kaufmann. Cpt. R. de VAcad. des Sciences, vol. LXV, p. 317, 1867. 

115 Le Mexique considere au point de vue medico-chirurgical.—'Paris, vol. I, 1S67; vol. 11. 
1868. 

110 Article Atmosphere. Dictionn. encyclopedique des Sciences medicates.— Paris, 1867; p. 
111-164. 

117 De I Influence de la compression et de la rarefaction de 1'air sur les actcs mecamques 
de la respiration. Thierry-Mieg translation— Gaz. med. de Paris, 1868. 

118 De ("Influence de In pression atmosph. ct de I'altitude sur la sante et les maladies de 
I'homme et des animaux. Ringuet translation.— Perigueux, 1S69. 

119 Theses du Concours d' agre nation. — Paris, 1869. - . 

120 Traite elementaire de physiologic, Book II. Chap. I, Section 244, Sixth edition; Paris, 
1870. 

121 Une Ascension au mont Blanc. Bibl. univ., Fourth series, vol. XXXI, p. 79-95, 1856. 
uzLoc. cit.: Bibl. univ.; 1865. 

123 Loc. cit.: Deux ascensions, etc.; 1869. 



314 Historical 

ni Observations sur la temperature du corps humain a differentes altitudes a I'etat du 
repos et pendant I'acte de i'ascension. Bibl. univ. de Geneve, Arch, des Sc. pliys. et nat.; Fifth 
series, vol. XXXVI, p. 247-289, 1S69. 

^Experiences sur la temperature du corps humain dans I'acte de I ascension des mon- 
tagnes — Extract from Bulletin de la Societe medicate de la Suisse Romande, First series, Geneva 
and Bale, 1871; Second and Third series, 1874. 

120 In his ascents M. Forel had not yet gone beyond la Cima di Jazzi (3818 meters). 

127 The effect of exercise on the bodily temperature.— Journal of Anat. and Physiol., Second 
series, vol. VII, p. 160-119, November, 1872. 

12S Observations on the Effects of Exercise on the Temperature and Circulation. Proceed, 
of the Roy. Soc, XXI, p. 374, 1872-73. 

129 Sur le Mai des Montagues. — Bullet, de la Soc. med. de la Suisse Romande, 1874, p. 
72-79. 

130 Sur le Mai des montagnes. — Bull, de la Soc. med. ae la Suisse Romande. 1874, p. 136- 
140. 

lj " Tvndall, Hours of Exercise in the Alps, Second edition.— London, 1871. 
"-Histoire du mont Blanc— Paris, 1873. 

133 Loc. cit.: On mountains, etc., 1872. 

134 Loc. cit. : The adventures, etc., 1853. 

135 Loc. cit.: Lahore to Yarkand, etc., 1873. 
lm Loc. cit. The Jiiinnoo, etc., 1875. 

137 Abeokuta — London; 2 vol., 1863. 

13S La Station medicale de Saint-Moritz (Engadine). — Paris, 1S73. 

139 Effets physiologiques du climat et des eaux de Bareges. — Mem. de VAcad. des. Sc. 
Inscr. et Belles Lettres de Toulouse, Seventh series, vol. IV, p. 214-231, 1S73. 

140 L'hommc americain, 2 vol. — Paris, 1839. 

^Instruction pour le Pcrou. Bull, de la Soc. d'Anthrop. de Pans, vol. II, p. 85-137.— 
Paris, 1861. 

ie Les altitudes de I'Am. trop.; Paris, 1861. 

143 Gas. hebd.; 1.863, p. 779. 

144 Descendance de I'homme, vol. I, p. 330. 

145 Influence de la pression de I'air; Paris, 1875. 

146 Influence de la pression de I'air sur la vie de I'homme, 2 vol. — Paris, 1875. 

147 Bulletin de I'Academie de medecine. Seance du 20 avril 1875, Second series, vol. IV, p. 
409-471. 

148 Bull, de la Soc. de Geogr. Sixth series, Vol. IX, 1875. 

149 First year, first volume. — Paris, 187a. 

130 Bull, de la Soc. de Geog., Sixth series, vol. X. 
151 First year, second volume.— Paris, 1875. 



Chapter IV 
SUMMARY AND CRITICISMS 

The time has come to summarize the long series of observa- 
tions, experiments, and theories, the details of which we have 
just related. After placing before the eyes of the reader nearly 
all that has been written about the effect of decreased atmospheric 
pressure, by the laborious but certain method of word for word 
quotations, we should now simplify his task by condensing all 
these varied assertions, often redundant and sometimes contradic- 
tory. 

We must, moreover, subject to careful examination the expla- 
nations suggested, opposed, or eclectically collected by travellers, 
physicians, physiologists, and physicists, who have considered in 
its various aspects this question, which is apparently so complex, 
but really so simple, as we shall show. In this part of my task I 
shall, of course, set aside the arguments drawn from my own 
experiments. It is by ideas previously known that I hope to prove 
that at the time when I began my researches, there existed in 
science no theory — I do not say demonstrated, for that is evident — 
which could sustain thorough criticism. Even the truth, when it 
was found, was mingled with so many errors or was so unfurn- 
ished with proofs that it could not force its clear evidence upon 
rebellious minds. Now anyone is right only when he can prove 
to everyone that he is right: "To keep on answering," Voltaire 
said, "is to prove that no answer has been given." 

The present chapter is naturally divided into three parts: the 
conditions under which mountain sickness appears, the summary 
of the symptoms which constitute it, the careful examination of 
the theories suggested to explain it. 

1. Conditions Under Which Mountain Sickness Appears. 

The most general fact emerging from our study is that when 

315 



316 Historical 

men and animals ascend to great heights above sea level, they 
always finally experience a series of more or less serious symp- 
toms, the combination of which constitutes mountain sickness. 

The very existence of these symptoms, however, has been 
denied, as we have seen; but these denials, which are rash and 
unscientific generalizations upon a few isolated cases, do not merit 
our attention here. 

The first striking fact, when we examine the series of data 
which we have collected, is the difference in altitude at which the 
dangerous symptoms appear, depending upon whether we are 
dealing with mountain journeys or balloon ascensions. Whereas 
in the first case travellers often become ill at about 3000 meters, 
and almost never mount above a height of 5000 meters without 
serious suffering, Gay-Lussac, Barral and Bixio, and M. Glaisher 
felt only a few slight disturbances at 7000 meters. In a moment, 
we shall easily find the reason for this enormous difference. 

On earth as in the air, the severity of the symptoms keeps 
increasing with the altitude; but in its ascending progress, it 
follows a law of progression, not of proportion. Up to 3000 meters, 
a traveller who set out from the level of the valley, 1000 meters 
for example, will be warned of the decrease of pressure only by 
a slight increase in pulse and respiratory rates; from 3000 meters 
to 4000 meters, the symptoms increase considerably in intensity; 
above that, each ascent of a few hundred meters is marked by a 
progressively increasing aggravation of them, and a moment comes 
when it is harder to climb 50 meters than it was to ascend 500 
meters at the beginning of the journey. It is not surprising, 
therefore, to see, as Captain Gerard reported, mountaineers of 
Koonawur, accustomed to observing sensations of this sort, esti- 
mate the altitude of the point which they have reached by the 
difficulty in breathing experienced there. 

