Hay fever: its causes, treatment and effective prevention

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HAT FEYEEs

ITS CAUSES, TREATMENT, AND EFFECTIVE PBEVENTION.

OPINIONS OF THE FIEST EDITION.

( Dr. Blackley's treatise is one of the most interesting that it
has been our fortune to read. It is a piece of real, honest
work, original and instructive, and will well repay perusal.'—
The Lancet, August 16, 1873.

* We must not occupy, as we should like, further space with
our notice of this really valuable and highly interesting work.
We trust Dr. Blackley will continue his well-planned re-
searches.' — Medical Press and Circular, August 6, 1873.

* We have read this very instructive and suggestive treatise
with much interest, and we have been much impressed with the
author's ingenuity in devising experiments, his industry in
carrying them out, and his obvious candour in giving the re-
sults of his observations.'— Dp. George Johnson in the London
Medical Record, June 18, 1873.

' Our own observations confirm Dr. Blackley's opinions, and
we think such an honest attempt to throw light on the subject
is entitled to the attentive consideration of practitioners/ —
Philadelphia Medical Times, November 15, 1873.

. * Trousseau was a great sufferer from hay-asthma. Had the
illustrious pnvfessor lived to read Dr. Blackley's book, a little
further light as to the cause of his attacks would have dawned
upon him? — The Doctor, August 1, 1873.

V

HAT FEVEB:

CAUSES, TREATMENT,

EFFECTIVE PREVENTION.

EXPERIMENTAL RESEARCHES.

CHAS. HARRISON BLACKLEY, M.D.

SECOND EDITION,

LONDON :

BAILLlfeRE, TINDALL, & COX,

KIHG WILLIAM STREET, STRAND.

PARIS: BAILLLfeRE. | MADRID: BAILLIER&

1880.

AT/.

On

SOI

PREFACE TO THE FIRST EDITION.

Hay-fever has, in England, been for some years attracting
a considerable share* of attention amongst the members of
the medical "profession and also in a less degree amongst
those who are unconnected with the profession. Hitherto,
however, its causes and, to some extent, its real nature
have been but imperfectly understood.

In the investigations which are detailed in the following
pages the object has been to test, by actual experiment, the
validity of the opinions held on the causes of the disease,
as well as to collect additional information upon points
which were uncertain or doubtful, and thus to help to clear
up some of the obscurities which have rested upon the sub-
ject. Being for the most part a record of the personal
experience gained in following out the inquiry, the observa-
tions are not intended to settle the question of cause for all
cases of the disorder. Nevertheless I believe that the
results of the experiments, along with the evidence collected
from other sources, fully warrant the conclusion that the
cases which are due to any other cause than that named
are so few in number that they may be considered mere
exceptions to a general rule.

To those members of the profession who have studied
hay-fever and have formed definite opinions upon it, it will
appear that the mode in which the subject is treated is
unnecessarily minute, but to those who are imperfectly

vi Preface to the First Edition.

acquainted with the disease, or to whom it is entirely new,
it will not appear that too much detail has been given.
Even in this country, where the disorder probably had its
commencement and where it is still more common than in
any other part of Europe, there are medical men to be
found who know very little about it ; and on the Continent
there are still some to be found who have never even heard
of the disease. To such as these especially the details I
have given will not be uninteresting.

It is a matter of regret to me, and I have no doubt will
be to some of my readers, that I have not been able to
speak at length and with some degree of certainty and pre-
cision upon the treatment of hay-fever. A determination
to adhere as closely as possible to the statement of such
facts as my own experience would enable me to vouch for,
compels me to say that treatment by medicines has so far
in my hands, been very unsatisfactory ; nor do I think that
it would have been found to be any more successful in the
hands of those who seem to have been more fortunate, if a
strictly logical method of testing the efficacy of treatment
had been followed. I do not, however, despair of a specific
being found for hay-fever, and offer the following pages as
a contribution which it is hoped may assist somewhat in
the search for the appropriate remedy.

In the course of the inquiry I have been indebted to
several medical friends for their kindness in calling my
attention to anvthing which bore upon the subject I had in
hand, and also for procuring for me books and papers relat-
ing to hay-fever, as well as for other important services
rendered during the time the investigations have been in
progress.

From some non-professional friends also I have received
very valuable aid. To my friend Mr. Herman G. Kindt,*
I am especially indebted for his kindness in translating for
ane the greater portion of the work of Professor Phoebus, as

* Now of Neustrelitz, Germany.

Preface to the First Edition. vii

well as for other valuable assistance which he gave in the
early part of the experiments. To my friend, Mr. James
Lord* I am also under great obligation for the help he
gave me in nearly all the experiments at high altitudes*
To each and all of these friends I tender my most sincere
thanks.

C. H. B.

Old Trafford, Manchester,
April 5th, 1873.

* Of Whalley Range, Manchester.

PREFACE TO THE SECOND EDITION.

In the former edition of this work two important questions
remained unsettled. One of these was the quantity of pollen
necessary to produce hay -fever: the other — the most impor-
tant question of all — was the treatment and prevention of
the malady. A chapter on each of these subjects has been
added to this volume. The first question has been more or
less thoroughly investigated, and may be considered to be
settled. The second has been only partially investigated >
but yet with an amount of success that has seemed to justify
the publication of the methods used.

Some of the writers who were kind enough to review the
first edition very favourably expressed a regret that there
had not been a larger number of persons experimented upon.
There were others, who also reviewed the work favourably,
that seemed to imply that there had been a degree of wilful
neglect in not having sought a wider field of observation.
Those who are disposed to blame me can have very little
idea of the difficulty there is in getting even a small
number of persons to try experiments that will cause them
inconvenience or suffering. Many attempts were made to
induce other sufferers from hay-fever voluntarily to try the
action of pollen upon the mucous membranes, but in no
case did I succeed. One patient told me with the utmost
naweU that he would be most happy to assist in inves-
tigating the action of pollen, but not upon himself To a

x Preface to the Second Edition.

considerable extent the same feeling prevailed in regard to
the testing of remedies. Many promises were made, and
several patients wrote, spontaneously offering to give any
help they could in my investigations. With some rare excep-
tions, however, I found that the notion these folks had of the
term * help ' consisted in a willingness, and in most cases an
anxiety, to try any remedy that was already known to be a
thorough cure for hay-fever.

No one can regret more than I have done the fact that
the experiments have been chiefly confined to myself.
Whether I shall have a wider field of observation in the
future remains to be seen.

C. H. B.

Old Tbaffobd, Manchester,
March 31tf, 1880.

TABLE OF CONTENTS.

CHAPTER I.

PAGE

INTRODUCTION ------- 1

CHAPTER IL

A KEVIEW OF THE OPINIONS HELD ON THE CAUSES OF HAY-
FEVER - - - - - - - -12

CHAPTER m.

EXPERIMENTS WITH, AND OBSERVATIONS ON, THE PRESUMED

CAUSES OF HAY-FEVER - - - - - 69

CHAPTER IV.

ON THE QUANTITY OF POLLEN FOUND FLOATING IN THE ATMO-
SPHERE DURING THE PREVALENCE OF HAY-FEVER, AND
ON ITS RELATION TO THE INTENSITY OF THE SYMPTOMS - 143

CHAPTER V.

ON THE GREATER PREVALENCE OF HAY-FEVER, AND ON THE

INCREASE OF ITS PREDISPOSING AND EXCITING CAUSES - 188

CHAPTER VL

ON THE NATURE AND SYMPTOMS OF HAY-FEVER - - 198

CHAPTER VII.

ON THE QUANTITY OF POLLEN NECESSARY TO PRODUCE HAY-
FEVER - ...... 238

CHAPTER VIII.

ON THE TREATMENT AND PREVENTION OF HAY-FEVER - 246

DIRECTIONS TO THE BINDER

Plate I. is to face page 122.

, rjT c are to be placed between pages 146 and 147.

Plate IV. is to face page 150.
Plate V. „ 170.

Plate VI. „ 175.

Plate VII. „ 17a

Plate VIII. „ 242.

DIRECTIONS TO THE BINDER

Plate I. is to face page 122.

Plates II. I ,_!,,_ , ^

and III ) are placed between pages 146 and 147.

Plate IV. is to face page 150.
Plate V. „ 170.

Plate VI. „ 175.

Plate VII. „ 178.

Plate VIII. * 242.

HAT FEVEE:

ITS CAUSES, TREATMENT, AND EFFECTIVE PREVENTION.

CHAPTER I.

of medicine has the in-
been carried on more
o day. During the last
ive been made in this
le of the work, and so
useparable from it, that
accomplished, and it is
nd also one of the least
hole domain of science,
.iinish occupation to the
it also offers an almost
: scientific explorer who
desires to travels «.. is. It is, moreover, pro-

bable that in this field of reseaicii there are to be found
some of the brightest laurels that can be won by the scientific
discoverer. It is, however, not on these accounts merely
that it ought to invite our attention. The successful elucida-
tion of the etiology of disease is fraught with consequences
the value of which it is scarcely possible to estimate, and it
is principally on account of its intimate connection with the
physical well-being of mankind that we ought to be desirous
of laying bare its secrets.

2 Experimental Researches on Hay-Fever.

§ 2. Though bearing somewhat on the germ theory, the
facts I shall have to detail in the following pages do not help
much to settle any of the vexed questions on this subject.
These facts will, however, show that, in some cases at least,
disease, without being contagious, is in some instances the
result of the operation of two principal factors : one of these
factors being that condition of the animal body which
permits the development of disease in it ; the other, the
action of some agent external to the body, and which ex-
hibits its power whenever a sufficient quantity of it comes
into contact with the susceptible organism. The first con-
dition, though often varying, is probably always present in
a greater or smaller degree even in the most healthy subject.
The second, in like manner, is probably as variable as the
first, and though possibly always present in the larger
centres of civilisation, is ever changing in its quantity or its
power.

§ 3. The essential nature of that state of the organism
which gives a proclivity to disease, and permits external
agents to act upon the animal body, so as to produce morbid
conditions, may never be fully known to us ; and it may be
that, with our present means of research, the active causes
of many of our most formidable maladies will elude our
grasp for long years to come. There are, however, some of
the more simple and less fatal diseases in which, by an
improved method of study, we may hope to obtain a better
knowledge than we now possess of the nature and modus
operandi of some of the external agents which act as ex-
citing causes; and it is, perhaps, in searching for such that
we shall, most easily learn valuable lessons in studj T ing the
etiology of disease.

§ 4. The importance of this study has been noticed by
some authors who have long since passed away. One of
these, who wrote in the early part of the present century,
in speaking of the study and practice of the art of medicine,
very forcibly says : 'As it is physical influences with which
we have chiefly to do in medicine, the main and ultimate
object in cultivating this art must cousist in ascertaining
the agency of external objects, whether salutary or noxious,

Introduction. 3

on the living body, and in applying these, or avoiding them,
so as to obtain the desired result, either of preventing the
occurrence of disease, or of converting the state of disease
into that of health. It is to the extent and correctness of
our knowledge of these agencies that the perfection of the
art of physic must consist/*

The remarks just quoted apply with considerable force to
the study of the malady which is the subject of the inquiries
and experiments described in the following pages.

§ 5. Hay-fever or hay-asthma was first known in this
country, and may, indeed, be said to have had its birthplace
in England. It was first described by Bostock, in the year
1819. In a paper read before the Medico-Chirurgical Society
of London, he gave an account of a case which was termed
* A Case of the Periodical Affection of the Eyes and Chest/-f*
and which was, in reality, a description of his own case.
Herberden had previously mentioned^ such a catarrh as is
understood to have been what is now termed hay-fever, but
he does not seem to have known anything of its real nature.
Cull en also remarks that in some persons asthmatic fits are
more frequent in summer, and more particularly during the
dog-days, than at other colder seasons of the year. In 1828
Dr. Bostock read a second paper§ on this subject before the
above-named society, and gave a more lengthened and exact
account of the symptoms of the disease.

§ 6. In the time which had elapsed between the reading
of his first and second papers, B»stock had either seen or
had received € distinct accounts of eighteen cases/ besides
about ten others in which ' the accounts were less perfect/
In the latter communication the disorder was designated
'catarrhus sestivus/ or 'summer catarrh/ It is by this

* Medical Logick, by Sir Gilbert Blane. London, 1819.

t * Case of a Periodical Affection of the Eyes and Chest/ by John
Bostock, M.D. Medico-Chirurgical Transactions, London, 1819, vol.
x. part i. pp. 161 — 165.

J Commentary on the History and Cure of Diseases. 4th edition.
London, 1816. Chap. ' Destillatio/ p. 113.

§ ' On Catarrhus iEstivus, or Summer Catarrh/ by John Bostock,
M.D. Medico-Chirurgical Transactions, 1828, vol. xii. p. 437 — 446.

1—2

4 Experimental Research** on Hay-Fever.

name it has since been more or less known among medical
men ; but from the circumstance of its having been noticed
that it commonly came on during the hay season, it has
obtained among the laity the name of hay-fever or hay-
asthma ; and I am inclined to believe that these names will
be found to be the most appropriate of any yet used.

§ 7. The literature of the disease was, up to a compara-
tively recent period, very scanty. Bostock's first paper was
published, as stated above, in 1819, and between this and
his second communication in 1828 there was an interval of
nine years, in which no other notice of the<disease appeared
in a printed form.

§ 8. In 1828 Dr. Macculloch* mentioned the disease, and,
in speaking of its causes, says, ' it is produced by hot-houses
or greenhouses, and in the public estimation it is particularly
caused by hayfields.' In 1829 Mr. W. Gordon published his
* Observations on the Nature, Cause, and Treatment of Hay-
Asthma. ,- f" In 1830 Mr. Augustus Praeter published a short
notice of a case he had seen in Paris some years before. In
1831 Dr. Elliotson noticed the disease in his lectures, and
again in 1833 he gave a more lengthened account of the
malady.

§ 9. From this latter period there was again an interval
of ten years during which there was not anything of a
special character published on hay-fever, but since the time
just mentioned the subject has gradually excited increased
interest amongst the laity and also amongst the members of
the medical profession; and it would seem that there are
now a greater number of cases to be met with than there
were formerly. Perhaps this may, in part, be due to the
increased attention, directed to this disease, having had the
effect of bringing the cases much more distinctly under the
notice of medical men than they have been brought at any
previous period ; but it may also be, in part, accounted for

* An Essay on the Remittent and Intermittent Diseases, by Dr. John
Macculloch, London, 1828, vol. L pp. 394 — 397.

t ' Observations on the Nature, Cause and Treatment of Hay-
Asthma/ by Wm. Gordon, M.E.C.S. Edin. London Medical Gazette,
1829, vol. iv. pp. 266—269.

Introduction. 5

by the greater prevalence of those conditions which act as
predisposing and exciting causes.

§ 10. This increased interest in the disease has shown
itself in the publication of numerous articles on it in the
periodical medical literature, and the works of various
writers on systematic medicine on the Continent, in America,
and in this countrj*-. There have also been several trea-
tises published in a separate form during the last few
years. Among the principal of those which have been pub-
lished in this country may be mentioned those of Dr.
Abbotts Smith,* Dr. Pirrie,t and Dr. G. Moore.J In
America an excellent work§ has been published by »Dr.
Morrell Wyman, and also one by Dr. Beard. || Of these I
shall have to speak further on. Although the disease has
been more prevalent in England and in America than it is
in any other part of the world, it is to a German author
(Dr. Phoebus, professor of medicine at Giessen,) that we are
indebted for the best monograph! that has yet appeared on
hay-fever**

§ 11. In speaking of the disease having been brought so
recently under notice, Bostock, in his second paper, pub-
lished in 1828, savs : ' One of the most remarkable circum-
stances respecting the complaint is its not having been
noticed as a special affection until the last ten or twelve

* Observations on Hay -Fever, Hay- Asthma, or Summer Catarrh,
by Win. Abbotts Smith, M.D., M.R.O.P. Lond. London, 1865. 2nd
edition.

+ On Hay-Asthma, or the Affection termed Hay -Fever, by Wm.
Pirrie, M.D., &c, <fcc. London, 1867.

X Hay- Fever, or Summer Catarrh: its Causes, Symptoms^ Preven-
tion and Treatment, by George Moore, M.D. London, 1869.

§ Autumnal Catarrh {Hay-Fever), by Morrill Wyman, M.D. New
York, 1872.

|| Hay- Fever, or Summer Catarrh: its Nature and Treatment, by
Geo. M. Beard, M.A., M.D. New York, 1876.

H Ber Typische Fruhsommer Katarrh oder das sogenannte Heufieber,
Heuasthma, von Philipp Phoebus, M.D., &c, <fcc. Giessen, 1862.

** It is to this work that 1 am indebted for the names of man of
the foreign authors, and for those of several of the English authors,
who have written on hay-fever.

6 Experimental Researches on Hay-Fever.

years. Except a single observation of Heberden's I have
not met with anything that can be said to refer to it in any
author, either ancient or modern.' As far as the researches
into the literature of the disease up to the present time
have shown, there does not appear to have been any dis-
tinct notice of it previous to that mentioned by Bostock.

§ 12. Considering the high character which the physicians
of that day bore as acute observers, it seems strange, at
first sight, if the disease did exist, that it should not have
been recognised and described by them. Whether the
malady had been unly recently developed when Heberden
first mentioned it, or whether it was then of much older
standing, we may not now be able to ascertain. Dr. Copland,
however, tells us that, up to the time of Sydenham, rheu-
matism and gout had been regarded as one and the same
disorder. These forms of disease have less similarity and
are more distinct in their characters than are the catarrhal
form of hay-fever and common coryza ; whilst in the purely
asthmatic form of hay-fever it is impossible to distinguish
between the latter and common asthma, except by deter-
mining what the exciting cause is. It may not, therefore,
seem so remarkable that hay-fever may have been long
mistaken for the ordinary form of coryza or of asthma ; and
when we consider that there are not wanting instances of
even medical men having been affected by this malady, and
who have not become fully aware of its nature until they
had suffered from it for some time, it may be considered
highly probable that it had occurred in isolated cases long
prior to the time when it was first noticed by medical
authors.

§ 13. Hay-fever is said to be an aristocratic disease, and
there can be no doubt that, if it is not almost wholly con-
fined to the upper classes of society, it is rarely, if ever, met
with but among the educated. Dr. Phcebus and other
writers speak of cases which have occurred among the
working part of the population. I have myself only seen
two such cases ; and I think it is tolerably certain that they
occur but very seldom. I have met with cases of chronic
catarrh among the working classes which seemed at first

Introduction* 7

eight to resemble hay-fever, but when tested in the manner
described in my experiments, the patients were found not to
be amenable to the same influences as those who suffer from
the genuine disease.

§ 14. In perusing the literature of hay-fever one is struck
with the great variety of opinion which prevails upon its
causes, and also, in some degree, upon its nature, but more
especially with the small amount of success which has ap-
parently attended its treatment. This want of unanimity
of opinion on its causes, and the want of success in its treat-
ment, have perhaps been the most marked where medical
men themselves have been the subjects of the malady ;
whilst, on the other hand, singular as it may appear, those
who seem to have been the most fortunate in treating others
have themselves never suffered from the disease.

This diversity of opinion and the failure which has
attended the efforts to cure the disorder may be, and pro-
bably are, to some extent, due to the absence of any attempt
to prove by inductive methods of experimentation the
precise nature of its causes, and also to not endeavouring to
ascertain by the same means the relative value of the
remedies used in its treatment; and, to use the words of a
recent writer, it is ' a matter of astonishment that greater
efforts have not been made to elucidate the doubtful points
relating to its history, causes, and treatment, and thus to
obtain a more certain guide to the relief or cure of the
disease.' *

§ 15. In the course of my reading on this subject I
became convinced that before we could say we had got hold
of ' the sum of the facts ' to which the disease owes its
existence, something more than had already been accom-
plished needed to be done. It seemed to me that we had
hitherto failed to grasp the idea that * the cause cannot be
anything which is present in other cases where the given
effect is not produced, unless the presence of some counter-
acting cause shall appear to account for its non-production.' •}•

* Preface to Dr. Abbotts Smith's first edition of his work on Hay-
Fever.

t Archbishop Thomson's Outline of the Laws of Thought.

8 Experimental Researches on Hay-Fever.

§ 16. In regard also to the mass of evidence already-
collected, there seemed to be a great need of this being
sifted and re-arranged on a more logical method ; and, more
than all, there appeared to be a necessity for a collection of
additional facts in order that we might fill up the missing
links in the chain of evidence, so as to give us the means of
a closer and more correct generalisation. The annual recur-
rence of the malady at a given period of the year, the
almost certain departure of it after a given time, the entire
freedom from it which most patients enjoy for the greater
part of the year, the absence of any dangerous symptoms,
except in rare cases, as well as the non-occurrence of sequelae
of a serious character, seemed to offer opportunities for safe
experimentation such as are rarely found in any other com-
plaint, whilst the presumed exciting causes were such as to
present no great obstacle to their being fairly tested during
the intervals of freedom from the disorder.

§ 17. If any reason needed to be given for the investiga-
tions having been undertaken by me, it is partly furnished
in the remarks made above, but principally by the circum-
stance that I have myself been a sufferer from this curious
malady for more than twenty-five years. Although I had
in the earlier years of my attacks carefully read over most
of the scanty bits of the literature of the disease then exist-
ing, I had not been able to form any very definite and settled
notion of the nature of the cause. I was inclined to re-
gard heat as the principal exciting cause, but my experience
did not quite coincide with the opinions of those who had
written on the disorder, and this experience had, unfortu-
nately, compelled me to come to the conclusion that, until
something more was known than I had learned from the
writings of others or from my own previous observations,
there was no chance of escape from the annual torment. I
had thus a personal interest in getting a more thorough
knowledge than I then possessed of all the phenomena of
hay-fever.

§ 18. The experiments, which I have to describe in suc-
ceeding chapters, were commenced in the year 1859, but
owing to various circumstances, which were not controllable

Introduction. 9

at the time, proceeded very slowly for some years. This
delay was in some measure owing to the difficulty there was
in sparing sufficient time for a lengthened and uninterrupted
course of observations during the spring and summer
months. For the purposes I had in view, it was absolutely
necessary that a number of observations should be made
each day during the period named, and that these should
commence some time before the grass came into flower, and
be continued until it had been all gathered in. It was also
necessary that some person who suffered from hay-fever
should be exposed, during a portion of the day at least, to
the influences which might prevail in the district in which
the observations were taken, and that the symptoms gene-
rated by such exposure should be registered daily. It
would have been more satisfactory, and would have brought
out more exact results, if the patient to be experimented
upon could have been kept within a short radius of the spot
selected for the first set of experiments ; but as this would
have involved a sort of imprisonment for at least ten weeks,
it was impossible for me to follow out the investigation in
this very precise manner. What, however, the observations
have lacked in this respect, I have endeavoured to some
extent to make up for by following out the inquiry under
varying circumstances and in different districts. It would
also have been well if I could have had the co-operation of
other individuals who, like myself, were sufferers from hay-
fever. In several attempts I have made to induce others
to undertake experiments upon themselves I have failed,
although these proposed experiments were of a very limited
and simple character*

§ 19. In the first years of the disease, in my own case,
it had more than once happened that, when some particular
plan of treatment was being pursued, this would seem for
a time to be successful in mitigating the severity of the
symptoms, and, in some instances, in apparently curing the
malady ; but suddenly, and without any change in the treat-
ment, there would be a decided relapse, and the condition
would become almost as bad as before. Subsequent experi-

* Vide preface to this edition.

10 Experimental Researches on Hay-Fever.

ence, in seasons when the disease was present, and when no
treatment of any kind was being used, convinced me that
these variations were principally due to variations in the
quantity or quality of the causes of the malady, whatever
these might be. It seemed, therefore, to be highly important
that not only the nature of the cause should be discovered,
but that we should have the means of measuring its varia-
tions in quantity as well as quality ; and that we should
particularly study those circumstances which lead to these
variations. There was also another question to which it
was important to obtain an answer, viz., whether in any
individual case the disease owned only one exciting cause,
or whether it had a plurality of causes. Until the latter
questions were satisfactorily settled it was clear that any
effort to gain relief, by avoiding the one supposed cause,
might be completely frustrated by the patient unwittingly
putting himself under the influence of other hostile circum-
stances. But once accomplish these objects, and we should
not only be better able to gain relief by avoiding the cause,
but we should have the means of erecting a standard by
which we should be able to estimate the value of the
methods used in the cure or the prevention of the disorder.
So long, however, as we were ignorant of the real nature of
the influences which give rise to the morbid conditions and
of the possible rates of their variation, we were constantly
liable to be misled in our estimate of the efficacy of the
means used.

§ 20. It was with the hope of accomplishing something
in the direction indicated that these experiments were com-
menced. One principal object was to find out what were the
exciting causes of the attacks in my own case ; but as an
examination of the records of other cases showed me that in
its symptoms, and in the conditions which seemed to give
rise to these, my own case was almost identical with a very
large majority of those I had investigated, it appeared to be
highly probable that, if I succeeded in ascertaining the cause
in my own case, I should also be doing the same thing for
a large number of other patients. If, after making the
attempt, I found that I was not able to do satisfactorily all

Introduction. 11

that I have indicated above, I still hoped to glean, in this
field of inquiry, some fresh facts which might serve as
stepping-stones for the further progress of those who might
follow me. The main object of my researches was, however,
to find remedies that would at least mitigate the force of the
disease, and, if possible, some means of prevention. Of the
amount of success I have had the reader will be able to
judge.

12

CHAPTER II.

A REVIEW OF THE OPINIONS HELD ON THE CAUSES OF

HAY-FEVER.

§ 21. In the last chapter I have mentioned incidentally
that in its two principal phases hay- fever resembles common
catarrh and ordinary asthma. Although this description is
very partial and imperfect, it will suffice for our present
purpose. When we, come to consider the symptoms of the
disorder in detail, I shall then be able to note their pecu-
liarities, and to give to each its due significance.

In the present chapter I propose to pass under review
most of the leading opinions that have been held on the
causes of the ailment. We shall by this means have a
better idea of their variations and peculiarities than would
be had if they were introduced in a fragmentary manner in
the course of remarks on other parts of the subject, and we
shall to some extent have the ground mapped out which I
have had to occupy in my experiments. Not only have the
opinions which have been entertained on the causes been
very varied, but, as I shall be able to show, these have in
some cases been very conflicting. The most opposite condi-
tions have, by both writers and patients, been thought to be
capable of producing the disorder.

In some cases high temperature, with dryness of the
atmosphere, have been held to be sufficient to produce the
symptoms of hay-fever in persons who are liable to it.
Some patients have thought that excess of moisture, with
high temperature, has brought on the disorder in their cases.
By some authors ozone is named as a possible exciting cause

A Bmew of the Opinions held on its Causes. 13

of the disease ; and by others odours of various kinds, espe-
cially those given off by plants, have been accused of being
the causes. In some cases common dust has been thought
to have a considerable share in bringing on the disorder,
whilst in a comparatively large number of instances the
agent which has given the popular name to the malady has
been taken to be the principal, if not the only, exciting
cause. In an equally large number of instances, however,
the pollen of grass, and other flowering plants, has been held
to be the most active and efficient of all causes ; but among
these the pollen of grass is by some writers held to be the
most powerful.

§ 22. All authors are, however, agreed on the existence of
some peculiarity of the constitution which predisposes to the
disease ; but whether this peculiarity should be regarded as
simply a local one, depending on a particular vascular or
other condition of the mucous membranes affected, or
whether it is to be sought for in the periphery of the nerve,
or in some part of the nerve-tract supplying these mem-
branes, or whether we must go to the sympathetic system,
or to the larger nerve-centres, and seek there for the pre-
disposing cause of the malady, is not yet decided. Curious
and unaccountable as the predisposition seems at first sight
to be, it is not any more remarkable than those which
give a proclivity to other and essentially different forms of
disease.

§ 23. Bostock, who was the first writer who gave a full
description of the ailment, believed that in his case it was
not caused by the effluvium of grass or hay. He thought
that heat had the greatest share of influence in producing
the attacks ; but after the attention of the public bad been
drawn to the existence of the disease, the idea prevailed
that it was caused by the effluvium of hay recently made.
Bostock was desirous of testing the accuracy of this opinion,
and made it the subject of study and close observation, so
that he might be able to determine the cause of the attacks
in his own case.

In speaking of this part of the subject, after he had care-
fully studied it and watched the effects of variations of

14 Experimental Researches on Hay-Fever.

temperature and other conditions ; and especially after he
had, as he thought, watched the effects which grass in
flower, and also when turned into hay, had in producing the
attacks, he says :* 'I think myself fullj r warranted in assert-
ting that, in my own case, the effluvium from hay has no
connection with the disease. The observations will, I think,
be sufficient to prove this position.

§ 24. ' In consequence of the benefit which I always ex-
perience from cool fresh air, I made choice of Ramsgate as
my residence during the summers of 1824, 1825, and 1826.
The last two of these years will be long remembered for
their excessive heat ; but by procuring a house on the cliff
exposed to the German Ocean, and commanding complete
ventilation, by avoiding bodily exercise, and, indeed, seldom
leaving the house until evening, during the year 1825 I
nearly escaped the disease. In the year 1826 I have reason
to believe that the disease was much mitigated by the com-
parative coolness of the situation, but still I had many
decided and some severe paroxysms.

'Now it is well known that there is not an acre of
meadow-ground in the whole of the Isle of Thanet, and in
the year 1826, in consequence of the great drought, all the
little patches of grass which may be supposed to exist on
the roadsides or elsewhere were completely burnt up. Nor
is this all. During many of the hottest days the wind blew
steadily from the south-east, so that the nearest land to
windward of the house which I occupied was on the French
coast a little to the north of Calais; yet during this time,
whenever I relaxed my plan of discipline and exposed myself
to the sun's rays, or by any means quickened the circulation,
the symptoms recurred in full force.

§ 25. 'The last year, 1827, with the exception of a short
period in July, was cold. I could not conveniently remove
to any great distance from London, and spent the summer
in Kew. This situation might have been chosen for the
purpose of experiment, for almost the whole of that part of
the country consists of hay-grass, which was cut whilst I
was in the neighbourhood. In consequence of the coolness

* Medico-Chirurgical Transactions, 1828, vol. xii. pp. 437—446.

A Review of ike Opinions held on its Causes. 15

of the season I did not confine myself to the house, bat
walked out daily, occasionally in Kew Gardens, and was
surrounded by many hundreds of acres of hay-grass, in all
different states ; yet, except during the few hot days, when I
suffered as usual, my complaint was in a much less degree
than the average. But although I think the evidence, so
far as respects myself, to be quite decisive, I acknowledge
that I have received accounts from various quarters of
individuals who have felt, no doubt, that the complaint was
brought on by the effluvium from hay, and was relieved
or prevented by avoiding this effluvium. I will not venture
to assert that this opinion is incorrect, but I believe that in
most cases we may explain the facts more naturally by
supposing that the patients, at the time when they conceived
themselves to be inhaling the effluvium from bay, were also
exposed to heated air or sunshine, or had been using bodily
exercise. Experience, however, must decide the question,
and when the subject is once fairly brought into view it will
not be difficult to collect a sufficient number of facts to
enable as to form an opinion.'

§ 26. There is in these observations of Bostock's an evident
effort to ascertain, by careful experiment, the real cause of
hay-fever. It is this honesty of purpose which has probably
led subsequent writers to accept his conclusions without
submitting them to a searching examination such as their
importance demanded ; and his statements have also, pro-
bably, given the cue to some authors who have written on
the disease without having had any personal experience of
it How far these statements of Bostock's are borne out by
the results of actual experiments I shall have occasion to
notice further on.

§ 27. Gordon, who was a contemporary of Bostock's,
took a different view of the cause of hay-fever. Whilst he
recognised the circumstance that many cases were on record
which showed that severe derangement of the function of
respiration was sometimes ' occasioned by the odour exhaled
by aromatic pungent bodies/ he thought there could be no
doubt that hay-fever was caused by the ' aroma emitted by
the flowers of grass, particularly from those of the Anthox-

16 Experimental Researches on Hay -Fever.

antkv/m odoratvm.' He had been inclined to adopt this
view by noticing that * whenever the patient remained
closely shut up in a house, even though this was situated in
the midst of the richest grass, he suffered considerably less
than if he walked abroad into the fields ; and if he removed
from the country to the centre of a large town he was never
at all affected ; but the moment he came into or approached
a meadow he immediately began to sneeze, and returned
home with wheezing and difficult respiration.'

§ 28. In summing up his observations Gordon says : ' I
have said that the Anthoxanthum odoratvm seems to be
the principal exciting cause of hay -asthma, and I am in-
duced to come to this conclusion—; first, because this plant
is one of the most strong-scented of the grasses; and
secondly, because so soon as it begins to flower, and not
until then, the asthma commences ; as the flowers arrive at
perfection the disease increases, and after they have died
away I have remarked that patients could pass through the
most luxuriant meadow with total impunity. The disease
then should rather be denominated grass-asthma than hay-
asthma, since hay seems incapable of producing it*

§ 29. Elliotson, who was also a contemporary of Bostock's,
argues forcibly against the views entertained by the latter,
and reviews his opinions at considerable length.-}- He, how-
ever, agrees with Bostock in believing that the disorder is
not caused by hay, but, contrary to what the latter affirms,
he believes it to ' depend upon the flower of grass, and pro-
bably upon the pollen/ Elliotson also contends that this
view of the case is supported by the circumstances that the
disease does not usually appear ' till the grass comes into
flower ; and as long as there is any flower remaining on the
grass the disease continues/

§ 30. In speaking of Bostock's account of his experience
in the Isle of Thanet, when he suffered very little from the
disease, and when the heat was so great that nearly all the
grass was dried up, Elliotson remarks : ' I can conceive that
a minute quantity of the emanations from the flower of

° London Medical Gazette, vol. iv., 1829, pp. 266 — 269.
t Ibid, voL viii., 1831, pp. 411—413.

A Review of iJie Opinions held on its Causes. 17

grass is sufficient to produce it — so minute that you can be
in few parts of the country at all, without the chance of its
reaching you through the atmosphere, emanating from some
grass or hay/*

§ 30. And again, in speaking of Bostock's experience
whilst staying at Kew, he says : ' Dr. Bostock mentions, as
another argument, that he was at Kew one summer when
there was a great deal of grass growing, but he did not then
have the affection severely. He mentions, however, that it
was a cold season, and in a cold season you are aware that
exhalations do not take place to anything like the extent
that they do in hot seasons. That, I think, would account
for the difference. But what makes me believe that it does
depend upon the flower is, that a lady has lately given me
an account of her own case, in which the symptoms appear
and gradually increase as the grass comes, more and more,
into flower, till at last they arrive at such an intensity that
she is obliged to leave home and go to the sea-side, and she
is always relieved by shutting herself up in a room.' f

§ 31. Dr. Elliotson also mentions that he had heard a
paper read at the Royal College of Physicians, on one occa-
sion, where the patient described suffered from hay-fever,
and was always seized with the symptoms of this disease
whenever she approached a field of sweet-scented grass. In
reference to this case he says : ' I do not know what kind
of grass produces hay-fever, but this would make it appear
that it arises from an emanation, for whenever the lady
approached a field of sweet-scented grass she was always
seized in this way.'

§ 32. Macculloch, who wrote in 1828, briefly refers to
hay-fever as a possible form of intermittent. J He speaks
of it as a well-known disease, and, as I have before stated,
says ' it is produced by hot-houses and green-houses, and in
the public estimation particularly by hay-fields.' He does
not, from the fact of hay-fever being a periodical catarrh,

* London Medical Gazette, vol. viii, 1831, pp. 411—413.
t Ibid.

X An Essay on the Remittent and Intermittent Diseases, by Dr.
John Macculloch, Loudon, 1828, pp. 394—397.

2

18 Experimental Researches on Hay -Fever.

mean to say that it must be, therefore, a mode of intermit-
tent disease, but he thinks, from the circumstance of its
' having a quotidian period and being the produce of heat
and vegetation, it at least presents features of analogy which
render it worthy of being noticed in his work, and also of
being more minutely studied ; as far, at least, as we can
investigate a disorder generally too trifling to attract much
notice/

§ 33. A paper published by Mr. T. Wilkinson King * is
chiefly remarkable for the manner in which the author
mistakes the true character of hay-fever, and for the way
in which it helps to confuse, rather than to clear up, the
subject in the mind of the reader. Mr. King had suffered
from the disease, he says, for about fourteen years, and
thought it worth while ' to set down his own conclusions,
together with an additional fact or two/ so that he might
' point to and confirm more general views of disease/ The
various causes of the local irritations as given in books,
Mr. King thinks are more curious than instructive, and,
after noticing the various conditions which affect asthmatic
patients favourably and unfavourably, he goes on to say :
' The preceding and countless vagaries are to be accounted
for by simple principles. (Vide a series of papers on
'Angina/ Medical Gazette, 1841.) We have to calculate
that according to circumstances, a certain number of hours
having elapsed after exposure (specific or general), eating or
lying down, capillary excitement or distention is to be
evinced by uneasiness, obstruction, and various forms and
quantities of secretion. Beyond this, we believe very few
of the phenomena of hay-fever or asthma will remain unre-
solved. The time at which the affections prevail is the
time of diminishing our clothing. It seems to me, in the
first place, not unreasonable to compare these affections with
summer eruptions .... I think I have, at different times,
experienced most of the symptoms described by Dr. Bostock,
but not only in summer. I am subject to slight attacks of

* ' On Summer Asthma, Catarrhus jEstivus, or Hay-Fever : its
Causes and Treatment/ by T. Wilkinson King. London Medical
Gazette, 1842— 1843, vol. ii. pp. 671—675.