The altitude at which the symptoms of mountain sickness 
appear varies considerably in the different regions of the earth. 
We have seen that in the Pyrenees serious symptoms appear only 
near the highest summits, that is, above 3000 meters and then they 
are very rare. At the same level in the Alps the accounts of trav- 
ellers begin to indicate some disturbances; they are rather 
customary between 3500 and 4000 meters; above that, their exis- 
tence constitutes a rule from which far fewer persons escape than 
the editors of the Alpine Clubs would have us believe. Etna, with 
its 3313 meters, is in this respect, as we have said, a limited moun- 
tain, as is the Peak of Teneriffe (3716 meters). In the Caucasus 
and the mountains of Armenia the level at which almost everyone 



Summary and Discussion 317 

is severely attacked seems a little higher than in the Alps; on the 
volcanoes of the Pacific, which exceed 4000 meters, the sickness is 
hardly worse than on the Peak of Teneriffe; the same thing is true 
of the Kamerun Mountains, and on Kilimandjaro, New reached 
an altitude of about 5000 meters without serious distress; in North 
America, Fremont and his companions were ill at about 3500 
meters; but in Mexico one must mount above 4500 meters, to expe- 
rience perceptible discomforts; they are not always very serious 
even on the summit of Popocatepetl (5420 meters). The long 
mountain chain of South America cannot be crossed at any point 
from Chile to Colombia without inflicting the terrible puna upon 
most of the travellers. But it seems that these sufferings do not 
appear at a completely uniform height; whereas on the passes of 
Santiago in Chile many are sick below 4000 meters, and almost 
all foreigners are severely attacked at La Paz (3720 meters), and 
even at Chuquisaca (2845 meters), and all at Cerro de Pasco 
(4350 meters), the ascent of the mountains near Quito causes 
almost no symptoms up to 5000 meters, and a thousand meters 
more present no unsurmountable difficulties from the physiological 
point of view. 

The immense mountains of central Asia may be compared to 
the Andes of Upper Peru from the standpoint of the line where 
mountain sickness appears. Passes less than 4500 meters high are 
crossed without serious sufferings; there are some more than 5500 
meters high which are considerably frequented; several travellers 
have reached,' 6000 meters, and the Schlagintweit brothers 
ascended to the prodigious height of 6882 meters on the sides of 
Ibi-Gamin. 

These inequalities, from our standpoint, among the different 
mountainous regions of the earth, stand out among the multitude 
of facts which we have listed; but one can easily find numerous 
exceptions to these general rules. Indeed, and this is not the least 
interesting fact revealed to us by these multiple observations, we 
see that in the same region of the earth, in the same mountain 
chain, certain definite places are particularly feared by travellers 
and natives; and these places are not always the highest, far from 
it. This peculiarity is noted even in the ascent of a given moun- 
tain; for instance, the Couloir of Mont Blanc, where symptoms 
often appear which disappear on the summit. In a word, and these 
facts have been noted particularly in the Andes and the Himalayas, 
the intensity of the symptoms is not always in proportion to the 
altitude reached. This was the origin of strange hypotheses imag- 
ined by the natives, to which travellers too often gave credence; 



318 Historical 

and thence came also the belief in metallic emanations, mephitic 
gases issuing from the ground, and fatal exhalations from different 
plants. 

But, barring these very interesting exceptions which we shall 
try to explain in another part of this work, the differences in aver- 
age height at which serious symptoms appear according to the 
parts of the world in which they are observed are in a remarkable 
agreement with differences in the altitude of the line of perpetual 
snow, when we consider them as a whole. The summary which 
we inserted earlier (see page 16) on this latter subject facilitates 
this comparison for the reader. But we must not go so far as to 
believe, as some travellers have done, that a direct relation, 
almost of cause and effect, exists between these two distinct 
orders of phenomena. Very evidently, no one has ever complained 
of mountain sickness in the polar regions, where the lowest hills 
are eternally covered with snow. But without having recourse to 
this reductio ad absurdum, we see that in our Alps it is almost 
always 500 meters at least above the line of melting where physi- 
ological disturbances appear with sufficient intensity to attract 
attention. The same thing is true upon the volcanoes of Ecuador 
and Mexico, the Rocky Mountains, and many other points. On the 
contrary, on the Bolivian Andes and still more on the Himalayas, 
the narratives previously published show us that travellers may 
be very sick when they are treading terra firma, and are still quite 
far from the zone of perpetual snow. But it is no less true to say 
that, in a general way, the higher the line of perpetual snow, the 
later will travellers in their ascent be threatened with the symp- 
toms which we have so often described. 

Besides these irregularities due to exterior circumstances, there 
are some which depend upon the idiosyncracies of the travellers 
who are subjected to the effect of decompression. 

Indeed, in the same region, on the same mountain, we see 
travellers sometimes complaining of severe sufferings, sometimes 
rejoicing or expressing surprise at having felt almost no distress. 
On the pass of Cumbre of Uspallata, most of those who are crossing 
the Andes are attacked by the puna; Samuel Haigh, Schmidtmeyer, 
and many others have testified to it: but we have seen that Miers, 
Brand, Strobel, etc. escaped it entirely. Whereas von Humboldt 
and Bonpland were very sick in their ascents of Chimborazo, M. 
Boussingault and Colonel Hall, who ascended higher than they, 
experienced only slight symptoms, and M. Jules Remy, who says 
that he reached the summit, states that he felt no symptom of ill- 
ness, On Popocatepetl, Bacon Gros and his six companions, and 



Summary and Discussion 319 

later M. Laverriere, complained of real distress; MM. Turqui and 
Craveri, M. Virlet d'Aoust declare that they were completely- 
spared, while the Scientific Commission of Mexico was a little less 
favored. 

These differences are still more striking on less lofty moun- 
tains. Riche and Blavier, when attacked by hemoptysis, gave up 
climbing the summit of the Peak of Teneriffe, which von Hum- 
boldt, Leopold de Buch, Elie de Beaumont, 1 and so many others 
reached without trouble. On Etna, Count de Forbin and A. de 
Sayve suffered greatly, whereas Spallanzani was unaffected, and 
Ferraro claimed to feel better than on the plain. 

The same thing is true of the Alps. In the hundreds of ascents 
of which its summit was the goal, Mont Blanc has given us the 
most contradictory results. De Saussure, Beaufoy, Clark and 
Sherwill, Hawes and Fellowes, Bravais, Martins and Lepileur, 
attest to violent distress, which they conquered only by prodigies 
of energy ;on the contrary, Clissold, Piachaud, and Albert Tissan- 
dier were hardly ill at all. I have heard "Alpinists" of repute state 
that they had experienced absolutely nothing unusual in this 
ascent which was formerly so much dreaded. By a striking 
contrast, Laborde, the brother of M. Lepileur, etc. were ill when 
they ascended merely to the Grand Saint Bernard (2490 meters) ; 
Spitaler and his companions relate the most painful details about 
their ascent to Venediger (3675 meters), when Desor and Gottlieb 
Studer affirm that they felt absolutely nothing when they ascended 
the Jungfrau (4170 meters) . In Armenia, Radde lay down exhaus- 
ted at 3700 meters, whereas daring travellers almost with impunity 
trod the summits of neighboring mountains of far greater height, 
Elbrouz (5620 meters), Kasbek (5030 meters), and Ararat (5155 
meters). More than that, in 1868, Freshfield, Moore, and Tucker 
made the ascent of Kasbek without any suffering; in 1874, moun- 
taineers who were no less experienced, Gardiner, Grove, Walker, 
and Knubel suffered considerably on the same ascent. I shall not 
mention other examples. We need only refer to what we have said 
in the preceding chapters to find, among so many observations, 
examples of inequalities no less great noted in the Pyrenees, the 
Himalayas, and other mountainous regions. 

These differences are especially striking when they appear in 
travellers who, in apparently similar conditions of health, hygiene, 
and previous training, make the same ascent simultaneously. On 
Pichincha, Ulloa fell fainting; La Condamine felt no difficulty in 
breathing. While ascending Cotopaxi (5943 meters), one of 
Steubel's muleteers was so sick that he could not go beyond 5600 



320 Historical 

meters; another felt absolutely nothing. On Mount Etna, de Gour- 
billon felt nothing, whereas his companion Wilson suffered greatly. 
In the ascent of the Finsteraarhorn (4275 meters), Hugi was in 
very good condition, as were his companions, except one of the 
sturdiest guides of the Oberland, who had vertigo and nausea. On 
the glacier of the Maladetta, Neergaard stopped, unable to continue 
an ascent which the celebrated geologist Cordier finished without 
any trouble. MM. Lortet and Durier ascended Mont Blanc on the 
same day; the accounts of their sensations are as dissimilar as 
possible. At 5300 meters, Croce-Spinelli in his balloon was seized 
with evident oppression; his travelling companions said that they 
experienced nothing. 

But that is not all; the same person, in conditions which seem 
to him identical, making the same ascent on two different occa- 
sions, does not always have the same sensations. On his first 
ascent of Buet, Canon Bourrit fell unconscious; the next year, he 
had no special experience. On the Breithorn (4100 meters), M. 
Lepileur, in 1875, felt no discomfort, whereas the following year 
he was seized there by an unconquerable drowsiness. There is a 
similar lack of agreement in the three ascents of Mont Blanc by 
M. Tyndall, and the two by M. Lortet. Observations made on the 
guides are still more conclusive. 

We must also note that while certain persons seem extremely 
sensitive to the effects of ascents, others without any complaint 
pass beyond the level where the great majority of travellers are 
attacked by the usual symptoms. We saw that Dr. Martin de 
Moussy had felt the puna at 1970 meters, whereas Jules Remy 
could ascend almost with impunity to the summit of Chimborazo 
(6420 meters). Victor Jacquemont seemed particularly immune 
in this respect, as we can see from the excerpts from his letters. 
Moreover, these facts are well known to all mountaineers; it is 
known that certain guides are unable to follow "their gentlemen" 
beyond a certain level, and travellers who were daring and tire- 
less on mountains of the second rank have had to renounce 
reaching the highest summits of the Alps. 

The numerous ascents, the narratives of which we have given, 
definitely differ then from one another in regard to mountain sick- 
ness, first, for reasons which seem to depend upon the mountain 
itself, and second, for reasons which depend upon the travellers; 
the latter may be constant or only transitory. The extremes of 
these differences may vary between 1500 meters (M. Javelle) and 
6000 meters; that explains, without justifying them, the thought- 
less denials which we have so often recorded. 



Summary and Discussion 321 

We should now apply ourselves particularly to the study of 
influences of a transitory nature, and by analyzing, in a more 
detailed manner, the narratives quoted find out whether it is 
possible to explain these differences by certain conditions of envir- 
onment, by circumstances in which the travellers are placed by 
chance, or by this combination of intrinsic conditions peculiar to 
each of us, some of which may be measured, others more or less 
unknown and designated by the general expressions of constitution 
and idiosyncracy. This is the place to investigate the effect of 
habit and acclimatization and to take into account the race to 
which the traveller belongs. 

In this last connection, the results observed seem quite contra- 
dictory: whereas d'Orbigny, Poeppig, Tschudi, de Saint-Cricq, 
Weddell, the Grandidier brothers, etc., note with astonishment the 
immunity of the Indians who run beside their mules without 
showing the least distress, we find, in von Humboldt's ascent of 
Chimborazo, a half-breed born in the lofty places suffering more 
than the Europeans; likewise the peons of Caldcleugh, Brand, and 
Steubel were sick when the travellers themselves felt almost no 
effects; and yet, in a general way, it is clear that in the Andes the 
Indians are much more resistant to the effects of mountain sickness 
than the Europeans are. 

I must quote in this connection a passage from an interesting 
letter written me by a French engineer, M. E. Roy, former assistant 
director of the School of Arts and Trades of Lima, who often 
visited the lofty regions of the Andes: 

The native Indian race is strong and vigorous; nature or the effect 
of a kind of atavism has endowed it with a powerful respiratory 
apparatus which permits it, probably by the respiration of a larger 
quantity of air, to find the oxygen equivalent necessary for its exis- 
tence and for the maintenance of a good constitution. The Indian of 
these high plateaux is thick-set, with an enormous torso and pelvis 
and relatively short legs; he is a walker of the first rank. Shod with 
his double woolen socks and his moccasins, he will walk 50 kilo- 
meters, without wincing, in his mountains and provided he has coca 
leaves to chew, he will make this distance in one stretch. For him 
and his llamas, a straight line is the shortest distance between two 
points: he does not try to wind around the valleys to go from one to 
another, he goes straight ahead, unless the mountain side is impassible; 
that shows you how necessary it is that he should breathe freely. 

Conversely, when these mountaineers go down to the seashore, 
they cannot perform any hard work, as they do in their mountains; 
many contract diseases of the lungs. At the school of which I was 
assistant director, many of the young men coming from these lofty 
regions had to return to their native air for this reason before finishing 
their studies, because the work of the shop was too hard for them. 



322 Historical 

The opposite seems to be true in the narratives of travellers 
in central Asia. Fraser complains bitterly of his coolies. Accord- 
ing to Dr. Gerard (page 137), the inhabitants of Koonawur, born 
on the lofty plateaux, are as sick as the travellers. Johnston relates 
that whereas the natives who accompanied him on the peak of 
Tazigand breathed with the greatest difficulty, he and his English 
companions felt no ill effects (page 139) . Oliver Cheetam, Godwin 
Austen, and Henderson tell similar experiences. To the Schlagin- 
tweit brothers, the difference in races seems of little importance. 
Drew saw a native of Punjab sick at 11,000 feet (3300 meters). 
So Indians, even those born in mountainous regions, seem at least 
as sensitive as Europeans to the effects of ascents. 

The same is true in Africa in the ascents of the Kamarun 
Mountains and Kilimandjaro; likewise in Hawaii on Mauna Loa, 
the natives were attacked by mountain sickness before the 
European travellers, and more severely than they. 