A Review of the Opinions held on its Causes* 19

dyspnoea, especially on lying down, attended by a very slight
ropy and clear secretion in the trachea. ... I make very
little doubt, also, that these same catarrhal disturbances of
summer are of more frequent occurrence under a less distinct
form, namely, that of aggravation of affections which, in
some degree, the sufferer considers as habitual, and almost
natural to him. One cannot travel without incurring
ophthalmia, another asthma. Many suffer in particular
localities, or seem to require peculiar circumstances to secure
tolerable ease. The above considerations, and my own
experience, make me conclude that none of the affections
are positively and necessarily confined to any season, or such
a specific cause as hay or ipecacuanha/

§ 34. This writer evidently confounds ordinary catarrh
and asthma with hay-fever, and if he suffered at all from
the latter disorder he was labouring under a mistake in
supposing that it could come on at any time of the year
independent of any specific influence such as he names.
There is one point however which Mr. King notices in his
remarks, in another part of his paper which I have not
quoted, in which, although contrary to the opiuion generally
entertained, his observations will, I think, be found to be
very correct, so far, at any rate, as regards hay-fever. In
speaking of the structures affected in this disease, he says :
'I make some exception to the conclusions of Dr. Bostock,
that the air cells of the lungs are especially affected ; and I
prefer to set down the dyspnoea as the result of turgescence
in the lining membranes of the air tubes.'

So far as hay-asthma is concerned I hope to be able to show
that this view of the case is more in accordance with facts
than that which is generally held by the writers on hay-fever.

§ 35. Dr. G. T. Gream, who was also affected with the
disorder, did not believe that it was owing to any strictly
specific cause, and held that the farina (pollen) of grass had
' no more influence in causing the disease than that of any
other flowers/ He says : ' The dust from beaten carpets,
from the roads, and from other sources, produces the same
distressing symptoms/ He also further remarks, ' I am led
to think that in the middle of summer, from the end of May

2—2

20 Experimental Researches on Hay-Fever.

to the end of July, at which time hay-fever generally ceases,
a quantity of fine dust floats in the atmosphere, finer than
any which is in the air at other seasons, increased, probably,
by the farina of the mass of flowers at that period in bloom,
but that during the later and earlier months, the more
frequent rains, and the dews at night, prevent these particles
from leaving the ground, and I have been induced to suppose
that this reasoning is correct by finding that however dis-
tressing the symptoms have been during the day, they are
all entirely removed by a shower of rain : the face becomes
cool ; the irritation of the nostrils and the eyes ceases, and
does not return until the heated atmosphere has again
evaporated the fallen rain/* Here, again, we shall find that
although, in supporting his views, Dr. Gream is somewhat
wanting in that exactness and precision which should
characterise inquiries of this kind, he has hit upon one very
important feature in the phenomena of hay-fever, namely,
the influence which rain has in diminishing the intensity of
the symptoms.

§ 36. Dr. Ramadge speaks of hay-asthma as a variety of
ordinary asthma; but, in this form of the complaint, he
regards the exciting cause as being more obvious than that
of other forms of the disease, ' inasmuch as we can refer to
a sensible material object, the presence of which is known
to produce it, and the removal of which is sure to be followed
by its subsidence/ After detailing the symptoms of the
disease and giving examples of it, Dr. Ramadge goes on to
say : ' When we take these facts into consideration we need
not feel sceptical as to effluvia from the flowers of grass, the
odour of the bean-flower, &c, being the occasional cause of
the variety of asthma of which we are now treating/ f

§ 37. Dr. Hastings, in referring to hay-fever, says : 'The
disease, in its severest form, is common in June, about the
period of hay-making, and there can be no doubt but that in

* ' On the use of Nux Vomica as a Remedy in Hay-Fever/ by Dr.
G. T. Gream. Lancet, 1850, vol. i. pp. 692—693.

t Asthma, its Varieties and Complications, or Researches into the
Pathology of Disordered Respiration; with Remarks on the Treatment
Applicable to each Variety, by F. H. Ramadge, M.D. London, 1847.

A Review of the Opinions held on its Causes. 21

some peculiarly constituted persons, an emanation from bay,
the exact nature of which is unknown, occasions an attack
of the disorder/*

§ 38. Dr. W. P. Kirkman seems, so far as I can learn, to
have been the first patient who has tested, by an experi-
ment upon himself one of the supposed causes of hay-fever
— the pollen of grass. f He tells us that a day or two before
Christmas he noticed, in his hot-house for flowers, one single
plant of the Anthoxanthum odoratum in blossom, loaded
well with pollen. He thought it would be a capital oppor-
tunity for trying this particular grass, so he plucked it,
rubbed the pollen with his hand, and sniffed it up his nose ;
almost immediately it brought on sneezing, &c., and all the
symptoms of hay-fever, which continued for an hour and
then left him.

§ 39. Dr. (now Sir Thomas) Watson mentions this dis-
order in his lectures,^ and quotes the testimony of Bostock,
Gordon, and Elliotson. He also gives accounts of some
interesting cases of hay-fever which have come under his
own notice, but does not enter into any lengthened con-
sideration of the causes of the disease. In his concluding
remarks, however, after mentioning that the powder of
Ipecacuanha produces similar symptoms to those of hay-
fever in some persons, he says : ' These effects of a powdered
root and certain emanations from grass or hay lend weight
to the hypothesis which ascribes the influenza to subtle
vegetable matter floating in the atmosphere.'

§ 40. Dr. Walshe, in speaking of hay-fever, says : ' A
singular variety of naso-pulmonary catarrh, which has been
supposed to follow the inhalation of the aroma of the sweet-
smelling spring grass and hay (Anthoxanthum odoratum),
is known under the name of hay-asthma, hay-fever, or
summer catarrh. The complaint occurs only at the periods

* Treatise on Diseases of ike Larynx and Trachea, dec, by John
Hastings, M.D. Edin.

f Quoted from Dr. Phoebus' Typische Fruhsommer-Katarrh, p.
137.

X Lectures on the Principles and Practice of Physic, by Dr. Thomas
Watson. London, 1857, ?oL ii pp. 52— 5d.

22 Experimental Researches on Hay-Fever.

of hay-making, or when the odour of grass is powerful, and
is of exceedingly rare occurrence. The susceptibility to
these emanations, indeed, constitutes a very remarkable
example of unalterable idiosyncrasy. Persons who have
once suffered invariably have a return of the disease, if
exposed even in a slight degree to the specific cause. . . .
The most effectual means the habitual sufferer can command
of preventing the attack, is by removing at the season to
the sea-side, by getting out of the reach of the odours of
grass and hay. But so exquisitely sensitive to such sensa-
tions are some individuals that a land wind, blowing for a
few hours only, will bring on an attack even at the sea-
shore. Once the complaint is established, total abstraction
of the exciting cause will not put an immediate termination
to the seizure. I have had a very precise narrative of a
case in which the patient retained his symptoms during a
passage across the Atlantic/ *

§ 41. Dr. Hyde Salter, when treating of the annual
periodicity of asthma,t remarks that asthma occurring once

a year is almost always winter asthma ' There is,

however/ he says, ' one kind of annual asthma that is not a
winter asthma, but a summer asthma; and that is that
curious disease called hay -fever or hay -asthma. This
begins and ends with the hay-season, and varies in the time
of the year, according as the hay season is early or late. As
long as the grass is in flower it persists, with that it ceases.
Its visits are, therefore, restricted to about a month or six
weeks in the early summer. It is not constant throughout
this time as one attack, but comes and goes with those other
symptoms of irritation of the respiratory mucous membrane,
of which it is a part. The neighbourhood of hay, bright,
hot, dusty sunshine, a full meal, laughter, &c, suffice at any
time to bring it on. It often affects a sort of diurnal rhythm,
being generally worse at night. While this condition lasts
the asthma is often so severe as to deprive the sufferer of

* A Practical Treatise on the Diseases of the Lungs, Heart and
Aorta, by W. H. Walshe, M.D. London, 1854.

t On Asthma: its Pathology and Treatment, by Henry Hyde
Salter, M.D., F.E.S. London, 1859.

A Review of the Opinions held on its Causes. 23

sleep for nights together, and he leaves his bed in the
morning, pallid, blear-eyed, and worn out. When the hay
season is over every symptom vanishes, and for ten or eleven
months the patient may calculate on a perfect immunity
from even the slightest asthmatic sensation.'

§ 42. Amongst the examples which Dr. Salter gives are
the narratives of two cases which are interesting as well
as instructive. The patients each tell their own tale, and
this they do, in each case, in a very clear and graphic
manner.

The first case is what we should call a typical case of
hay-fever, or what Dr. Phoebus would say, was an example
of the ' whole disease.' When referring to the cause of the
disorder the patient says : — ' The country I never face in
the grass-flowering season, and have not for years. I have
long ago determined for myself beyond all dispute, that
this — the grass- flowering — is the cause of the malady.'

§ 43. In this case the patient tells us that the attacks
first came on when he was about eight years of age, and in
speaking of their commencement he says : ' I well remember
the first attack of those symptoms which, now more deve-
loped and more regular in their appearance, I recognise as
my annual hay-fever torment I was at the play-
work of haymaking with my young companions, surrounded
by newly mown grass, when I was suddenly seized with all
the eye and nose symptoms of hay-fever — profuse lachry-
mation, swelling of the conjunctivae and lids, with intense
ecchymosis, well-nigh blinding me, and ceaseless sneezing.
I recollect that I was taken into the house by my elder
companions, and speedily recovered. It was, however, about
the fifteenth year of my age before I was conscious of my
annual infirmity — before I understood that at every early
summer I was liable to sneezing fits if I ventured into the
country; but from that time to the present this tendency
has been abiding, has manifested itself every year, and has
always governed my habits and residence during the month

of June, and part of May and July I am now

usually first attacked by sneezing and lachrymation about
the middle of May, though this is much determined by the*

24 Experimental Researches on Hay-Fever.

nature of the season ; the warmer the weather, and the more
advanced the vegetation, the earlier does my malady show
itself. It usually lasts till the end of the first week in July
(when it leaves me very suddenly), though this also is
determined by the rapidity and shortness of the haymaking
season ; for in a hot, dry season, in which the hay is rapidly
made and carried, my immunity from trouble occurs a week
or ten days earlier.'

§ 44. The second case shows that hay-fever came on after
the patient had suffered from ordinary asthma for many
years, or that it must have been an accompaniment of the
latter disease, without the patient having been aware of it.
In commencing to describe the hay-fever symptoms the
patient says : ' It seems reasonable to suppose that I must
have been liable to hay-fever, at the ordinary season, during
the whole course of my life, but till within the last few
years I was never aware of its presence, or of the existence
of such a malady. From the frequency of my asthma, and
common colds in early life, it is probable that the recurrence
of asthma at a particular season, and the other symptoms of
hay-fever, were overlooked; and that when I became less
generally subject to asthma, the tendency to hay-fever
remaining, that complaint more distinctly declared itself;
or it may be that of late years I have become constitution-
ally liable to hay-fever — either more suspectible of the
influence, whatever it may be, or have acquired a constitu-
tion capable of evolving its symptoms I have

suffered most from paroxysms whilst taking country walks,
walking through grass meadows, and especially in one
particular garden surrounded by fields. The prevalence of
the influence in this locality i3 very remarkable, as there is
nothing peculiar in the neighbouring soil or its products.
J know one other locality where the influence is still more
excessive ; here there is an abundance of flowering grass
and rushes, the region is flat, the soil marshy, and in the
neighbourhood there is a great variety of indigenous vegeta-
tion. If the influence arises from the grass, it is not neces-
sary it should be cut and dried, that is to say, the presence
of hay is not essential.'

A Review of the Opinions held on its Causes. 25

§ 45. In the early part of the year 1859 Dr. Phoebus
{Professor of Medicine at the University of Giessen), who
had previously taken up the special study of hay-fever, sent
out a circular, which was published in various medical
Journals in this country and on the continent. The object
of the author, in sending out this circular, was to obtain
contributions on the pathology and therapeutics of the
disease, and to extend the knowledge of its literature.
Information was also sought on the following subjects : —

1st. On the geographical distribution of the disease.

2nd. On the ethnographical distribution of the malady
•(that is to say, as to whether it affected natives or foreigners
most in countries where it prevails).

3rd. On the influence of sex in predisposing to attacks of
the disorder.

4th. On the effect of social position and education in pro-
ducing a liability to the malady, and on the frequency or
non-frequency of its occurrence among the working classes.

5th. As to whether the persons predisposed to attacks of
this disease are distinguished by any marked peculiarities
which make this predisposition at once manifest; and, in
such a case, whether any such escape the attacks at any
time.

6th. Whether any difference, such as is named above, is
to be found in members of the same family, where one of
the family may be predisposed to attacks of hay-fever, and
•other members not predisposed.

7th. Whether it always occurs, in those who suffer from
it, at one particular time of the year, or at various periods
of the year.

§ 46. In the preliminary remarks to the questions, of
which only a summary is given above, Dr. Phoebus draws
•attention to the leading features of the disease, and particu-
larly to the circumstance of its showing itself exactly with
the first heats of summer. In this latter observation there
is, if not a little tendency to prejudge the case, at least an
-evident leaning to the theory of causation which the learned
author has since adopted. Of this I shall have more to say
hereafter.

26 Experimental Researches on Hay-Fever.

The circular of Dr. Phoebus called forth a number of
responses, and resulted in the accumulation of a mass of
very valuable information on the subject. Several medical
men on the continent, as well as several in America and in
this country, sent contributions to the various medical
journals, and to Dr. Phoebus, in answer to the inquiries
made in the circular.

§ 47. Dr. Cornaz, of Neuchatel, Switzerland, in answer to
the inquiries of Dr. Phoebus, published an interesting paper*
on hay -fever, in which he records the histories of six cases
with which he had become acquainted. After giving the
particulars of these, the author discusses the question of
nomenclature for this disease. On the whole, he prefers the
name ' catarrh/ because in all the cases which he describes
there was coryza, accompanied by catarrhal symptoms. The
author also prefers the denomination 'de foin' (of hay) to
that of ' d^t^ ' (of summer), and the reason given for this
preference is, that in each of the six cases, the flower of
grass seems to be the agent which brings on the attacks.
At the same time, however, Dr. Cornaz affirms that hay,
when being gathered, will bring on the disorder, although
to a less degree than the flower of grass. The last-mentioned
of these terms (d^t^) Dr. Cornaz thinks might, in some
respects, be considered an appropriate name, inasmuch as it
has the very important advantage of not appearing to pre-
judge the cause of the ailment; but this advantage is, to
some extent, counterbalanced by the circumstance that the
name ' summer catarrh ' (catarrh d'6b£) is given to a disease
which often sets in before summer has fairly commenced.
On the other hand it is admitted that the term ' de foin ' is
also open to objection, inasmuch as it is applied to a disorder
which is known to lessen in severity, if not altogether to
disappear, when grass has been converted into hay; and
also because it is well known that, in some cases at least,-
the pollen of cereals has the same influence in bringing on
the symptoms.

* ' De l'Existence du Catarrhe des Foins en Suisse.' — 12 Echo Midi-
cale, No. 7, July, 1860.

A Review of the Opinions held on its Causes. 27

§ 48. Dr. Longuevilie,* who wrote an account of his own
case in answer to the inquiries of Dr. Phoebus, tells us that
he suffered from attacks of ordinary asthma, and says he
also found that proximity to hay was sure to bring on similar
attacks ; but he did not consider that in the symptoms which,
in his own case, followed those attacks which were caused by
hay, there was anything which would warrant the designa-
tion fever.

§ 49. Dr. Labosse, of Nitry, wrote an articlef in reply to
the observations of Dr. Longuevilie, and took the latter
somewhat sharply to task for his statement ' that there is
not anything which should be called " fever" in the symp-
toms brought on by hay/ The former gentleman says we
may have the feverish symptoms well characterised in hay-
asthma, and he believes that the attacks of asthma from
which Dr. Longuevilie suffered were widely different, in
their symptoms, from true hay-fevep or hay-asthma. Dr.
Labosse had seen three persons who were annually attacked
by this disorder, and in each case the symptoms were cough ,
dyspnoea, coryza,and injection of the conjunctivae ; and these
began to come on precisely at the period when the natural
or artificial meadows were in blossom, lasted as long as the
time of blossoming, and returned periodically, every year,
in those individuals who were subject to the disease.

In these observations we have the influence of the period
of blossoming clearly pointed out, and it seems that in the
case of the patient (a farmer) whose symptoms are here
given, the influence of heat had never been supposed by
him to have much to do with the occurrence of the attacks.
It is also especially worthy of notice that whenever the
saintfoin (the herb with which he fed his sheep) had gone
beyond the period of flowering, to the ripening of the seed,
the patient could handle it without bringing on any un-
pleasant feelings, or any of the symptoms of hay-fever.

§ 50. Dr. Laforgue, of Toulouse, in a paper which was

• Of France, but of what city or town I have not been able to
ascertain.— C. H. B.

t ' Nouvelle Observation de Catarrhe de Foin.' — L'Abeille M/dicale,.
August 20, 1860, p. 270.

28 Experimental Researches on Hay-Fever.

also published in answer to the inquiries contained in the
circular of Dr. Phoebus, gave an account of two cases of
hay-fever which hod come under his own notice.* In one
of these cases the patient is said to have always enjoyed
excellent health during the cold weather, with the exception
of an occasional attack of coryza, which, however, was never
attended with any difficulty of breathing, or any of the
symptoms of asthma. As soon, however, as the warm
weather set in, she always began to suffer from coryza, and
after a short time her breathing would become impeded, and
as long as the warm weather continued she suffered severely
from both the catarrhal and asthmatic form of hay-fever;
and, in spite of all the means used to prevent these attacks,
or to moderate their severity when Once developed, the
malady returned regularly every summer.

Dr. Laforgue thought that in this case heat was the
exciting cause, and in concluding his remarks on this
patient, he says : • The great heat of the last summer strongly
affected Mdlle. X — ; beginning with coryza, the cold (rhumes)
has become such intense spasmodic bronchitis, that the
dyspnoea has for several times shown a threatening character.

This observation, methinks, enters well into the

category of the facts collected by Dr. Phoebus, of Giessen.
It furnishes a good example of those catarrhal affections
which, developed under the acting influence of heat, present
all the symptomological characters of asthma.'

§ 51. In an anonymous paper published in one of the
French medical journals,f the author of the article, in
describing bis own case, expresses a very decided opinion
on the cause of the attacks. In speaking of the effects of
heat he says : ' The heat has no extraordinary effect upon
me ; I suffer from it as anybody else does, but I do not feel
any symptoms which may remind me of hay-fever. The
hay being safely stored away, my pocket-handkerchiefs
remain undisturbed until the following year; they only

* * Observation de Catarrhe d' et6* par M. le Docteur Laforgue de
Toulouse. V Union M/dicale, No. 149, 17th December, 1859.

t * Un dernier mot surla Fi&vre de 'Foin.'—L > AbeilleMSdicale,21fit
May, 1860.

A Review of the Opinions held on its Causes. 29

serve me for wiping my forehead during the heat of summer.
.... After the hay is gathered in, the heat or atmospheric
changes do not bring on, afterwards, any attack of coryza.
Having the head only very lightly covered, the heat, how-
ever excessive it may be, does not trouble me any more than
it does other people. But when hay-making is going on, at
a time when it is much less warm than in August, I suffer
in the most severe manner. I do not believe in an atmos-
pheric cause or coincidence in regard to hay-fever attacks.
I have collected many proofs respecting the effect of hay on
my head in different countries which I have visited.'

§ 52. Dr. Phoebus, to whom we are indebted for bringing
together and putting into an available form all that was
known of hay-fever up to the time he wrote, has pursued
the inquiry into the causes of the disease with a care and
minuteness which is quite characteristic of the mode in
which the German mind deals with obscure and little-known
subjects. No phase of this curious disorder has escaped his
scrutiny, and such has been the result of his labours that
we may say with justice that we owe to him the creation
of a considerable portion of the literature of hay- fever.

This question of cause is confessedly one of the most
difficult parts of the subject with which we have to deal, but
whilst it is desirable that we should enter into every phase
of it with the greatest care and circumspection, it is never-
theless true that the process of refinement and subdivision
may be carried too far, and in our anxiety to get hold of
and to examine minutely every possible cause of the disorder
we may fail to recognise the true cause, and may spend our
time in the examination of those things which have no
relation whatever to the malady, and which a more simple
and logical method of viewing would have put out of court
altogether.

§ 53. If we have any fault to find with the way in which
Dr. Phoebus has done his work, it is with the over-refine-
ment which characterises that work, and the want of a
more rigid process of elimination in considering its causes.
An example of this latter fault is to be found in the refer-
ence which has been made to ozone as a cause of hay-fever,

SO Experimental Researches on Hay-Fever.

by Dr. Phoebus. Although this substance has been supposed
to be a possible cause of the malady, it is well-known to all
who have paid any attention to its treatment that no method
of cure or prevention is more successful than that of sending
the patient to the very spot where ozone is most abundant
and most constantly to be found, namely, to the sea-shore.
With this part of the subject, however, I shall deal in
another chapter.

The great amount of time and labour which Professor
Phoebus has expended upon the investigation of this disease
entitles his opinions to be received with respectful attention ;
but at the same time the conclusions he has arrived at
demand a careful examination, because, as he has embraced
a wider range of causes of the malady than most other
authors, he has, as a consequence of this, increased in a
corresponding ratio the possible sources of error ; and more
especially because subsequent writers seem to have been
largely influenced by the opinions he holds.

§ 54. Like all other writers, Dr. Phoebus makes predis-
position to be the starting point of the disorder, but in
what part of the system this predisposition has its seat he
does not attempt to decide; and he thinks that between
those who exhibit a liability to its attacks and those who
are free from such liability, no well-marked line of separa-
tion exists. Almost all temperaments and all states of the
system, from feeble to robust health, are to be found
amongst hay-fever patients. Curiously enough, however,
Dr. Phoebus suggests that the predisposition may not be
present during the whole year, but may 'repeat itself
annually at the season of the attack/ and that it may
possibly be produced in some unknown manner by the
action of one or more of the exciting causes. He also
thinks it possible that the disease may be present in a
latent state before it first shows itself, and consequently
there is no necessity for considering the first attack as the
commencement of ' the whole disorder/ For the same
reason we may imagine the disease to be present in a latent
state during the intervals in which the patient is free from
any visible signs of it ; and it may also be further supposed

A Review of ike Opinions held on its Causes. 31

that variations in the conditions of the separate organs may
possibly be a cause of the attacks having a somewhat inter-
mittent character — occurring on one day and not on another
— during the season when the disease prevails.

§ 55. These views imply a possibility of the predisposi-
tion having been in some cases essentially of a temporary
nature, but this is believed to be warranted by the analogy
which exists in other diseases of a nervous character ; but,
as the author (Dr. Phoebus) remarks, ' in no other disease in
so constant and logical a form as in hay-fever.' One thing,
however; is considered certain, namely, that when once a
patient has had an attack, this leaves a condition of the
system which, to a certainty, leads to others.

It will be seen that these opinions of the modes in which
the predisposition may vary in its manifestations are some-
what complicated, and also a little conflicting, but as some
of the facts I shall have to communicate have an important
bearing upon the opinions here advanced, I shall not enter
into any lengthened consideration of them at present.

§ 56. Professor Phoebus places the exciting causes under
three heads: viz., 1st. Causes of each single attack. 2nd.
Causes of exacerbations. 3rd. Causes of the variations of
the groups arid of other variations .* It is with the first
and second of these I shall have principally to deal, and if
we succeed in demonstrating the cause of each single attack,
in any one year, we shall have made some advance towards
discovering the second cause named, and probably there will
not be much difficulty in showing that the causes of each
single attack and of the exacerbations are, with very rare
exceptions, one and the same. The third cause is more
complicated, and will not be so easily cleared up until more
research has been devoted to it than has yet been expended
upon it ; indeed, in the present state of our knowledge, the
causes of the mode in which the agent acts, and the reason
why it sometimes acts upon one organ and sometimes upon
another, may long remain hidden from us.

* Dr. Phoebus has also divided the symptoms of the disease into
groups, according to the part principally affected, viz., into Nose
Group, Eye Group, Throat Group, Chest Group, <fec. ; of the&fc &v*\-
sions I shall have something to say further on.

32 Experimental Researches on Hay-Fever.

§ 57. In considering the evidence which has been brought
in favour of the various substances which have been already-
noticed as being the active agents in producing hay- fever.
Dr. Phoebus draws attention to the fact that some authors
and some patients accuse one agent and some another ; but
no one, he says, 'has accused these agents en masse ; and,
although some experiments have been tried with one or
another of these, no one has yet pursued a systematic course
of experiments which, on the one hand, would prove that
the presence of any given noxious agent (or supposed
exciting cause) was always followed by an attack of the
disorder; and, on the other hand, that the absence of this
same agent has always given complete freedom from the
attacks. Another source of error, Dr. Phoebus thinks, lies
in the circumstance that ' as soon as one of these noxious
agents has caused its effect, the symptoms of the intensity
of the disorder have shown themselves immediately/ and it
has almost always been overlooked that the symptoms of
' the stage of development ' had already preceded these, and
the patients have thus taken the more complete form of the
disease for the beginning of it. ' If people in future/ he
says, ' will be more attentive and especially observe more
than one patient carefully, the author does not doubt that
the accusation against these noxious agents will, in greater
part, fall to the ground/

§ 5K. Whilst recognising the fact that the attacks of hay-
fever occur during the time that the greatest number of the
natural and artificial grasses are in bloom, and that the
duration of the disease is synchronous with the period of
flowering, Dr. Phoebus thinks that the proofs which some
authors have brought have shown ' that this or that noxious
agent of the grasses is not the only cause of the access,
obvious in all cases/ and with regard to these he says:
' Such proofs were formerly very desirable, but have now
lost much in value, for we now know that more than one of
these noxious agents is accused, with apparently good
reasons, whilst the first heat of summer, however, is a
stronger cause than all the grass emanations put together/
He then goes on to say : ' I have already shown that the

A Review of the Opinions held on its Causes. 33

supposition that the attack begins with the first heat of
summer, and that its occurrence depends on the latter, is
supported by numerous and important authorities far more
than the assertions which give the following as the causes :
A, the common grass blossom ; B, the beginning of grass
being generally in flower ; C, any blossoming grass not in
too small a quantity; D, the first blossom of the sweet-
scented spring or vernal grass ; E, the blossom of rye ; F,
hay ; G, roses in bloom ; H, pollen of all blossoms ; I, dust
in general/

§ 59. In concluding his observations on this part of the
subject Dr. Phoebus says : — ' From what is said in the pre-
ceding paragraphs, I think myself justified in drawing the
following conclusions: 1st. Nobody has yet succeeded in
showing with certainty the exciting causes of each single
attack. 2nd. With probability the following circumstances
(momenta) may be accepted as such causes : A, the first heat
of summer (which, however, only acts in an indirect manner
as an exciting cause) ; B, the longer days (which act, per-
haps, through the stronger influence of light, or, perhaps,
also through ozone) ; C, the same (or nearly the same) odours
and different kinds of dust which we positively know as
causes of exacerbations of the attacks. Amongst these hay
and the blossom of rye have the greatest probability in their
favour. 3rd. It may be possible that one of these causes is
the only true one, and that the facts in regard to the other
causes have been falsely understood. It is more probable,
however, and the after access especially speaks in favour of
the supposition, that all these influences act as exciting
causes of the attacks.

' Some patients might be susceptible to only a part of
these influences. I do not doubt that future and more
accurate observations, especially comparisons of the pheno-
mena of the disease with the meteorology and vegetable
phenomena, will bring certainty instead of probability and
possibility merely/

§ 60. The English medical authors, and also one of the
American authors, who have written on hay-fever since the
work of Dr. Phoebus was published, have, to a considerable

% 4

34 Experimental Researches on Hay-Fever.

degree, followed his teaching, and, with some modifications,,
have arrived at much the same conclusions with regard to the
nature of the causes ; but, in some cases, they have gone
further, and have expressed the opinions he holds in a much
more decided manner than he himself has expressed them.

Dr. Abbotts Smith, whose work* has passed through four
editions, gives numerous cases in which the exciting cause
of the attack seems to have been the emanations from grass
and other flowering plants. He also states 'that strong
light as well as great heat will induce or aggravate the
symptoms ;' but he does not believe that the ozone theory
of Dr. Phoebus is sufficient to account for the attacks, or the
exacerbations of hay-fever.

§ 61. Dr. Smith mentions that M. Vogel, many years
since, ascertained that benzoic acid exists in two of the
grasses, which, by some authors, are considered to be the
most important agents in the production of hay-fever,
namely, the Anthoosanthum odoratvm and the Holcus
odoratus, and he suggests the question ' whether hay-fever
may not, in some degree, especially when it arises in persons
who are affected by the aroma of grass or hay, be attributed
to the irritating effects of benzoic acid, which is liberated
from the above-named grasses by the agency of summer
heat/ In support of this idea he says, ' It may be observed
that the attacks of hay-fever are almost invariably worse
during the continuance of hot, dry weather, while they
generally assume a milder character in wet weather, or
when the temperature is much reduced; at these latter
periods the sublimation of the benzoic acid, contained in the
flowers, would be less than in hot weather.'

Dr. Smith states that he has been informed by Messrs.
Davis, Macmurdo and Co., manufacturing chemists, 'that
the inhalation of the vapour which incidentally escapes
during the sublimation of benzoic acid, causes considerable
irritation of the throat and violent paroxysms of sneezing
and coughing.'

§ 62. One case is given by Dr. Smith, which he thinks

• On Hay -Fever, Hay- Asthma, or Summer Catarrh, by Wm.
Abbotts Smith, M.D. 4th edition. London, 1866.

A Review of the Opinions held on its Causes. 35

* bears upon the fact that the smell of decomposing vegetable
matter is sometimes the cause of this affection.' The patient
says : ' I was occupied in adding fresh water to some flowers
in a vase, in which the water had been standing several
days, and was foul, and as I poured it away my annual
visitor came on.' In reference to this case, I have to remark
that it is surprising how easily facts may be misunderstood,
and wrong inferences drawn from them. It was a similar
incident that occurred to myself, many years ago, which
first drew my attention to the real nature of the cause of
the malady.

§ 63. Another case is given by Dr. Smith as an example
of the effects of heat. The patient had resided for seven
years at the sea-side, and, from his experience whilst residing
there, considered that his case quite agreed with that of
Dr. Bostock, in not being dependent upon the smell of hay,
' but merely on the approach of really hot weather. This
year (1865)/ he says, ' the disease first came on, whilst I
was on the sea yachting with a friend. It was a hot day in
May, with the wind from the south-west, the nearest land to
windward being nine miles distant. I felt myself, after
some exertion in assisting to hoist the sails, suddenly seized
with sneezing, and I have had it ever since/ (The date of
the letter was June 13th).

After noticing the causes spoken of by Dr. Phoebus, Dr.
Smith says: 'Each of the principal causes just enumerated
has, doubtless, much to do with the causation of summer
•catarrh ; and, as in all other affections, sometimes one, some-
times another, cause may preponderate / but he afterwards
adds, ' the majority of sufferers from this disorder, attribute
their illness to the presence of ripe grass or hay in their
immediate neighbourhood/

§ 64. Dr. Pirrie* thinks that there are two distinct forms
of the disease. He notices the circumstance that the
emanations from ripe grass and some other plants, in flower,
are recognised as the grand causes of both the catarrhal and
the asthmatic form of the disease ; but he says that cases

* On Hay- Asthma and the Affection termed Hay -Fever, by Win.
Pirrie, M.D. London, 1867.

36 Eocperimental Researches on Hay-Fever.

have come under his own notice where the sufferers have
attributed their indisposition ' to solar heat and intensity of
light/ and his own observations lead him ' to conclude that
sufficient importance has not been attached to their opinions
on this point/ One form of the disorder Dr. Pirrie regards
as spasmodic in character, exhibiting its effects on the mucous
membranes of the respiratory tract, and as being caused by
subtle volatile emanations from flowering plants acting upon
the nervous filaments distributed to these membranes. In
some cases, he thinks the disorder may also arise from
irritation of the filaments of other nerves, or it may be
caused by a ' primarily tumid and swollen state of the lining
membranes ' (of the air-passages), such as heralds in attacks
of measles or common catarrh. In the other form of the
illness it is thought that the cause does not operate directly
upon the mucous membranes, or upon the nervous filaments
distributed to these, 'but on certain nerve centres of the
cerebro-spinal and sympathetic system/

§ 65. In the first form of the disease, Dr. Pirrie says, a
change of residence and the use of other remedial measures
are mostly followed by speedy relief. In both forms of the
illness we may have severe catarrhal and pectoral symptoms ;
but in the latter, ' the vascular relaxation and the associated
nervous paresis are the results of the debilitating effects of
great solar heat, assisted in many cases by intense light, on
the cerebro-spinal and sympathetic systems, of certain pecu-
liarly constituted people/ Dr. Pirrie also gives cases which
seem to favour the idea that in these the ailment was due
to the action of solar heat and light. Into the consideration
of these I shall not enter at present.

§ 66. Dr. George Moore* holds much the same opinions
of the symptoms and causes of the disorder as those held by
the two last writers I have mentioned. He, however,
expresses his opinions in a little more decided manner than
these writers have expressed theirs ; or, to put it in a more
definite form, almost everything in relation to this disorder
is a settled thing. The causes are with him clear and

* Hay- Fever, or Summer Catarrh : its Causes, Symptoms, Preven-
tion and Treatment, by George Moore, M.D. London, 1870.

A Review of ike Opinions held on its Causes. 37

definite, and the symptoms are placed before the reader in
a precise and exact manner. Like the writers above men-
tioned, Dr. Moore believes the disorder is, in some cases,
caused by solar heat and light; in others by the effluvia
from hay, or by the emanations from other flowering plants,
and from those of decaying vegetable substances.

§ 67. Dr. Moore quotes Dr. Bostock's case as an example
of that form of the disease which is caused by great heat
and strong light, and he tells us that, in these cases, * sea-
voyaging, out of the reach of putrescent and other effluvia,
affords no protection or exemption/ He, however, does not
give us the particulars of any cases of the disorder which he
has himself had the opportunity of watching, or of which he
has obtained the histories. It is to be hoped that in a
future edition of his brochure, Dr. Moore will be able to
supply the details of cases with which he has become
acquainted, and particularly of such as have any bearing
upon the question of cause.

§ 68. Another supposed cause of hay-fever is alluded to
by Dr. (now Sir William) Gull in his Harveian oration,
delivered at the Royal College of Physicians, June 24th,
1870. It was stated by Helmholtz, that vibriones had been
found in the nasal mucus of patients suffering from this
disease. In reference to this supposed action of vibriones,
Dr. Gull says : ' No new fact bearing on the propagation of
contagious disease has been reached by the recent investi-
gations on dust ; nor can we infer the nature of summer
catarrh because the nasal mucus, under such circumstances,
and at no other time, was found peopled by vibriones, since
decomposing mucus is always populous with this common
race of infusoria/

§ 69. A most remarkable example of a supposed cause of
hay-fever is given by Dr. Charlton Bastian. It was whilst
working at the anatomy of the Ascaris Tnegalocephala (one
of the parasites of the horse) that Dr. Bastian thought that
emanations from this parasite had the most decided and
poisonous influence upon him, and this not only when the
animal was in a fresh state, but after it had been preserved in
methylated spirit for two years, and even then macerated in.