But it should be stated at once that the natives and the Euro- 
peans were not, during these journeys, in identical conditions, 
either of clothing, or food, or exertion. 

If natives belonging to races which seem, according to the 
expression of Dr. Gerard, "born to live and die in inaccessible 
regions", are attacked by mountain sickness, the same thing should 
be true, for an even stronger reason, of the people of European 
races living in lofty places. All the accounts of Chapter I show, in 
fact, that the porters and the guides become ill as quickly and as 
seriously as the travellers, when the latter have already become 
used to exercise in the mountains. Sometimes even, the former 
become ill first; the account of Dolomieu (page 71) is quite charac- 
teristic. The slight advantage which they show, on the average, 
is rather quickly acquired by people of the plains whom wander- 
lust urges into the mountains. 

Another proof, and that not the least striking, of the slight 
importance of acclimatization in lofty places is drawn from the 
intensity with which the disease attacks domestic animals. All 
the accounts of travellers in the Andes and the Himalayas are 
rich in melancholy details of the pitiful condition of the mules or 
the horses which are carrying burdens; the latter often die; camels 
are no better off; the mules of de Saussure uttered plaintive cries 
on the glacier of Saint-Theodule; the wild cattle themselves, when 
they are hunted, often vomit blood, von Humboldt says, and we 
have seen what a sorry picture they made sometimes, according 
to de Castelnau, in bull fights. Dogs are also severely attacked, 
and have difficulty in running. Cats particularly seem to possess 



Summary and Discussion 323 

excessive susceptibility, since, according to Poeppig and Tschudi, 
they cannot live above 4000 meters (pages 40, 46) . However, we 
must note that, in the opinion of Tschudi and Elliotson, animals 
born on the mountains are not as sick as the others. 

But it must be admitted that all of this relates to imported 
domestic animals. The' native species seem very comfortable at 
the greatest heights; only Captain Webb saw yaks attacked by the 
sickness (page 134); llamas seem completely immune, and in the 
free state graze at altitudes of more than 4000 meters. Since the 
time of Ulloa, everyone has been struck with astonishment at the 
sight of condors soaring habitually at 4000 or 5000 meters, and 
sometimes above 7000 meters; in the Himalayas, the lapwings and 
other sparrows live at altitudes of more than 5000 meters. 

Here we are dealing with one of the most interesting points 
of this birdseye view of the subject. The influence of habit or 
custom on mountain sickness is undeniable; but its conditions have 
been both exaggerated and poorly determined. 

On the testimony of d'Orbigny, Poeppig, Gay, Tschudi, and 
Guilbert, one can become quite accustomed to living in the lofty 
regions of the Andes, and the often unendurable distress which 
attacks the European in the early part of his sojourn gradually 
disappears. "In the streets", says Guilbert, "it is easy to distinguish 
the newcomers; every forty or fifty steps they stop for a few 
seconds" (page 54) . Analogous effects have been noted on our 
European mountains; a novice who, when newly arrived from the 
plains, is sick at a low altitude, can later make much higher ascents 
with impunity. But we must not think that this immunity is 
absolute; a fairly great change in level or peculiar circumstances 
may suddenly bring on the sickness that had disappeared; we 
shall find the proof of that in the accounts of M. Weddell, M. 
Pissis and d'Orbigny himself. In a word, the same thing is true 
of arrival in the mountains as of all sudden changes to which we 
may be subjected; the passage of a certain time' permits the 
reestablishment of the equilibrium which was shaken for an 
instant, and which slower transitions would have left unaltered. 

We shall try later to determine the nature and the importance 
of the conditions changed by the act of ascent; but even now we 
can assert the reality of habit or, as we usually say, acclimatization 
to lofty places. 

But here, as we cannot repeat too often, we are dealing only 
with the violent and sudden symptoms of mountain sickness, in a 
word; we have no intention of plunging into the delicate and com- 
plex study (in which the means of demonstration are the more 



324 Historical 

numerous as they are less convincing) of real acclimatization, in 
lofty regions, of successive generations tending towards the 
formation of a race. 

With certain reservations, for it seems to be proved that certain 
persons cannot become accustomed to sojourn in lofty places, we 
simply state that a traveller who has been in the mountains for 
some time will feel no unusual sensations at a level where at first 
he was ill; that his descendants, if he founds a family there, will 
preserve his relative immunity; that the race thus formed will 
enjoy the same advantages, so that the traveller who is a new- 
comer will be surprised. But with the reservation already made 
that there is nothing absolute in this. 

We must also have an understanding in the matter of habit. 
Indeed, as we shall say in a moment, fatigue plays a great part in 
the intensity of mountain sickness. One of the consequences of 
prolonged exercise in the mountains is a lessened tendency to 
fatigue. The same thing is true of this special gymnastics as of all 
others; one finally contracts only the muscles, only the muscular 
bundles indispensable for the movement one seeks to make; one 
brings them only to the degree of contraction which is precisely 
necessary; in a word, one reduces the expenditure of energy to a 
minimum. Moreover, the muscles, and no doubt the nerves also, 
more frequently stimulated to action, from which a more active 
local circulation constantly removes the wastes, can suffice for a 
greater dynamic storage and expenditure, become, as we say, 
stronger, and, for the same work, give the sensation of fatigue in 
a much lessened degree. 

And therefore one fits himself for acclimatization on the heights 
by the simple gymnastic exercise of moderate ascents, with which 
the professional "Alpinists" always take care to preface their 
feats of lofty altitudes. For failure to comply with this rule, the 
most energetic often pay a forfeit. One of the members of the 
Austrian Alpine Club, very familiar with the lofty summits of 
the Alps, who boasted to me that he had felt no symptoms on 
Monte Rosa or Mont Blanc, confessed that he had been very ill 
one day because he had made an ascent of 2500 meters, coming 
from a sedentary life with no transition. That is one of the reasons 
why the moderate mountains of the valley of Chamounix, Buet 
and sometimes even Brevent (2525 meters) , cause illness in trav- 
ellers coming from Geneva; it is also this lack of training which 
explains the frequency of the symptoms of mountain sickness in 
the ascent of Mont Blanc, when that of Monte Rosa is much less 
feared in this regard; it is because the former ascent is often made 



Summary and Discussion 325 

by novices or even by "mountaineers" who have experience, but 
who a few days before were living in the atmosphere of London 
or Paris, whereas usually no one attempts Monte Rosa without a 
series of preliminary exercises which have disciplined the loco- 
motor apparatus. 

Examples of the effect of fatigue are numerous in the very 
accounts which we have quoted. 

While listing the symptoms of mountain sickness, we must 
dwell on the fact of its aggravation by exercise, even the most 
moderate. Here, we should simply mention the cases in which it 
appears only under the influence of fatigue, and we may even say 
a passing fatigue, due to violent exercise. I myself have felt rather 
serious symptoms because I climbed a hill about a kilometer long 
at a quick step, on the road to the Grand Saint Bernard at an 
elevation not above 1500 meters. It is to the effect of fatigue, of 
burdens borne on the backs of men, that we should chiefly attri- 
bute the violent symptoms which sometimes attack the peons of 
the Andes and especially the coolies of the Himalayas Defore the 
European travellers are affected. 

The latter, moreover, usually allow themselves to be borne 
quietly along on the backs of horses, mules, or yaks. We have 
mentioned many cases in which the sickness attacked them sud- 
denly, as soon as they dismounted to walk beside their animals. 
If they are walking on difficult footing or on new snow into which 
the body sinks, the fatigue is increased and with it the intensity of 
the symptoms. 

If, as travellers usually do, we apply the word fatigue not 
only to the result of exaggerated muscular contractions but also 
to the effect of other exhausting causes, this factor of mountain 
sickness takes on still more importance. So insomnia and lack 
of rest and comfort are not to be neglected. On their second ascent 
of Mont Blanc, MM. Lortet and Marcet were much less ill than 
on the first; they had passed a good night at the Grands-Mulets. 
Most of the symptoms, when one is climbing this mountain, are 
partially caused by the fact that the resting place, the hut of the 
Grands-Mulets, is very poorly furnished; on the contrary, on Monte 
Rosa there is the inn of the Riffelberg, where one rests comfort- 
ably, and where one can stay several days at an elevation of 2570 
meters. 

To fatigue and insomnia we must add insufficient or poor food. 
The guides are unanimous in urging one to eat little, but often 
and substantially. A bad condition of the stomach or the intes- 
tine infallibly brings on the symptoms long before the usual level. 



326 Historical 

Guides have frequently become ill at a fairly low level, because 
they had been drunk the night before; peons who have bad 
habits suffer more from the puna than the others, says Caldcleugh 
(page 35). 

The following are the principal circumstances, variable and 
accidental, which may affect the intensity of mountain sickness: 
lack of acclimatization, lack of training, fatigue, insomnia, poor 
food, and temporary ill health. Different constitutions seem un- 
evenly affected. According to most of the travellers, according to 
A. Smith (page 44) , Tschudi (page 46) , Burmeister (page 52) , and 
Pissis (page 56), the plethoric and also the aged or very weak 
persons are especially affected. It is not rare to see persons appar- 
ently frail, but bilious or nervous, make with impunity ascents on 
which corpulent people fail. We may say that they have less 
weight to carry, which is important, especially when they are 
walking in the snow, into which they sink less; besides, their 
pulmonary surface is, like that of children, greater in proportion 
to their weight, but whatever the explanation is, the fact is com- 
monly observed. 

The state of ill health, for whatever cause, likewise predisposes 
one to be sick sooner. "When I was not well", said Al. Gerard, 
"I was sick at 13,000 feet, but in good health I felt no effects at 
16,000 feet" (page 138). 

An effect of general nature is that of cold, which predisposes 
to mountain sickness. As we have seen, it usually appears in the 
region of perpetual snow, and in intertropical lands it recedes with 
the snow line to enormous heights. All travellers agree in declar- 
ing that when the icy wind of high places rises, it makes the 
symptoms unendurable, and may bring on death; this fact was 
first noted in the Andes by Acosta (page 25) . 

If then to the fatigue of walking and of burdens borne we add 
insufficient food, the privations of poverty, and clothing insuffi- 
cient to keep out the cold, we find united all the causes which may 
increase the intensity of mountain sickness. These causes, not to 
mention bad habits, combine to attack the unfortunate Indian 
coolies and also, though to a less degree, the peons of the Andes; 
that is enough to explain the violence with which they ordinarily 
suffer from the puna or the bies, to use their expressions. 

If now we refer to the differences mentioned at the beginning 
of this section among the different mountains in regard to the 
height at which the symptoms usually appear, we can explain 
them in part by the observations which have just been abstracted. 

If in' the tropics mountain sickness hardly ever appears below 



Summary and Discussion 327 

4500 meters, whereas in our Alps it is not rare a thousand meters 
lower, temperature certainly has much to do with this considerable 
irregularity; as I remarked a moment ago, the zone of eternal snow 
is almost the same as that in which the symptoms appear. If the 
city of Cerro de Pasco is so much dreaded by all travellers, that is 
because its icy climate increases the severity of the symptoms 
caused by the altitude. Evidently it is to their position on the 
equator that the immense mountains which surround Quito owe i> 
part the relative immunity enjoyed by the persons who ascend 
them. At Quito, says Jameson,- the average temperature is about 
14°; the thermometer fluctuates between 18° and 8°. 

But this element is not the only one. There is a great differ- 
ence, judging by what we said before, between a mountain situated 
on the shore of the ocean, like the Peak of Teneriffe (3715 meters) , 
for example, and another of the same height in the main range of 
our Alps, like Galenstock (3800 meters) . To make the ascent of 
the former, in fact, the traveller starts from sea level, and in one 
stretch covers a considerable vertical height; in the case of the 
second, the distance to be traversed is lessened by at least 1000 
meters. In the latter case, the transition is infinitely slower. More- 
over, one cannot even approach the foot of the Alps without 
having had a sort of acclimatization with muscular training, in- 
stead of merely disembarking at the foot of the Peak or Etna. 
And so on these mountains of moderate height, in spite of the 
high temperature of their region, symptoms are still more fre- 
quent than on mountains of similar height in the Alps. 

For the same reason, in addition to their situation in the torrid 
zone, Chimborazo, Antisana, Cotopaxi, etc. cause only moderate 
symptoms; the city of Quito, which is at their feet, and from which 
one starts after a longer or shorter sojourn, is situated at an alti- 
tude of 2910 meters, so that there remains a vertical ascent of only 
1950 meters to the summit of Pichincha; and so here we recall the 
irreverent comparison of Canon Bourrit (page 13) . 

The reader may convince himself, by reviewing the journeys 
across the Andes (pages 22-59) , that the symptoms are much more 
general and much more severe among travellers going from the 
Pacific to the Atlantic, than among those going in the opposite 
direction. In my opinion, the explanation of this apparent pecu- 
liarity lies partly in the fact that from the coast of Chile the 
ascent is extremely steep, whereas it is slow and progressive for 
the traveller going from the east to the west. 

The considerable height to which one must ascend in the Hima- 
layas before being attacked by mountain sickness may be due to 



328 Historical 

the same cause. In the enormous range in which the Indus, the 
Bramapoutra, and the Ganges rise, one reaches the dangerous 
passes only after he has walked for a long time over hilly territory, 
the strata of which, rising higher and higher, gradually prepare 
him for the effects of the lofty heights. The transitions there are 
very slow; the dreaded symptoms should appear very late, and 
this actually happens. 

But of course this great effect must be reconciled with climatic 
conditions and other causes of variations which we have already 
noted. It seems to us that, except for a few cases which are still 
hard to interpret and upon which the discussion of theories sug- 
gested will cast some light, the strange irregularities which we 
mentioned at the beginning of this section can almost all be 
explained satisfactorily. 