38 Experimental Researches on Hay-Fever.

a solution of chloride of lime for several hours before it was
submitted to examination. In his account of this occur-
rence, Dr. Bastian says : ' I first examined this species in the
spring of 1863. The effects were a greatly increased secre-
tion from the Schneiderian membrane, with irritation of it,
causing continued sneezing, irritation of the conjunctiva,
itching about the eyelids, and caruncula lachrymalis; great
desire to rub them. Rubbing immediately gave rise to a
swollen and puffed condition of the eyelids, swelling of the
caruncula, and extreme vascular injection of the conjunctiva ;
if the rubbing was persisted in, actual effusions of fluid
would take place under the conjunctiva, raising it from the
subjacent sclerotic and cornea (?). A few minutes would
suffice to produce these serious effects upon the eyes ; but
after a little bathing with cold water and a rest in a re-
cumbent position for a couple of hours, they would again
have resumed their natural condition. At the same time
that these effects were produced upon the mucous mem-
brane, the skin of the face and neck was also affected, so as
to cause a sensation of itching, something similar to what

exists in a mild attack of nettle-rash My system

became, at length, so sensitive to the emanations from this
animal, that I was even unable to wear a coat which I had
generally worn during these investigations, without con-
tinually sneezing, and suffering from catarrhal symptoms.
In two months the symptoms ceased, and did not return
till next May, when it continued six weeks into June.
Dr. Schneider and other anatomists were not affected in
this manner.' *

§ 70. In 1870 Mr. William Wright Wilson read a paper
before the Birmingham Queen's Hospital Medico-Chirurgical
Society, entitled ' Notes on British Poisonous Plants.' In
the notes on aconite, remarks are made which in part cor-
roborate the statements I make on the mode in which
pollen gives rise to hay-fever. When I come to treat of the
manner in which pollen disturbs the normal action of the
respiratory mucous membranes, I shall take the liberty of
referring to these remarks again.

* Philosophical Transactions, vol. clvi., 1866, note to p. 583.

A Review of the Opinions held on its Causes. 39

§ 71. The work of Dr. Wyrnan* is an exceedingly valuable
contribution to the literature of hay-fever. The author
deals with some questions I have not touched upon in the
first edition of this work. One of these is the hereditary
character of the disease. Another interesting point which
Dr. Wyman dwells upon, is the geographic and ch orographic
relations of the malady. To a consideration of these sub-
jects I shall return in another place.

Although himself a sufferer from the disease, Dr. Wyman
does not seem to have any settled and exact opinion of the
nature of the cause. The difficulties which surround the
subject seem to him to be too great to allow of the question
of cause being definitely settled.

The disease is said to commence in America at two
different periods — in the month of June, as rose cold, hay-
cold or June cold, and in the month of August as autumnal
catarrh. According to a more recent writer (Dr. Beard),
it is said to commence at three different periods — June,
July, and August. The symptoms of the malady as seen at
these different periods, are essentially the same in their
character, and if they differ at all, it is in their in-
tensity.

§ 72. Like other writers on hay-fever, Dr. Wyman makes
individual predisposition the starting-puint ; but he believes
'there is no peculiarity of constitution, furm, or condition
observed in those predisposed.'f He also thinks the
autumnal catarrh of the United States does not exist in
Great Britain, and in support of this opinion he gives a
number of cases in which the patients (Americans who
suffered from autumnal catarrh at home) travelled in Great
Britain during the critical period — August and September —
but had no attack of catarrh. This was also the case with
some whilst travelling in France, Switzerland, and Germany.
Dr. Wyman holds that American autumnal catarrh is not in
any case produced by hay or by grass in flower, inasmuch

* Autumnal Catarrh (Hay-Fever), by Morrill Wyman, M.D. Late
Hersey Professor Adjunct of the Theory and Practice of Medicine in
Harvard University. New York, 1872.

t Ibid ., p. 87.

40 Experimental Researches on Hay -Fever.

as the hay is generally made one or two months before the
catarrh comes on.

§ 73. In speaking of the causes of the paroxysms of the
catarrh, Dr. Wyman mentions the following : the dust and
smoke of a railway train ; the dust of the highways ; strong
light and sunshine ; the odour of flowers, especially that of
a full-blown rose ; the smelling at, or the eating of, fruits of
various kinds. With some patients Indian corn (maize),
when in flower, produces sneezing and other signs of hay-
fever; but the plant that brings on the most decided
symptoms of the disease is the Roman wormwood (A mbrosia
Artemisicefolia). This plant commences to flower about
the middle of August, or a little later, and continues to
flower till late in September. 'An approach to it/ Dr.
Wyman says, ' will, during the critical period, produce a
paroxysm with a very large number of persons. This, with
the fact that its flowering corresponds with the critical
period, lends strength to the supposition that it may be the
real cause. It grows very generally in those regions where
the disease exists, and most luxuriantly near the sea-coast.
It grows very sparingly in mountainous regions, and is
there generally short and feeble/ Most causes of paroxysms,
like fruit and flowers/ Dr. Wyman tells us, ' cease to pro-
duce their specific effects with most persons in non -catarrhal
regions. With this plant it is not so; a majority of those
exposed to it experience a paroxysm nearly as severe in the
one region as in the other. On the other hand, it has been
planted in February, has flowered in July — a full month
before the ordinary time of catarrh — kept in the sleeping
room of a subject of the disease, while in flower, without
effect. It has also been gathered with care when in full
flower and sniffed late in February, also by a subject ; it
was followed in one experiment by some stuffing of the
nostrils, and discharge of a limpid fluid, but perhaps no
more than might follow any other irritation of the nasal
mucous membrane ; in another it had no effect.' *

§ 74. At a meeting of the French Academy on August
25th, 1873, M. Decaisne gave the results of eight years

* Autumnal Catarrh, by Morrill Wyman, M.D., pp. 101, 102.

A Mevietv of ilie Opinions held on its Causes. 41

study of hay-asthma or hay-fever. His conclusions are as
follows : 1. This affection seizes indifferently those who are
exposed to emanations from forage plants, and those not so
exposed. Without absolutely denying the influence, in
some cases, of such emanations, as aggravating the disorder,
their part is to be considered merely a secondary one.
2. All the symptoms appear at any season, in consequence
of insolations and coolings, the body being in a state of
perspiration; and they specially occur in emphysematous
persons, exposed to irritant powdery emanations. 3.
Annual periodicity does not appear proved ; most of the
subjects observed having sometimes remained several years
free from the disorder. 4. As to dyspnoea, generally re-
garded as a pathognomonic symptom of hay-fever, it seems
to be merely the extension, more or less marked, of irritation
affecting the conjunctiva and the nasal and pharyngea.
mucous membrane, as often occurs in influenza, without
indicating a form of idiopathic asthma, o. The affection is
to be regarded as a catarrhal fever, influenced in its cause
and progress, and according to individual constitution, by
the atmospheric conditions which produce acute affections
of the bronchi. 6. It should be struck out of the nosological
category.

As I proceed I shall be able to show that the conclusions
of M. Decaisne, are in nearly every case opposed to those of
almost every writer on hay-fever, and that it is highly
probable that he entirely misunderstood the disease of
which he was speaking.

§ 75. The most recent systematic work on hay-fever, with
which I am acquainted, is the work of Dr. Beard, to which
I have before alluded. The author is not himself a sufferer
from the malady, and it was, he tells us, only in the autumn
of 1873 that ' the subject was first forced on his attention,'
while spending a portion of a vacation in Bethlehem, White
Mountains — a place of resort for patients during the critical
period. A circular, containing interrogations on the subject
of hay-fever, was drawn up, and was sent out to patients.
The answers contained in these circulars when returned
were tabulated, and along with the conclusions drawn from

42 Ea^pervmentaZ Researches on Hay-Fever.

them are given in the volume. Thus, in a little more than,
thirty months, the author had collected his information, had
obtained some experience of the disease, and had written
and published his work upon its nature and treatment.

Dr. Beard is a member of two neurological societies, and
seems to think it quite correct to place hay-fever among the
neuroses. In treating of this part of the subject, he says :*"
'Hay-fever is essentially a neurosis — that is, a functional
disease of the nervous system The debilitating in-
fluence of heat and the external irritation of a large number
of vegetable and other substances, are exciting causes
merely, widely varying in their effects with different in-
dividuals, and of themselves are powerless to induce, or at

least to sustain, an attack As the disease is not due

to any single specific cause, animal or vegetable, as has been
supposed, no specific will ever be found for it.'

§ 76. The question which relates to the cause of the
malady, the author tells us, ' was prepared after the first
edition of the circular of inquiry, and the names of the
exciting causes were taken from the replies to that circular.
In this question the patients are asked : s Which of the
following causes are most likely to excite the paroxysms ?'
Cinders ? Out-door dust ? In-door dust ? Roses ? Other
fragrant flowers ? Fresh hay ? Old hay ? Smoke ? Gases ?
FovZ air? Pollen of corn? Bright sunlight? Bright
gaslight ? Camphor, hartshorn, and ether ? Fruit of any
hind ? Dampness ? Sudden chills ? Night air ? Per-
fumes of any kind ? Over-exertion ? Brimstone matches t
Indigestion ? Roman wormwood ? " Sneeze-weed " ? Are
there any other causes that excite the paroxysms in your case?*

' The three facts of most significance that are brought out
by this inquiry/ Dr. Beard tells us, ' are : —

'1st. That the number of special exciting causes of hay-
fever is very large. Over thirty are here specified.

'2. Hay, either fresh or dried, only comes about the
middle of the list, while dust leads off by a large plurality.
The disease might be more appropriately termed dust-fever
or sun-fever than hay-fever.

* Ray-Fever, by Dr. Beard, pp. 77, 78.

A Review of the Opinions held on its Causes. 43-

' 3. In few, if any, cases are the symptoms excited only
by one agent. Usually two, three, or more of the above
causes are cited, and some declare that all on this list are
obnoxious/

§ 77. It would occupy too much of my space to give all
the answers in detail, but as some of these have an im-
portant bearing upon remarks I shall have to make upon
this part of the subject, I must briefly notice some of them.
We find that dust (in-door and out-door) is credited with
being the cause in 104 cases ; sunlight in 48 ; gaslight in
36 ; (Anders in 23 ; chills in 25 ; brimstone matches in 23 ;
gas in 23. The remaining patients are distributed in vary-
ing proportions amongst the other causes named.

Two other important questions I must also notice before
I pass on. The first of these relates to the time at which
the attack comes on, and the second to the time at which it
ceases.

By the replies to the first question, we find that out of a
total of 198, 142 patients have their attacks commencing in
the month of August ; 10 in the month of September ; 8 in
the month of May ; 19 in the month of June ; and 19 in the
month of July. There is a total of 162 patients who sent
in replies on the time at which the attacks ceased ; we find
that in 135 cases the attacks terminated in September or
October. On all these points I shall have some observations
to make further on.

§ 78. A very valuable contribution to the literature of
hay-fever was made by Dr. Elias J. Marsh in 1877, in a paper
read before the New Jersey State Medical Society.* The
writer (Dr. Marsh) has been a sufferer from this disease
since childhood, and has had it in all grades of severity,
from a troublesome coryza to a spasmodic asthma. For
many years he did not ascertain, or even suspect, any
special cause, but he thought it was in some way connected
with vegetation. A voyage in 1865 arrested the disease.
About 1870 his attention was called to the ragweed
{Ambrosia artemesicefolia) as a possible cause of the malady,

* Hay -Fever, or Pollen Poisoning, an" Essay read before the New
Jersey State Medical Society, by Elias J. Marsh, M.D., of Paterson,.
Newark, U.S., 1877.

44 Experimental Researches on Hay-Fever.

although he had not previously known the plant even by-
name. In 1875 and 1876 Dr. Marsh made experiments on
the plan I pursued, aad recommended in the first edition of
this work. The experiments gave most important results.
These I shall notice more in detail, when I come to speak of
the action of pollen, and of its presence in the atmosphere
during the hay-fever season. In summing up his con-
clusions, Dr. Marsh says: 'From these investigations the
writer has formed the opinion that autumnal catarrh, like
the English hay-fever, is caused by the presence of the
pollen of flowering plants in the atmosphere, and its irri-
tant action on the respiratory mucous membrane of suscep-
tible persons/

§ 79. I have now to notice one of the most remarkable
contributions I have ever met with on any scientific or
medical question. It is in relation to the supposed cause of
hay-fever mentioned incidentally at § 68. Professor Helm-
holtz, who has the misfortune to be a sufferer from hay- fever,
had the impression that it was caused by certain vibrio-like
bodies, which he found in the nasal mucus during the
prevalence of the disease, but at no other time. Receiving
from Professor Binz, of Bonn, some observations on the
poisonous action of quinine upon infusoria, he determined to
try some experiments on the supposition that the described
vibrios, if they did not give rise to the disease as a whole,
might, by their motions and by their products of decomposi-
tion, make it much more uncomfortable. A saturated
solution of quinine was injected into the nostrils, and
.appeared to give relief each time it was used. On the
presence of the vibrio-like bodies, and on the action of
•quinine upon these, I shall have something to say when I
come to speak of the changes which pollen undergoes in
contact with the mucous membranes of the nasal and other
cavities. The above is, however, merely introductory.
Professor Binz had been at considerable trouble in spreading
the knowledge of Professor Helmholtz's supposed cause of
hay-fever, and its imagined cure by quinine, and judging
from the tone of the paper from which I am about to quote,
•the principal object of making the experiments there

A Review of the Opinions lield on its Causes. 45

described, was to endeavour to disprove the correctness of
the conclusions I have arrived at on the cause of hay-fever.
§ 80. Dr. G. F. Patton, of Mississippi, U.S., who, it would
appear, is a subject of hay-fever, being on a visit to Bonn,
determined, at the suggestion of Professor Binz, and mostly
in his neighbourhood, to try some experiments on the action
of pollen on the various parts of the system. ' These ex-
periments/ Dr. Patton says, ' may serve to make the pollen
theory somewhat doubtful/ The experiments I must give
entire, in order to give my readers a fair opportunity of
judging accurately of their character, and of the quality of
the logic that leads the writer to the conclusions he arrives
at. The experiments are as follows : —

1. Being quite free from any nasal or laryngeal catarrh,
I inhaled on the 10th of June, last year, at 12 noon, a strong
dose of the pollen of Festuea pratensis and Dactylis glome-
rosa. The temperature in a room with a northerly aspect
was 14° C. Very soon I discovered uneasiness and obstruc-
tion of the nostril operated upon. After an hour and a
half, however, every symptom had vanished.

2. On the 13th and 14th of June I repeated the experi-
ment, the last time with a still larger quantity. The
temperature of the room on the two occasions was 185° and
19° C. The result was the same as before. On the 15th of
June, I placed a smaller quantity of pollen in the left eye.
Lively itching took place, moderate injection of the vessels,
and tolerably strong secretion of tears. After an hour no
trace of these appearances was left.

3. On June 20th, at noon, with the aforesaid northerly
room at 24.5° C, I blew into the nostrils, by means
of an elastic tube, a strong dose of the pollen of Secale
cereale, which, according to Blackley, produces the highest
degree of irritation. Out of doors, where I had been walking
for some time, the weather was unusually hot. The irritation
and obstruction were greater than before ; but after two or
three hours all had passed off. On June 23rd, at 12 noon,
with the temperature slightly higher, I repeated the experi-
ment in the same way. The result was less marked

Application of a small quantity of Secale pollen to the con-

46 Experimental Researches on Hay-Fever.

junctiva on the 20th of June, had the same effect as on the
15th. Kubbing in the pollen of grasses to scarified spots on
my extremities, and bandaging these spots with strips of
linen, had for result only very transitory irritation.

After giving these details, Dr. Patton goes on to say :
4 As we see, I gave myself every chance of taking hay-fever,
but the accredited cause — pollen — left me in statu quo, either
because it is not the cause of hay-fever, or because it did not
find present in me the still unknown causes, under the in-
fluence of which it becomes a genuine irritant/ How far
the symptoms obtained by the above experiments help to
disprove the pollen theory of the cause of hay-fever, the
reader will be able to judge when I come to speak of the
symptoms of the disease, and of the disturbance produced
.artificially by the application of pollen.

§ 81. I shall now give extracts from the histories of some
of the cases I have seen, or which I have had communicated
to me.

Patient 1. A military officer who has spent some years in
India. In answer to my inquiries in reference to his case,
he says : € I was in India for some years, and during that
time I had no hay-fever whilst in the plains ; but one season
I took an excursion into the Himalaya Mountains, about
the month of June, and I found that on many days when I
was in parts of the hills, which from their elevation corre-
spond with the heat and climate of England, and where
crops were growing somewhat of the same nature as European
cereals, I had violent attacks of hay-fever, although no grass
wa3 cut for hay-making and the grain crops were nearly
ripe. The cultivation, however, was very scanty and partial
— small patches levelled in the hills about the native villages
— so that I was more inclined to attribute the attack to the
temperature than to the cultivation. Long grass, however,
was growing in places on the hills/

§ 82. Patient 2. The wife of a military officer, residing in
the South of England. In this case the patient says : ' The
attacks always begin some time in May, and occasionally
continue until September ; but in London they have ceased
about the middle or end of August, and they certainly seem

A Review of the Opinions held on Us Causes. 47

to follow the growth of the grass ; but roses affect me so
severely that if I gather them a very severe attack instantly
supervenes, worse than from any other flower. The attacks
*re very severe in a hay-field during haymaking, and the
illness does, not seem to cease with the haymaking season ;
but the climax of suffering, hitherto, has been from the
middle of June to about the middle of July/

§ 83. Patient 3. Sir , Bart, in speaking of the

•exciting causes of the attacks in his case, says : ' The attacks
generally begin about the 4th of June, and cease about the
•second week in July. In wet weather I seldom or never
suffer. The hotter the weather (particularly if there is no
wind) the worse I am. I am quite certain that, in my case,
hay-fever is caused by the minute particles which come
from, not only grass, but flowers and trees of all sorts.'

§ 84. Patient 4. In this case the patient is a medical man,
holding the rank of surgeon-major in the British Army.
Having spent many years in India, and being well acquainted
with the climate, his testimony is, on this account, veiy
valuable. In answer to my inquiries about his experience
of the disease in India and in England, he says : ' I have
suffered from hay-fever for about thirty-five years. I have
had it both in India and in England. The period at which
the attacks come on is not fixed, the date of the attack
depending more on the grass ripening late or early than on
any other circumstance. They always begin towards the
end of the hay season, when the grass is fully in flower, and
cease slowly and gradually — not directly — on gathering in
the grass. In India the attacks come on after the rains,
about August or September. Changes of atmospheric tem-
perature do not increase or decrease the severity of the
symptoms; I have been attacked as severely in the cool
climate of Simla, as in the heat of the plains. At sea I
have escaped the attacks, and also at some northern stations
in India — at Kurrachee, for instance.'

§ 85. Patient 5. A lady residing in one of the midland
counties, sends me the following particulars of her case : ' I
have suffered from hay-fever twelve or fourteen years. The
attacks generally commence some time in May ; but they

48 Experimental Researches on Hay-Fever.

come on earlier in a warm season than a cold one, and they
are sure to come on with the first scent of spring flowers.
May blossom, or a bean-field in bloom, is as trying as a hay-
field, and the elder-flower is the worst of all. The attacks
sometimes cease before the hay is all gathered in ; a cool
grey day restores to temporary health, whilst heat and sun-
shine cause great suffering, but the symptoms are less severe
after rain unless the weather is very close.'

§ 86. Patient 6. A young lady, set. 31, residing in a
suburb of Manchester. In this case the disease first came on
nine years ago. As far as she could observe there had been
no change in the constitutional tendencies or in the habits.
Each year the attack has commenced at the time the*grass
has begun to come fully into flower, and as long as the
patient has remained under the influence of the emanations
from flowering grass, the attacks have continued. In some
seasons, however, since the disease commenced, the patient
has, a few days after the attack has shown itself, removed to
the sea-side. On every occasion this change of locality has
brought relief in a few hours, and in the course of twenty-
four or thirty-six hours the patient has described herself to
be, what she considered, almost well.

On one occasion Blackpool, on the Lancashire coast, was
selected as a place of residence during the usual period of
the attack. On two other occasions, I believe Llandudno in
North Wales was the place resorted to.

§ 87. Patient 7. A lady, who was sister to a clergyman of
the Church of England. This patient, who died at the age
of fifty-four years, suffered from the disease for about twenty-
years. When the attacks first came on she resided near
Sheffield ; but during the last nine years of her life she
resided near Manchester. As far as the patient could re-
member she suffered from both the catarrhal and asthmatic
form of the disease at the commencement, but in later years
the asthmatic form of the complaint had been the most
marked.

The attack generally began in a mild way about the latter
end of May. This always went on increasing in severity up
to the middle or latter end of June, and from this time to

A Beview of the Opmions held on its Causes. 49

the middle of July the symptoms were somewhat severe ;
they then gradually declined, and by the time the second or
third week in August had arrived, she was free from the
disease. The disorder attained its maximum severity gene-
rally between the beginning and the middle of July —
sometimes earlier and occasionally later.

Although grass in flower appeared to be the most frequent
cause of the attacks, the patient had thought that flowers
having a strong odour had brought on the symptoms.

On one occasion, when on a visit to a relative who resided
near Bradford, in Yorkshire, she was out walking in a meadow
where grass in flower was being mowed, about the latter end
of thl month of May. She had not proceeded far when an
asthmatic attack came on, and she found it necessary to
leave the neighbourhood as soon as possible.

Atmospheric changes of temperature did not increase or
decrease the severity of the symptoms. She had sometimes
felt as well in the latter part of August, when the weather
had been excessively hot, as she had been at any part of the
year (so far as hay-fever was concerned). She had also
often found that a room with the windows closed, and the
heat greatly increased by this means, had been much less
injurious than it had been when the windows had been
opened and the room cooled. Rain always mitigated the
severity of the attacks.

§ 88. Patient 8. This patient resides a few miles from
London, but attends to business in the city each day. In
giving me a history of his case he says : < I should first tell
you that, as a lad, I suffered severely from asthma — paroxys-
mal. A stay of two years at Geneva put me right, and,
although troubled at times (which I now remember has
almost entirely been confined to the hot months), I have
until lately enjoyed an almost entire immunity from the
disease. Last year (1872), however, after a garden party
on the 22nd of June, I had a very severe attack. All put
it down as congestion of the lungs, brought on by cold. I
had the greatest difficulty in breathing, and for some days
the slightest exertion almost suffocated me. I went on the
6th of July following to Ryde, where a fortnight put me

4

SO Experimental Researches on Hay -Fever.

right. This year (1873) I felt very unwell about the
10th or 12th of June, and on the l'8th I had a similar
attack, but not quite as severe. I got away to Ryde on
the 30th, and picked up flesh and strength on the sea
rapidly. .... I have forgotten to say that the running at
the nose and the intense irritation of the eyes, ears, and
palate are all visible for weeks before the chest symptoms
show themselves. The former, though very disagreeable and
even painful in their intensity, I count as nothing : They
do not disable me, though the journey to town and back is
a terrible trial ; the dust, etc., acting so much on the mucous
membranes.

* During the whole of June one is timid of grass-fielcfe, but
I have frequently had severe sneezing fits in the under-
ground railway : surely there is no pollen to be found there.
Indeed, a sulphurous smell seems to act on me like hay-
pollen. And, again, were I foolish enough to beat a carpet
— I was once — I should have a fearful fit of sneezing, etc.

' This year I had, whilst walking in Hyde Park, on the
11th of May, a good deal of the heat and nose-running
accompanying hay-fever ; but I had no more until early in
June, though I had taken no precautions. Then the nose-
running, etc., troubles me whilst at work in the city. My
handkerchief is always pendent at my side for immediate
use, and my work is often hindered for a minute or two at
a time with sneezing and the nose-running. Often in the
early morning the accumulation of mucus in the nostrils is
drawn into the mouth and spat out: the passage thus
cleared becomes very sensitive, and violent sneezing ensues.
.... I am already thinking of next year, and wondering
whether I had better be off to Ryde in June, or stay at
home indoors for a whole month (an awful idea to me, who
am fond of work or something in the shape of outdoor

exercise), or find rooms in the city near my office

Every severe bout of asthma which I have had, and all
wheeziness or troubled nights, have, I am sure, for years
been in the hay-season. My best and healthiest time is
during the six winter months. Then travel or sport in all
weathers of the hardest description is undertaken with.

A Review of the Opinions held on its Causes. 51

nothing but good results. The intensest cold of Russia
simply exhilarates me; so does a wet day in the saddle.
But a balmy June day is poison/

§ 89. Patient 9. A clergyman residing in Bedfordshire.
In describing his case to me he says : ' I have suffered from
the complaint (hay-asthma) more or less for upwards of
forty years. I had slight sensations of asthma occasionally
when seventeen years of age. For two months, one spring
before I went to Cambridge, I was with a tutor at a parish
on the marshes,, near Eastbourne, and suffered from asthma
all the time, except for two or three days when I went on a
visit to a house in the Downs. At Cambridge, for two or
three years, I was quite well. . . . , After leaving college I
had a curacy in London for eight years, where I was quite
well except for a month or six weeks, when I went for a
holiday into the country, in June or July. Where I live
now I have been the last twenty-iive years. I have had an
attack of asthma sometimes of much severity in June, and
for a little before and after, accompanied with sneezing and
the symptoms of a cold in the head. I am asthmatic now,
but not very bad yet, though they are making hay around
us. Once, about fifteen years ago, I had occasion to spend
the winter in Hastings, but not on my own account, because
I am generally quite well in winter, and do not feel the
cold at all. But that winter, during a very severe frost, I
had a most troublesome attack of asthma all the time I was
there. With that exception I have, for the last twenty-
eight years, been perfectly well except from the end of
May to the middle of July.'

§ 90. Patient 10. This patient was formerly in the Man-
chester business, but for some years prior to the time at
which this account was written he had been out of busi-
ness. His time was, however, fully occupied with educa-
tional and other work. He had suffered from the catarrhal
form of hay-fever for ten or twelve years. The exact date
at which it commenced he could not remember. During the
time he had been troubled with the malady the patient had
resided iq> a village four miles from Manchester, in a south-
westerly direction, the situation of his house being about

4s— *i

52 Experimental Researches on Hay-Fever.

six hundred yards from the spot where my first set of
atmospheric experiments were tried (see Chapter III.).

The attacks have usually commenced about the 10th to
the 12th of June, but in 1875 he had very decided symp-
toms as early as the 8th of June. The first symptoms are
generally itching of the roof of the mouth and of the eyes,
with a slight watery discharge from the nose, and a feeling
as if he had some dust in the eyes. If he remains in this
district the symptoms increase in severity up to the end of
June, and then gradually decline. By the middle of July
he is tolerably free from the ailment, but he is generally
very prostrate for some weeks. A cool wet day gives great
relief, but a bright, hot, sunny day is sure to increase his
suffering if it happens at any time between the middle of
June and the middle of July. He suffers much less in the
city than he does in the country. A trip to the sea-side
during the hay season is sure to bring relief if a sea breeze
is blowing.

§ 91. Patient 11. This patient wrote to me after read-
ing the first edition of this work. In giving an account
of his case he says : ' As I have been annually a sufferer for
nineteen years, anything on the subject is eagerly read, but,
I may add, with little profit until yesterday. The mass of
evidence you have collected is wonderful and very con-
clusive. I have for some time been sure that in my case
the exciting cause is pollen, and my children know quite
well in what stage of growth grass or flowers will make me
sneeze and must not be brought into the house.

' You mention that instances have never occurred to you
of a first attack of hay-fever coming on after the fortietli
year. I can tell you of two — one that of a gentleman about
sixty years of age, who first became ill in the summer of
1868, and another of a friend, aged 43, who began just a
week ago. I believe I know thirty persons affected more
or less with the complaint. In my case I feel persuaded
that when once the complaint is established an attack of
sneezing may be produced very easily without the presence
of pollen ; a dusty road, railway carriages which only travel
a few miles and never go into other districts, turning over

A Review of the Opinions held on its Causes. 53

calicoes, being in workrooms when being swept, the very-
slightest use of the pepper-castor, and various other things
will produce an attack, not only when I have the disease
fully developed, but also when coming on. Light has also
an effect at these times. I cannot read for the same length
of time that I am able to do when well. Being a botanist,
I have not unfrequently had attacks when looking over
specimens of dried plants. I have also noticed that certain
grasses apparently affect me more than others. I say
" apparently," because my observations have been only made
on the grasses I have examined when out walking, without
regard to the quantity of pollen likely to be diffused at that
particular time. What I took for the effect of a particular
pollen might only be the effect of larger quantities of pollen
in the atmosphere.'

§ 92. Patient 12. In this case the patient wrote to me
spontaneously, after a correspondence on the subject of hay-
fever in the local papers. The circumstances under which the
first attack came on point definitely to pollen as the cause of
the first attack. In the account given of this occurrence the
patient says : € I never had hay-fever before one summer
some fifteen or sixteen years ago, when, in company with
some young friends, I was playing in the hay-fields and got
buried under the hay. When I got out I had to be taken
home and kept in a darkened room, my eyes having to be
bathed copiously with warm water. It was thought at the
time I had got some seeds in the eyes. I never remember
having hay-fever before, but I certainly have had it almost
every summer since — certainly for twelve years back. I
am now twenty-nine years of age During the hay-
season smoke affects me sooner than the smell of hay, but
at other seasons of the year I rather enjoy the smell (of
cigars) than otherwise, though I do not smoke myself. I
have noticed, in my various excursions to the sea, that
where the shore is rocky and covered with sea-weed I
derive more benefit from that than from the sea-breeze
itself, but I find the greatest relief from a short sea- voyage
— say for four or five days/

§ 93. Patient 13. In this case the patient is a native of

54 . Experimental Researches on Hay-Fever.

Manchester, and resides at the present time four miles from
the city ; but the whole day— on business days— is spent in
the centre of Manchester. In writing to me he says : ' The
first recollection I have of this complaint (knowiog it to be
such) was when I was about eighteen years of age. I was
spending a day in the field helping to make hay, and I have
a very vivid remembrance of the misery of that day. The
incessant and violent sneezing, the intense burning sensa-
tion in the eyes, together with alternate hot and cold per-
spirations, followed by complete exhaustion and aching in
every joint in my body, made me glad to leave the hay-
field, convinced that I was suffering from something more
than an ordinary cold.

' Though carefully avoiding hay-fields as much as possible
when the grass is in flower, I have had a return of the
sensations every year since the time I name, commencing
when the grass is properly in bloom and ending when the

bulk of it is carried to the hay-stack I do not find

the symptoms worse in the country where I reside than they
are in the town, unless I walk through or near a field of
ripe grass or hay, and then they become very violent. This
tendency to hay-fever is, I believe, hereditary in our family ;
I had an uncle who was very sensitive to dust of any kind,
and I have a sister who suffers more than I do, though she
lives at the sea-side. In my case it must have begun sud-
denly, because in the two years previous to the one above
mentioned I worked and played amongst the hay with as
much impunity as most other people. On the 30th of July
this year, when the symptoms of hay-fever appeared to be
quite gone, I ventured, out of curiosity, to smell at a bag of
hay seeds, and was, in consequence, punished unmercifull}'.'

§ 94. Patient 14. E L , set. 52. Has suffered

from hay-fever seven years. The first time he ever remem-
bers it troubling him was on one occasion when walking
through the fields in the month of June, in the village of
Chorlton-cum-Hardy, about four miles from Manchester.
He thought at the time he must have taken a violent cold.
He had terrible attacks of sneezing, accompanied with a
watery discharge from the nostrils, but the eyes were not

A Review of the Opinions held on its Causes. 55

so much affected as they have been for the last three or four
years. He has had the attacks every year since the first
one mentioned above. Slight itching of the eyes and nose,
with an occasional discharge of thin serum from the nostrils,,
are amongst the earliest symptoms of the disease, but, as it
progresses, attacks of sneezing come on, and these become
severe and prolonged whenever he ventures into the country.
There is at the same time a copious discharge of thin serum
from the nostrils ; the eyes itch intensely and become much
inflamed, especially if he rubs them. He has, however, no
asthmatic symptoms. The attacks usually commence about
the 10th of June, but this year (1879) they did not come on
so early. He went to Dolgelly, in North Wales, on the 12th
of June, and had walking excursions in that neighbourhood
for the following two days. The weather was hot, and on
the 14th he noticed that the grass was rapidly coming into
flower. On this day (14th) he went for the day to Bar-
mouth by rail, and suffered severely. After a stay of a
couple more days at Dolgelly, during which time he had the
attacks more or less sharply, he went to Aberystwith,
where he remained until the 25th of June. During a good
portion of the time spent in Aberystwith there was a fresh
sea-breeze blowing, and so long as he kept near the shore
he was comparatively easy. The patient says that he has
always noticed that he is worse on the bright hot sunny
days if out in the country, but at the sea-side he is always
better if a sea-breeze is blowing, however high the tempera-
ture is. The day he came home (by rail) was fine and
warm, and his attacks were very severe ; in fact, this was
the worst day he had during the whole season, but during
the remainder of the time the symptoms were milder than %
they usually have been at this part of the year.

§ 95. Patient 15. This patient, in giving me the history
of his case, says : ' I feel pretty sure I first noticed the
attack in 1874. I was then twenty-four. I thought it was
an ordinary cold, and was surprised it did not yield to
ordinary remedies. It happened at Cambridge, during the
long vacation. The times at which the attack comes on have
been as follows: in 1876, June 12th to 19th; 1877, June

56 Experimental Researches on Hay-Fever.

4th to 11th ; 1878, June 3rd to 10th ; 1879, June 9th to
16th. This year the attack was very mild from June 9th
to 16th, but was much worse from the 23rd to the 28th of
June, making almost a new start. With regard to the
question whether the grasses or the cereals affect me most, I
should fancy it is the grasses that have the most powerful
influence, but I cannot say that the cereals do not also
affect me. The sea-side has not given me much relief this
year, but the wind has been off shore, and so it is hard to
judge. A sojourn at the sea-side agrees with me very well
when free from hay-fever. Rainy weather and also sitting
quietly indoors are both very comforting to me when 1 am
suffering from the malady.'

§ 96. Patient 16 (the author's own case). I have, as I
have previously said, suffered from hay-fever for more than
twenty-five years, but the exact time at which the disorder
first commenced I cannot now remember. The attacks at
first lasted only a few days, and then declined rapidly ; and
they seemed then, to me, to be in some way dependent upon
the commencement of warm weather. For several of the
earlier years the attacks came on about the middle or latter
end of June, but I noticed that a cold season would delay
the time for a week or ten days. From the circumstance of
my noticing that the advent of the disorder seemed always
to occur when the heat began to be such as warranted the
designation 'summer weather/ and particularly from the
fact that a walk into the country on a hot sunny day, whilst
the attack of hay-fever was on me, was invariably attended
by a great increase of the severity of the s}ncnptoms, I was
inclined to regard heat as the principal cause of the disease.
After hearing of Bostock's case I was still more inclined to
take this view of the cause, but circumstances which oc-
curred subsequently considerably altered my opinions.

§ 97. In the year 1857 I had occasion to go down to the
sea-side * for a day or two. The hay had been nearly all
gathered in in the neighbourhood of Manchester, and I was,
as a consequence, just beginning to feel free from my usual
summer illness. When I had got within the distance of six

* Blackpool, on the Lancashire coast.

A Review of the Opinions held on its Causes. 57

or eight miles from the sea-shore, I felt that the hay-fever
was coming on again, and before three hours had elapsed I
was suffering as severely as I had done during the attack I
I was just recovering from. The disorder did not at all
abate for the time I then remained (two days). The heat
was certainly not greater than it had been in Manchester.*
I returned home at the end of the time named, and was not
a little surprised to find that, from the time I reached
Manchester, my hay-fever rapidly disappeared. In about
five days I made another journey to the same part of the
sea-coast, and when about the same distance from the sea-
shore that I was when the attacks came on on the former
journey, I began again to have all the characteristic symp-
toms of hay-fever ; but, strange to say, when I got to my
journey's end these quickly disappeared, and I was not
troubled again during my stay of seven or eight days.

I was considerably puzzled with the very erratic manner
in which the disease had come and gone after the usual
period of the attack had passed ; but in thinking the matter
over, I remembered noticing that, at my first journey, the hay
grass for some miles inland was uncut, and also that much
of it was in flower. Another concurrence of circumstances
also impressed me much at the time, and helped very greatly
to alter my views with regard to the action of heat, namely,
that during my first stay there was a land wind blowing,
and that during my second stay the wind was from the sea
nearly all the time, whilst the heat was somewhat in excess
of what it had been during my first visit.

§ 98. Another circumstance, which occurred in 1859,
helped still further to cause me to doubt whether heat had
any direct influence in producing the symptoms in my own
case. A bunch of one of the grasses (I think it was the
Poa neTnoralis) had been gathered by one of my children
and placed in a vase in one of the rooms at home which I
seldom entered. I happened, however, to notice the vase in

9 I made memoranda of the heat at the time, but these I have
unfortunately mislaid, and cannot now find them. I have, how-
ever, a distinct recollection of the fact that the heat was slightly less
than it was on my leaving Manchester.

58 Experimental Researches on Hay-Fevei\

going into the room a few days after the grass had been
placed there, and on disturbing it to examine it, a small
cloud of pollen was detached and came in close proximity
to my face. I commenced sneezing violently in the course
of two or three minutes, and had what I considered a rather
smart, though short, attack of my usual summer disorder.
As this grass flowers much earlier than the majority of the
grasses cultivated for hay-making, and as there was little or
no grass in flower in the meadows at the time, I was
satisfied that the symptoms were due to the pollen which
had escaped accidentally during the examination. From thia
time my investigations commenced, and these have been
carried on up to the present time as opportunity has offered-

§ 99. Patient 17. In the spring of 1878 a gentleman
called to consult me in reference to slight attacks of coryza
and sneezing, which had been pronounced to be hay-fever,
and on account of which he had been advised not to go to
live in the country, as he had proposed doing previous ta
the ailment coming on. I found on inquiry that the attacks
came only after the patient had been having very active
exercise, and had got into a state of profuse perspiration,
and whilst in this condition had got chilled with remaining
in the open air without exercise. Moderate attacks of
sneezing, with some discharge of fluid from the nostrils,,
generally followed these exposures. The attacks always
passed off when the patient got into his usual routine, and
as they only came on in the early spring, and not specially
in the summer, I concluded that the case was not one of
hay-fever. I therefore thought the patient might with
safety go to live in tbe country. He removed at once to a
house about five miles from Manchester, which stood in
the midst of meadows that had been used for more than a
century for the growth of hay-grass. The patient was ex-
posed every day to the pollen which pervaded the atmos-
phere when the grass was in flower, and also assisted in
making the hay in a field attached to his own house, but
had no hay-fever, nor yet any symptoms which in any
degree resembled it.

§ 100. Patient 18. M A , set. 54. At the age-

A Review of the Opinwns held on its Causes. 59*

of seventeen to eighteen years began to be affected in a
curious way whenever a rabbit was brought near to him.
So far as he can recollect the symptoms came on in the
first instance suddenly, and at the same time severely : his
eyes began to water, he had violent sneezings and a profuse
discharge of serum from the nostrils. The breathing became
oppressed and the eyes became inflamed. This extraor-
dinary susceptibility has continued to the present time, but
he thinks it is not quite so marked as it was earlier on ; it-
is still, however, so strong that if he continues to be sub-
jected to the emanations for any length of time, the breath-
ing becomes so bad that he feels as if he would be suffocated ;
the eyes become bloodshot and the sneezing greatly in-
creases in severity. But the most curious thing is that if
he eats a portion of the flesh of this animal from near the
bone, he is made very ill with symptoms not unlike those
experienced by some persons after eating mussels. If the-
lips or tongue are either of them pricked with a splinter of
rabbit bone, the part swells up and becomes hot and pain-
ful. The flesh of roasted hare does not affect him so severely,
but if he takes jugged hare the stomach and the esophagus
are both much affected.

§ 101. The extracts I have just given are taken from the
reports of a large number of cases that have come more or
less directly under my own notice. Some of these hav&
been taken from the answers to a set of questions (a copy of
which was sent to each patient), framed so as to obtain as
much information upon the causes of the disorder as it was
possible to get without appearing to have a leaning to any
theory which might bias the mind of the patient in giving
the answers. To save repetition, the questions* in these in-
stances have been dispensed with, the answers being thrown
into a connected form. In other cases the reports are given
more or less verbatim.

The last case I have given is a remarkable one, but, as
the patient is a shrewd, intelligent, and educated person,
and more particularly as I had the details of his case from
his own lips, I can have no doubt whatever of the accuracy
of the statements made.

60 Experimental Researches on Hay-Fever.

In the foregoing quotations I have endeavoured fairly to
represent every variety of opinion held on the causes of
hay-fever, and although I have done this at some length,
and consequently at the risk of being somewhat tedious, I
have by no means exhausted the matter I bad at hand. I
have, however, given enough to prove the truth of the
adage, ' quot homines tot sentential!

§ 102. It will have been seen that, even before the time
of Bostock, the popular idea was that hay or grass in flower
was the exciting cause of this disease. Bostock, however,
by his observations upon his own case, laid the foundation
of the theory that heat was a much more active cause of the
disorder than the emanations from grass or hay. His ex-
periments seem, at first sight, to be tolerably conclusive, but
when we come to examine them carefully, and to compare
them with the observations of other patients and with the
results of other carefully conducted experiments, we shall
see that his reasoning was based upon the results of a mode
of observation in which there were several sources of error
which he did not discover.

With an acuteness which was quite characteristic, Elliot-
son not only took a comprehensive view of the phenomena
of hay-fever, but at the same time did not fail to notice
some of its important, though less prominent, features ; and,
as the reader will have seen, he pointed out some of the
probable causes of fallacy in the conclusions which Bostock
had arrived at. Although the opinions of the latter have
had great weight with most of the authors who have studied
the subject since his time, it may be said that opinions have
been pretty equally divided between the two theories. Like
many questions, however, which have remained in an un-
settled state for a length of time, this question of the cause
of hay-fever has given rise to speculation ; and causes have
been named which could only have been thought of in
obedience to a strong impulse to catch at anything which
seemed at all likely to have any share in the production of
the disease, but which the simplest crucial experiment would
have shown to have no such power as that which has been
claimed for it. The question has in the last fifteen years so

A JReview of the Opinions held on its Causes. . 61

expanded itself that, from being, as it was at first, confined
to the consideration of the two conditions named by Bostock,
we have now, according to one author, at least thirty of
these supposed causes presented for examination.

§ 103. When Dr. Phcebus took up the study of hay-fever
comparatively little had been done to furnish sufficient data
for accurate conclusions ; and considering the state in which
he found the subject, he has accomplished as much as any
one man could have accomplished in the study of a disease
in which there is so little chance of continued clinical obser-
vation. Not being himself a sufferer from the disorder,
he had no opportunity of observing its peculiarities, or of
making any experiments upon himself; and from the cir-
cumstance of the disorder being comparatively rare in
Germany, he had, as he tells us, only the opportunity of
observing one patient. If Dr. Phoebus had been himself the
subject of hay-fever, and at the same time had had an
opportunity of observing a greater number of patients, it is
possible he might have arrived at somewhat different con-
elusions. As it is, however, he is a warm advocate of
Bostock's theory, but, unlike the latter, he claims for the
first heats of suminer a power which does not belong to
the later heats of summer, and seems to infer that the former
have some specific character which the latter do not possess.
Of what this consists, however, he does not satisfactorily
explain; nor, so far as I am aware, do any of the authors
who have adopted the opinions of Dr. Phcebus on this point,
make any successful attempt at explaining them.

§ 104. The necessity for believing that solar heat has
different qualities at different times, and, as a consequence
of this, has the power per se of effecting at one time of the
year what it cannot accomplish at another, is one of the
weakest points in the theory which claims heat as the most
efficient cause of this malady. It is well known that the
heat obtained from different sources has different qualities,
but I am not aware that it has ever been shown that solar
heat changes its properties with the seasons, and before we
c&n accept the above theory as the true one, it should be
shown at what temperature, or between what ranges of

•62 Experimental Researches on Hay-Fever.

temperature, a patient who is amenable to the influence of
heat will have the symptoms of the disease developed in him,
and at what precise point he can depend upon being free
from them. It should also be shown that at any time and in
any place where a patient happens to be who is known to be
the subject of this form of hay-fever, when the temperature
rises to the point indicated, an attack is sure to come on.

Then again, in claiming for the other agents named in
the foregoing pages the power of producing the morbid con^
ditions which characterise the disease., we should be equally
•exact in our requirements. It should not only be shown,
in any individual case, that the attacks come on at a certain
time of the year, when the substance, which is the supposed
-cause of the malady, is generated in the largest quantity,
but it should be shown that at any time when a patient,
who is presumed to be susceptible to the action of this
substance, is brought in contact with it, it will to a certainty
bring on the attacks. The cause of the malady should, in
fact, be as capable of being proved to be so by repeated
experiment as any chemical reaction is capable of being
again and again demonstrated by the ordinary processes of
•chemical manipulation. Only in the case of one substance
has this been done.

§ 105. In Dr. Smith's treatment of the subject there is
an evident wish to fall in as much as possible with the views
of Dr. Phoebus, but at the same to recognise and to give fair
prominence to the views of English observers. There is,
however, no attempt at recording anything more than what
may be fitly termed fragmentary observations on the in-
fluence of heat, and of the other causes named.

Dr. Pirrie, as will have been seen from the quotations
already given, has gone a step further, and has distinguished
the attacks which are said to be caused by heat from those
which are thought to be due to other and very different
influences. He, however, does not give us the history of
any case where the symptoms and the apparent cause have
been observed, season after season, and where the dates and
localities are given in the manner in which Bostock has
given them.

A Review of the Opinions held on its Causes. 63

In Dr. Moore's pamphlet we have the symptoms, causes,
and treatment of the malady given in a most orderly and
concise manner, but although the author has evidently
devoted a great amount of attention to the disease, he does
not give us the history of even a single case.

§ 106. The work of Dr. Wyman is, as I have previously
intimated, a very valuable work. It is the production of
one who has had a long experience of the malady of which
he treats, and who has looked at the subject from both a
theoretical and a practical point of view. Himself a suf-
ferer from hay-fever (autumnal catarrh), Dr. Wyman has,
in consequence of this susceptibility, had great advantages
in studying its character, and the circumstances which favour
or hinder its development. His leanings seem to be rather
in favour of the opinion that pollen is one of the principal
causes — if not the only cause — of the malady. But some
difficulties which appear to him to stand in the way of the
pollen theory prevent him being able to accept this theory
unreservedly. These doubts were caused by the sup-
posed want of uniformity in the results of experiments
tried with pollen. The few experiments Dr. Wyman did
perform undoubtedly demonstrated that pollen had the
power of bringing on the symptoms of hay-fever, but on one
or two occasions it failed to produce any disturbance. When
I come to speak of the action of pollen on the mucous mem-
branes and of the influence of heat and cold, I hope to be
able to show that some of the difficulties under which Dr.
Wyman laboured might have been easily removed. To me
it seems a matter of regret that the experiments which were
commenced were not followed up continuously and syste-
matically. Had they been followed out in this manner I
have, very little doubt they would have led Dr. Wyman to
much the same conclusions I myself have arrived at.

§ 107. Dr. Charlton Bastian's attacks whilst dissecting the
parasite of the horse were, if due to the emanations from
this parasite, very remarkable. I am, however, strongly
inclined to believe that the symptoms — which were
exactly those of hay-fever — were due to the presence of
pollen, the origin of which Dr. Bastian did not ascertain

64 Experimental Researches on Hay-Fever.

The whole history of the case brings to mind an occurrence
of a not unlike character, which happened to me in the
early part of my investigations on the causes of hay-fever.
A patient from one of the country villages of Lancashire (a
master blacksmith, I believe) called to consult me. Having
occasion to examine his chest, his coat and waistcoat had to be
taken off. Before he had replaced these and completed his
toilet I began sneezing violently, and had what was really a
short attack of hay-fever. At a second visit, paid in about
ten days, the some phenomenon occurred. I was very much
puzzled to account for these attacks. It was then the early
part of October (1862), and, so far as I could tell, there
seemed no possibility of my having come in contact with
pollen. As I had, however, in the early summer, been try-
ing some of the experiments with pollen which I shall have
to give in another chapter, and finding the symptoms almost
identical with those I had whilst examining my patient, I
felt sure that these symptoms were due to the same cause.

§ 108. If I had followed the reasoning Dr. Bas tian adopted,
I should certainly have said that the emanations from my
patient produced in me the symptoms of hay- fever. I might
also have followed this mode of reasoning still further, and
have said that ' so sensitive did I become to these emana-
tions that even the coat which the patient wore would bring
on violent attacks of sneezing and lachrymation.' This
latter statement would, as will be seen presently, have been,
in a certain sense, quite true ; but I was sure, from the
reasons I have given above, that the emanations from the
patient himself had really nothing to do with the symptoms
produced by his presence. The facts of the case were simply
these : the patient came to see me in a suit of clothes he
generally wore as a second-best or business suit; and, on
being questioned, he remembered that he had in the latter
part of June and beginning of July, twice had a walk of
many miles through the hay-fields in this same suit, which,
he said, might not get brushed as often as it should. At
that time I had no conception of the immense quantity of
pollen clothing may be made to carry, but, as I have since
demonstrated this by actual experiment, there is no doubt

A Review of the Opinions held on its Causes. 65

that the clothing of my patient was the indirect cause of
my troubles.

§ 109. Of the work of Dr. Beard it is difficult to speak
with unreserved commendation. It has some excellences,
but it has also some important defects. The author is not
himself a sufferer from hay-fever, and consequently lacks
the advantage which a personal acquaintance with the
malady would give him in the study of its causes. The
work is, however, one of considerable pretension, but, after
a careful perusal, one is impressed with the idea that the
quality of it scarcely equals the pretension, and that in
several parts of the work there are signs of haste. If the
author had given himself more time to study the disorder
in a careful and discriminating manner, he would probably
have known more and have written less ; or, at any rate,
he would have written in a less positive and dogmatic tone
on some of the more doubtful and difficult parts of the
subject.

§ 110. So far as relates to the causes of hay-fever, two of
the principal defects of Dr. Beard's work are: 1st. The
mode in which the information on this part of the subject
has been collected ; and, 2nd. In the use to which he puts
this information, without any test being applied to deter-
mine its actual value.

In asking for information, Dr. Beard tells us he has
sought for facts, not for opinions * but when we come to
examine the so-called facts closely, we find that, if we bear
in mind the use to which the author puts them, they will
not bear this appellation. The patients are asked what, in
their opinion, is the cause of the malady in their case, and
when the answers are arranged it is found that there are,
as we have previously seen, about thirty supposed causes of
the ailment, but no proof is given that any of these causes
have really the power of producing hay-fever. The author
seems entirely to forget that any given phenomenon may
occur side by side with any other phenomenon without the
two being connected as cause and effect. The principal
causes are said to be dust (indoor and outdoor), sunlight,

* Hay-Fever, or Summer Catarrh, by Dr. Beard, p. 31.

66 Experimental Researches on Hay-Fever:

gaslight, heat, and over-exertion. These various influences
are said to be the exciting causes of the attacks in two
hundred and forty-six cases, in varying proportions. At
this point it is necessary to bear in mind that in the
immense majority of the cases, here and also in America,
hay-fever commences and disappears within given dates.
In England the malady comes on in May or June, and
ceases at the end of July. In America it varies in the times
of its advent more thau it does in England, but still it is
present for only a small portion of the year, and, in a large
proportion of the cases, this amounts only to a few weeks.
Now, in order to enable us to accept the influences named
as the exciting causes of the attacks, and at the same time
to satisfy the demands of a strictly logical method of in-
quiry, we must suppose that when the effect ceases the
cause must disappear, or that the patient must keep out of
its reach. Thus we are driven to the conclusion that dust,
sunlight, gaslight, etc., disappear, or that the patients get
beyond the reach of these agents for ten months in the year.
I hardly need point 'out to my readers the absurdity of
either of these conclusions.

. § 111. But, after giving the various agents named abovo
(along with twenty-five others) as the exciting causes of the
malady, Dr. Beard, in a curiously illogical manner, qualifies
the statement and tells us that ' in the United States the
more prominent exciting cause appears to be Boman worm-
wood and the pollen of corn, both of which flower about the
middle of August, and both of which, without doubt, excite
the paroxysms in some persons, even when applied in the
non-catarrhal regions of the mountains. Other irritants/
he also adds, 'as cinders, dust, smoke, bright sunlight, gas-
light, etc., are common to the whole summer season ; but
they are not sufficiently powerful to induce protracted
attacks of the disease, unless stronger vegetable irritants
start the malady and co-operate with them in maintaining
it/* There can be no doubt that some of the agents named
may in some degree alter the severity of an attack, when
once set up, but if the presence of pollen is necessary to
• Hay -Fever, or Summer Catarrh, by Dr. Beard, p. 115.

A Review of the Opinions held on its Causes. C7

commence and to keep up the disease, then pollen must be
the cause. I am not at present anxious to determine whether
this or that agent will alter the force of an attack. The
most important points for myself and other sufferers from
hay-fever are, first, to know what that agent is, the pre-
sence or absence of which will determine the presence or
absence of the malady ; and, lastly, to know how we can
relieve or prevent the disease. Before I conclude I hope to
be able to show that all these ends can be attained with-
out the necessity of doing violence to a strictly logical
method of reasoning, and at the same time quite in accord-
ance with a scientific mode of working.

§ 112. The conclusions Dr. Patton draws from his ex-
periments* are, as I have previously intimated, very re-
markable. He produced some of the symptoms of hay-
fever without knowing it, and evidently must imagine the
malady to be something very different to what it really is.
Dr. Patton does not tell us if he himself has ever been liable
to hay-fever. If he is not, his testimony is all the more
remarkable, and shows that even in those who do not
ordinarily exhibit any susceptibility to disturbance of the
mucous membranes from the pollen floating in the atmo-
sphere during the hay-season, symptoms may be produced
by applying pollen in larger quantity artificially. In this
respect the experiments correspond with some that a friend
tried for me many years ago, and where the artificial appli-
cation of pollen disturbed the normal condition of the
mucous membranes to which it was applied ; and I believe
I am right in stating that Dr. Zuelzer, of Berlin, tried the
same experiment with a similar result. However this may
be, Dr. Patton produced irritation in almost every instance,
and yet he tells us it is not, in his case, ' a genuine irritant/
because the symptoms passed off when the pollen ceased to
be applied. It would be just as reasonable if we were to
declare a purgative drug of any kind not to be a purgative
because its effects soon passed off after it ceased to be ad-
ministered.

§ 113. It would be unreasonable to suppose that the
* Vide Virchow's Archives, vol. lxix., March, 1877.

68 Experimental Researches on Hay-Fever.

experience of one individual would be able to decide the
question of cause in every case having symptoms like those
of hay-fever. I lay no claim to having done this, nor even
to having attempted it. I have already shown (§§ 99, 100)
that there are cases that are due to other causes, but a long
experience has convinced me that these are exceptional, and
that they form but a very small percentage of the whole.
What I have attempted, however, is to show that we have
a disorder that attacks its victims only during a given and
limited portion of the year — in the summer-time — and that
these attacks are dependent upon two conditions : 1st. A
certain degree of susceptibility in the individual attacked ;
and 2nd. The presence of a certain amount of pollen in the
atmosphere during the time the disorder prevails. It has
been supposed by some writers that I have an undue bias
in favour of the pollen theory. This is a false impression.
When my researches commenced (now twenty years ago) I
endeavoured to steer clear of all preconceived notions as to
the causes of the malady ; but if I had any leanings at all,
these were towards Bostock's theory, and it is only by the
force of the logic of the facts given in the preceeding and
following pages that I have formed the opinions I now hold.

CO

CHAPTER III.

EXPERIMENTS WITH THE PRESUMED CAUSES OF HAY-FEVER.

§ 114. The main object aimed at in these experiments has
been to single out the agent which I believe is the principal,
if not the only, exciting cause of the disease ; but I have
also wished to show the ground I have gone over, as well as
to indicate the point I have arrived at, in the hope that
some one else may be induced to take up a similar line of
investigation, and thus assist in correcting or in strengthen-
ing the conclusions I have come to.

The plan adopted has been, where practicable, to make
each of the supposed causes the subject of separate as well
as of combined and repeated experiment, and by these means
to endeavour to eliminate such as have no power to produce
the symptoms of the disorder.

§ 115. In the early part of the course it was deemed
absolutely necessary to make each experiment as distinct
as possible, so as not to allow the results of one to interfere
with those of another; but in the latter part, when ex-
perience had been gained, and had shown that this rule
need not be strictly adhered to, the experiments were per-
mitted to follow each other more rapidly. This was often
done where it was desirable to see what effect could be pro-
duced by the re-application of any particular substance
when convalescence had not been fairly established after a
former experiment.

Various circumstances, which were to some extent unavoid-
able, contributed to render the course of experimentation
apparently somewhat irregular. The nature of some of the

70 Experimental Researches on Hay-Fever:

agents, combined with the accidental way in which these
had to be obtained, made it sometimes impossible to conduct
the experiments in as systematic a manner as might have
been wished. This irregularity, however, had one advan-
tage, namely, that it brought out the results of such
observations in strong contrast with those which were
made in a more regular manner and under more normal
conditions.

§ 116. The agents which have been named as the ex-
citing causes of hay-fever admit of several modes of classi-
fication. One of the best of these would be to place these
agents in three categories, according as they are mechanical,

chemical, or physiological in their action ; but here we are
met with the difficulty of not being able to determine in all
cases to which of the three classes an agent may belong.
After close observation for a long period I am not able to
decide which mode of action takes the lead in the case of
the substance which I believe brings on the disease.

For practical purposes a very simple method of classifi-
cation will perhaps answer better than a more elaborate
one in enabling us to decide which are the exciting causes
of the disorder. By this method of arrangement we place
these causes in two divisions. In the first are included
those substances which are more or less under the control of
the operator, and which can be generated at pleasure, or
can be gathered and stored for future experiment. In the
second division we place those agents which cannot be
produced artificially and which are not capable of being
controlled or altered in any way when generated natural^.
In the first division will be found benzoic acid, coumarin
(the substance which gives the odour to newly-made hay),
other odours of various kinds, ozone, dust, and pollen. In
the second division we place solar heat and light

§ 117. In respect to the facility with which we can con-
duct experiments with these two groups of agents there is a
wide difference. In one case we can have these made under
circumstances of our own choosing if not of our own
creating ; but in the other we shall generally have to trust
to observations merely, and these will often have to be

Experiments with Benzoic Acid. 71

made in the presence of disturbing elements which are
difficult to detect, and even when detected are frequently in-
capable of being set aside. These circumstances must ex-
ercise a considerable influence upon the manner of conducting
the experiments, and upon the deductions we make from
the phenomena observed, but at the same time need not
prevent the conclusions we arrive at being sound and trust-
worthy.

The account of the experiments will be given in much
the same order in which the agents are mentioned in the
two classes into which they are divided, viz. : —

A. Experiments with benzoic acid.

B. Experiments with coumarin.

C Experiments with odours of various kinds.

D. Experiments on the action of ozone.

E. Observations on the effects of dust.

F. Experiments with pollen.

G. Observations on the influence of light and heat.

A. Eocperiments with Benzoic Acid.

§ 118. The experiments with this substance were tried in
three different ways, 1st. By exposing the acid to evapo-
ration, at ordinary temperatures, and inhaling the vapour.*
2nd. By applying a watery or spirituous solution of the
acid to the mucous membrane of the nares. 3rd. By sub-
liming the acid at high temperatures and inhaling the
fumes.

In the first form of the experiment the acid was spread
thickly on glass plates containing a superficial area of
one hundred square inches, these being carefully weighed
before being exposed. The room in which the plates were

* Seeing that Benzoic acid does not sublime at less than 293° Fahr.,
it seems useless to try experiments with it at ordinary temperatures ;
but as according to some authorities in chemistry it contains a small
quantity of essential oil, which accompanies the acid during the sub-
limation, in the process of manufacture, it was not impossible that
this oil might be given off at ordinary atmospheric temperatures, and
that it might assist in producing the symptoms of hay-fever.

72 Experimental Researches on Hay-Fever:

placed was a small room about 15 feet by 12 feet, and was
kept at a temperature varying from 65° to 75° Fahr. ;
the average being about 68 # . The room was kept closed
for ten hours at a time, and after being so closed I entered
it and spent a couple of hours in it on three separate
occasions, so as to breathe the vapour if emy had been given
off from the acid. No effect whatever was noticed, which
could be fairly attributed to the presence of the acid in
any of the three trials. The plates were weighed again at
the conclusion of the experiments, and were found not to
have diminished in weight after a lapse of forty-eight
hours.

§ 119. In the second form of the experiment cold distilled
water was saturated with the acid.* A small .strip of lint
steeped in this solution was applied to the mucous mem-
brane of one nostril, and was kept in this position for an
hour. Another solution was made by dissolving a quantity
of the acid in hot distilled water, t This was applied to
the nostril at a heat of 120° Fahr. in the same way as
the one above had been applied. Another solution was
made by adding two drachms of proof spirit to eight
drachms of water, and dissolving in this mixture twenty
grains of the acid. This also was applied to one nostril in
the same manner.

In order to be able to distinguish the effect of the
alcohol from that of the acid, a mixture of proof spirit and
water (minus the acid) was applied to the other nostril im-
mediately after the conclusion of the last experiment. A
slight burning sensation was felt in each nostril after the
conclusion of the experiments, and the mucous membrane
was found to be slightly reddened in each case, but there
was no difference perceptible between the action of the
mixture containing the acid and that which was composed
of alcohol and water. These experiments were repeated
several times, but no effect which in any degree resembled
the phenomena of hay-fever was seen in any of the trials.

§ 120. In the third form of the experiment, 5j of the

* Cold water takes up ^th of its weight of the acid (Miller),
t Boiling water takes up *Vth of its weight of the acid (Miller).

Experiment? with Benzoic Acid. 73

acid was placed in a crucible, and was held over the flame
of a Bunsen's burner, so as to cause the former to sublime
more or less rapidly. At first the heat was applied gently,
so as to allow the vapour of the acid to be only just per-
ceptible, but in later trials the heat was increased until it
brought out dense fumes.

During the progress of these trials I was present, and,
indeed, manipulating all the time, but had no sensations
like those of hay-fever. I had some dryness in the throat,
with a feeling of irritation about the larnyx, and a slight
disposition to cough; but these sensations were not so
marked in my case as in the cases of other persons who were
in the room with me during a part of the time the experi-
ments were going on, and who had never been the subjects
of hay-fever. In the case of one of those who was present
the dense fumes of the acid brought on a slight cough, with
a feeling of suffocation, as if there was some little tendency
to spasm of the glottis ; but this passed rapidly off on going
into the open air. It is almost needless to say that in each
of these trials I inhaled the vapour of the acid freely, taking
especial care in some of the later experiments to inspire
through the nostrils only.

§ 121. From the uniformly negative results of all these
experiments with benzoic acid, when applied in the various
ways I have described, I think I am warranted in conclud-
ing that it has no power to produce any of the symptoms of
hay-fever. Moreover, unless it can be shown that the acid
exists, in the grasses in which it is found, in combination
with some base or some other body which renders it much
more volatile than it is in the uncombined form, we are
forced to the conclusion that it cannot possibly be a cause
of hay-fever, since the heat which is required to volatilise it
is beyond anything which exists naturally in the atmosphere
in any part of the world.

b. Experiments with Gov/marvn,.

§ 122. This substance is an odoriferous principle found in
some of the grasses and in the plants of several of the other
natural orders. It is one of those singular bodies which boil

74 Experimental Researches on Hay-Fever:

at high temperatures* only, and yet readity give off odorous
vapours at ordinary atmospheric temperatures. Its formula
is C9H6O2. It is, as before stated, found in several of the
grasses,t but it is most easily obtained from the Tonka bean
(Coumdrouma odorata). A tincture made from the pow-
dered bean in the proportion of one part, by weight, to ten
parts of proof spirit gives a solution which has a strong
odour of newly made hay.

The experiments with this substance were made, in my
case, by placing ten drops of this tincture on a porcelain
plate, and exposing this to evaporation in an apartment
which was kept closed during the period of the experiment,
except when I entered it or left it. In about fifteen minutes
after the tincture was exposed to the air the room was filled
with a strong odour of newly made hay, and though the
quantity of the solution was comparatively small, it was
sufficient to cause the air of the room to be permeated with
its characteristic odour for quite thirty-six hours. During
this time I entered the apartment, and remained in it a
couple of hours at a time several times, taking care now and
then to move about, so as to inhale as vigorously as I should
have done if I had been walking in the open air. Several
other persons were present for different periods during the
time named, but neither in their cases, nor yet in my own,
was there any effect produced beyond the perception of the
somewhat agreeable odour of newly made hay.

§ 123. Three such experiments as that described above
were made upon myself in different years, and at different
times in each year, but in no one of them was there the
slightest approach to any of the symptoms of hay-fever.

Four experiments with this same substance were tried

# Coumarin fuses at 122°, and boils at 518°, Fahr. (Miller).

•f* Anthoxanthum odoratum, Holcus odoratus, Ilierochloa borealis,
and one or two other grasses. It is also found in the Myroodlon
toluiferum, Melilotus cerulea, Melilotus officinalis, and other species
of Melilotu8 (Legumenosas), also in the Asperula odorata (Itubiacece),
in the Prumis Mahaleb {Rosacea:) , in the Orchis fusca, Angrecum
fragrans y and Nigritella alpina (Orckidece), and in the Herniaria
glabra (Portulaceas).

Experiments with Coumarin. 75

upon patients Nos. 6 and 7 (§§ 86—87). The first of these
trials was made upon patient No. 6 in 1870. With the
exceptions that the apartment was not kept closed during
the time the tincture was exposed, and the circumstance
that the patient did not remain quite so long at one time in
the room, the conditions were just the same as they had
been in my own case. Another experiment, with exactly
the same quantity of material, and under pretty much the
same conditions, was tried in the early part of 1871. In
both these cases there were several other persons, who never
suffered from hay-fever, in the room during the whole time
the tincture was exposed, but in no case were there any un-
pleasant symptoms produced. The patient, as well as several
of the other persons present, very quickly detected the
characteristic odour of the coumarin ; but in no case were
they aware of the object of the experiment, nor yet of the
nature of the substance employed.

§ 124. Two experiments were also tried with patient No.
7, but under somewhat severe and more trying circum-
stances. In the first of these trials the quantity of tincture
exposed for evaporation was tho same as in the other cases,
but in an hour after the experiment had been commenced
the quantity was doubled. The vessel containing the tinc-
ture was, during a good part of the time, not more than four
feet from the patient, so that the odour was very strong in
her immediate neighbourhood. An important circumstance
in this experiment was, that the patient remained in the
same room night and day during the whole time the experi-
ment was going on. In this case also the patient was not
in the least aware of the object of the experiment, nor of
the nature of the ordoriferous agent used. No symptoms
which could fairly be attributed to the presence of the
coumarin were developed.

The entire absence of results in this series of observa-
tions makes it absolutely certain that in these cases, as well
as in my own, coumarin has no power to produce any of the
symptoms of catarrhus sestivus.

76 Experimental Researches on Hay-Fever:

c. Experiments with odours of various kinds.

§ 125. In addition to the trials made with coumarin, I
have also experimented upon the effects of many other
volatile bodies, amongst which I may mention Paraffin oil,
Camphor, Oleum terebinthince, Oleum menthxz piperitce,
Oleum juniperi, Oleum rosmarini, Oleum lavendulce, etc.,
I have also tested the odours given off by the flowers and
herbs of wild and cultivated plants, such as the Chamomilla
matricaria, Rosa canina and other species of roses, Viola
odorata, IMium tigrinum, Liliu/m album, Cyrwglossum,
and many other flowering plants which it would serve no
purpose to enumerate here. I have also tried the odours
given off by several of the fungi.

§ 126. The experiments with camphor were tried much
in the same way as those with coumarin, as were also those
with some of the volatile oils. In all cases they were made
sufficiently exact to permit me to say decisively whether
any of them had the power of producing the symptoms of
hay-fever. The experiments with the vapour of the oil of
turpentine were more severe and extensive than those with
any of the other volatile bodies ; but this was not because
I believed it was more capable than the other bodies of
generating the specific symptoms I was seeking for, but
because the opportunity for testing it somewhat extensively,
without any trouble or inconvenience to myself, came in
my way. The necessary conditions were, in fact, ready
made to my hand at any time when I chose to avail myself
of them. I had the opportunity of visiting an establish-
ment where a considerable quantity of copal varnish was
used. In a room set apart for the purpose, from one to
two thousand superficial square feet of varnished paper were
often exposed at one time. Ordinarily copal varnish does
not contain much oil of turpentine, but in this case it was
the custom to add twenty or thirty per cent, of the oil in
order to facilitate the working, and to help the drying. This,
of course, was evaporated in the drying, and the atmosphere
of the room was, as a consequence, highly charged with the
vapour of the oil of turpentine. I have frequently entered

Experiments with, Odours of Various Kinds. 77

the room, and have breathed the air for half an hour to an
hour at a time. I have also taken the opportunity of doing
this at the time I have been suffering from hay-fever, a3
well as when I have been quite free from it, but have not
noticed any difference in the effect produced.

§ 127. The experiments with paraffin oil were tried under
somewhat similar conditions to those last named, but were
not so frequently repeated, nor yet could I say that the
atmosphere of the room was so highly charged with the
vapour of the oil as in the other case.

The volatile oils all produced head symptoms more or
less severe in character, in some cases scarcely to be felt,
but in other cases becoming rather unpleasant when long
continued. The effects of the oil of turpentine were always
the most marked, but this was probably owing to the fact
that a much larger quantity of the vapour was inhaled than
of any of the other substances. In no instance, however,
were there any symptoms set up which in the least degree
resembled those of hay-fever.

§ 128. The odour of the Chamomilla matricaria had a
marked effect both upon myself and others. The plant had
been gathered fresh in considerable quantity, and spread out
in the room which we occupied as a dining-room during one
of our seaside visits, so that we inhaled the volatile prin-
ciple given off pretty freely. Severe aching pain across the
forehead, with nausea, dizziness, and pain at the epigas-
trium, were the principal symptoms, and these became so
unpleasant on the second day after the plant had been
placed in the room that I was glad to have it removed.
There were, however, none of the symptoms of hay-fever
produced.

§ 129. The inhalation of the odour of one of the micro-
copic fungi (Chcetomium) also produced rather unpleasant
symptoms with me, but these were not at all like the
symptoms of hay-fever; but the spores of another of the
microscopic fungi (Penicillium glaucum) I have reason to
believe will, when brought into contact with the respira-
tory mucous membrane, generate symptoms not unlike those

78 Experimental Researches on Hay-Fever:

of hay-fever in some respects, but differing materially in
others.

I had noticed many years before that the dust from straw
sometimes brought on attacks of sneezing with me, and
that this seemed to occur more frequently when we had
had a long spell of wet weather. I therefore determined to
try what fungi could be generated on damp straw. For
this purpose wheat straw, slightly moistened, was placed in
a closed vessel, and was kept at a temperature of 100° Fahr.
In about twenty-four hours a small quantity of white
mycelium was seen ; this increased slowly for three or four
days, and in a short time after was followed by the appear-
ance of minute greenish-black spots dotted here and there
along the surface of the broken straw, apparently coming
out more readily on the inner than on the outer surface.
This, I found on examination, was the Penieillium glaucum.
After a few days another crop of dark-coloured spots were
seen, but these became almost jet black, and had quite a
different contour. These I found to be the bristle mould
(Chcetomium elatum).

§ 130. The spores of the above-named fungi were sown
again separately on straw which had been placed in se-
parate vessels after having been subjected to the action of
boiling water for a short time. A crop of the spores of each
fungus was thus obtained.

The odour of the Penieillium produced no perceptible
effect upon me, but the odour of the Chcetomium brought
on nausea, faintness, and giddiness on two separate occa-
sions. By inhaling the spores of the Penieillium, in an in-
voluntary experiment, a severe attack of hoarseness, going
on to complete aphonia, was brought on. This lasted for a
cpuple of days, and ended in a sharpish attack of bronchial
catarrh, which almost unfitted me for duty for a day or two.*

* This experiment would seem to some extent to agree with the
observations of Dr. Salisbury, of America, who states that he has
seen the mycelium generated on damp straw produce many of the
symptoms of measles among the troops engaged in the American war,
(the specific rash amongst other symptoms). — Vide American Journal
of the Medical Sciences, July, 1862.

Experiments ivith Odours of Various Kinds. 79

The sensations caused by the two last-named agents were
so unpleasant that I have never cared to reproduce them.
In the case of the first-named fungus I inhaled the odour
given off by the plant, on two occasions, in an experimental
way. In the case of the second I was the subject of the
involuntary experiment of which I have spoken, and which
gave me so much trouble and inconvenience that I have not
wished to subject myself to these again.

§ 131. The symptoms developed by the inhalation of
some of the odours I have mentioned were sufficiently well-
marked to make this a subject worthy of close investigation,
but, as we have seen, it cannot be said that in any case the
phenomena produced bore any resemblance to those of hay-
fever. The action of the spores of Penicilliu/m, comes near
to that of the exciting cause of this disease; but when the
former comes to be thoroughly tested, I believe it will be
found to produce symptoms of a much more acute and
dangerous character.

From the results of these few experiments it is not easy
to decide whether the effects produced by the agents I have
mentioned are due to idiosyncrasy merely ; or whether the
liability to be affected by them is due to a constitutional
condition which is widely spread. In the case of the vapour
of those bodies which are allied to the hydro-carbons, the
liability to be acted upon by these will probably be found
to be very common ; but in the case of the spores of fungi,
it is possible that the phenomena they exhibit may be
restricted to comparatively few individuals ; as I have said
above, however, it is a subject which calls for much more
careful and extensive investigation than it has yet re-
ceived.

d. Experiments on the action of Ozone.

§ 132. Dr. Jno. Davy was apparently the first to recog-
nise the existence of a substance in the atmosphere having
properties similar to those of ozone,* and it is to him that
we owe the first formula for a chemical test to be used in its
detection: It is however to the late Professor Schonbein, of
Basle, that we are indebted for the earliest systematic in-

* Lectures on Agricultural Chemistry.