2. Symptoms of Mountain Sickness. 

Mountain sickness, the veta, puna, mareo, or soroche of the 
South Americans, the bis, tunk, dum, mundara, seran, or ais of 
the mountaineers of central Asia, the ikak of the natives of Borneo, 
is composed, at its maximum intensity, of a group of dangerous 
symptoms, which affect at the same time all the great physiologi- 
cal functions: innervation, locomotion, circulation, respiration, and 
digestion. We shall first summarize them in accordance with the 
preceding accounts, assigning them to each of these divisions of 
natural phenomena. 

Digestion. Exaggerated thirst, distaste not only for eating, but 
even for the sight and smell of food, lack of flavor in liquids, 
nausea, and vomiting have been noted by almost all travellers. 
One eats very little on lofty mountains; Martins and Bravais, with 
three guides, made a good meal on the rations for one man. As 
for violent symptoms, nothing is more striking than the descrip- 
tion given by Acosta: "After vomiting food, phlegm, and bile, one 
yellow and the other green, I even threw up blood" (page 24) . The 
modest euphemism of English travellers about "heavings of the 
diaphragm" and "distress in the stomach" give glimpses of the 
picture energetically drawn by the old Jesuit. In the narratives 
of the first chapter, we shall find it difficult to make a selection 
among the many descriptions. Sometimes the stomach becomes so 
sensitive that it cannot endure a spoonful of water (page 158) . 

Diarrhea has been noted, probably as a result of the spurts 
of bile injected into the intestine during the efforts to vomit. "My 
companions were exhausted with vomiting and defecating", Acosta 



Summary and Discussion 329 

also says (page 24) . However we must say that in some cases it 
seems to be due simply to the cold, to wet feet, etc. 

The combination of these phenomena is always that which has 
most astonished and terrified the travellers; to these phenomena 
is due the old comparison which has given its significant name to 
mountain sickness, mareo. 

Secretions. Secretory disturbances are not very important; 
their relation of effect to cause with the act of ascent is far from 
demonstrated. If there is an exaggerated flow of perspiration, the 
violent exercise and the direct action of the rays of the sun are 
sufficient explanation for that. The decrease in urinary secretion 
may be the consequence of the same causes, but several travellers 
see in it the direct effect of lofty regions. Besides, no exact meas- 
urement has been taken, nor has any chemical analysis been made. 

Respiration. Respiration which is more frequent, shorter, then 
difficult, broken, and uneasy has been experienced and noted by 
everyone. Oppression is often accompanied by pains in the chest. 
This, along with exaggerated fatigue, is the first manifestation of 
mountain sickness. Animals are not immune. We have seen what 
importance has been attached to the increased respiratory rate by 
the theorists who have considered the question; we shall return to 
it in a moment. 

The observations of M. Lortet (page 111) have fixed the modi- 
fications in the respiratory rhythm caused by the altitude: the 
amplitude decreases if the number increases. Vivenot in his appa- 
ratuses has also noted this (page 280) . 

As to the consequences, in regard to respiration, of a permanent 
sojourn in lofty places, the data reported seem to contradict these 
results. To quote only the most recent authors, M. Jaccoud states 
that the number and the amplitude of the respirations increase on 
the Engadine (page 297) . Drew also finds "the respiration more 
rapid and more ample" (page 295) . M. Armieux reaches the same 
result in regard to number; moreover, he reports an increased 
respiratory capacity in the hospital attendants at Bareges. Every- 
one seems to agree on the question of frequency; but that of 
amplitude requires additional research. The same thing is true, 
for greater reason, if we take up the question of races (page 301). 

Circulation. The acceleration of the pulse, though it has not 
been noted by all travellers, like the digestive and respiratory 
disturbances, is no less constant. One can verify this, even though 
no feeling of discomfort attracts the attention. While I was making 
the very modest ascent of Nivolet (1558 meters) near Chambery 
(269 meters) , my pulse rate and that of all the other persons who 



330 Historical 

composed our little caravan rose by 4 to 8; it was counted, of 
course, after a long rest. Lieutenant Wood only by chance noticed 
the extraordinary rapidity of his pulse, so that he thought he was 
feverish (page 143) . 

When the difference in level is very great, the acceleration 
becomes considerable. Moreover it is, as de Saussure said (page 
85) , in proportion to the intensity of the distress experienced. The 
extraordinary rates of 130 and 140 are not very rare on lofty moun- 
tains: "My heart", says Mistress Hervey, "was going a railroad 
pace" (page 149) . Parrot tried to establish a sort of ratio, which 
might have served as a measure of the height, between his pulse 
rate and the altitude reached (page 122). The table published by 
Lortet (page 114) is very interesting in this regard; but such a 
regularity is far from being general. At great heights, the acceler- 
ation of the pulse becomes unendurable; it is accompanied by 
buzzing in the ears, throbbing in the carotids and temples, and 
more or less violent palpitations which become terrifying. This 
acceleration does not seem to be controlled by the use of digi- 
talis (page 151). 

This modification is not transitory; it continues through the 
whole sojourn in lofty places. It is regrettable that exact obser- 
vations on this point are extremely rare. So I think I should quote 
here those which were recently published by M. Mermod. 

M. Mermod" counted his own pulse rate repeatedly at the 
three stopping places of Erlangen (323 meters), Lausanne (614 
meters), and Sainte-Croix (1090 meters); the sojourn in each ot 
these places lasted several months. These observations were made 
with meticulous care, and all necessary precautions were taken so 
that the causes of error might be less than the variations, evi- 
dently very slight, which the circulation might show under equally 
slight differences in altitude. The average of 900 observations 
made at Erlangen was 62.76 heart beats, that of 577 observations 
made at Lausanne was 66.68, and that of 333 observations at Sainte- 
Croix 68.87. The increase of the number with the altitude was 
noted at all hours of the day. 

M. Jaccoud (see page 297) also observed on the Engadine a per- 
sistent acceleration of his own pulse rate. 

I should, however, mention on the opposite side the observ- 
ations of Dr. Armieux (page 299) , who found an average decrease 
of 3.85 heart beats from Toulouse (200 meters) at Bareges (1270 
meters) . 

The frequency does not show the only modification in the pulse. 
Its strength is greatly diminished, it becomes irregular, very 



Summary and Discussion 331 

plainly dicrotic, and is progressively smaller and more easily de- 
pressed. The tracings made by M. Lortet during the ascent of 
Mont Blanc (see page 112) are very clear in this regard. The 
arterial tension decreases considerably. 

Other observers, on the contrary, have found the pulse full, 
strong, "vibrating," says Guilbert, "as in aortic insufficiency" (see 
page 54) . According to Junod, who experimented in closed vessels, 
it is full, depressible, frequent (page 229) . Without losing strength, 
says M. Lepileur, the pulse increases in rapidity considerably 
(page 236). 

The venous system displays no less striking phenomena; full- 
ness of the blood vessels, congestion of the skin, the lips, and the 
conjunctiva; face violet or reddish, swollen; lips blue and swollen. 

Then sometimes the picture suddenly changes completely; the 
face becomes pale; syncope seems imminent. Sometimes it actually 
appears, going as far as complete loss of consciousness. Upright 
posture is very likely to bring it on (see pages 79, 106) . 