80 Experimental Researches on Hay-Fever:

vestigations into the properties of ozone. Since the publi-
cation of his first paper in the ' Memoirs of the Academy of
Munich/ few subjects have occupied more attention or
excited more discussion than has the question of the nature
and composition of ozone, and of its ally, antozone. Into
the vexed question of the exact composition and the rela-
tion of these two bodies it is not necessary for me to enter ;*
neither is it necessary, for the purposes I have in view, that
I should attempt to decide whether the supposed action of
ozone is due to that body alone or to it and some other
agent present with it. Whether it acts singly or in com-
bination with other agents, the presence and influence of
ozone in the atmosphere is recognised by almost all the
scientific men of the present day.

§ 133. Schonbein was the first to discover, during the
course of his experiments, that when air highly charged
with ozone was inhaled, it brought on € a painful affection
of the chest — a sort of asthma with a violent cough, which
obliged him to discontinue, for a time, his investigations.
Reflecting on this circumstance, he began to suspect that
certain catarrhal disorders might be caused by atmospheric
ozone. He got several physicians at Basle to compare their
lists of catarrhal patients with his tables of atmosphero-
ozonometric observations, and he and they were struck by
the unusual number of catarrhal cases, on the days, or
during the periods when M. Schonbein's papers (test papers)
showed that ozone was unusually abundant in the air/f It
is to these experiments that we owe the idea that ozone
might be a cause of hay-fever, and it was the acceptance of
this idea by one writer on hay-fever that led me to decide
upon carrying out the course of observations of which I am
about to give the details. At the time the observations
were commenced, I was not aware that many other medical

* Those of my readers who wish to enter fully into these questions
will find them exhaustively treated in Dr. C. Fox's admirable work,
Ozone and Antozone; their History and Nature. London : J. and A.
Churchill.

t Watson's Principles and Practice of Physic, 4th edition, pp.
47—48.

Experiments on the Action of Ozone. 81

men had extended Schonbein's experiments upon the action
of ozone in the atmosphere. These seem to have been
carefully conducted, but with results so contradictory that
no sound conclusions can be drawn from them respecting
the production of catarrh or influenza, and still less con-
clusive are they in respect to the production of hay-fever
by atmospheric ozone.*

* In the years 1853, '54 and '55, Dr. Seitz, of Munich, made obser-
vations on the amount of ozone in the atmosphere, and the number
of patients attacked with catarrh of the respiratory organs during
the periods of observation. His observations led him to the conclu-
sion that a small amount of ozone was attended by a large number of
cases of catarrh, and, vice versd, a large amount of ozone gave a small
number of cases of catarrh. — (Ozone and Antozone, p. 137.)

'A negative result followed also the observations as to the amount
of ozone in the air and its relation to prevalent diseases, conducted
during the year 1856 by the Medical and Scientific Club of Konigs-
berg, in Prussia ' . . . . and it was found ' that a sudden and con-
siderable increase in the amount of ozone did not appear to be a
cause of the commencement of catarrh of the respiratory organs.' —
(Ibid., p. 138.)

'Dr. Ireland noticed at the hospital at Umballa, Bengal, that a
sudden decrease in the amount of ozone was followed by a threefold
increase in the number of patients, and by the prevalence of rheuma-
tism and influenza, and that when there was an increase of ozonic re-
action the patients recovered.' — (Ibid., p. 139.)

'Faber, Wunderlich, Schiefferdecker, T. Boeckel and other ob-
servers, believe that there is no connection between the development
of ozone and the prevalence of catarrhal affections.' — (Ibid., p. 139.)

'MM. Houzeau and Leudet, jun., show that there is no agreement
between the prevalence of respiratory affections at Kouen, and the
depth of ozonic reaction, as presented by true ozone tests.' — (Ibid., p.
140.)

* Mr. Harris, of Worthing .... has always remarked, during the
prevalence of N.E. and E. winds, when no ozone is present in the air,
the great frequency of irritative affections of the mucous membranes
of the throat and air passages.' — (Ibid., p. 140.)

Dr. Spengler made observations at Roggendorf, in Mecklenburg.
Just before an epidemic of influenza no ozone was to be detected.
Directly, however, catarrhal affections set in, and every one was cough-
ing, an abundance of ozone was manifested. As the disease gradually
diminished, so did the indications of this body decrease. — (Ibid., p.
139.)

* Dr. Heidenreich found that a strong ozonic reaction coincided

82 Experimental Researches on Hay-Fever:

§ 134. It will have been seen, from what I have said
before ('§ 53), that I do not conceive it to be possible for
ozone, in the quantity in which it is ordinarily found in the
atmosphere, to bring on hay-fever. It would therefore seem
to be inconsistent in me to be seeking for an effect which I
believe cannot be produced. Whilst, however, I hold that
we have abundant evidence to show that, in the .quantity in
which it is ordinarily met with, ozone will not produce hay-
fever, we have little or no evidence to show that it may not
do this when present in a larger quantity.

In this disorder, as in many others — and even in some of
the so-called zymotic diseases — the qyuantity of the exciting
cause may have almost as much influence in determining
the occurrence of an attack as the quality has, and as I was
investigating the effects of all the presumed causes of hay-
fever, it seemed in this case also to be necessary to show by
actual experiment that ozone has no such effect as that which
it has been supposed to be capable of, even when present in
what may be called maximum quantities, such as are often
found on or near the sea. In order to make these observa-
tions as complete as possible I determined to make an effort
to ascertain the relative amount of ozone present at various
points of the scale.

§ 135. The first test-papers tried — made on Schonbein's
method* — were procured from one of the London makers.
These yielded very unsatisfactory results. If half a dozen

with an exacerbation of catarrh symptoms and the appearance of
pulmonary affections, while a diminution of these took place when
it was feeble.' — {Ibid., p. 139.)

' Dr. E. Boeckel having made careful comparison between the ozone
observations conducted at Strasburg, and the number of cases of dis-
ease occurring there during each month of the years 1853, '54 and '55,
is of opinion that the influence of ozone in the production and aggra-
vation of pulmonary affections is beyond doubt, and is greater than
that of temperature. 7 — {Ibid., p. 139.)

' The authorities at the hospital at Metz have found that there is a
certain relation between the variations in the quantity of atmospheric
ozone, and the number of cases of bronchial affections which present
themselves/ — {Ibid., p. 139.)

* Schonbein's paper is soaked in boiled starch and potassium-
iodide.

Experiments on the Action of Ozone. 83

slips were exposed for a given time, and placed under exactly
the same influences, I very rarely found that these slips
were of the same tint at the termination of the experiment;
and frequently it happened that no two of them would be
alike. Another trial which I made with test-paper which I
prepared myself, according to Schonbein's method, was more
satisfactory, but still was far from being as exact as was
deemed to be necessary in experiments of this kind.*

It occurred to me that I would try the effect of covering
one surface of the paper with unboiled starch and solution
of potassium-iodide. This plan answered better, but on
account of the difficulty of covering the paper evenly it did
not meet all my requirements. The method ultimately
adopted was to deposit the starch granules — after being
suspended in water — on the surface of the paper. f This plan
answered admirably, and in the regularity and smoothness
of the surface, it far excelled the work of the most skilful
hand. The surface is a pure white, and so delicate is the
power of adjustment by this method that the quantity of the
material laid upon a given area, say half an inch square, can
be regulated to the l-1000th of a grain. The surface pre-
sented to the atmosphere has also the important advantage
of being composed only of the two substances to be acted
upon, namely, the starch and the potassium-iodide. When

* I do not know what may be the experience of meteorologists in
this matter, but it would appear that that of the late Dr. Daubeny
was in some respects similar to my own. In the concluding remarks
in a paper published in the Journal of the Chemical Society, January,
1867 (pp. 1 — 28), he says : * I cannot rely upon different samples of
either paper (Schonbein's or Moffat's) yielding, under the same circum-
stances, exactly similar results, and, therefore, am loath to confide in
their indications as furnishing corresponding measurements.'

t Strolling one day by the sea-side during one of my summer holi-
days I noticed what is often seen on the sea-shore, namely, a stretch
of sand that had been left by the receding tide as smooth and flat as
it would have been if trowelled by a careful and skilful hand. The
idea at once struck me that if water would deposit grains of sand in
this manner it might be made to deposit granules of starch in the
same way. On my return home I had a very simple apparatus con-
structed, by means of which I was enabled to deposit a thin layer of
starch on one surface of a sheet of blotting-paper.

84 Experimental Researches on Hay-Fever :

brought into contact with ozone, unlike Schonbein's and
Moffatt's papers, the colour produced varies from the palest
yellow to a deep cinnamon-brown, or even to a brownish
black. The earlier experiments were tried with Schonbein's
paper — the later with my own.

§ 136. The first observations were made at Grange, on
the north-western shore of Morecambe Bay, Lancashire,
during the latter end of August and beginning of Septem-
ber, 1865. As I was merely testing for the effects of ozone
upon the respiratory organs, and for the purpose of ascer-
taining the amount of ozone present, I did not pay much
attention to barometrical indications, to hygrometric con-
ditions, or to temperature. I was quite free from any sign
of hay -fever at the time.

The papers were exposed in a garden overhanging the
shore and running down close to high- water mark. Twelve
experiments were tried on six different days, commencing
on August 27th, and terminating on September 2nd. The
papers were exposed for twelve hours at a time, viz., one set
from 9 a.m. to 9 p.m., and another set from 9 p.m. to 9 a.m.
the following morning.

I was present during the time of the experiments four
days out of the six, and, except during meal times and
sleeping hours, was pretty constantly in the open air and
for the most part on the sea-shore close to the water's edge.

§ 137. The total quantity of ozone registered in the
twelve experiments was 93° (Schonbein), the mean for
twelve hours being 775°. The highest point attained in
this series of observations, in twelve hours, was 9°, and the
lowest 6°, and from a comparison of the total quantity
registered during the nights and the days it was found that
there was scarcely any difference between the two. The
total amount registered during the six days was 47°, and
the total amount for the six nights was 46°.

The average amount of ozone present was comparatively
large, especially if we take into account that the period of
exposure was only twelve hours, but it must not, however,
be supposed that because twelve hours gives a mean of
7*75°, an exposure of twenty-four hours would give double

Experiments on the Action of Ozone. 85

that amount on a scale. My experiments have shown un-
mistakably that it requires a vastly greater amount of
ozone to increase the depth of the colour in a slip of iodised
paper from 9° to 10°, than it does to change it from 1° to 2° ;
or, in other words, the higher we go in the scale the greater
is the amount of ozone needed in moving from one degree to
another. A similar set of experiments was made in the
same spot in 1866, with much the same results.

§ 138. Another set of experiments was made at South-
port, on the Lancashire coast, during the months of February
and March, 1 866. The amount of ozone was generally large
when a sea breeze was blowing, and usually lower when a
land wind prevailed. The highest point attained several
times exceeded the highest degree (= 10°) on Schonbein's
scale ; and when this happened to be the case the wind was
generally very strong. On such occasions I found that ozone
could be detected in close proximity to the backs of the
houses facing the main street of the town. The farther I
went inland the longer time* did it take to produce a given
effect on the test paper, and, as a matter of course, the
nearer I approached to the sea the more rapid was the
effect, providing no building intervened. The maximum
effect was got at the end of the pier when the tide was
coming in, and when a steady and tolerably strong breeze
was blowing in from the sea.

§ 139. A few observations were also made at Blackpool
during the latter part of October, 1869, but those that I
consider to be the most valuable and the most conclusive
were made at Filey Bay, on the coast of Yorkshire * in the
month of July, 1870. Here we have an expanse of sea from
three to four hundred miles in a straight line, so that when
a sea breeze is blowing, it has a long journey to make with-
out touching land ; consequently, whatever action the ocean
may exercise in generating ozone, we may expect to have
the full extent of this action exhibited here.

On many days during my stay at Filey, the temperature
was very high, so that the place and the season were favour-
able for observing the effect of heat as well as that of

* About seven miles south of Scarborough.

86 Experimental Researches on Hay-Fever :

ozone; and I also found the place favourable for deter-
mining other questions connected with the study of hay-
fever, in relation to which a geographical position of a
certain character, such as we find here, is absolutely needed
before any approach can be made towards deciding these
questions. I had, in fact, selected the place for this purpose.

§ 140. A glance at the map of Yorkshire will show a
narrow strip of headland* to the left of Filey Bay, which
runs out to seaward, half a mile or so in length. This
forms the northern boundary of the bay. At the extreme
point of this headland is a low reef of rocks/f* which are left
high and dry when the tide is out, but which are for the*
most part covered with water when the tide is in, and
especially at spring tides. This was an excellent spot for
experimentation, and was a favourite resort during my stay.
I found here a large amount of ozone at all times — larger
than at any other place I had visited; but this was no
doubt, in part, owing to the character and position of the
spot selected for the experiments, and also in some measure
to the force and direction of the wind during the time these
were in progress. It several times happened that five or six
hours' exposure would produce a depth of colour on the
test-papers equal to 7° (Schonbein), and in some cases, when
the test was exposed for twenty-four hours, the colour was
much beyond the highest point (10°) in Schonbein's scale.

§ 141. One experiment was tried on the water, the test-
paper being a portion of the time three or four miles away
from the shore. In two hours this gave a colour equal to
5°, but in a test-paper exposed for the same time outside the
house we occupied in one of the streets of the town (at right
angles with the shore) the test only reached 3°, although the
wind was blowing in from the sea all the time.

It is scarcely necessary to say that I was present during
the time when many of the experiments were in progress,
and frequently it happened that I was at the extreme point
of the reef of rocks I have named for several hours at a
time, so as to place myself fairly under the influence of the
abundant supply of ozone found at this place.

The Car Naze.' t ' The Brig/ or Bridge.

* <

Experiments on the Action of Ozone. 87

Two sets of observations were made at Llandudno in
North Wales, one in 1877 and another in 1878. These
were made in the month of August in each year, and were
principally for the purpose of determining the relative and
positive amount of ozone absorbed by the test-paper at each
point on the scale. Another set of observations was made
in Scotland in the month of August, 1879 (at Moffat in
Dumfriesshire, and at Oban in the Western Highlands), and
it was somewhat a matter of surprise to me that the reaction
obtained on exposing the test at Moffat was quite as great
as I have generally seen at the sea-side.

§ 142. In other experiments ozone was formed by per-
mitting sulphuric acid to act upon potassium permanganate.
A comparatively small quantity of the two agents named
was placed in a jar or wide-necked glass bottle ; these con-
tinued to give off ozone for several hours, and at the com-
mencement of the experiment gave off sufficient to colour a
test-paper, placed over the mouth of the jar, up to 6° or 7°
(Schonbein) in a couple of hours.

Several experiments were tried on the effect of ozone
generated in this manner. The gas was inhaled as it formed,
and the odour denoted that the quantity was, for the space
it occupied, much larger than in any other experiment I
have ever tried, except, perhaps, where a current of electric
fluid is thrown silently on the mucous membrane of the
nostrils*

§ 143. Whilst describing these experiments, I have pur-
posely refrained from giving the results in any case, for the
reason that the same statement will serve for all. From the
details and the dates I have given, the reader will have seen
that the observations were made at all times of the 3 T ear ; in
the autumn at Grange, when the hay season was quite over,
and at a time when I scarcely ever had any of the symptoms

* This is easily done by having a sharply-pointed wire connected
with the prime conductor of an electrical machine. If the wire is in-
sulated by cementing a piece of glass tubing over it, it may be held
in the hand of the operator, and the current of electricity will pass off
silently in the form of a luminous brush or cone, which has its apex
at the point of the wire, whenever the machine is put in operation.

88 Experimental Researches on Hay-Fever:

of the disorder lingering about me; in the winter and spring
at Southport, at a time of the year when I never remember
the disease troubling me; at Filey, in the middle of the
summer, when I was still suffering a little from hay-fever,
and in Wales and in Scotland, when the time for my usual
attack was just over.

In not one of these trials with atmospheric ozone could I
say that it had any unpleasant influence upon me. In the
experiments made with that which was generated artificially
the only effect produced was a slight senss of dryness in the
throat, but there were not any symptoms of hay-fever set
up, and I cannot say that at any time my experience corre-
sponded with that of Professor Schonbein. Perhaps it might
be that in my case a much less quantity of ozone was inhaled
than in M. Schonbein's; nevertheless, I am satisfied
that I inhaled a larger quantity, at times, than is ever met
with in the atmosphere in the same volume of air, and I
think it is fair to conclude that it cannot at any time bring
on this curious disorder with me.

§ 144. In addition to the experiments already detailed,
two different sets of observations were made for me by
patients who crossed the ocean to Australia in the latter
part of 1866 and the early part of 1867.

The variations of temperature and other meteorological
conditions were also noted, but as these have no direct
bearing upon the subject we are considering, I shall not
specially refer to them, but shall merely give such facts as
relate to the quantity of ozone observed on each voyage,
and to some of the circumstances which seemed to influence
this. It will be well to observe here that the numbers will
not always exactly agree with Schonbein's scale, as the
test-paper was not made in the same way as his, or with
the same proportions of the re-agents. Nevertheless, the
numbers given will suffice to give a tolerably fair idea of
the amount of ozone met with. These patients were not
affected with hay-fever, and the experiments cannot, there-
fore, have any direct bearing upon my own case ; but as
ozone has been so often mentioned as a possible cause of the
disease, it seemed to be an opportunity which ought not to

Experiments on the Action of Ozone. 89

be let pass without endeavouring to glean a little informa-
tion on the quantity met with on the open sea, and thus
possibly to throw some fresh light on those very rare cases
of the disease which are said to occur whilst the patients
are on the sea.

§ 145. The first patient went on board the vessel he
sailed in on November 6th, 1866. He commenced his
observations on the 20th November. Ninety-two observa-
tions were taken during the voyage. The test-papers were
exposed for twelve hours at a time, viz. from 10 p.m. to 10
a.m. on the following day. The first observation was made
on November 20th, when the vessel was about one hundred
miles from Lizard Point, and the last one on February 20th,
1867, when off Cape Otway (Victoria). The total amount
of ozone registered during the voyage was 572°, or a mean
of 6*2° for each twelve hours. The highest amount was 10°,
and the lowest 3°. During the whole of the experiments
ozone was never absent.

The second patient sailed from Plymouth on November
22nd, 1866. One hundred and twelve observations were
taken, commencing on November 28th, 1866, and terminating
on February 4th, 1867. The result of these experiments
agrees in the main with those given above, and particularly
in the circumstance that the quantity of ozone registered on
damp or wet days was always much greater than on dry
and fine days.* As in the other case, also, ozone was never
found to be entirely absent.

§ 146. As in my own observations at Grange and else-
where, the time of exposure — twelve hours — should be taken
into account in estimating the quantity of ozone met with.
When this fact is borne in mind the figures show that the
amount registered is comparatively large.*!*

* In the first set of experiments forty-five damp or wet days gave
a total of 332*5°, whilst forty-seven dry days gave a total of 239*5°.
During the first-named period the wind came from almost all points
of the compass, with perhaps, on the whole, a slight bias to the south ;
whilst in the last-named period the wind was quite as variable, but
came a little more from the north or north-east than from any other
.quarter.

f In comparing the amounts registered in different directions of

90 Experimental Researches on Hay-Fever:

These experiments show pretty conclusively that if atmo-
spheric ozone is a cause of hay-fever in any case, the disorder
ought to show itself more or less frequently whenever the
patient ventures near the sea, and as ozone seems to be al way&
present on the open sea, the disease should never be absent
whenever he is at a sufficient distance from land to be free
from the influence of land breezes. We ought also to expect
that if the disease is in any case produced by ozone, it should
vary in intensity with the rise or fall in the quantity of this
agent. How far this is shown to be the case I shall have to
consider further on.

E. Observations on the effects of Dust.

§ 147. In speaking of dust as a cause of hay-fever most
authors have used the designation ' common dust.' In the
strict sense of the term, however, there is no such thing aa
common dust. A careful examination of the dust of any
district will show that, in addition to those matters which
may with propriety have the name ' common ' applied to
them, it contains ingredients to which this cannot be
applied, and the nature of which will to a large extent
depend upon the season, upon the geological character of
the district, and upon the nature of its botanical productions.
The number as well as the kind of germs and other organic
bodies found in the dust of any district will also largely

the wind, some rather curious results were brought out ; the two
highest mean quantities obtained being with the wind at opposite
points of the compass, viz. from S.S.E. and N.N.W. The observa-
tions made while the wind was blowing from the first-named quarter
gave a mean of 8°, while those made whilst it was blowing from the
opposite quarter gave a mean of 7 # 6°. With the wind from the N.W.
the mean was 7*18°, and whilst blowing from the S.E. it was 7°. This
sort of balancing or compensating action seemed also in some degree
to hold good in the lower numbers ; as, for instance, in those with the
wind from the N.N.E. where the mean was 5*4°, whilst in those with
the wind from S.S.W. it was 5'6°.

Whilst, however, the above results were brought out by comparing
sections of the observations, a comparison of the whole experiments
did not seem to show that in any one direction of the wind there was
a larger amount of ozone present than in others.

Observations on the Effeots of Dust. 91

depend upon the meteorological conditions which prevail in
that district.

When I come to give an account of experiments tried for
the purpose of obtaining information on this point I shall, I
think, have abundant evidence to show that the statements
made above are, for the most part, borne out by the results
of a long course of observation. For the present I shall
content myself with mentioning, and with offering one or
two remarks on, the incident which first drew my attention
specially to this phase of the question.

§ 148. I had several times noticed that dust could at
certain times of the year produce some of the milder and
less-marked symptoms of hay-fever, but there was this
peculiarity about these attacks, that generally they came on
only during the time that hay-fever prevailed (and then as
exacerbations) or immediately after the hay season was over,
but rarely, if ever, during winter or early spring.

There was also another peculiarity which these attacks
had, namely, that they were more fitful and more ephe-
meral, coming and going in a more irregular and transitory
manner than the ordinary attacks of the disease ever do
when they have once set in. At first I was considerably
puzzled, and was unable to account for the fitful appearance
and departure of the symptoms. 1 also noticed that the
attacks were more frequent whenever I had to pass through
any dusty lane in the country, when the hay had been
recently all gathered in. I was consequently inclined to
think, as Dr. Phoebus and others have since thought, that
common dust was one of the causes of the disorder.

§ 149. In one of the earlier years of my attacks, before I
had made up my mind to follow out a systematic course of
observations on the subject, and when I was just getting
free from the disease (about the middle of July), I was out
in the country and had to walk through a lane which was
apparently not often used for the passage of vehicles. A
carriage which passed me at a rapid rate raised a cloud of
dust in which I was, for a time, completely enveloped and
-compelled to inhale pretty freely before I could get out of
it A very violent attack of sneezing immediately came on,

92 Experimental Researches on Hay-Fever :

and continued at intervals for about an hour. As I had to
pass over the same road on the following day, I determined
to see if the same result would follow by disturbing the dust
voluntarily. I found that I could bring on the symptoms
in this way to the fullest degree of severity.

The first examination of the dust under the microscope,
made with that which had been scraped from the road and
examined in its dry state, did not show anything very
special A second examination of the upper layer of dust
mixed with glycerine was more successful, and revealed to
me the presence of bodies which I now easily recognise as
the pollen grains of the grasses.

So far as I can now recollect, the weather during this
season had been very favourable for the rapid growth and
flowering of grass— first a few hours of rain, then a day of
sunshine — and when this got to be nearly ready for cutting,
and before the period of flowering was gone by, the weather
had settled down so as to give three or four weeks without
any rain.

§ 150. With the help of subsequent experience it is not
difficult to see why such a season as I have described should
have given rise to a condition of things which would quite
account for the symptoms from which I suffered, but it must
be confessed that it is not easy to say why I had the attack
more severely in this particular spot than I had in any
other under similar circumstances. Perhaps if I had then
been as well acquainted as I now am with all the various
channels by which the cause may reach a patient, in out-of-
the-way places and at unusual times, I might have been
able to explain the matter. At that time, however, I could
only do as some writers on hay-fever have since done —
speculate on the causes of the phenomena.

§ 151. Before I conclude my remarks on this part of the
subject I must allude to some circumstances which have
several times attracted my attention, and which may serve
as examples among many others which might be given of
the accidental and apparently causeless manner in which
the symptoms of the disease may be developed. I allude
first to the fact that an attack of the malady has often fol-

Observations on the Effects of Dust 93

lowed a ride in a railway carriage even when the train has
been going into a part of the country where the hay-making
has been finished, and where, so far as could be seen, there
could not be any possibility of the attacks being caused by
hay or by grass in flower. I am now satisfied, however,
that these attacks were generally brought on by getting
into carriages which had come from places much more north
than Manchester, and where the hay-making is much later.
For a similar reason I think the disorder may be brought
on earlier than usual by a patient travelling in and inhaling
the dust in carriages which have come from parts of the
country where the grass ripens earlier than it does in the
part where the patient may live. Then, on the other hand,
people who come from a district where the grass is in full
flower may for the time being infect any carriage in which
they may ride. That these are not matters of mere specula-
tion my own experience abundantly proves.

The incident I have related above, along with the other
circumstances alluded to, caused me after some time to
decide upon investigating the matter; but before I could do
so satisfactorily it seemed necessary to make some experi-
ments upon the action of pollen on the respiratory organs.

F. Experiments with Pollen.

§ 152. In the preceding pages I have shown that pollen
has been named by many authors as one of the principal
causes of hay-fever. Before the time my observations were
made no one had, so far as I am aware, put this agent to the
test by following out a systematic and continuous course of
experiments with it.

In the early history of the disease the nature of its cause
was enveloped in great obscurity, and those who suffered
from it were probably few in number ; it is not, therefore,
surprising that greater success should not have attended the
earlier efforts made to clear up this obscurity. But when we
remember the great differences of opinion which have of
late years been held on the causes of the malady, it strikes
one as a most remarkable circumstance that authors and
patients should have been content to go on theorising upon

94 Experimental Researches on Hay-Fever:

the cause of the disorder when a few comparatively easy
experiments would, so far as pollen is concerned, have set
the matter at rest in any individual case. It is, however,
much easier to theorise than to try experiments, and
especially when these would have to be tried on the
theoriser's own person. At the present time even, when so
much more is known of the disorder than formerly, opinions
are very much divided, and in some cases maintained in
defiance of the simplest rules of logic. In some instances
it is assumed that a disease which is as constant in its
symptoms as almost any disease we might name, owes its
origin to causes which are as diverse in their nature as it is
possible to bring together. It is, moreover, affirmed by
some authors that at one time one of these dissimilar causes,
and at another time another, may operate in producing an
almost unvarying set of symptoms ; or, in other words, that
in this disease like effects are produced by unlike and totally
different causes.

§ 153. In the experiments already detailed I have in
most instances had to record only negative results. In the
observations I am now about to describe we enter upon a
very different course. Almost every experiment is followed
by a greater or smaller amount of definite and unmistakable
effect which seems to point to pollen as the most powerful
if not the only cause of the malady.

In investigating the action of this agent on the respiratory
and other organs the questions which presented themselves
were : —

1st. Can pollen produce the symptoms of hay-fever ?

2nd. Does this property belong to all the pollens, or is
it confined to the pollen of some one or more orders of
plants ? and, if so, to what natural orders does it belong ?

3rd. To the pollen of which natural order, or of which
species of this order, are the actual attacks of hay-fever, as
they occur in early summer, due ?

4th. Is this condition or property found in the dried as
well as in the fresh pollen ?

5th. To what special substance in pollen is this supposed
action due ?

Experiments with Pollen. 95

The first four of these questions can be answered more or
less satisfactorily : the remaining one will still have to be
considered sub judice.

§ 154. There are certain conditions which are required in
the case of any agent which is to be accepted as the exciting
cause of hay-fever. In the first place, it should be shown
that this agent, whatever it may be, will, when brought
into contact with the respiratory mucous membrane, produce
the symptoms of the disease to which it is supposed to give
rise. In the second place, it should be shown that the dis-
order manifests itself whenever this agent begins to be pro-
duced in large quantity.* In the third place, the attacks of
the disease should lessen in severity as the production of
this agent diminishes, and should be entirely absent during
those parts of the year in which the latter is not generated.
As I proceed we shall see that these conditions are well
fulfilled in the case of pollen.

§ 155. The first experiments were made with the pollen
of the grasses, but the pollens of the plants belonging to
thirty-five other natural orders were also tried. The
experiments were made at all times of the year. In
some cases the dried pollen was used after it had been
kept some months, but for the most part this was
used during the period in which the plants indigenous
to this country were in flower, and whilst the pollen was
fresh.f

* I have made ' large quantity* a special condition, because I shall
have to show that the presence of a small quantity will not in some
cases produce well-marked symptoms ; but this term is, after all, only
used in a relative sense.

j* Pollen from the following plants was tested during the course of
experimentation, viz. : Aconitum 1 ; Helleborus niger ; Ranun-
culus acris ; ft. Jicaria; Anemone nemorosa; Caliha palustris ;
Aquilegia vulgaris (Ranunculaceae). Papaver rkceas (Papaveraceae).
Fumaria capreolata (Fumariaceae). Cardamine pratensis ; Nastur-
tium %; Cheiranthus cheiri (Cruci ferae). Viola tricolor; V.

odorata (Violarieae). Silene maritima ; Stellar ia media : Agrostemma

Githago (Caryophylleae). Malva sylvestris (Malvaceae). Hypericum

perforatum; Hypericum Andrososmum (Hypericineae). Geranium

? (Geraniaceae). Ulex Europo3us ; Cytisus scoparius ( Legumi-

noseae). Mubus fruticosus; Rosa canina (Rosaceae). Grategus
oxycanthus; Pyrus % (Pomaceae). Cucumis ovi/era (Cucur-

96 Experimental Researches on Hay-Fever :

This was tried in five different ways, viz. 1st, by apply-
ing it to the mucous membrane of the nares ; 2nd, by
inhaling it, and thus bringing it into contact with the
mucous membrane of the larynx, trachea, and bronchial
tubes; 3rd, by applying a decoction of the pollen to the
conjunctiva; 4th, by applying the fresh pollen to the
tongue, lips, and fauces ; 5th, by inoculating the upper and
lower limbs with the fresh-moistened pollen.

The incident related at § 98 seemed to indicate that the
pollen of grass was at least one of the causes of hay-fever.
Subsequent experiments confirmed the results of this
accidental trial, and furnished an answer to the first question
given above.

§ 156. The pollen of a number of the grasses was first
tried, and in every one of these trials this gave distinct and
unmistakable evidence of its power to disturb the healthy
action of the respiratory mucous membrane. When a small
portion of pollen, just sufficient to tinge the tip of the

bitaceae). Conium maculatum; Heracleum sphondylium (Umbelli-
ferae). Sambucus niger (Caprifoliaceae). JScabiosa columbaria (Dipsa-

ceas). A rctium lappa ; Centaurea 1 ; Tussilago farfara ;

Senecio vulgaris; Chamomilla matricaria; Calendula officinalis
(Compositae). Campanula rotundifolia ; C. hederacea (Campanul-
aceae). Vinca minor (Apocyneae). Convolvulus sepium (Convolvul-
aceae). Cynoglossum officinale (Boragineae). Solanum dulcamara;
Atropa belladonna; Solanum tuberosum (Solan eae). Veronica cha-
masdrys ; Euphrasia officinalis ; Digitalis purpurea ; Linaria cymba-
laria (Scrophularineae). Mentha piperita (Labiatae). Primula vul-
garis (Primulaceae). Plantago major ; P. lanceolata (Plantagineae).

Polygonum per 'sicaria ; Rumex % (Polygonaceae). Euphor-

bium ? (Euphorbiaceae). Betula alba; Castanea vulgaris

(AmentaceaB). Urtica urens (Urticacese). Arum maculatum (AroideaB).

Tulipa ? (Liliaceae). Hyacinthus non-scriptus ; Allium ursi-

num (Asphodeleae). Iris pseudacorus (Irideae). Narcissus pseudo-
narcissus (Amaryllideae). Anthoxanthum odoratum; Alopecurus
pratensis ; Aira ccespitosa; Poapratensis ; P. nemoralis; P. trivialis;
Lolium ltalicum; Triticum sativum; Secale cereale; Hordeum dis-
tichum; Avena sativa (Graminaceae). Eriophorum vaginatum (Cyper-
aceae). The pollen of a number of exotic flowering plants, the names
of which I had no time to ascertain, was tried and yielded results
much like the average of those given above.

Experiments with Pollen. 97

finger yellow, was applied to the mucous membrane of the
nares, some of the symptoms of hay-fever were invariably
developed, the severity and continuance of which were
dependent upon the quantity, and upon the number of times
it was used.

In an experiment made with the pollen of the Lolium
Italicwm the first sensation produced was that of a very
slight degree of anaesthesia of the spot to which this had
been applied. This was followed by a feeling of heat which
gradually diffused itself over the whole cavity of the .
nostril, and was accompanied by a slight itching of the part.
After some three or four minutes a, discharge of serum came
on, and continued at intervals for a couple of hours. The
mucous membrane appeared to swell, and eventually became
so tumid that the passage of air through the nostrils was
very much impeded. No sneezing occurred in this case, but
this might partly be accounted for by the circumstance that
the quantity of pollen applied was very small, and probably
also by the fact that this was not fresh when applied.

§ 157. In another experiment tried with the pollen of the
Alopecui*us pratemis the lining membrane of one nostril
was charged with the pollen by this being rubbed on with
the point of the finger as far as this would reach. About
one fiftieth of a grain was applied. Similar sensations to
those described above came on, but showed themselves
more rapidly than in the former case. In a few minutes a
violent attack of sneezing came on ; there was also a pro-
fuse discharge of serum, which continued for some hours,
gradually diminishing towards the latter part of the time.
In two hours after the experiment had commenced the
mucous membrane had become so much swollen that no air
could be drawn through the nostril in any attempt at
inspiration.

§ 158. The pollen of Secale cerecde (Rye) produced
symptoms of a much more severe and lasting character than
either of the grasses named above. This is, I think, in
part due to the fact that the pollen of this plant is much
larger than that of most of the grasses. In one experiment
the sternutations were very strong and long-continued ; the

7

98 Experimental Researches on Hay -Fever:

discbarge from the nostrils was very copious, and produced
more excoriation than in either of the other cases. The
pollen was taken fresh from the growing plant, and applied
on the spot, consequently I could make no attempt at
ascertaining what was the exact quantity applied; but from
the circumstance that fresh pollen is much more adhesive
than it is when dried, it is very probable that the quantity
would be considerably larger than was usually applied.

§ 159. The day on which the above experiment was made
was warm and moist — just such a day as would bring the
pollen rapidly to maturity. A profuse coryza came on in
less than a minute after the application. In thirty minutes
the nostril was completely occluded, so that it was quite
impossible to pass any air through it. During the day the
sneezing and coryza kept up at intervals, and lasted for six
or eight hours. During the night the nostril which had
been closed became patent again once or twice, but curiously
enough the nostril to which no pollen had been applied
became almost entirely impervious to the passage of air,*
and on each occasion violent attacks of sneezing came on.
The experiments with Rye (Secale) were tried several times,
and were always marked by decided symptoms varying in
intensity according to the quantity of pollen used ; having
a milder character if this was used dry instead of fresh.
The attack induced by three applications, at intervals of an
hour, lasted twenty-four hours, and could even then be
scarcely said to have cleared away. The discharge of the
serum gradually altered by the latter becoming more inspis-
sated, taking in this respect pretty much the same course as
is seen in a case of ordinary catarrh, namely, by the dis-
charge gradually changing to a puriform mucus, which >
under the microscope, was seen to be much of the same
character as that of the subsiding stage of ordinary catarrh.

§ 160. The action of the pollen of Triticum (Wheat)
comes very near to that of the Secale) but is perhaps not
quite so severe, nor does it develop its symptoms so rapidly.
It is, however, quite as severe as that of any of the grasses,

° The cause of this phenomenon I shall be able to explain
further on.

Experiments with Pollen. 99

and seems to have a tendency to produce a more lasting
impression than many of these.

In the case of the A vena sativa (Oat) the action seemed
much the same as in some of the larger grasses. In two
experiments which were tried with the pollen of this cereal,
it was, as in the case of the SecaU, applied whilst quite
fresh. The symptoms were more severe and more rapidly
developed than they are found to be when the plant is
gathered and the pollen collected and dried before using.

§ 161. Only one experiment was tried with the pollen of
Hordeum distichum (Barley), consequently I am not able
to speak so decidedly upon it as in the case of the other
cereals and grasses. Nevertheless, its action was sufficiently
well marked to show that it had, in common with the pollen
of all the plants tried belonging to the order Graminacese,
the property of disturbing the normal action of the respira-
tory mucous membranes in hay-fever patients.

In an experiment which was tried with the infusion of
the pollen of the Lolium Italicnm the action was very
distinct so far as it went, but in this case there was no
sneezing, and only a very small quantity of serum was dis-
charged. The most marked effect produced was the tume-
faction of the lining membrane of the nostril. This was
slow in developing and equally slow in disappearing.

§ 162. The pollen of the Lolium Italicnm was used with
patient No. 6 on two occasions in a manner similar to that de-
scribed above. In both experiments symptoms much the
same as those produced in my own case were developed.
There was sneezing, discharge of serum, and partial occlusion
of the nostril. One experiment was also tried on patient No. 7
with the pollen of Alopemrus pratensis. Profuse watery
discharge from the nostril followed the application. There
were also several attacks of sneezing in the course of a few
hours, but in this case the occlusion of the nostril was not
so marked as in my own. In neither case was the patient
aware of the nature of the substance used, nor yet of the
object of the experiment. In both instances the dried pollen
was used. This was applied on one occasion early on in the

7—2

100 Experimental Researches on Hay-Fever:

year before the grasses were in bloom, and on the other in
the early part of winter when few plants are in leaf.

The action of the pollen of the order Graminacese was on
the whole very distinct and well marked. In some cases it
was comparatively mild, and in other cases, as we have seen,
somewhat severe.

§ 163. In the case of plants of some of the other natural
orders the action was quite as well marked as in any of the
grasses. The pollen of the Corylus avellana, for instance,
developed its symptoms moderately rapidly. A small por-
tion of this pollen was applied to the mucous membrane of
one nostril in the usual manner. In ten minutes a violent
lit of sneezing came on, and was quickly followed by a
copious discharge of thin serum. There was a sensation of
heat in the nostril, and there was also some oppression of
the breathing, which in this case must have been caused by
reflex action, as there was, so far as I could judge, no pollen
inhaled. Why this should be the case with some pollens
and not with others I am at present unable to say. I am,
however, satisfied that asthmatic symptoms may be brought
on as hay-asthma by reflex action. The mucous membrane
of the nares was so much swollen in fifteen minutes after
*Jhe pollen was applied that the air was with difficulty
drawn through the nostril, and in thirty minutes the occlu-
sion was complete. -

The pollen of the common Tulip brought on a profuse
discharge of serum, and produced great tumidity of the
mucous membrane, but singularly enough there was no
sneezing until the middle of the night, twelve hours after
the experiment had commenced.

§ 164. One experiment was tried by using two different
pollens for the two nostrils in as nearly the same quantity
as possible. One nostril was charged with the pollen of the
Tilia media (Linden tree), and the other with the pollen of
the Jasione (Sheep's bit). The latter was the quickest in
its action and also apparently the most powerful. There
was first a sense of pressure in the nostril combined with
slight itching; then swelling of the mucous membrane — or
to speak more correctly of the submucous cellular tissue —

EocperimenU with Pollen. 101

and discharge of serous fluid. The latter was most profuse
in the nostril to which the pollen of Jasione had been
applied. The symptoms produced were much the same as
those brought on by the use of the grass pollens, and the
circumstance of both nostrils being affected at the same time
did not seem to have any influence on the rapidity with
which the symptoms disappeared. A walk in a park, where
there were a great number of linden trees in bloom at the
time, invariably brought on a smart attack of sneezing and
coryza with me. and also seemed to have a tendency to pro-
duce more decided asthmatic phenomena than I have ever
noticed when the grasses have been in flower.

§ 165. The inhalation of pollen, without permitting this
to pass in any quantity through the nostril, generally
brought on asthmatic symptoms, and in these cases only
could I say that constitutional symptoms were developed.
An example of this occurred accidentally in the month of
March before any of the grasses were in flower.

In preparing the pollen of one of the Amentacese for the
microscope a considerable quantity was accidentally inhaled
before I was aware that it had been thrown off from the
catkins so abundantly. A violent attack of sneezing came
on in a few minutes, but this was not by any means so
violent nor yet so persistent as I should have expected from
the quantity of pollen which seemed to have been disengaged.
Later on there was a moderately copious discharge of thin
serum which kept up for some hours. After the sneezing
and coryza had continued for a couple of hours the breath-
ing became very difficult as if from constriction of the
trachea or bronchial tubes, giving me just a slight experi-
ence of the misery those have to endure who suffer severely
from the asthmatic form of hay-fever. In the course of five
or six hours I began to have aching and a sense of weari-
ness over the whole body, with pain in the head and spinal
column. A very restless night was passed ; the pulse rose
from its usual number (68) to 100. Occasionally there was
slight cough with expectoration of thin frothy sputum, and
for twenty-four hours I felt as if passing through an un-
usually severe attack of influenza. During the succeeding

102 Experimental Researches on Hay-Fever:

night a violent perspiration set in, and as this proceeded I
began to feel more easy. The pain in the head and the
sense of weariness gradually abated, and at the end of the
second day I was fit for duty again. In the early part of
the attack, as I have mentioned above, there was expectora-
tion of frothy sputum. This gradually changed to a thick
puriform mucus, which was during the latter part of the
time brought up for the most part by the mere effort of
hawking.

§ 16t>. Another occurrence of a similar character took
place whilst preparing some of the pollen of Alopecurus
pratensis for the microscope. In this case the symptoms
were similar to those given above, but not by any means so
severe, and in addition to the symptoms detailed above
partial loss of voice came on, accompanied by a sense of
irritation just behind the pomum Adami.

One experiment of a similar kind was voluntarily tried
with pollen of Loliu/m Italicum. A very small quantity
was inhaled and was not allowed to pass through the nostrils
in the process. No constitutional symptoms were developed.
The only symptoms were difficulty of breathing, as if from
narrowing of the bronchial tubes, with slight cough and
expectoration of frothy sputum. Probably the mildness of
the attack was due to the smallness of the quantity of pollen
inhaled.* The suffering and inconvenience caused by the
former experiment prevented me from carrying this latter
to such an extent as to run the risk of producing as much
disturbance as in the former case ; it was, however, carried
sufficiently far to show that the possibility of inducing the
most violent asthmatic symptoms was only a question of
quantity."}*

§ 167. With the view of ascertaining what would be the
effect of a watery and spirituous extract of pollen when
applied to the nostril, an infusion of that of the Lilium
tigrinum was made. The infusion was filtered, and proof

* Whether the constitutional symptoms in the first experiment
were caused by the pollen I am not prepared to say, but I have no
reason to doubt that they were.

t Probably also to some extent a question of kind of pollen.

Experiments with Pollen. 103

spirit was added to the residuum, and this was again filtered
after macerating for a few days. The two filtrates were
evaporated to a syrupy consistence and mixed together. A
portion of this mixture was applied to the lining membrane
of the nostril in the same manner as the pollen had been
applied. No effect which could be attributed to the applica-
tion followed. The pollen of LUium is not very active
when applied fresh, but still it is sufficiently so to show
that it possesses the property of deranging the action of the
mucous membrane of the air-passages.

§ 168. A decoction of the pollen of Gladiolus was made
by boiling a portion of this with one hundred times its
weight of distilled water. One drop of this liquid was
placed in contact with the conjunctiva of the right eye*
The effect was almost instantaneous. The first sensation
was that of intense burning and smarting, coupled with a
feeling such as might be imagined to be caused by fine sand*
being blown into the eye. The photophobia was so severe
that for some minutes the eye could not be opened for more
than a single second at a time. In about thirty seconds the
capillary vessels of the conjunctiva were seen to be greatly
distended. With the aid of a lens the larger vessels of the
conjunctiva could be seen to be raised above the surface.
Movement of the eyeball gave great pain, just as is felt when
dust has been blown into the eye. In six minutes the con-
junctiva had become quite cedematous, but showed its closer
attachment as far as the outer margin of the cornea. The
oedema increased until very severe chemosis was set up.
The eyelids also became much swollen. In two hours after
the fluid had been applied the smarting and burning had
much abated, and the congestion of the conjunctival vessels
had considerably lessened, but the chemosis remained and
was even more marked than it had been an hour before
There was a moderately copious discharge of fluid from the
eye and also some little from the nostril. In six hours the
eye still felt uneasy, but there was very little pain on
moving the eyeball, although the vessels of the conjunctiva
were still injected. The chemosis still remained as severe
as before. In eighteen hours there was scarcely any con-

104 Experimental Researches on Hay-Fever;

gestion of the vessels remaining, but the chemosis was still
very distinct. In thirty-two hours all traces of the derange-
ment had disappeared. During the course of this experi-
ment no effect was ^produced on the sclerotic coat of the
eyeball, nor yet, so far as could be seen or felt, on the
deeper structures. The action seemed to expend itself
upon the conjunctiva and upon the cellular tissue of the
eyelids.

§ 169. One grain of the pollen of Alopecurua pratensis
was applied to the fauces for the purpose of ascertaining if
it would have any effect upon the tonsils and upon the
mucous membrane of the mouth and fauces. Slight itching
came on in the course of a few minutes, and in half an
hour the mucous membrane of the fauces was seen to be
somewhat congested, but this was more seen in the engorge-
ment of the larger capillaries than in a diffused redness.
The itching was quickly followed by a sensation as if some
hard angular bodies stuck in the throat. There was also
a feeling of constriction about the fauces, although there
was no swelling perceptible on examining the throat. I
am, however, convinced from subsequent experience that
the sense of constriction was caused by oedema of the sub-
mucous cellular tissue of the pharynx. The symptoms
remained stationary for two or three hours and then
gradually diminished.

" § 170. Whilst I was still suffering from my usual attack
of hay-fever, during the summer of 1865,* as much pollen
as could be obtained from two anthers of the Loliwmltalicum
was applied to the centre of the anterior surface of one
forearm after the skin had been abraded as in the ordinary
mode of vaccinating. A space of about a quarter of an inch
was abraded, and to this the quantity of pollen named was
applied after being placed on a piece of wet lint the size of
the abrasion. This was covered with a piece of thin gutta
percha, and the whole was held in position by a strip of
adhesive plaster. The centre of the other forearm was
treated in exactly the same manner save and except that no
pollen was applied to it. The scratching with the lancet

'• July 13th.

Experiments with Pollen. 105

raised a wheal such as is seen in urticaria or in stinging
with nettles. In a few minutes after the pollen had been
applied the abraded spot began to itch intensely ; the parts
immediately around the abrasion began to swell, but this
was not apparently due to any action on the cutis vera.

§ 171. In the above experiment the swelling seemed to
be entirely due to effusion into the subcutaneous cellular
tissue. There was no heat or redness more than what had
been caused by the abrasion, and these were much the same
on each arm. Although the swelling had the appearance of
oedema, it located itself at first exactly around the abrasion
to which the pollen had been applied, and gradually spread
from this point and formed a flattened tumour, which had
its centre at the abraded spot. There was no tenderness,
and any part of the swelling was easily made to pit on
pressure. The wheal caused by the lancet did not increase
much in size after the pollen was applied. The tumour in-
creased in size until it measured two and a half inches in
length, by one inch and a half in breadth, and was raised
above the ordinary level of the surface nearly three quarters
of an inch. No pain was felt in the limb, nor was there
any heat or redness present at any time, beyond the very
slight amount to which the abrading of the cuticle gave rise.
The swelling attained its maximum in six hours, and then
remained stationary for other eight hours; after this it
gradually subsided, and in forty-eight hours it had entirely
disappeared. The arm to which no pollen had been applied
did not exhibit any sign of swelling or irritation.

§ 172. In the latter part of September in the same year
another experiment of a similar character was tried. Much
the same effect as was seen in the former one followed, but
the swelling was not so great, and subsided more readily.

In the following year the experiment was repeated by
applying the pollen to the integument covering the centre
of the right tibia. This spot was chosen because we have
here only skin and cellular tissue, with a hard unyielding
surface of bone behind these; consequently, whatever in-
crease there is in the bulk of the part operated on, it must
declare itself more distinctly and more exactly than it is

106 Experimental Besearches on Hay-Fever:

possible for it to do when there are soft structures under-
lying it. The same conditions were observed as in the
experiment described above. When the pollen had been
applied for a few minutes, the same intense itching of the
part came on, as in the former case, but owing probably to
the circumstances of the pollen being larger in quantity, this
was more severe, and longer continued.

§ 173. In about fifteen minutes after the above experi-
ment commenced the limb began to swell, and gradually
increased in size, until the tumour measured four inches in
length by two inches in width, whilst the centre was raised
quite three quarters of an inch above the surface of the
bone. The increase in the size of the tumour was much
slower than in the other cases named. The swelling attained
its maximum in about twelve hours, after which it remained
stationary for other twelve or fourteen hours. At the end
of four days the limb had assumed its usual size and form,
the derangement having entirely passed away. During the
time the tumour had somewhat changed its location, as if
the fluid contained in the subcutaneous cellular tissue had
gravitated ; the portion of the swelling which disappeared
last being quite an inch below the spot where the pollen
had been applied. There was neither pain, heat, nor red-
ness present during the whole time.

§ 174. Dr. Wyman, to whose work I have before referred,
also tried experiments with pollen. In speaking of these he
says :* ' Early in September, 1870, I gathered, in my
grounds at Cambridge, Mass., some Boman wormwood in
full flower, covered with pollen, taking the whole plant,
stalk and roots. This was carried to the White Mountain
Glen, about 1200 feet above tide, where we remained till
September 23rd in the afternoon. The parcel containing it
was then opened, and freely sniffed by myself and my son.
We were both seized with sneezing and itching of the nose,
eyes, and throat, with limpid discharge. My nostrils were
stuffed and my uvula swollen, without cough, but with the
other usual symptoms of autumnal catarrh. These troubles

* Autumnal Catarrh (Hay-Fever), by Morrill Wyman, M.D.,
p. 101.

Experiments with Pollen. 107

continued through the night, and did not disappear till the
afternoon following. Professor Jeffries Wyman, who was of
the same party, did not sniff the plant, and had none of the
symptoms just described/

§ 175. ' A portion of the same plant/ Dr. Wyman says,
'was sent to friends at Waumbec House, Jefferson Hill.
The results of the experiments tried were as follows:
'Eight persons sniffed the plant. One was seized with
asthma and stricture in the chest, and did not entirely
recover from the effects until the next day. This person is
severely affected with asthma, and particularly sensitive.
One was attacked with catarrh, as he would have been at
the same period at home, and the eyes were irritated for
several hours; one had sneezing and coughing for some
little time ; two had sneezing only. One had sneezing and
watering of the eyes ; one had only irritation of the eyes for
some time; and one experienced no effects whatever.
Eight other persons were in the house at the time who are
subjects of the disease, but did not sniff the plant, and
were not similarly affected.'

In another experiment tried upon himself, Dr. Wyman
says : ' In February, 1865, I planted in a pot a quantity of
the seed of the Roman wormwood (Ambrosia artemesue-
folia) and kept it in a warm room ; as soon as the weather
was suitable it was placed out of doors and properly cared
for. It began to bud early in July ; 16th July it was in
flower ; the pollen was apparent but not copious. It was
then placed in my sleeping-chamber, and there remained
until it ceased to flower. Nothing which I could attribute
to its influence followed/ In another experiment the pollen
of the Roman wormwood was gathered when in full flower,
preserved in its dried condition and sniffed late in February
by a subject. In one trial it had no effect, but in another it
was followed by some stuffing of the nostrils and discharge
of limpid fluid.

§ 176. Dr. Elias J. Marsh, of Paterson, New Jersey,
(U.S.), who, as I have previously stated, is a subject of hay-
fever, has also tried experiments with pollen upon himself
and one other sufferer. In the excellent paper to which I

10& Experimental Researches on Hay- Fever:

have before referred he says:* 'On August 6th, 1874, I
picked a few racemes of Ambrosia, the flowers of which were
in full bud, but not quite opened, and placed them in a glass
of water in my office. This hastened the ripening, so that
the next day they scattered pollen abundantly on handling
them carelessly in the preparation of some specimens for the
microscope. For twenty-four hours afterwards I suffered
from a severe coryza, with occlusions of the nostrils and
serous discharge. The symptoms then passed off, and I had
no return of them until August 13th, when I repeated the
experiment and also applied some pollen directly to the
nostrils. This produced immediately such severe catarrhal
symptoms, that the next day I took a hypodermic injection
of morphine for their relief. The symptoms did not pass off
but continued into the regular attack, which should have
commenced a few days later. A friend, not subject to the
disease, at the same time tried the same experiment, and
was entirely unaffected. On August 23rd I left home for
the White Mountains, and while there, finding a few plants
of Ambrosia, tried the same experiment upon myself and
another subject of hay-fever. We both being quite well,
applied the ripe pollen freely to the nostrils, and almost
immediately a very severe inflammation of the membrane
began, with all the symptoms (except thoracic) of hay-
fever. It continued severely for several days, and then
subsided. Since that time I have never intentionally re-
peated the experiment, being fully convinced that the pollen
of the Ambrosia is a very severe irritant to my mucous*

membrane On August 9th, 1876, I handled rather

carelessly, in preparing for the microscope, some flowers
of another variety of Ambrosia, the Ambrosia tri/oUa*
These flowers were covered with pollen, and I suffered
slightly from coryza for the next twenty-four hours, when
the symptoms passed off/ Dr. Marsh also made some
experiments on the presence of pollen in the atmosphere, on
the plan I myself pursued. To these I shall refer when I
come to speak of the correspondence between the quantity

* Hay-Fever, or Pollen Poisoning, an Essay read before the New
Jersey State Medical Society, by Elias J. Marsh, M.D., pp. 14, 15.

Experiments with Pollen. 109

of pollen found in the atmosphere in England during the
hay-fever season, and the intensity of the symptoms in my
own case.

§ 177. We have seen that experiments were tried with
pollen in various ways by Dr. Kirkman (§ 38) ; Dr. Wyman
<§§ 174—175) ; Dr. Marsh (§ 176) ; Dr. Patton (§ 80) and
more extensively by myself (§§ 156 — 173). The total number
of persons experimented upon was sixteen. In every case
but one some of the symptoms of hay-fever were produced,
and in some the disturbance was very severe and very
Characteristic. On the other hand the experiments made
with the other supposed causes of hay-fever yielded, as we
have seen, no symptoms of the malady.

In a correspondence which occurred between Dr. Wyman
and myself in 1873, I expressed the opinion that the
American autumnal catarrh was in all probability caused
by the pollen of Indian corn (Zea mays). At that time I
had not much information of the extent and distribution of
some of the plants belonging to the American flora. There
is no doubt that the pollen of the Indian corn has a con-
siderable share in the production of the malady in some
parts of the country, but from the facts I give below, I think
it is highly probable that the pollen of the Ambrosia
<irtemisicefolia is one of the greatest causes, if not the chief
•cause.

§ 178. My attention was first called to the extreme
luxuriance and wide distribution of the Artemisise in some
parts of America by a passage in the work of Dr. Pickering.*
When speaking of Oregon, he says: 'The country, as
throughout a great part of the interior, did not appear to
become green at any part of the year, but presented a hoary
aspect chiefly from the prevalence of Artemisia.' Dr.
Wyman f also speaks of the Ambrosia artemisicefolia as
growing ' very generally in those regions where the disease
exists/ and as the disease is said to prevail in most of the
Northern States, the plant must therefore have a wide dis-

* The Baces of Man, and their Geographical Distribution, by
Charles Pickering, M.D. London, Bell and Daldy, 1872, p. 30.
+ Autumnal Catarrh, by Dr. Wyman, p. 101.

110 Experimental Researches on Hay-Fever:

tribution. Dr. Marsh * says : ' I have noticed the extreme
abundance and wide diffusion of the Ambrosia during my
travels to escape it. In this section of the country it may
be said to grow everywhere. Road-sides, stubble-fields,
waste-places, everywhere abound with it; and few of the
most highly cultivated gardens are free from it. It is only
after the attention has been directed to the plant that its
univeral presence is observed. It seems to spring up by
magic everywhere. I have counted hundreds of plants
within a few blocks in New York City, in the neglected
courtyards, and spaces about houses and churches. I have
found that it extends up to the limit of the catarrhal
regions, and not at all, or in extreme rarity, in the exempt
regions.'

§ 179. The examples of the action of pollen taken from
my own experiments have been selected from a large number.
These give a fair idea of the nature and extent of this action.
In most cases the experiments were repeated several times,
and in some instances, where the details were not noted
down at the time, the action was quite as severe as in those
I have cited.

Extending as they do over a good number of years, the
trials must have been made in very varied physical and
mental conditions, even within the limits of health ; but
some of the experiments have been made when the system
has been in a state bordering upon, if not actually suffering
from, disease. I have not found, so far as I have noticed,
that these varying conditions have had any influence in
increasing or diminishing the intensity of the symptoms
produced.

§ 180. With some rare exceptions, the action of the
pollen of the plants named in the list given was sufficiently
perceptible to show that this action was in some degree
common to all. The intensity of the symptoms, however,
varied in using the pollen of different plants, and also in
that from the same plant at different times. There seemed,
in fact, to be some circumstances which had a controlling or

* Hay- Fever j or Pollen Poisoning, by Elias J. Marsh, M.D., pp.
13, 14.

Eocperiments with Pollen. Ill

modifying influence upon the production, as well as upon
the activity of pollen. Probably some of these modifying
influences consist in those subtle atmospheric conditions,
of the nature of which we are at present profoundly
ignorant.

There are, however, some circumstances which exercise
an important influence, and with whose nature we are toler-
ably well acquainted. One of these is temperature. A
high temperature is in itself favourable to the generation of
pollen, but a high temperature with severe drought will, in
the case of the grasses, check their growth, and thus
prevent the formation of pollen. In proportion as tempera-
ture and moisture are suitably combined, so will be the
production of pollen, but where these happen to be unusually
favourable, we mav have the grass arriving at maturity
rapidly, and as a consequence this may be quickly cut and
converted into hay and housed. Under such circumstances,
hay-fever patients may have a short season of attack, but
the symptoms may be very severe whilst they last.

§ 181. Low temperature operates in quite another manner
with the majority of the grasses. Growth may go on
moderately well with a comparatively low temperature,
especially in some of the grasses, but a temperature below a
certain point will not permit the flowering process to go on
in a normal manner. Not only will the quantity of pollen
thrown off by a given number of plants be lessened, but
that which is generated will have much less vigour than it
has in favourable seasons. In the same manner pollen
.obtained from plants which have flowered prematurely does
not seem to possess the same activity as that which is
generated later. The pollen of Bettis perennis (common
daisy) gathered during the earliest period of flowering, in
the month of March, did not seem to have the same power
as that which was gathered in the middle of summer,
although this plant blooms from early spring to autumn.

Some of the cereals, however, will arrive at maturity,
and maintain a vigorous and healthy condition during their
period of growth, with a much drier state of the atmosphere
and soil than is borne by many of the grasses. It is well

112 Experimental Researches on Hay-Fever:

known thai wheat will thrive and do well with much less
moisture than the grasses need. Thus it happens that in
cold and wet summers hay-fever patients will suffer much
less than in better seasons ;* whilst in a very hot summer,
with continued drought, patients may almost escape the
disease, even if they reside in a part of the country where
hay-grass is largely cultivated. But when the cereals come
to be in flower they may suffer very severely for a time. I
think it was in this way that the attacks which Bostock
had in the Isle of Thanet might be accounted for, and the
mistake he made was in supposing that grass in flower was
the only thing, besides heat, which could bring on the
disorder.

§ 182. Overgrown pollen also seems not to be as active as
that which is fresher and younger. The pollen of Atropa
belladonna (deadly nightshade) showed very little activity
when gathered whilst the plant was in fruit, and when only
a few half- faded flowers were found on it. From the fact,
however, that the pollens of Solanum dulcamara and
Solanum tuberosum have only a mild action, it is probable
that the pollen of Belladonna will not be found very active
«ven when gathered at the height of its flowering season.
This, however, cannot be considered a settled point; but
certain it is that in some cases pollen is not as active when
gathered too early or too late, as it is when taken at the
middle of the flowering season ; and whatever circumstances
interfere with the usual course of this process, these will
Alter the quality of the pollen produced.

Whatever may be the nature of the influences which
modify the activity or power of pollen in producing hay-
fever, this power was always present in a greater or smaller
degree in almost all the plants experimented with. In some
it was so mild that it was necessary to repeat the experi-
ment several times and under varying circumstances in
order to be certain that it was present. In others the action
was both rapid and vigorous, and such that, if continued,
would have led to severe suffering, if not to dangerous
symptoms.

* The summer of 1879 was a good example of this.

Experiments with Pollen. 113

§ 183. Before proceeding to inquire what particular
portion of the pollen grain or what particular substance con-
tained in this is the active agent in producing hay-fever, it
will perhaps be well to notice some conditions which seem
to have no influence whatever either in bringing on the
attacks or in modifying their intensity when once produced.

The pollen grains of different orders of plants vary
much in size and in weight ; in some cases not being more
than one-twentieth the size or weight of others. This
circumstance, however, does not always aflfect their power
of producing hay-fever. The size of the pollen grain has no
constant relation to the intensity of the symptoms * A large
pollen grain may produce a mild attack, whilst a smaller
one may produce much more severe derangement.

§ 184. Pollen grains also vary in shape and in the rough-
ness or smoothness of their outer coat. In the state in which
the pollen comes to be when in contact with the mucous
membrane of the Dares, or of the trachea and bronchial
tubes, in some cases the outer coat will be perfectly smooth
and oven, such as for instance in the cereals or the grasses.
In others the surface is studded over with sharp points, as
in the orders Compositse and Malvaceae ; and whatever may
be the varying conditions such pollen is placed under, with
regard to excess or deficiency of moisture, this roughness is
never entirely got rid of. Between these two extreme
characters of surface there are all degrees, but in no case
have I noticed that the shape, or the degree of roughness of
the surface, has any influence in regulating the intensity of
the symptoms produced.

We have seen that in the list given there are several
plants of a poisonous character. This circumstance, how-
ever, seems not to affect the quality of the pollen, so far at
any rate as the production of hay-fever is concerned. In
one of the most poisonous families (Solanese), the pollen
produced even milder symptoms than that of the grasses.

§ 185. In commencing the inquiry into the question as
to what constituent of pollen is the exciting cause of hay-
fever, we encounter some difficulties which are not easily

* When equal quantities by weight are applied.

114 Experimental Researches on Hay-Fever:

removed. Whatever part the pollen-cell may take in the
generation of the varied and beautiful forms of plant life,
even with the aid of the most powerful instruments it gives
to the vegetable physiologist no indication of the possession
of those wonderful powers which belong to it and which lie
hidden in its apparently structureless granular matter.

In like manner, if we seek for any sign of pollen being
the cause of this disease, we find no special character in
any portion of the cell which will enable us to account for
the phenomena of hay-fever. Pollen is, in its recent state, a
living structure, and if we attempt to examine it by
chemical means or by any mode of manipulation which
alters the relation of its separate parts, we may change its
character and lessen its vitality. It will no longer be the
active and living organism it was before our examination
began, and the changes we have brought about may involve
the alteration or destruction of those very qualities upon
which the production of morbid phenomena depends. These,
as I shall be able to show, do to some extent depend upon
the vitality which it possesses in common with all bodies of
the same class ; consequently in all our examinations we are
constantly met by the difficulty there is in keeping intact
the disease-producing quality whilst we isolate that portion
of the pollen to which it belongs. There are, however,
some of the symptoms of hay-fever which are probably due
to mechanical causes, but which are nevertheless produced
by pollen.

§ 186. Examined under the microscope a pollen cell is
seen to be a simple cell with granular contents. Its cell
wall is generally composed of two layers, only — an vntine
or inner coat and an extine or outer coat.* In addition to
these two membranes pollen of almost all kinds is covered

* There is also a third coat in some pollens. In the pollen of the
Cucurbita ovifera I have found this third coat to consist of an ex-
ceedingly delicate membrane, which seems to lie between the inner
and outer coat It is not seen until the pollen has been immersed in
water, or in water and glycerine, for a short time ; it then protrudes
and lifts up the minute lids which cover the pores in this pollen
grain.

Experiments with Pollen. 115

with a substance which resembles an oleo-resin, and in some
instances I have thought that a portion of this substance
has come from the interior of the pollen grain. In some
•cases this oleo-resin is of a rich amber colour, when seen
under the microscope, whilst in others it is of a pale straw
colour. It varies in quantity in different pollens. In that
of Milium album it is especially abundant and also in that
of the Calendula officinalis, as well as in several other
plants of the order Composite. It is very little soluble in
water or in proof spirit, but dissolves readily in ether and
in oil of turpentine. I believe it slowly volatilises at
ordinary temperatures, but of this I cannot speak very
positively. It is this substance which causes pollen to
.adhere to any body with which it comes in contact when
fresh.* Some of the pollens which have the largest quantity
of this oleo-resin about them are not so active in producing
hay-fever as those which contain much less of it. All the
pollens of the grasses that I have examined have a very
small quantity about them, and yet they are amongst the
most active in producing the symptoms of hay-fever. From
these considerations I conclude that this body has little or
no influence on the disease, and that we must look to some
other portion of the pollen grain for the exciting cause of
the malady.

§ 187. Seen under the microscope, when fresh, pollen
grains have generally a definite and regular shape. When

* Keferring to this subject Lindley says : ' In all cases where there
Are asperities of the surface or angles in the outline, pollen is asserted
by Guillemin to have a mucous surface, which was first observed in
Proteaceae by Brown ; but Mohl finds that the presence of mucosity
upon pollen is a constant character, at least, when the grains first quit
the anther ; and that a power of secreting a viscid substance is one
of their functions when perfectly smooth, as well as when covered
with points and inequalities. He, however, admits that hispid pollen
is generally more viscid than that which is smooth.' This supposed
mucus, or mucosity, is really the substance which I have described
above. When properly tested, however, it may be found to be a wax
and not an oleo-resin, and may possibly be one source from which
bees obtain wax for cell-building. Any substance of the nature of
mucus would not be soluble in oil of turpentine. — C. H. B.

J16 Experimental Researches on Hay-Fever :

dried they usually also shrink into a shape more or less
regular in character, but in a certain portion of the contents
of any anther the dried grain will have the appearance of
an amorphous particle of silica. The outer coat is seen to
be pierced with small round holes or slits — pores. The
inner membrane stretches across these openings, and never
in any case, so far as I have observed, allows the interior of
the cell or its contents to be exposed to the atmosphere
until this membrane has been ruptured.

§ 188. When water* is allowed to come into contact
with the dried pollen this quickly swells and assumes its
normal shape, and if the quantity of moisture is not too
great it will retain its natural shape for a considerable time.
If moisture continues to be supplied it loses its form, and
whatever may have been its shape previously it tends to
become more or less spherical. Carried still further, the
granular contents of the cells are seen to alter their
'position ; the inner membrane is seen to protrude more or
less through the pores, and to form in this way minute
mastoid processes, in some cases bulging very considerably
beyond the outer coat. The granular contents will, in the
case of the pollens of the grasses, move to the end at which
the single pore is, in this pollen, situated, leaving one-third
or one-half of the cell comparatively empty. After a short
time, varying according to the condition of the pollen, when
placed in contact with water the portion of the granular
contents of the cell which is nearest to the pore is expelled
with great force — so much so that I have frequently seen a
pollen grain driven by degrees half way across the field of
the microscope by this expulsive force.f

* Other fluids will also act in a similar manner, but none more
quickly than water.

t Lindley says this enlargement and bursting of the pollen grain is
the effect of endosmosis. This, however, would not force the granular
matter to one end of the pollen grain unless some special apparatus,
adapted for this purpose, was within the cell. This I believe to be
the case. I have on three occasions seen what appeared to me to be
a small membranous sac within the inner coat of the pollen grain,
and situated at the end farthest from the pore. When the water has
been applied for some time, this sac has been seen to expand gra-

Eocperiments with Pollen. 117

§ 189. After the granular matter has escaped it diffuses
itself gradually in the surrounding fluid. When carefully
observed the granules are seen to vary very much in size.
According to Lindley they are, in some cases, not more
than the 30,000th of an inch in diameter."* Immersed in
water or in any fluid which is not of greater density than
water they readily take on molecular motion, f This is
most perceptible in the smallest granules and seems to be
more sluggish as the granules get larger, until in some
pollens we find the largest granules to have little or none
of this movement. It was said by Brown and others to be
caused by the particles ' moving on their axes/ and setting
up in this way a sort of rotatory motion. A little observa-
tion will, however, show that in addition to this they have
a vibratory motion, and that they slowly move in different
directions, and sometimes I have noticed that they seem to
work together in small groups as if attracted by some force
which operates to bring certain of the granules together.J

dually, and by this expansion to force the granular matter against
the end where the pore is situated. After the inner membrane is
ruptured and the granular matter has begun to escape, the sac seems
to collapse or in some way to become so indistinct as not to be seen;
I have seen it twice in the pollen of grass and once in that of Gera-
nium ; but, although I have carefully watched for the phenomenon
on several other occasions, I have not been able to detect it except in
the three instances named. When it is seen it is perceptible for a
very short time only.

* Lindley's Introduction to Botany, p. 190.
r t This was first noticed by Gleichen, and subsequently by Amici,
Guillemin and Brown, and has since been called, after the latter
observer, the Brownian motion.

X Molecular motion is seen in almost all animal or vegetable fluids
if these are not too viscid to permit the molecules to move. Granular
matter is especially abundant and active in vaccine lymph if taken
on or before the eighth day, and also in the fluid thrown off by per-
spiration in rheumatic, typhoid and other fevers. It is also seen, but
to a less extent, in the perspiration of health.

Any watery fluid which holds in suspension finely divided mineral
or earthy matter will also show the molecular movement, but in this
case I have never found it to be as vigorous or as long continued as
it is when the granular matter has been derived from animal or vege-
table bodies.

118 Experimental Researches on Hay-Fever:

§ 190. With a solution of Iodine the granular matter
becomes dark blue, showing by this change that it contains
an amyloid substance. The finer particles colour, in pro-
portion to their size, more deeply than the larger particles.
Immersion in antiseptics has no influence on the motion
unless these are strong enough to destroy the form of the
granules. Boiling the granular matter, also, does not inter-
fere with the motion, but any liquid more viscid than water
lessens the extent of the motion in proportion to the density
and viscidity of the liquid. Immersion in glycerine will
almost entirely put a stop to it.

The grouping of the granular matter to which I have
referred above was peculiar. Commonly the granules
would be seen in pairs, and not unfrequently in trios, dis-
posed in a single line or in the form of a triangle. Occa-
sionally, however, they were seen as rods of five, six, or
seven granules in a line, and several times I have seen them
assume the form of a cross. In examining the nasal mucus
when suffering from hay-fever I have several times seen
these same groups of granules, although they were by no
means common, for the reason that they are rapidly carried
away by the serum which is so profusely thrown out when
the disease is once established. When I first saw the rod-
like form of the groups I was particularly struck with them,
and had I not known that they were in all probability
derived from the pollen grains I should have imagined they
belonged to the infusoria. I think it is highly probable that
some of the bodies seen by Professor Helmholtz (§ 79) were
really granules, from the inhaled pollen, grouped in the
manner I have described.

§ 191. If instead of bringing the pollen grain into direct
contact with water we allow the vapour of water to act
upon it, the changes described above occur much more
slowly. We reproduce, in fact, the condition in which
pollen is placed when it is brought into contact with the
respiratory mucous membrane by being inhaled, and we are,
with suitable appliances,"* able to watch changes such as

° One of the readiest methods of observing the changes which
occur in pollen under the influence of watery vapour is to use what

Experiments with Pollen. 119

occur when pollen is brought into contact with the mucous
membranes. In the one case, however, we have mucus and
watery vapour acting upon the pollen, whilst in the other
we have only watery vapour present. Nevertheless, from
what I have been able to learn, by immersing pollen in
liquids of similar density and viscidity to those of mucus
it is very improbable that the latter has any effect which
would not be produced by the vapour given off from the
lungs during expiration.

§ 192. The pollen which is found floating in the atmo-
sphere during the prevalence of hay-fever is, as I shall have
to show further on, dry and shrivelled. A few minutes*
exposure to the air and the sun on a summer's day is suffi-
cient to deprive it of the moisture which it contains in its
normal state whilst enclosed within the walls of the anther.
If we imitate this action by allowing the pollen to dry before
we subject it to the influence of the vapour, we can then
observe all the physical changes which take place when
pollen is inhaled during the hay season.

As I have said above, one of the first changes is that the
pollen grain begins to swell. In contact with water this is
accomplished somewhat suddenly, but under the influence
of vapour it is produced more slowly and with accompani-

may, for convenience, be called a water cell. This may be constructed
in the following manner. A drop of distilled water is placed, whilst
still warm, in a microscopic cell about one-tenth of an inch deep by
half an inch in diameter. The upper surface of the cell wall is coated
with black varnish, and this is allowed partially to dry. A disc o
thin microscopic glass, on which a portion of fresh pollen has been
dusted, is then placed on the cell in the form of a lid, care being
taken that the surface on which the pollen has been placed is turned
downwards. If the varnish has not been allowed to become too dry
the edges of the thin glass will adhere to it, and thus a cell will be
formed which is hermetically sealed. Care should also be taken that
the water is only just sufficient to cover the bottom of the ceil.

If it is desired to have the pollen as a permanent preparation after
the changes have taken place in it, it is necessary to leave two or
three spaces on the surface of the cell wall untouched with varnish.
The water will then slowly evaporate, and the changed condition of
the pollen is rendered permanent.