The most terrifying, if not the most serious, of the circulatory 
disturbances is hemorrhage; it appears less frequently than is 
generally said; in order of frequency, we note first nasal and pul- 
monary hemorrhages, then hemorrhages from the eyes, the lips, 
the ears, and the intestines; finally, M. Martins experienced a 
slight hematuria. Mile. Dangeville found that her menstrual period 
was considerably advanced; but the violent exercise might explain 
that. 

These losses of blood have been observed in animals, especially 
horses and cattle. I mention in passing the important observation 
of Dr. Clark, who remarked that the blood coming from the nose 
was "darker than usual" (page 91). 

Locomotion. The heaviness of the lower limbs, the "blow on 
the knees", a fatigue which the efforts made do not explain, are 
among the first signs of mountain sickness. We have seen in 
numerous quotations that at a certain height it becomes impossible 
for the sturdiest walkers to take more than a few steps without 
stopping. And this is a matter of altitude, not of the ordinary 
difficulties of mountain journeys. "I made 34 miles on foot," says 
Captain Gerard, "through country which would be called moun- 
tainous by those who do not know the difficult parts of Koonawur, 
more easily and quickly than I could walk 12 miles in these lofty 
regions. When the altitude is more than 14,000 feet, every mile, 
even when the road is good, requires at least twice as much time as 
at the height of 7000 to 8000 feet" (see page 138) . 



332 Historical 

It is not only walking that becomes painful. The slightest 
weight wearies the shoulders; a task, moderate in ordinary regions, 
cannot be carried out in the mountains without real sufferings, 
sometimes dangers. "We could not use our arms," said Dr. Gerard 
(page 136) , "to break off a piece of rock with a stroke of the ham* 
mer." Hamel says that "even talking tires one" (page 90) . And the 
Schlagintweit brothers, who make the same observation, add that 
"one heeds neither comfort nor danger" (page 155) . 

I have found convulsions mentioned only in the narratives of 
Mistress Hervey (page 147) and, in spite of the disrespect of the 
connection, in the horses whose story is reported by Liguistin 
(page 272) . But in both cases there is perhaps some other cause in 
addition to the effect of lofty places. 

Innervation. At the head of this category come the headaches, 
which are so violent and unendurable, compared to "an iron ring 
compressing the temples" (Guilbert), as if "the head were going 
to split in two" (Mrs. Hervey), of which travellers in the Himal- 
ayas complain in particular. 

The sensory modifications, and especially the mental depression, 
have been noticed much less than the preceding symptoms. How- 
ever, rather frequent mention is made of buzzing in the ears and 
a blunting of hearing and taste. The weakening of hearing is 
explained by the lessened intensity of noises transmitted by the 
thin air. Mention is more rarely made of sight, although we have 
quoted examples of travellers whose sight failed or who com- 
plained of dazzled or dimmed vision, etc. (see pages 94, 147) . Loss 
of consciousness, total swooning as a result of syncope, they say, 
is also mentioned. But only an unwilling report is given of what 
Captain Gerard frankly called "mental depression" (page 138), 
and Henderson called "great prostration of body and mind" (page 
158). 

And yet when we read travellers' accounts carefully, we almost 
always find the manifest trace of it. Many disguise it under the 
name of drowsiness; there is no hesitancy about speaking openly of 
a desire to sleep which sometimes becomes unconquerable; but 
we do not admit so willingly that the senses are dulled, the intel- 
lect weakened, the energy lessened, that the mind like the body is 
invaded by extreme indolence, or, by a strange reaction, thrown 
into unhealthy exaggerations. 

Count de Forbin, however, declares (page 72) that he was 
"enfeebled, agitated by the terrors of a feverish brain. Weariness 
of the senses, exaltation of the imagination cast one into a state 
of near-delirium." Henderson also speaks, and de Saussure had 



Summary and Discussion 333 

done the same long before him, of a great excitability of temper. 
On the other hand, de Saussure admits that he did not work with 
much zest on the summit of Mont Blanc. M. Lepileur goes further 
and relates (page 103) that he and his companions journeyed me- 
chanically, without thinking, so to speak, He attributes to this 
mental prostration the contradictions which he notes in the 
accounts of mountain climbers who preceded him. As for me, who 
have read hundreds of accounts of ascents, in the collections of 
Alpine clubs of all nations, I cannot help thinking that their mon- 
otony, their lack of real interest, the want of more than average 
thoughts which characterizes almost all of them, result largely 
from the unconscious state of mental depression of their authors, 
caused by the sojourn in lofty places. The average account of 
ascents to lower levels is infinitely more interesting, richer in out- 
side observations and evidences of intellectual activity; gymnastic 
feats and culinary preoccupations are much less in evidence in 
all cases. 

Aeronauts have noted similar facts, that is, slow depression 
leading to indifference and sleep: "The mental powers fail before 
the physical powers. First one loses memory and care. He forgets 
to give heed to the balloon; soon a slow and gentle sleep lulls all 
the members" (Robertson, page 183). In other cases, there is a 
strange excitement. Finally, at great heights, the aeronaut, even 
in the most complete physical calm, is suddenly struck by complete 
insensibility. That happens to Zambeccari and M. Glaisher. 

Such are the grievous symptoms produced by the influence of 
lofty places. At the beginning, a sensation of inexplicable fatigue, 
short respiration, rapid panting, violent and hasty palpitations; 
distaste for food; then, buzzing in the ears, respiratory distress, 
dizziness, vertigo, weakness constantly increasing, nausea, vomit- 
ing, drowsiness; finally, prostration, dimming of the vision, various 
hemorrhages, diarrhea, and loss of consciousness. Such is the as- 
cending series of symptoms, in proportion to the altitude reached. 
Among all the accounts which we have collected, which picture 
vividly all these distresses, in my opinion, there is none which is 
more vivid and complete than that of Tschudi, falling unconscious 
on the ground, in the icy Puna of Peru (see page 47) . 

Even death, an immediate death, may be the result of these 
serious symptoms. We have given some instances of this in the 
Andes (see pages 25, 33, 37, 43) and in the Himalayas (page 137). 
And it is not only men who may succumb; animals, cats, dogs, 
camels, mules and horses in particular, die still oftener. 

The intensity of these symptoms is considerably aggravated 



334 Historical 

by walking, running, any expenditure of energy. We have had 
many examples of this: one of the best guides of the Oberland 
(page 94), whom a rather strenuous effort twice makes blind; the 
traveller Weddell, till then immune to the soroche, who is stricken 
after a rapid excursion (page 48) ; de la Touanne, falling on the 
ground almost unconscious, because he wished to go faster sud- 
denly (page 36) ; d'Orbigny, who, thinking himself acclimated, 
was compelled to stop every time he waltzed (page 38) ; Hedringer 
falling on the snow, because he wished to run to the summit of 
Mont Blanc (page 96) ; an inhabitant of the Alpine mountains, who, 
trying to outstrip his companions, rolls over "as if some one had 
shot him" (page 116). Travellers say that it is to the eagerness of 
the horses, which spring forward under the spur, that their fre- 
quent deaths are due, whereas the mules, patient and obstinate, 
survive because they refuse to quicken their pace. It is walking 
uphill which especially fatigues and exhausts. 