1 20 Eayperimental Researches on Hay-Fever :

ments which may possibly help us to account for some of the
phenomena of hay-fever. This enlargement is not brought
about by a steady increase in size. The change is produced
in many of the pollen grains by a series of jerks, as if the
cell wall resisted for a time the expansive force of the
moisture which had condensed around it and then suddenly
gave way, and in doing so not only altered its shape but also
slightly changed its position. After this change has taken
place the granular matter begins to escape, but it does so
much more slowly and less vigorously than when in contact
with water, though occasionally this sudden and spasmodic
mode of exit is seen.

§ 193. In both cases the granules have a tendency to
diffuse themselves in the surrounding fluid, but with water
they do so more completely than with vapour. In both
instances a portion of the matter will remain in contact
with the grains, grouped together as if held in close contact
by the viscid mucus in which they are imbedded whilst in
the pollen grain ; the least mechanical disturbance, however,
will set a large number of them free, and in such case they
at once commence the molecular motion.

If placed under a micrometer whilst the granular matter
is being ejected, the squares of the instrument enable us to
measure the rate of movement and also the distance the
pollen travels. When everything is properly arranged the
pollen grain is seen to move slowly across the field of the
microscope, or if this remains stationary the stream of
granules is pushed in an irregular or zigzag line away from
it. In some cases a dozen or more pollen grains may be
seen undergoing this change in a single field, and when we
consider that in the space of one square centimetre (=£$ths
of an English inch) we have more than six hundred fields,
some idea may be formed of the extent of mechanical action
which goes on in a comparatively small surface of the mucous
membrane of the nares, trachea, and bronchial tubes, during
the time when grass is in flower.

§ 194. When pollen is immersed in water, if it is quite
ripe some of the grains will burst in a few seconds, others
will take an hour or two, and some will not discharge their

Experiments with Pollen. 121

contents however long they are kept moist. Sometimes the
granular matter is seen in close contact with the pollen-
grain from which it has been ejected. In some instances
the contents of a grain may be discharged at a single stroke,,
whilst in others the evacuation may go on more moderately,
and in the latter case it sometimes happens that a large
group of granules may partially block up the pore, whilst
smaller detachments are being discharged by pushing their
way past the side of the larger group.

As in the other case the pollen grains are sometimes seen
to move across the field of the microscope, or to push the
granular matter from them, but this they generally do more
suddenly and more vigorously than when under the influence
of vapour only. The granular matter diffuses more rapidly
in the surrounding fluid, and the number of granules which
take on molecular motion is larger, whilst at the same time
this is more vigorous; but the chief difference between the
two modes of operating consists in the difference in the time
taken to accomplish the results.

§ 195. The two modes of action described above do, in
practice, slide so gradually from one to the other, and
become so intermingled, that it is very difficult to ascertain
the precise point at which the one ends and the other begins.

At the commencement of an attack the first symptoms
will, no doubt, be produced by the combined action of the
vapour exhaled from the lungs and the mucus secreted by
the mucous membrane. If the quantity of pollen which is
brought into contact with the mucous membrane be small,
or if its vitality is lessened by any circumstances, this mode
of action may be kept up some time, but when a discharge
of serum begins we shall at once have the more rapid and
vigorous action commenced which is seen when pollen is
placed in contact with water. Thus it happens that the
fluid which is discharged in great profusion in severe
attacks of hay-fever is at once a cause and an effect; and so
long as a free supply of pollen is kept up this fluid helps in
no small degree to perpetuate and to intensify the symptoms
generated.

§ 196. The form of cell which I now use for demon-

122 Experirrcental Researches on Hay-Fever:

strating the effect of vapour upon pollen is shown at Figs.
1 and 2 (Plate I.). A cell of this form possesses several
advantages over the simpler one described in the footnote to
§ 191. One advantage is that the observer can, whilst
witnessing the changes which take place under the micro-
scope, accelerate or retard these at pleasure, and can also
bring them to a termination at any particular stage. With
these exceptions the process followed, in using this instru-
ment, is a pretty close imitation of what takes place when
pollen is inhaled.

When fresh pollen has been placed on the under surface
of the glass disc d, if we breathe gently through the mouth-
piece e, the vapour exhaled from the lungs will pass through
the cell b, b, and will condense on and around the pollen.
By increasing the speed at which the respired air is made
to pass through the cell, we may gain a tolerably accurate
notion of the rate at which the changes before-mentioned
take place in varying rates of respiration, and by this means
we are able to see that, whilst active exercise must
necessarily increase the quantity of pollen inhaled during
the hay season, it must also greatly accelerate those changes
which produce some of the symptoms of hay -fever. If we
are desirous of imitating the natural process of respiration
in the operation, we can do so by drawing the air in through
the cell, and passing it out by the same way. The only
advantage in pursuing this method is, that it enables us ta
determine with tolerable accuracy the time which elapses
before the changes, which I have described, are completed.

§ 197. There is also another change brought about in
pollen by the influence of vapour which, although it may
not have much share in producing the symptoms to which
pollen gives rise, it would not be well to pass by without
noticing.

When pollen is discharged from the anther a considerable
portion of it comes into contact with the stigmata of the
plant to which it belongs. In this position the inner
membrane* of the pollen grain very soon begins to protrude

* It is possible that the inner membrane (intine) does not in all
cases form the pollen tube, but that in some it is formed by the
delicate membrane (exintine) of which I have spoken (§ 186).

Fig. 1. — A perpendicular section of the instrument represented.
a, glass plate (one tenth of an inch thick) ; b, b, circular brass
cell, cemented to the glass plate a, and perforated on opposite
sides for the passage of the glass tubes c, e, which latter are
cemented into the cell b, b ; d, a disc of thin microscopic glass,
which rests on the upper margin of the cell b, b, the pollen in-
tended for observation being placed on the under surface of this
glass ; t, a short piece of glass tube, to be used as a mouth-piece ;
f, f, brass steps cemented to the upper surface of the glass plate
a, the tubes e, c, being cemented to semicircular recesses in the
steps/,/; g, caontohouo tube, attached by one extremity to the
month-piece e, and by the other to the tube c. This tube should
be sufficiently long to reach the mouth of the operator easily
when the cell is in position on the stage of the microscope. A, A,
brass cap to fit over the cell b, b. The cap is raised a little, so
as to show the disc of thin glass if ,- but when in position, the
under surface of the horizontal portion of the cap will press upon
the disc and keep it firmly fixed.

Fro. 2.

Fig. 2.— A view of the upper snrface of Fig. I. a, a, glass
plate (an ordinary microscopic slide will answer the purpose) ;
c, c, glass or brass tubes cemented to the steps/,/, and to the
cell b, b, which is here concealed by the cap A, A ; g, caoutchouc
tube attached to the month-piece e (shown in Fig. 1), and to the
tube e ; k,h, brass cap which holds the disc of gloss d in position,
and covers the cell b, b (shown in Fig. I ).

Drawn to a scale of frds.

Experiments with Pollen. 123

through one of the pores, and eventually becomes elongated
into a fine transparent tube {pollen tube), which is filled
with the granular matter (fovilla) of the pollen grain. In
fulfilling its proper function this tube passes into or between
the cells and tissue which form the stigma. So far as
relates to the pollen cell itself, when in its normal position,
this change is physiological in character ; but so far as it
relates to the mucous membrane with which the former is-
in contact, when inhaled, it is purely mechanical.

§ 198. This development of the pollen-tube may be seen
to occur in a very small number of the cells, when placed
under the microscope, in the instrument shown in Figs. 1
and 2 (Plate I.) ; and there can be very little doubt that the
same change takes place when pollen is brought into contact
with the mucous membranes of the respiratory passages.
Generally the proportion in which the change does occur is
very small, and it is only in certain states of the pollen that
it is to be seen at all. What the exact nature of this con-
dition is is not at present known.

Occasionally the tube may be seen to grow rapidly, so
that in the course of thirty or forty minutes it may grow to
a length which is two or three times the diameter of the
pollen cell. Whether the tube simply stretches along the
surface of the mucous membrane, or whether it penetrates
into the mucous follicle, it is impossible at present to say ;
nor can we feel at all sure that its presence does assist in
producing any of the symptoms of hay-fever. I think it i&
not improbable, however, that it does in some few instances
penetrate the mucous follicle, and thus give rise to irritation,
which at least increases that set up in other ways*

* At § 70, 1 have referred to a paper written at the latter part of
1870, by Mr. Wm. Wright Wilson, of Birmingham. The paper in
question is entitled ' Notes on British Poisonous Plants.' The author
in his notes on Aconite states that, 'It is affirmed by some able old
writers that the pollen dust being blown on to the surface of the eye,
has been known to cause pain and swelling. Now this supposed
property of the pollen grains admits of easy explanation. If any
pollen grain becomes an inhabitant of any warm, moist place, endos-
mosis and exosmosis instantly commence, and in a little time the
external coat, or extine, of the pollen is ruptured, and the internal

124 Experimental Researches on Hay-Fever:

§ 199. I have thus shown that pollen possesses the power
of producing hay-fever, both in its asthmatic and its catar-

coat, or intine, is protruded, forming what is known as the pollen
tube ; the use of these tubes being to ramify through the cellular
spaces of the stigma and style of the plant until it reaches the ovary,
where it enters or attaches itself to an ovule, and therein discharges
its granular contents or fovillum. Now this will happen upon the
■eye. The moment that the pollen becomes surrounded by the lachry-
mal secretion, which is constantly washing the surface of the cornea
and conjunctiva, a change takes place. The grain enlarges, bursts its
extine, protrudes its intine as a tube, and finally, after wandering
over the eye for some little distance, the intine or pollen tube bursts,
and discharges its fovillum on the surface. These granular contents
are even smaller than the red blood-corpuscles ; and I think that if
the corpuscles can pass out of the small blood-vessels between the so-
called epithelial chinks, in like manner the fovillum grains might
pass into such small blood-vessels. Of course the presence of these
minute filaments or tubes and the granular fovillum on the surface
of the eye must be very painful, and a constant source of irritation
until removed. My theory, then, of mechanical irritation fully
accounts for all the symptoms described by some authors of pain and
swelling, and which could no doubt be found to be the case with any
kind of pollen grains ; and I have no doubt hut that hay-fever, so
called, is due to the inhalation of pollen grains, which, settling on
the mucous membrane of the nose, eye, bronchial tubes, etc., burst
and ramify over the surface, causing intense irritation, and giving
rise to febrile disturbance, with the usual train of symptoms and
results.'

In a letter written to the editor of the Lancet (August 22nd, 1873),
Mr. Wilson complains that I claim to be the originator of the ' pollen
"theory* of hay-fever, whilst the credit of this really belongs to him.
As a matter of fact, the credit of this does not belong either to Mr.
Wilson or to me. For some three or four years after I first found out
'(now twenty years ago) that pollen would cause the symptoms of
hay-fever, I imagined that I was the first to make this discovery ;
•and it was only when I became better acquainted with the literature
of the disease that I found that fully thirty years before the time to
which I refer, Elliotson had said that pollen would probably be found
to be the cause of this malady. Elliotson, however, gave no proof of
his assertion, but it is to him that the credit of first naming the
probable cause is due. I have nowhere claimed to be the originator
of the pollen theory, but have been specially careful to show that the
first definite idea of this was broached by Elliotson. What I do
claim, however, is that, so far as I know, I am the first to show, by a
long course of carefully conducted experiments, the correctness or

Experiments with Pollen. 125*

rhal form ; and I have also shown that, with very rare
exceptions, this power is common, in some degree, to the
pollen of almost all the plants experimented with. And,
although those belonging to the order Graminacese have this
property in a more marked degree than some, there are plants
belonging to other orders which have it to almost, if not
quite, an equal extent. How far this property would be
found to extend through the plants which form the entire
flora of any given district I cannot at present say, but I do
not doubt that the exceptions would be comparatively few.
From the results obtained in the experiments I have

incorrectness of the theoretical opinions that have been held on the
cause of hay-fever.

Mr. Wilson's opinions, like those of many other authors I have
passed under review, are at best only theoretical, and although cor-
rect in some particulars, are erroneous in others. In a second letter,
also written to the editor of the Lancet (October 6th, 1873), he gives
a further explanation of his idea of the mode in which pollen acts
when in contact with the mucous membranes. In this Mr. Wilson
says : c Now it is proved that pollen does produce the symptoms of
hay-fever, when introduced into the body under favourable conditions.
These conditions are heat, moisture and absence of light .... Now,
if this be true, each plant that has a long pistil must require pollen
grains, the intine of which must be capable of great extension and
possess the power of travelling, as in some lilies, a distance of two or
three inches. , Mr. Wilson then goes on to say that pollens with a long
pollen tube must have one that will wander a long distance over the
mucous membranes. These must from this circumstance have the
greatest power of causing irritation of these membranes, and that there-
fore such pollens must bring on the severest symptoms of hay-fever.
It is not quite correct to say that absence of light is a condition neces-
sary to the growth of the pollen tube. I have seen the pollen tube
of some of the cereals grow rapidly whilst exposed to strong sun-
light under the microscope. Then, every botanist knows that the
anther and the stigma in all the Graminacese are exposed to the sun
light the whole day long, when fertilisation is going on.

In all my experiments with the grass pollens, the development
of the pollen tube was seen to be a very exceptional phenomenon
and the still more important facts against Mr. Wilson's theory
are : 1st, that in the grasses there is no necessity for a long pollen
tube ; 2nd, that grass pollen is the grand cause of hay-fever in Eng-
land ; and 3rd, that the pollen of the order Liliaceae is one the least
powerful of all the pollens I experimented with.

126 Experimental Researcltes on Hay -Fever:

described, I have come to the conclusion that the dis-
turbance caused by pollen is due partly to its mechanical
and partly to its physiological action. From the circum-
stance, however, that the coating of wax or oleo-resin, of
which I have spoken (§ 186), probably has some volatile oil
combined with it, it is possible that this may commence the
disturbance ; but whether this is chemical or physiological
in its character is not certain.

§ 200. The mechanical changes I have described would
be quite sufficient to account for some of the earlier symp-
toms of hay- fever ; but some of the later phenomena will,
no doubt, be due to the physiological action of the granular
matter of the pollen.

This granular matter, as I have shown at § 189, will,
with suitable conditions, take on the Brownian or molecular
movement. It might, at first sight, appear likely that
this movement would assist in bringing on or in prolonging
the symptoms produced by the other mechanical changes.
But when we remember that all very small particles of
mineral and organic matter will, under similar conditions,
take on the same movements,* though not in all cases to
the same extent, we are compelled to believe that this can
have no share in producing hay-fever. If molecular motion
was an efficient cause for any of the important symptoms of
the disorder, patients who are liable to it would suffer more
or less from it at all times, because experiment has shown
that there is an abundance of finely divided matter present
in the atmosphere at various parts of the year, independent
of any particular season.

* In speaking of the nature and causes of this movement, Valentin
says : ' There can be no doubt that direct mechanical agitation, and
indirect thermic movements, exert an important influence on tbe
phenomena we are now considering. And although the results differ
with the nature of the molecules and the fluid, still the mutual
physical relations may assist to determine the amount of original dis-
placement and the duration of the subsequent vibration. The question
whether these are the sole exciting causes, or whether the molecular
movement is not based upon other attractive forces, cannot at present
be decided. The forces to which it is due are, at any rate, easily
overcome by the ordinary phenomena of adhesion.' — (Vide Text-
Book of Physiology, p. 356).

Experiments with Pollen. 127

§ 201. The power which the granular matter of pollen has
may, however, be due to qualities which are very different
in their nature. It may, and I believe does to a large
extent, depend upon the vitality which all bodies of this
class have in their active state. And I hope to be able to
show that to the extent that this vitality can be destroyed
in the pollen grain as a whole, before it reaches the
mucous membranes, to a similar extent will its power of
producing hay-fever be lessened. On the other hand, it
may, when all the chemical constituents of pollen come to
be known, be found, in part at least, to depend upon the
presence of a substance belonging to the alkaloid or to some
other class of bodies. Until the pollen of the grasses and
cereals has been subjected to a more careful chemical
investigation than it has yet undergone, this part of the
question must be considered unsettled.* This much, how-
ever, may be considered to be tolerably certain, namely,
that the sneezing — and possibly the discharge of serum —
which occurs in the first stage of hay-fever is due to the
mechanical changes of which I have spoken, and that the
swelling caused by the effusion of fluid into the submucous
cellular tissue is due to the presence of some substance or
quality in the granular matter, the exact nature of which is
at present unknown. If, however, we can succeed in
partially destroying the vitality of the pollen before it
reaches the mucous membrane, we shall, to some extent,
prevent both its mechanical and its physiological action.

* Fritzche discovered starch and sometimes inuline amongst the
granular matter, and also minute drops of essential oil. In addi-
tion, the fovilla (granular matter) contains a certain proportion
of sugar and various other azotized materials. Geraud found in the
pollen of the Antirrhinum majus (snapdragon) potassa, and raphides
of phosphate of lime among that of the Tradescantia virginica
(spiderwort). Fourcroy and Vauquelin found malic acid in the
pollen of the date tree. In addition to sugar, gum, albumen, cerin,
resin, etc., Herapath found as much as 46 per cent, of a peculiar
inflammable azotized principle, insoluble in nearly every liquid,
which Girardin called Pollenine, in the pollen of Cereus speciosis •
simus, and nearly as much in two species of lily. — (Manual of Botany,
by Robt. Brown, M.A., Ph.Dr., F.L.S., F.R.G.S. London, Wm.
Blackwood and Sons, 1874.)

128 Experimental Researches on Hay-Fever :

I have found by experiment that the granular matter of
pollen may, by dialysis, be made to pass through membranes
which are thicker than those that line the air-vesicles and
bronchial tubes ; and from this circumstance I think that it
is highly probable that the finer particles of this matter do ,
in some cases, pass through the mucous membrane of the
respiratory passages, and by getting into the circulation in
this way give rise to the constitutional symptoms we see
developed in some cases * Why it should not be so in all
cases is, however, not very clear. In some instances it may
be due to the greater power of resistance which some
patients have; and in others it may depend upon the
quantity and kind of pollen inhaled.

§ 202. There is another supposed cause of a form of hay-
asthma to which I have not as yet adverted, namely, the
odour given off by certain animals. The presence of cats,
rabbits, or guinea-pigs, will in some cases cause a form of
asthma which cannot be distinguished from hay-asthma.
One such case — the only one I have ever fallen in with —
I have given at § 100, but I think it is possible that some
of the cases which have been reported, would be found on
very close investigation to be capable of being explained in
a different way.

I have shown that, when pollen is subjected to the in-
fluence of moisture, the pollen grain when ripe, bursts and
discharges its granular contents. If, in the process of
making, the hay has been wet by any means, much of the

* The granular matter of pollen consists, in part, of what Beale
would call vegetable bioplasm. The smallest particles probably con-
sist almost entirely of this material, but the larger particles have a
portion of formed material combined with it.

Beale is entirely opposed to the idea that any bioplasm of vegetable
origin can be the cause of contagious disease. 1 In the present state
of our knowledge it is unwise to dogmatise too persistently on this
question. I have shown that one form of vegetable matter can give
rise to a disease which is not transmissible, and it is not impossible
that a vegetable bioplasm may be found which can play the part of a
Kiffiv after it has obtained an entrance into the circulation, and thus
set up some form of contagious disease.

1 Vide Disease Germs : their supposed Mature, p. 9.

Experiments with Pollen. 129

pollen which is in contact with the partially dried herb will
undergo this change, and thus it will happen that, when the
hay is completely dried, it will have mixed up with it not
only a large number of perfectly formed pollen grains, but
also a quantity of the finely divided granular matter in a
dried state. Now in the case of the two species of animals
last-named it is well known that they are often kept almost
constantly amongst hay, and in the case of the first their
excursions in search of mice are often made in lofts where
large quantities of hay are stored, and it may therefore with
very great propriety be suggested that the fur of these
animals may be simply the carrier of the granular matter
and of the pollen.

G. Observations on the influence of Light and Heat

§ 203. Light ha3 been referred to by Dr. Phoebus and
other writers on hay-fever as one of the probable causes of
the disorder ; but on what ground this assertion has been
made does not appear. Light is one of the most universally
diffused agents we have. We have abundant evidence to
show the important influence it has in aiding those changes
which make up the sum total of life in the animal and
vegetable kingdom, but we have no evidence to show that it
has the power to produce symptoms which have even a
remote resemblance to those of hay -fever, and, so far as I
am aware, no author has yet made experiments which prove
that light can produce the fully developed disease.

Both light and heat have been thought by some authors,
and also by some patients, to give rise to exacerbations of
the disorder, when once it has been established, but we have
no evidence to show that the actual exciting cause of the
disease has not been present when these exacerbations have
come on, apparently through exposure to light. Then, again,
it has not been proved that the period at which we have the
greatest average intensity of light is the period at which
hay-fever prevails. Until evidence which will clear up
these uncertainties, is brought, we shall be justified in
refusing to accept the statements of those who maintain
that light is one of the causes of hay-fever.

130 Experimental Researches on Hay-Fever:

§ 204. The powerful influence which heat has in derang-
ing the whole economy of the animal frame has been recog-
nised from very early times, but in searching the works of
writers on medicine, and especially of those who have treated
upon the action of heat as a cause of disease, we look in
vain for any description of symptoms resembling those of
hay-fever. The derangements produced by exposure to
intense heat are, in fact, very different in character and
severity to those we observe in catarrhus aestivus. But
notwithstanding this, the ill-recognised changes which heat
produces on the nervous and vascular systems seem to have
attracted the attention of some authors who were wishful to
find a powerful cause for this curious disorder. Other
authors have followed in the wake of these, and in some
cases have adopted their conclusions without ascertaining
the nature of the evidence upon which these rest.

§ 205. Bostock was, as we have seen (§ 23), the first to
ascribe the malady to the influence of heat. His experi-
ments seem at first sight to bear out his conclusions, but
when we closely examine the evidence he brings we find
that the former were not very logical.

The principal thing that strikes us in these observations
is the circumstance that although heat was thought by
Bostock to be the sole cause of his disorder, he passed
through two of the hottest summers (1825-26) we have had
during the present century and had fewer attacks of the
disease than was usual in ordinary years. Again, in the
first year of his residence at Ramsgate (1824) the summer
was not warmer than usual, and yet he does not say that
he suffered less than in the two hot summers. If his theory
was correct, and he had the disorder in so mild a form
during the hot weather, he ought to have been almost
entirely free from it in the cooler weather of 1824. If this
had been the case one would think he would not have
failed to notice the fact, since he tells us he made choice of
Kamsgate a3 a residence in order to try to lessen the
severity of the attacks. He, however, does not say he
escaped, or that he had the disease in a milder form even,
and we are therefore led to infer that he must have
suffered in the usual way during the first summer.

On the Influence of Light and Heat. 131

§ 206. Bostock believed that the cooler air of the sea
coast was the cause of the comparative immunity he
enjoyed during the two hot summers. There is, however,
not a sufficient difference between the temperature of the
air in this situation and at a distance from the sea, to
account for the non-occurrence of the attacks at the former
place. Bostock says that whenever he walked out, or, as
he terms it, ' relaxed his plan of discipline/ he was sure to
have an attack. But the average temperature of the air in
a room would, during such summers as we had in 1825 and
1826, be quite equal to what it is in ordinary years in the
open air, and it is well known that hay-fever is quite as
severe at such times as it is in very hot summers. It has,
in fact, sometimes happened that I have had the disorder
in a milder form in a hot and very dry summer than I
have when the air has been cooler and more moist. The
year 1868 was, so far as the neighbourhood of Manchester
is concerned, a fair example of the kind of summer which
tends rather to lessen than to increase the severity of hay-
fever.

§ 207. The year 1827 was cool, and during this summer
Bostock resided at Kew, and whilst there he ' walked out
daily in the midst of hundreds of acres of meadow-grass,'
yet, except during one or two hot days in July, he had no
attacks. This experience seems to favour his theory much
more than that gained by his residence at Ramsgate. I
have, however, shown (§ 181) that in a cool summer very
little pollen is formed by grass, and I shall be able to show
as I pass on that a rise in the temperature, during the hay-
season, will sometimes cause large quantities of pollen to be
formed and thrown off.

It has several times in the course of my experiments
seemed during a period of comparative coolness of the
atmosphere, if the temperature has not gone down too low,
as if the pollen has been, as it were, reservoired for a time,
and as soon as the temperature has risen beyond a certain
point the accumulated stock has been rapidly thrown off.
But however this may be, certain it is that heat and
moisture favour the growth and evolution of pollen, and

132 Experimental Researches on Hay-Fever:

that cold and dryness will almost completely put a stop to
these processes.

§ 208. As it bears upon this part of the subject I will
mention here an incident which occurred to me at Filey in
1870. This occurrence shows the manner in which attacks
of hay-fever may come on even at the sea-side, and it also
shows how careful we should be in forming our opinions
before we have investigated all the circumstances attending
an attack.

It was on one of the hottest days which occurred in July
that I went down to the sea-sbore for the purpose of trying
some of the experiments named at § 140. The day was
very hot ; a sea breeze was blowing at the time, and had
been blowing more or less for two days. I was quite free
from any of the active symptoms of hay-fever at the time.
I remained from ten o'clock in the morning till five in the
afternoon, moving about on the cliffs or on the shore close
to the water. At the termination of the day's experimen-
tation I returned to the town by a field-path which leads to
the older part of the town. I had not proceeded far along
this path before some of the earlier symptoms of hay-fever
began to show themselves, and in the course of a very
short time a violent attack of sneezing and coryza came on.
So sudden and, so far as the action of pollen appeared to
be concerned, so causeless was the attack that I began to
think that after all there might be occasions in which light,
heat, ozone, or all combined, might bring on hay-fever. I
had only just quitted the sea-shore, and there was only a
comparatively narrow strip of cultivated land intervening
between me and the sea. On searching, however, I found
that on this narrow belt of land there was a field of wheat
in full bloom, and, on examining closely, the ripe anthers
could be seen to be ejecting their pollen in the way wl-iicli
may frequently be witnessed in many families of plants,
and especially in those belonging to the order Graminacese *

* If an ear of one of the Graminacese with large anthers (Rye, for
instance) be placed, whilst in full flower, in a vase of water, or in a
portion of wet earth or sand, and left in a room where the air is kept
moderately still, some of the anthers may be seen to discharge their

On the Influence of Light and Heat. 133

It is scarcely necessary to say that as soon as I got away
from the wheat the symptoms which had shown themselves
so suddenly began to abate.

§ 209. I had here a fair opportunity of testing the action
of light, heat, ozone, and pollen. After several hours'
exposure to the three agents first named no effect was
produced, but in the case of the pollen I had not been in
contact with it many minutes before its characteristic symp-
toms began to be developed.

In order to be quite sure that the sea air did not carry
any pollen, a short series of experiments — six in number —
were tried by a method which I shall have to describe in
the next chapter. By these experiments I found that when
the wind had been blowing in from the sea for some hours,
if the instrument was placed close to the margin, and a
few feet above the surface, of the water, the air did not con-
tain any pollen or any solid matter whatever. I was
therefore satisfied that the absence of the symptoms of hay-
fever during the greater part of the day was due to the
absence of pollen, and that its sudden occurrence in the
latter part of the day was due to a temporary exposure to
its influence at the spot named.

§ 210. As I have before intimated when speaking of the
experiments on ozone, this particular spot (Filey Bay) was
selected because we have here an expanse of ocean which
stretches three to four hundred miles in a straight line from
the English coast ; so that when the wind blows in from
the sea a sufficient length of time to insure its having
crossed the entire distance, we have here a fair opportunity
for determining whether pollen or other organic matter can
cross large tracts of ocean. In this case we have seen that
the sea air was free from any form of solid matter ; but it is
important to observe that under some circumstances it may

pollen in a sort of jet, which is thrown out at short intervals. It
seems as if only a portion of the anther opens at once and discharges
a part of its contents by the action of some vis a tergo which causes
the pollen to be thrown a line or two in advance of the spot it would
occupy if it dropped perpendicularly. What the cause of this mode
of ejection is, is not easy to make out

134 Experimental Researches on Hay-Fever:

not be found to be so. In cases, for instance, where the air
passes only a short distance over the sea, we shall often
have it charged with solid matter ; and where a land breeze
is driven back after having crossed the sea a little way only,
this may carry back the matter it has brought from the
coast. In cases, also, where a land wind is driven back
after having crossed the ocean a short distance, and where
this return current comes back by a path different from
that taken in its outward course, the matter it contains may
be thrown upon a part of the coast quite different to that
from which it came. Thus we may have the products of
one part of a continent distributed to another and totally
different part. We know so very little of the modes in
which small particles of matter may be transported by
atmospheric currents, or of the immense distances these may
travel, that it is unwise to presume that they are absent at
any time unless they are proved to be so by careful
experiment.

§ 211. Bostock seems not to have had any idea of the
existence of facts such as those I have just mentioned, and
consequently is not at all influenced by them in drawing his
conclusions, and other writers who have treated of the
disease since Bostock's time have, as we have seen (Chap.
II.), also attributed it to the influence of heat. Dr. Phoebus,
as I have previously shown, has to resort to the curious
hypothesis which makes the early heats of summer the most
active cause of the malady, and speaks of this idea as being
supported by the testimony of numerous and important
observers.

If this hypothesis is intended to be used in a qualitative
sense only, then it should be shown that solar heat does
possess a property in the early part of the summer which it
loses at the later part; and, although it might be impossible
to demonstrate the exact nature of this property, its effects
should be capable of being shown by experiments made at a
time when no other supposed cause of hay-fever is present.
If, however, the hypothesis is intended to be used only in a
quantitative sense, or merely to indicate intensity, it should,
as I have said before, be shown that an increase of tempera-

On the Influence of Light and Heat 135

ture beyond a certain point invariably brings on the dis-
order. In no case Las this yet been done.

§ 212. Dr. Smith agrees with Dr. Phoebus in believing
that great heat and strong light will induce or aggravate
the symptoms of hay-fever, but he does not bring us the
history of any cases which show conclusively that these
agents have the power they are said to have. One case,
however, is given in which the attack came on whilst the
patient was engaged in unfurling the sails of a yacht a
short distance out at sea.* In this case it seemed as if heat
and physical exertion had brought on the disorder. The
experiments I shall have to describe in the next chapter
will, however, show that it is highly probable that the sails
had become the receptacles for pollen which had been
blown on to them from the land, and that the unfurling of
the sails had disturbed the pollen and caused it to be inhaled
during the period of exertion.

§ 213. Another case is given by Dr. Smith in which the
symptoms of the disorder came on whilst the patient was s
walking through Piccadilly (London) on a hot, dry, dusty
day.f The intense heat and the dust, Dr. Smith thinks,
were quite sufficient to account for the sudden appearance
of the attack. Unless, however, it can be shown that the
patient had been suddenly and temporarily brought under
the influence of these agents, we shall be warranted in
doubting the correctness of this conclusion ; and I am my-
self the more inclined to do so from the circumstance that I
have several times had similar sudden attacks when there
seemed to be no probability of these being due to pollen, but
which were found to be so when a close examination of the
attendant circumstances was made. One example of such
an occurrence is given at § 149, and another at § 208.

Dr. Smith also gives several examples of the disorder in
which the attacks were undoubtedly due to the presence of
hay or of grass in flower. For the details of these I must
refer my readers to Dr. Smith's work, J but I may be allowed

* On Hay-Fever, or Summer Catarrh, by W. Abbots Smith, M.D.
London, 1866, p. 50. f Ibid., p. 52.

X Ibid., London, 1868, 4th edition, pp. 26, 27, 35, 36 and 40.

I

136 Experimental Researches on Hay-Fever:

to remark here that the examples of this class, of cases are
greatly in excess of those that are said to be due to heat.

§ 214. Dr. Pirrie gives a number of cases where the
patients attributed their attacks to the heats of summer.
One of these patients, in describing the circumstances under
•which an attack would sometimes come on, says, ' Any day
I have occasion to be out in summer under a strong sun I
am sure to have an attack of the complaint. I am always
best in cold, cloudy days in summer.'* Another patient
says, s I cannot go out on a very bright hot day without
being so ill, and I think it is more from the general effect of
heat on me than anything else/f Another patient, a lady,
told Dr. Pirrie that 'she was always ill for many weeks,
and was always worst when the season was a bright and
sunny one.'j The case of an Indian officer is also mentioned
who, while in England, had his attacks at the beginning of
June, but who on one occasion was seized when out at sea.'§

Another example of the effect of heat is given where the
patient was also an officer in the Indian army. In this
case the disease ' showed itself in England in the months of
June and July. When in India the attacks were more
frequent during the whole course of the year than in
England, and the worst time for it was from the end of
July to the end of September.' The patient, however,
remarks that ' during the hottest season, from March to
June, in western India, vegetation is dried up, and the
sneezing would be constant enough if excited by the sun.'||

§ 215. From the circumstance that the disease makes
its appearance at different times, which accord with the
time at which summer is said to commence in the various
districts, Dr. Pirrie thinks 'all this has a direct relation
to the advent of the hot summer days.' He also says, in
referring to the occurrence of the disease in India, 'ifc
appears in the hot dry weather from March to June ; but
also in the period intervening between the end of July and
the end of September, but it has also been said to have

* On Bay- Asthma and the Affection termed Hay- Fever, by William
Pirrie, M.D. London, 1867, p. 28.
t Ibid., p. 29. t Ibid., p. 29. § Ibid., p. 30. || Ibid., p. 33.

On the Influence of Light and Heat 137

appeared among Europeans in India daring the months of
February and March, and then it has been attributed by-
some to the blossom of mango and some other trees which
are then in flower/*

Dr. Moore in his pamphlet agrees with the three last-
mentioned authors in attributing the disorder in many
cases to the influence of heat, but no cases which give con-
clusive evidence in support of this opinion are cited by
him.

§ 216. No author but Dr. Phoebus makes any distinction
between the earlier and later heats of summer ; and, with
all except this writer, it is more a question of intensity
than of quality. When we come, however, to inquire into
the effect of heat in countries where the temperature rises
far above what we have in England, we find that the expe-
rience of the disease gained in these hot countries, gives no
countenance to the opinions held by some authors on the,
effects of heat.

Since the information contained in § 82 was sent to me,
the patient whose case is there mentioned has spent several
years in the United States. In one of these years she
resided at Salem, on the shores of Lake Erie, and here she
had the disease just as in England. In speaking of this
she says, 'I arrived here the first week in May, and, as
usual, it was at its worst in June, bad in July, better in
August, and well in September/ In the two following
years the summers were spent in South Carolina, and here,
although the heat must have been much greater than in
England, or on Lake Erie, the patient 'had not the slightest
vestige of an attack.' The cause of this she believed to be
'the small proportion of grass and no hay-making.'

§ 217. Another patient, whose case I have not previously
mentioned, tells me she has suffered from hay-fever in both
the catarrhal and the asthmatic form for nine years, except
during the time she has been abroad. Whilst she has been
in England she has resided in various parts of the country,
but has always had an attack at the usual time — from the

* On Hay-Asthma and the Affections termed Hay-Fever, by William
Pirrie, M.D. London, 1867, p. 49.

138 Experimental Researches on Hay -Fever:

middle of June to the middle of July. In 1874 she went
to Valparaiso, and returned in 1877, but during this time
she had no attacks of hay-fever, although the heat was at
times very great.

§ 218. Dr. Wyman also gives very conclusive evidence of
the untenability of the doctrine that heat is a cause of hay*
fever. In a map which he gives of the catarrhal and the
non-catarrhal regions in the United States, he shows that
nearly the whole of the Southern States are almost free from
hay-fever, and many cases, he says, have occurred where
patients who have suffered from the malady in the North
have escaped it entirely whilst in the South, as in bhe case
I have cited above (§ 216). Then in referring to this
question of heat as a cause of the disease, Dr. Wyman says:*
' It has been thought that the cause of the return (of the
disease) at a certain season is the summer heat. But the
maximum of heat has already passed, and the nights have
become cool, when the outbreak commences. The greatest
heat, as a general rule, occurs in the last week in July, and,
taken as a whole, that month is hotter than August. After
the fifteenth, when by far the larger part begin to be ill, the
heat has very materially declined, and continues to decline
during the month of September, while the disease is worse,
and so continues till frost appears.

€ It has been supposed that the relief at the mountains is
due to the lower temperature of these more elevated regions.
So far as the White Mountains are concerned, this supposi-
tion is not borne out by facts. The temperature of these
regions is almost identical with that of the homes of some
of those who obtain relief there.'

§ 219. Then if we turn to the evidence furnished by
medical men, and by patients in India, we find that whilst
sufferers have mostly escaped attacks on the plains, they
have often had them when they have ascended into the
cooler atmosphere of the hills (§ 81) ; and when patients
have had it in both situations, although there are some ex-

* Autumnal Catarrh (Hay-Fever), by Morrill Wyman, M.D.,
pp. 90, 91.

On the Influence of Light and Heat 139

ceptions, the general testimony is that they have had it less
severely in the former than in the latter place.