This fatal effect of muscular activity is felt at all altitudes. But 
in regions of moderate elevation rest is sufficient to dissipate its 
effects and restore complete calmness. And that is perhaps the 
most peculiar characteristic -of mountain sickness. To the uneasi- 
ness of the traveller, to his extreme fatigue, to his grievous dis- 
tress, there succeeds an unexpected comfort, as soon as he stops, 
sits down, or particularly lies down: his heart regains its rhyfhm, 
respiration becomes regular, a feeling of energy returns, all as if 
by enchantment; so that after a few minutes, astonished both by 
these unknown discomforts and this sudden cure, the inexpe- 
rienced traveller confidently resumes his climbing. But soon he is 
again attacked and conquered. 

On loftier mountains, rest, even rest in a horizontal position, 
even if it dissipates the most violent symptoms, does not, however, 
restore calmness. Palpitations, suffocations, trouble or prevent 
sleep. Sometimes a strange symptom appears; during the night, 
at dawn especially, sudden respiratory distress awakens the sleeper 
with a start (see pages 39, 54, 55, 132, 149, 155, 158, 160) . A few deep 
inspirations restore calmness; probably it is a consequence of this 
forgetting to breathe of which de Saussure had spoken (page 83) ; 
imminent asphyxia awakens the sleeper suddenly. 

Such is the series of symptoms which, in different degrees, at 
different altitudes, attack mountain climbers and aeronauts. It 
seems that there is no great difference, except in intensity, be- 
tween the symptoms observed in the different mountainous 
regions. Although the symptoms which we have described appear 
sooner in our Alps than in the Andes and the Himalayas, they 



Summary and Discussion 335 

never reach there the dangerous severity which threatens the 
lives of travellers and their guides, even natives, in the other 
regions. That is because the height of Mont Blanc (4810 meters) 
is the maximum which one can reach in our Europe, and because 
one remains there only a few hours at the most. Conditions in the 
Himalayas are far different, because there one remains for a long 
time on plateaux at an altitude of more than 4000 meters, crossing 
almost every day passes which reach an elevation of 5000 to 5500 
meters. 

A harmful influence whose dangerous effects many travellers 
have mentioned is that of the wind. "There blows in this place," 
says Acosta, whom I must constantly quote, "a little wind which 
is not too strong or violent. But it is so penetrating that men fall 
dead from it, almost without perceiving it" (page 25) . M. Lepileur 
also suffered from the wind to a much less dangerous degree (page 
103). The Schlagintweit brothers also complain of it very bitterly 
(page 155) , and Henderson claims that it often kills travellers 
(page 159). 

Many narratives agree in stating that the symptoms are parti- 
cularly severe at points on the mountain where the air is renewed 
with greater difficulty. Should this irregularity be attributed to 
the heating of this air, expanded by the sun? Or to the tediousness 
of walking in these monotonous passages? The observations of 
M. Javelle and M. Forel tend to support this latter hypothesis. 
They state, in fact, that mountain sickness disappears in dangerous 
spots (page 289) and also as a result of attentive observation of 
the landscape or oneself (page 292) . 

It would not be very interesting to dwell on the medications 
used by the natives against the symptoms of mountain sickness. 
They generally agree in forbidding alcoholic beverages; in 
America, they praise bleeding, especially for animals. In the Andes 
protective powers are attributed to garlic or onion placed in the 
nostrils of the animals; in the Himalayas, acid and dried fruits are 
used. Almost everywhere it is recommended that one should eat 
little and often. M. Dufour declares that he dispelled an already 
violent attack of mountain sickness merely by eating a piece of 
bread (page 290). 

3. Theoretical Explanations. 

We may divide into two great categories the hypotheses and 
the theories put forward to explain mountain sickness: some of 
them, by far the most interesting, try to settle the mechanical, 
physical, or chemical role of the diminished atmospheric pressure; 



336 Historical 

the others, the most peculiar ones, seek the cause of the symptoms 
in something other than the fall of the barometer. We shall begin 
with the latter. 

Pestilential exhalations. The explanations which put forward 
pestilential exhalations, either from the ground or from toxic 
plants, must be given a moment of our time. 

They have their origin in the absolute ignorance of the native 
peoples about the very existence of an atmosphere. Therefore the 
Indians and the Tartars of the Himalayas, the Redskins of the 
Andes and their successors, almost as uncivilized as they, did not 
hesitate to attribute the symptoms which struck them and their 
domestic animals to some mysterious poisoning. In the Andes, the 
frequent presence of metallic ores and the evident effect of moun- 
tain sickness upon the unfortunate miners gave rise to the belief 
that there issued from buried metals, and particularly from anti- 
mony, "which plays," says Tschudi, "an important part in their 
physics and metallurgy," emanations dangerous to all those who 
passed over their veins. Hence the name soroche, which means 
both antimony and mountain sickness. 

In central Asia, the idea of exhalations from the earth also 
occurred to the people, especially towards China; we saw that 
Father Hue did not hesitate, with his usual credulity, to declare 
that the symptoms of Bourhan-Bota were due to carbonic acid 
from the ground (page 238) . 

Volcanic mountains, like Etna, the Peak of Teneriffe, the moun- 
tains of North America, because of deleterious vapors which rise 
from certain crevasses, have caused among travellers a much more 
pardonable confusion between the effect of the altitude and that 
of the mephitic gases; we have seen examples of it. 

All through the Himalayas, the mountaineers do not hesitate 
to attribute the distress from which they suffer to volatile poisons 
emanating from flowers or plants. Generally the narratives of the 
travellers limit themselves to these vague expressions; but when 
they are more exact, the strangest divergences appear. 

The Chinese author whom we quoted (page 129) gives rhubarb 
as the cause. When Fraser's coolies complain of the seran and 
blame the flowers which cover the ground, he looks around him 
and finds primroses, heather, and polyanthus (page 132) . For Mis- 
tress Hervey, whose distress we have narrated, it is a sort of moss, 
the boottee, which the natives show her as the cause of all her 
troubles (page 148) . They could not show Cheetam the dewaighas, 
the mysterious and toxic plant (page 153) . Henderson reports that 
they blamed artemisia (page 295) , and Drew, the onion (page 295) . 



Summary and Discussion 337 

These hypotheses, natural product of the ignorance of the 
natives, have sometimes been accepted by European travellers. 
They served as an easy explanation of this curious fact that the 
intensity of the symptoms is not regularly proportional to the alti- 
tude, and that at certain points, sometimes of moderate elevation, 
almost everyone is sick. It is especially travellers in the Andes 
who believe in emanations from the ground. Some of them would 
say, like the peons of Brand: "There is much puna here" (page 36) . 

However, very few admit their credulity clearly; they are satis- 
fied with saying that there are "accompanying causes, which are 
unknown, and which act with the rarefaction of the air" (page 55) ; 
that "the atmospheric pressure is not included in the causes of the 
soroche, which should perhaps be attributed to emanations from 
the ground" (page 58) . 

Asiatic travellers have been more prudent. Hodgson alone 
allows one to glimpse a certain credulity (page 223) ; but all the 
others refuse to admit intoxication by plants; those who have 
deigned to take note of it declare