A native medical practitioner, educated in England, in
answer to inquiries made through a friend, informs me that
he has never known a patient — either native or foreign —
to be affected with hay-fever in the plains, and he believes
that the disease has never been known to occur in natives
either on the plains or in the hills. Two medical friends —
surgeons in the Indian Service — also inform me that during
a residence of some years in India, they have never known
the disease to occur in the plains. The cause of this differ-
ence is not very far to seek. During the hot season in
India, vegetation is almost burnt up in the plains, whilst in
the hills grass and many of the cereals are grown in abun-
dance, and flower and throw off their pollen just as they do
in European countries,* and where the disease does occur
in the plains it is tolerably certaiti that it is caused by the
pollen of the grasses or of other plants which are in flower
at the time.

§ 220. Patient 4 (§ 84), in answer to my inquiry respect-
ing the time at which he suffered from the disease in India,
says : ' It has usually come on after the rains, when the
grass is in flower/

The same gentleman, in a letterf written to the editor of
the Lancet, in describing his case, says : ' My earliest
acquaintance goes back to school days, where I was at first
suspected of malingering. .... From that time, however,
up to 1868 (a period of some thirty-five years), when in
Kurrachee, I suffered regularly every summer as it came

* Dr. Joseph D. Hooker, of Kew, has kindly given me the follow-
ing information respecting the grasses and cereals which grow in the
Himalaya. In answer to my inquiries Dr. Hooker says : 'None of
the English grasses which you mention are indigenous to the Hima-
laya, but some occur there sparingly as escapes. With regard to the
native grasses, they are legion ; many of them are of the same genus
as European, and if hay-fever is due to grasses in England it would
be so in Himalaya. Of Himalayan cereals they cultivate wheat and
barley, and, more sparingly, oats ; also abundantly, maize, rice,
millet, etc., as in the south of Europe/

t Lancet, March 23, 1872.

140 Experimental Researches on Hay-Fever:

round. Kurrachee during the months of susceptibility, viz.,

June, July, and August, possesses an unusually constant

damp and windy climate from the south-west monsoon. It

is situated with the sea in front, and a howling desert

around it ; not a blade of grass visible ; a barren, sandy,

and rocky soil, treeless and verdureless, with no green

thing,

* " Where the bird dare not build,

Nor insect wing flit o'er the herbless granite."

Since my sojourn in it, however, in 1868 (including two
years spent in England), I have been quite free from any
return of hay-fever/

§ 221. Sir Ranald Martin, in speaking of the hot dry
season, which, in Bengal, extends from the beginning of
March to the middle of June, says : ' The temperature rises
gradually from 80° to about 90° — 95° in the shade, and

reaches to 100°— 120°— 130° in the open air Of

Calcutta it may be said, however, with truth that it is " a
city of stone, in a land of iron, with a sky of brass," the soil
of the surrounding country being rent and riven as if baked
over a volcano. . . * . The local newspapers of May, 1851,
speak of the heat as more intense than it has been for years.
The thermometer in the coolest room stands at 92° to 94°,
and the breeze which should bring refreshment at the close
of a sultry day has been as the breath of a furnace.'*

If heat would produce hay-fever, it would, with those
who are liable to it, be certain to be developed in India
under such circumstances as those described above. But not
only should the disease be developed, but it should also
be continuous and severe whilst the temperature is high.
Such, however, is seldom or never the case. In the few
cases which do occur, the intensity of the disorder does not
at all correspond with the degree of heat.

§ 222. If we look to the symptoms produced by heat in
tropical countries, we find these to differ very materially

* Influence of Tropical Climates in producing the Acute Endemic
Diseases of Europeans, by Sir James Ranald Martin, C.B., F.R.S.
pp. 42, 43.

On the Influence of Light and Heat. 141

from those seen in attacks of hay- fever. Sir Ranald Martin,
from whose work I have already quoted, gives the following
description of the sun-fever — heat apoplexy— of tropical
climates : ' First, we have vertigo and headache, with sense
of burning in the eyes, the conjunctiva being injected ; a
full and frequent pulse, vomiting, great heat, sometimes
floridness, of the skin, a devouring thirst, oppressed respira-
tion, and swollen face. Then come lividness, sinking and
running of the pulse, clammy sweat, exhausted nervous
energy, faltering of the tongue, coma, convulsion, and
speedy death ; these constitute the course of events in true
heat apoplexy.'*

In character as well as in severity the symptoms here
given will, when we come to consider those of catarrhus
sestivus, be found to be very unlike those that are present
in this disorder. To this, however, I shall return in another
chapter.

§ 223. The experience we have of the disorder in
England agrees in the main with that obtained in America
and in India. It is well known that the disease often makes
its appearance here before the summer has fairly com-
menced, and in a very large majority of cases it begins to
decline, and frequently entirely disappears, at least for a
time, whilst the summer heat is nearly at its maximum. A
second attack will also sometimes come on in the autumn,
when the temperature is considerably lower than it is
during the first attack. The table of curves, No. 1, shows
that the disease commences whilst the temperature is com-
paratively low, and that this remains high whilst the
severity of the attacks is diminishing.

In England also patients generally suffer more severely
in the country than they do in the towns, but it is nowhere
contended that the heat of a town is very much less than
that of the country in the summer time ; and it is well
known that some patients remain almost entirely free from
the disease if they reside in the centre of a large town or

° Influence of Tropical Climates in producing the Acute Endemic •,
Diseases of Europeans, by Sir James Ranald Martin, C.B., F.RS.
pp. 42, 43.

142 Experimental Researches on Hay-Fever.

city during the hay season. A sojourn at the sea-side, too,
whatever the temperature may be, will in almost all cases
free the patient from the disorder whilst a sea breeze i 8
blowing.*

§ 224. A careful search through the works and published
papers of all the authors with whose writings I have become
acquainted has shown me that in no instance has it ever
been satisfactorily demonstrated that the disease was due to
heat, and heat only. It is true that many cases are given
where solar heat seems to have been the exciting cause, but
in not one of these has it been shown that the real exciting
cause, pollen, has been absent.

The facts I have just brought forward, along with the
experiments I shall have to detail in the next chapter, have
shown me that this proof is always needed in order to make
the evidence at all conclusive, and from a consideration of
all the circumstances I have named, and from all the
testimony I have gained from the writings of the various
authors I have consulted, as well as from that furnished by
my own observation and experiments, I am led to conclude
that heat has no direct influence in producing hay-fever ;
and, to use the words I have already quoted, I believe e the
cause cannot be anything which is present in other cases
where the given effect is not produced, unless the presence
of some counteracting cause shall appear to account for its
non-production/f

* Except under the circumstances named at § 208.

t Archbishop Thomson's Outline of the Laws of Thought.

143

CHAPTER IV.

ON THE QUANTITY OF POLLEN FOUND FLOATING IN THE
ATMOSPHERE DURING THE PREVALENCE OF HAY-FEVER,
AND ON ITS RELATION TO THE INTENSITY OF THE
SYMPTOMS.

A. Experiments at ordinary levels.

B. Experiments at high altitudes.

A. Experiments at ordinary levels.

•§ 225. We have seen in the preceding pages that pollen
can produce the symptoms of hay-fever, but no one up to
the time these experiments were commenced had attempted
to show what relation there was between the quantity of
pollen found in the air during the prevalence of the
disorder and the intensity of the symptoms in any given
•case.

The researches of Needham and Spallanzani during the
last century, and of Boussingault, Pouchet, Pasteur,
Schrceder, Salisbury, and others* during the present
century, had shown that organised vegetable matters are
found floating in the atmosphere. Pollen had frequently
been found amongst these matters, but no one had thought
it worth while to see what quantity was to be found in any
given volume of air or during any given portion of time.
Nor yet had anyone attempted to determine what family of
plants furnishes the largest number. The greatest uncer-
tainty has prevailed on this subject, and this, no doubt, has

• Crookes, Samuelson, Tyndall, Angus Smith, Dancer, Maddox,
Charlton Bastian, Marsh, etc.

144 Experimental Researches on Hay-Fever:

led to many of the contradictory statements which have
been made on the influence of heat, but which would not
have been made if our knowledge of atmospheric deposits
had been as complete as it ought to have been.

§ 226. It seemed highly probable that grass pollen would
be largely in excess of all others, and that this would be the
principal cause of a disorder which prevails mostly during
the hay season; but without carefully conducted experi-
ments no correct estimate could be made of the quantity
of this pollen to be found in the atmosphere nor yet of the
share which other pollens might have in developing the
disorder.

Dr. Phoebus, in referring to this part of the subject, says :
'It is a question whether we have to seek the exciting
cause of the whole attack in those atmospheric conditions
or in those matters which are found floating in the atmo-
sphere, which we shall speak of as decided causes of aggra-
vation. It is, however, scarcely probable that they, passing
more or less quickly, contribute considerably to the creation
of the attack — an attack which recurs periodically for life.
The scantiness of the causes would, we 3hould think, stand
in a disproportion to the greatness of the effect.'

Like Dr. Phoebus, I was at first disposed to think that
the quantity of pollen in the atmosphere was too small and
too quickly passing to produce the effects we see developed
in hay-fever. One or two imperfect trials showed me,
however, that this idea might not be correct, and I there-
fore determined to put the matter to the test of a careful
investigation.

§ 227. The principal objects of the experiments were :—

1st. To determine whether the commencement of the dis-
order depended on the presence of pollen in the atmosphere.

2nd. To ascertain what number of pollen grains would be
deposited on a given space each day during the prevalence
of hay-fever.

3rd. To determine the height to which pollen would rise
and the distance to which it might be transported by atmo-
spheric currents.

Atmospheric Experiments. 145

4th. To discover what relation the quantity of grass pollen
bears to that furnished by other orders of plants.

5th. To see what relation the quantity of pollen found
had to the severity of the symptoms produced.

§ 228. The first experiments were made with a very
simple apparatus. A glass tube twelve inches long and
three quarters of an inch in diameter was filled with air
taken in the open country during the hay season, and after
having a disc of thin microscopic glass placed at one end so
as to stop up the lower orifice, the tube was placed in a per-
pendicular position, and was allowed to remain quiescent a
sufficient length of time to permit any solid particles the
enclosed air might contain to deposit on the thin glass. In
order to be able to judge of the relative number of pollen
grains deposited, a cell, one centimetre square, was formed
on the disc with black varnish. Subsequently a metal tube
four feet long and an inch and a quarter in diameter was
used. My object in proceeding in this manner was to see
what was the smallest quantity of air that would give any
reliable results, but in neither case did I find these at all
satisfactory.

Occasionally the microscope revealed the presence of
pollen grains on the disc of glass ; but frequently, when I
found none in this situation, I could find them on the dust
which settled on the inner surface of the tube, and I always
found a deposit of some kind on both the glass and metal
tubes in spite of all the care that was taken to keep them
exactly perpendicular. I could only account for this by
supposing that the friction of the external air gave rise to
an electric condition of the tube which caused the smaller
particles of matter to be attracted by it. Whatever was
the cause it helped to defeat the object of the experiments.
As a test of the presence of pollen this plan failed as often
as it succeeded, whilst as a test of quantity it was an utter
failure.

§ 229. Another method which I tried was to draw a
given quantity of air through an aspirator, and in doing so
to cause the stream of air to impinge against a glass plate

10

146 Eocperimental Researches on Hay-Fever:

covered over with a thin layer of glycerine. The current of
air was made to pass through a small tube fixed with the
nozzle almost close to the glass plate *

Another method which was tried was that which had
previously been used by M. Pasteur in his researches on
spontaneous generation. The aspirator was made to draw
the air through a tube in which was placed a portion of gun
cotton ; this latter acting as a filter by retaining the parti-
cles of solid matter in its meshes. By dissolving the gun
cotton in ether, and allowing the particles to settle, these
could be seen under the microscope.

Another plan was to fix a piece of thin fine muslin over
one end of a tube attached to the aspirator. This muslin was
previously moistened with glycerine, but to such a degree
that the threads only would be saturated, whilst the square
openings between the threads were left patent. When the
aspirator was set to work the air was drawn through the
muslin, and whatever solid particles this had in it, if they
were not small enough to pass through the meshes, they
were at once arrested.

§ 230. All these methods answered well as tests of the
presence of solid bodies in the atmosphere, but as tests of
the quantity they were too difficult, and occupied too much
time in the working to permit me to adopt them. In the
first plan there was a difficulty in determining whether the
whole of the pollen in the air drawn through the tube
adhered to the plate charged with glycerine. Unless this
could be determined with certainty, the plan was really use-
less as an indicator of quantity. In the second method the
trouble involved and the time taken made it impossible to
work it,Jwith the time I had at my disposal.

Another plan which was adopted was to aspirate the air
through a given quantity of fluid, and then to examine a
portion of this under the microscope. A single drop was
found to be sufficient to make three or four cells, each of

* Similar to the arrangement adopted by Dr. Maddox in the ap-
paratus invented by him. In his instrument, however, there is no
aspirator used. The air is made to pass through the tube by the
force of the wind.

Fig. 3.— A perpendicular section of the instrument ropi-eaented.
a, a, brass plate to which the bran cylinder b, b is soldered ; e, a
square of thin microscopic glass, on which a cell one centimetre
square is made with black varnish ; d, a loose cap, which screw!
on to the cylinder 6, 6. When screwed down, the under and
inner surface of this cap rests on small pins, which surround the
square of thin glass, e, a smaller cylinder, which is made to
screw into the plate a,a; /, a brass or glass tube cemented or
screwed into the cylinder b, b ; g, brass step screwed to the plate
a, a, the tube/ being cemented into a semicircular recess on the
upper surface of g ; A, a short length of glass tube to be used as
a month-piece j i, i, caoutchouc tube, attached by one extremity
to the tube/, and by the other to the mouth-piece h. This tube
should be sufficiently long to reach the mouth of the operator
when the instrument is placed in position on the stage of the
microscope, and the eye of the operator is iu position at the
eye-piece. A slip of thin glass is shown to be inserted in the
tube/,- j, a disc of thin brass, perforated with a square opening
rather larger than the cell on the thin glass. This disc is mode
to rest upon the upper edge of the cylinder 6, 6.

Drawn to a scale of jrds.

@HQ

Fig. 4. — A view of the upper surface of the din of thin
brass j. The square of thin glass c ia olio shown in positiun.

Fig. 5 A view of the upper surface of Fig. 3 (the cap if and

the dioc j being removed), a, brass plate to which the cylinder
b ia soldered, and into which the smaller cylinder e is screwed ;
/, glass or brass tube cemented into the cylinder i, and to the
step g, g.

When in position the disc j rests on the upper edge of the
cylinder b, as shown in Fig. 3. The thin glass c ia kept is posi-
tion by the short pins along its edge, these being screwed into
the disc j. The india-rubber tube i, i, and the mouth-piece A,
are supposed to be removed.

Atmospheric Experiments. 147

one centimetre square,* and, although this method promised
at first to be the most scientific and reliable in its results, it
was found to be more uncertain and more tedious than any
of the other methods.

As there is considerable interest taken in the subject of
atmospheric deposits at the present tine, I have ventured to
give a sketch of the various plans adopted, notwithstanding
that these were, for the purposes I had in view, almost
useless. The record of my failures may, however, possibly
prevent other observers, who may think of repeating my
experiments, from wasting time in attempting to work in
the same way.

§ 231. By an apparatus similar to that shown at Figs. 3,
4 and 5 (Plates II. and III.), I could ascertain the presence
of pollen in the atmosphere at any time, and could form
some idea of the quantity inhaled ; but the use of this in-
strument also revealed to me the existence of some dis-
turbing influences and causes of uncertainty, which made
it impossible to depend upon experiments tried for short
periods.

This instrument I devised for the purpose of viewing the
deposit whilst it was forming. By placing it on the stage
of the microscope, and inhaling through the mouth-piece h,
the glass plate c is for the time being made to take the
place of a portion of the mucous membrane of the nares,
and the observer can see the deposit as it forms on the field
of the microscope. The air being made to enter at the
point 6, passes up the cylinder and strikes against the thin
glass c, this latter being charged with a small portion of the
prepared fluid named at § 235. The air then passes over the
top of the cylinder e into the tube /, along the tubes i i and
A, and into the mouth of the operator. A slip of thin glass
is shown to be inserted in the tube /. This is done with a
view of ascertaining what amount of matter escapes bein g

• The smallest quantity of fluid that could be used to aspirate
through would make quite one hundred slides, each having about
seven hundred microscopic ' fields ' in it. I found that unless a very
large number of slides were counted, no dependence could be placed
on the result.

148 Experimental Researches on Hay-Fever:

deposited on the plate c. If it is thought to be desirable
the caoutchouc tube i i may be divided at different points,
and a short length of tube, with a slip of thin glass placed
in it, may be inserted. In this way some idea may be formed
of the distance to which atmospheric deposits can penetrate
into the bronchial tubes. In this case, however, it will be
necessary to coat the inner surfaces of the instrument and
the tubes with a thin layer of the prepared fluid (§ 235) so
as to imitate the condition of the mucous membrane of the
buccal cavity, trachea, and bronchial tubes.

§ 232. For observations where it was not deemed necessary
to watch the deposit as it formed, a much more simple
instrument, constructed on the same principle, was used.*

Either of these instruments seemed at first to be likely
to be all that could be desired, but, as in many other cases,
the apparent advantages were not found to be so great in
practice as they promised. I found that the quantity of

* This consists of a glass tube six or eight inches long, and rather
less than an inch in its inside diameter. This tube is fitted with a
square cork sufficiently large to permit it to slide easily into the tube
when a moderate force is applied, and yet to remain fixed at any
point when untouched. To one end of the tube a brass cap is fitted.
This is furnished with an opening rather less than one square centi-
metre in size. On one surface of the cork a slip of thin glass is
fastened by means of two small staples made with thin wire, and
placed so as to secure two opposite corners of the glass. If the ex-
periment is intended to be made for the purpose of determining the
exact amount of pollen or other deposit a certain number of inspira-
tions will give, it will be necessary to form a cell upon the thin glass
in the manner shown at Fig. 4. When all are in position, the cork,
with its thin glass, should be about a quarter of an inch from the
opening in the brass cap ; and this latter should be made to corres-
pond exactly with the position of the cell on the glass.

If air is drawn through the instrument by placing the free
extremity of the tube in the mouth of the operator, much the same
result may be obtained as with the instrument shown at Fig. 3, with
this exception, that the deposit cannot be viewed whilst forming.
The slip of glass can be taken out for examination, and should be
placed on an ordinary glass slide, so that the lines forming the boun-
daries of the cell will be parallel to those described by working the
screws of the microscope stage. The mode of examining a deposit
obtained in this and other ways I shall give further on.

Atmospheric Experiments. 149

pollen in the atmosphere during the hay season was an
ever-changing quantity. In no case could I make the pro-
duct of one, two, or three hours' experimentation agree with
the hourly average obtained when the experiments were
continued for twenty-four hours at a time. In the middle
portion of the day the amount of deposit obtained in a
short period was always, or nearly always, largely in excess
of the average for a longer period. Then the deposit
obtained in twelve hours of the day was generally much in
excess of that obtained during the twelve hours of the
night. Occasionally, however, the night deposit would be
large, whilst that of the following day would be small in
amount. As I have said above, these facts show, that the
amount of pollen in the atmosphere was constantly
changing.

If it had been possible for me to have attached an aspirator
to the instrument, and to have kept this constantly going,
some of these difficulties might, have been obviated ; but
as one series of the experiments had to be conducted in
the country, some three miles away from my own residence,
this was not practicable.

§ 233. Then there were other difficulties and irregularities
which even this would not have obviated. I found, for
instance, that a very slight alteration in the position of the
instrument, or in the position of the observer, would make
a considerable difference in the amount of the deposit, and,
as a matter of course, an equal difference in the quantity in-
haled. The shelter of a hedge or wall would lessen the
quantity perceptibly if the instrument or the patient were
placed to the leeward ; whilst a wood or large plantation
would diminish it more than one half if the trees were in
full leaf. Then, again, I found that the force of the wind
made some difference in the amount of pollen deposited. A
quiet state of the atmosphere in the height of the hay
season generally gave a large amount, but a strong wind
lessened the quantity. In the latter case, however, if the
wind was not very strong, I found the ophthalmic suffering
to be more severe than in a quieter state of the atmosphere.

§ 234. The centre of the city, as might be expected, gave

150 Eovpcrimcntal Researches on Hay-Fever:

a very much smaller deposit than was got in the country,
and as my duties frequently called me into the city whilst
the experiments were going on in the country, this intro-
duced another element of uncertainty.

Another and very important cause of irregularity was
the occurrence of rain during the hay season. If this was
very local, and confined to a comparatively small area in
the district where the experiments were going on, it would
lessen, or entirely put a stop to, the deposit of pollen in this
district; but if my duties called me into a part of the
country where there had been little or no rain, I should
have the symptoms well developed notwithstanding that not
a single pollen grain might be shown with the instrument in
my own neighbourhood.

§ 235. Ultimately, I was led to adopt a very simple plan,
which I afterwards found was recommended by Dr. Phoebus.*
This consists in the exposure of slips of glass to the open
air for a given length of time, so as to allow any solid
matter the air may contain to deposit upon the glass. Each
slip of glass had a cell formed upon it with black varnish,
so as to enclose a space one centimetre square,^ This
square was coated with a thin layer of fluid prepared for the
purpose.J After being exposed for twenty-four hours, each
slip was placed under the microscope, and any deposit it
contained was carefully examined, and the number of pollen
grains counted. The apparatus on which the glass slips were
exposed is shown at Figs. 6 and 7 (Plate IV.).

The ultimate object of these experiments was of course
to determine as nearly as possible what number of pollen
grains floated in the air during each twenty-four hours of a
period fixed upon. At first sight it would appear that this
apparatus was not very well adapted for this purpose, and,
if very exact estimates are sought for, the remark would be
quite true. I found, however, in practice, that this plan of

* *

And has also been used by Dr. Salisbury and other observers.

t As shown at Fig. 4.

J In the following proportions : One part of water, two of proof
spirit, and one part of glycerine. Five grains of pure carbolic acid
are dissolved in each ounce of this mixture.

PLATE IV.

Fig. 6.

Fig. 7.

flr--

Fig. 6. — a, roof or cover to the stage d; 6, pillar which sup-
ports the roof a; c glass slips seven-eighths of an inch square;
e, socket which fits on to the upper part of a pillar of wood four
feet six inches long, and which has its lower extremity fixed into
a block of wood which rests on the ground.

Fig. 7. — A view of the upper surface of the stage d f the cover
a being removed ; a, a, a, a, slips of glass seven-eighths of an
inch square, on which the cells b 9 b are formed by the borders
of black varnish.

Drawn to a scale of £th.

Atmospheric Experiments. 151

proceeding gave me much more even and reliable results
than I had been able to get by any other method, and
although they were not quite as exact as might have been
desired, they were such as answered well the purposes I had
in view.

§ 236. As it was obviously impossible to remain in one
spot and thus avoid some of the irregularities of which I
have spoken, I determined to use the form of instrument
shown above, so as to imitate some of the conditions which
I have mentioned as the causes of irregularity in the
quantity of pollen to which a patient may be exposed in his
daily routine.

By a reference to Figs. 6 and 7 it will be seen that there
are four slips of glass exposed. Whichever way the wind
happens to be blowing, one of these must be more or less
under the shelter of the central pillar 6, and it was astonishr
ing to see what an amount of difference even this little
shelter made in the quantity of pollen deposited. During
the hay season a patient must, in moving about, be neces-
sarily exposed to similar variations, in some cases amount-
ing to a complete escape from the influence of pollen, and
in others to contact with a large quantity. But these
variations will often occur under circumstances which will

K

not permit the keenest observer to discover the cause of
them.

§ 237. In making these experiments it was not only
desirable to pursue a method which would be comparatively
easy and which would give results that could be depended
upon, but also that this method should allow of the deposit
being examined in sitd before it had undergone any dis-
turbance. Whilst, on the one hand, I was satisfied that
pollen was the most powerful cause of hay-fever, I was, on
the other hand, not certain that other organisms might not
be found floating in the atmosphere along with pollen, and
that some of these might not help to intensify the symptoms
set up by it in the first instance. It was therefore impor-
tant that the organic matter collected should be subjected
to as little manipulation as possible, so that if any delicate
organisms were by chance found along with pollen, these

152 Experimental Researches on Hay-Fever :

should be uninjured and remain on the glass as they were
first deposited. It was principally for this reason that the
plan named at § 235 was adopted.

§ 238. To accomplish the objects aimed at it was, as I
have said before, necessary to form some estimate of the
comparative number of the pollen grains to be found in the
atmosphere during each twenty-four hours of a given period.
To show the exact relation there is between the intensity of
the disorder and the quantity of pollen in any given case,
it would, as I have before intimated, have been needful for
the patient experimented upon to remain on the spot where
these experiments were conducted during the whole of the
time they were going on. But as it was not possible to pursue
the inquiry in this very precise manner, this rendered it
difficult to make an exact comparison between the quantity
of the materie8 morbi and the intensity of the symptoms
produced. It will therefore happen that some allowance
will have to be made for the difficulty to which I have just
alluded, and for the disturbing influences of which I have
previously spoken. Nevertheless when we make due allow-
ance for all these difficulties I think it will be seen that the
plan adopted has given results as accurate as the nature of
the case admits of.

§ 239. Two sets of experiments were tried with the
instruments placed at the average breathing level (four feet
nine inches from the ground). The spot selected for the first
set of experiments was a meadow about fifteen acres in ex-
tent, and was situated about four miles to the south-west of
Manchester. This land had been used for the growth of
hay-grass for more than half a century. In the first part of
the experiments the slips of glass were placed in various
situations. In some cases they were sheltered by a hedge
or wall, in others by the trunk of a tree or by a gate-post.
In many cases, however, the glasses were placed in the open
field.

The quantity of pollen obtained in these different posi-
tions was very variable. After a short time the instru-
ment shown at Figs. 6 and 7 (Plate IV.) began to be
used, and although the quantity of pollen was not quite

Atmospheric Eayperiments. 153

so variable, the number was never the same on all the four
glasses. The glass which was placed to the windward of
the central pillar invariably contained a much larger
number of pollen grains than the one which was placed to
the leeward, except where the wind had gone round from
one side to the other whilst the experiment was going on ;
curiously enough, however, the glasses placed in the other
two positions rarely contained the same amount of pollen.
Probably this arose also from some variation in the direction
of the wind.

§ 240. At first the glasses were dry when exposed, but I
soon found that this plan was a very uncertain one. Occa-
sionally one of the glasses would have little or no pollen
upon it, whilst the others would have a fair quantity upon
them, and whilst at the same time I myself had suffered
from hay-fever to a degree which quite corresponded with
the largest quantity of pollen found : the cause of this
irregularity I was some time in discovering. I believe now
that the pollen was occasionally consumed by insects, as it
was not an uncommon occurrence for me to find the scales
of some of the Lepidoptera on the slide. In some attempts
also which I made to ascertain the exact weight of pollen
contained in one anther, the experiment was often spoiled
in consequence of the pollen being consumed by the common
blowfly. Then again I found that in the open air a high
wind would clear away a considerable portion of the pollen
from the dry glass after it had been deposited. To obviate
these difficulties I coated the surface of the glass with a
mixture of glycerine and water, but this also I found was
liable to the depredations of insects, and ultimately I was
led to use the fluid, the formula for which is given at
§ 235 *

* If this fluid is intended to be used for the collection of very small
and delicate organisms, it will be necessary to exercise great care in
preparing it. The spirit should be placed in an ordinary chemical
* wash-bottle/ or in a bottle from which it can be drawn by means of
a syphon. After being allowed to stand some days, three-fourths of
the spirit should be decanted by means of the tubes in the wash-bottle
or by the syphon, so as not to disturb any sediment which may have
been deposited, the object being to get rid of all solid matte* &\^^s^

154 Experimental Researches on Hay-Fever:

The coating of the surface of the cells with the above-
named fluid prevented the deposits being disturbed by
insects, and the quantity of pollen was also found to be
rather less variable. The glasses were exposed for twenty-
four hours at a time, for five days in the week, and for the
whole of the forty-eight hours of the remaining two days.

§ 241. The observations were commenced in the early
part of April, 1866, and were continued until the 1st of
August. For nearly a month after the observations com-
menced very little pollen was found. On the 30th of May the
quantity increased, and was considerably beyond anything
that had been collected previously. From this time up to
the 1st of August pollen continued to appear on most days
whilst the trial was continued.

It will be seen that occasionally there are days on which
no return of quantity of pollen is given. This was generally
caused by some accident happening to the slides during the
time of exposure ; sometimes a* high wind with drenching
rain would partially wash the pollen away, so that the ex-
periment was not to be depended upon.

§ 242. In the first set of experiments the glasses were
always placed in a horizontal position, and after being
exposed the requisite time, each cell — containing about
seven hundred microscopic 'fields' — was examined sepa-
rately under the microscope, the number of pollen grains
being carefully counted*

At first sight it would seem to be rather a formidable task
to examine daily four slides, each having the number of
fields named above. If, however, instead of regarding each
cell as consisting of seven hundred separate fields, we

in the fluid. After the water, glycerine, spirit and carbolic acid have
been mixed together, the fluid may be again decanted in the manner
described, and is then ready for use. It is scarcely necessary to say
that the mixture should never be allowed to remain open to the atmo-
sphere until placed on the glass.

* For investigations where it is intended to ascertain the exact
number of organic bodies deposited in a given space, it is necessary
to use a microscope with a stage which traverses by screws, or by
racks and pinions. A stage which only allows the slide to be moved
by the fingers will be almost useless in such experiments as these.

Atmospheric Experiments. 155

suppose it to consist of a certain number of lines, each line
having the width of one field, we simplify the task very

much.*

§ 243. The state of the barometer was noted and regis-
tered during the greater part of the first course of experi-
ments, but as the barometrical variations had no direct
action either in increasing or decreasing the quantity of
pollen deposited, no attention was paid to this matter in the
latter part of the course.

The hygrometrical condition of the air was not ascertained,
so that I am not able to say much upon the effect which
vapour in the atmosphere has upon the formation of pollen;
but although I cannot say exactly what influence a dry or
moist condition of the air has upon its formation, I am
tolerably certain that a dry state of the atmosphere will
cause it to be thrown off more easily when it has been
formed than it will be when the air is charged with vapour..

§ 244. In order to try what effect an atmosphere highly
charged with vapour would have upon the discharge of
pollen the following experiment was tried. A number o£
ears of rye, after having their stalks inserted in wet earth,
were placed under a glass shade so that the air about them'
might be kept still and be thoroughly charged with vapour..
An equal number of plants were treated in a similar
manner, but were not placed under a glass shade, and thus*
were freely exposed to the air of the room in which the-
experiment was tried. In each case the anthers were quite?
ripe, the plants being taken from the same part of the field,

* When the slide is examined it should be placed in the centre of
the microscope stage, so that the line described by working one of the
stage screws will be parallel with the line of varnish which forms one
side of the cell. By moving the stage slowly from one side of the cell
to the other, a line, which is one centimetre long and one field in
width, will all be brought into view. By moving the stage with the
other screw, just the width of a field, another line is brought into view,
and may be examined in the same manner as the first. And so the
operation may be continued until the whole surface of the cell has
been examined. When the quantity of pollen is very great, it is
sometimes necessary to use a micrometer with the lines ruled so as to
form squares.

Table of Curves showing the number of Polli August »t 1866 ;

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Atmospheric Experiments. 157

from wet to dry weather has taken place, but if the heat
keeps up very high the supply after a time suddenly lessens,
and does not increase again very rapidly unless rain falls
within a given time.

§ 247. For some days after pollen began to appear in
appreciable quantity the amount was very small, and if the
number had remained at this point — if I may judge from
the absence of any very perceptible effect in my own case —
it is probable that, in the majority of instances, no symp-
toms which would particularly attract the attention of the
patient would be produced. And this leads me to observe
that in some parts of the country a similar state of things
will be almost a constant condition in the summer-time.
Lands which are used for pastures and which are kept
moderately well cropped scarcely ever give rise to hay-fever,
for the reason that the greater part of the grass never
arrives at that degree of maturity to permit the formation
of pollen. In lands also which are considerably above the
sea-level, and where the average temperature may be com-
paratively low, the growth of grass may go on, but the
flowering may be so imperfect that the quantity of pollen
which is thrown off will be but small. In such a case hay-
fever, if developed at all, will be very mild in character.

§ 248. In the series of curves shown at Table No. I. we
see the general rate of increase and decrease, the variations,
and the dates on which these occurred. In these it will be
seen that at times the number of pollen grains collected
suddenly went down from a high point to a very low one.
Until I found that such variations did occur I was never
fully able to account for the alteration in the intensity of
the symptoms which I often noticed during the hay season.
In the earlier years of my attacks I was inclined to attribute
the amelioration to the action of the remedy I happened to
be using at the time. I am now satisfied that the remedies
used did not exercise anything like as much influence upon
the intensity of the symptoms, as the variations in the
quantity of pollen did.

§ 249. These sudden diminutions in the quantity of
pollen, when they occurred in the ascending scale— or on

Table of Curves showing the number of Polll August ist 1866 ;

w

. _V y.v VI 11 / ! J « J (

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Atmospheric Experiments. 157

from wet to dry weather has taken place, but if the heat
keeps up very high the supply after a time suddenly lessens,
and does not increase again very rapidly unless rain falls
within a given time.

§ 247. For some days after pollen began to appear in
appreciable quantity the amount was very small, and if the
number had remained at this point — if I may judge from
the absence of any very perceptible effect in my own case —
it is probable that, in the majority of instances, no symp-
toms which would particular^ attract the attention of the
patient would be produced. And this leads me to observe
that in some parts of the country a similar state of things
will be almost a constant condition in the summer-time.
Lands which are used for pastures and which are kept
moderately well cropped scarcely ever give rise to hay-fever,
for the reason that the greater part of the grass never
arrives at that degree of maturity to permit the formation
of pollen. In lands also which are considerably above the
sea-level, and where the average temperature may be com-
paratively low, the growth of grass may go on, but the
flowering may be so imperfect that the quantity of pollen
which is thrown off will be but small. In such a case hay-
fever, if developed at all, will be very mild in character.

§ 248. In the series of curves shown at Table No. I. we
see the general rate of increase and decrease, the variations,
and the dates on which these occurred. In these it will be
seen that at times the number of pollen grains collected
suddenly went down from a high point to a very low one.
Until I found that such variations did occur I was never
fully able to account for the alteration in the intensity of
the symptoms which I often noticed during the hay season.
In the earlier years of my attacks I was inclined to attribute
the amelioration to the action of the remedy I happened to
be using at the time. I am now satisfied that the remedies
used did not exercise anything like as much influence upon
the intensity of the symptoms, as the variations in the
quantity of pollen did.

§ 249. These sudden diminutions in the quantity of
pollen, when they occurred in the ascending scale — or on

158 Eaypervmental Researches on Hay-Fever :

any date between the 28th of May and the 28th of June-
were invariably due to a fall of rain, or to this latter and a
fall in the temperature. This remark also holds goods with
regard to the descending scale, but perhaps not quite to the
same extent. A good example of this is seen in the changes
which occurred between the 10th and 12th of June. On the
first of these days the temperature was 74° Fahr.* On the
11th the temperature was 66° Fahr., and on the 12th the
number of pollen grains had gone down from 285 to 12 ; but
in the time which had elapsed whilst these changes had
taken place rain had been falling for twelve hours ; chiefly,
however, between the 11th and 13th.

Another notable example of the effect produced by a fall
of rain and a decrease of temperature is seen in the descend-
ing scale. On the 30th of June the temperature was 90°
Fahr., and the number of pollen grains collected was 650.
On the 4th of July the temperature had fallen to 63°, and
the number of pollen grains to 10. Rain had fallen during
each day, and in the early part of the time it was very
heavy.

§ 250. On taking an average for twenty of the days on
which the greatest number of pollen grains were deposited
we find that whilst the mean quantity for each day was
364*8, the mean temperature for each day was 792Vf- On
twenty days in which there was the smallest deposit the
average was 75*75, whilst the average temperature for these
days was 71*5° Fahr. These results would seem to favour
the idea that temperature has a direct and independent
influence upon the quantity of pollen formed. When we
examine more closely, however, we find that this is more
apparent than real. As I have before observed, temperature
has a very important action in determining the quantity of
pollen formed, but there is no fixed relation between the
two.

§ 251. In the early part of the course of experiments
three -of the warmest days, with an average temperature of
74° Fahr., gave a total of fifty pollen grains for the three

* In all cases the temperature in the sun is indicated.

t Taken between the hours of 10 and 12 ; generally about 11 a.m.

Atmospheric Experiments. 159

days. On three of the coolest days the average temperature
was 65*3° Fahr., and the entire number of pollen grains
collected was eight hundred and fifty-eight — more than
seventeen times the number obtained in the warmer days.

One fact was particularly noticeable, namely, that the
average temperature of the days which comprise the ascend-
ing scale was not so high as that of the descending scale.
In the first case we have an average of 76° Fahr. for each
day. In the second case the mean is 76*5°. The lowest
temperature on any day on which pollen was deposited in
appreciable quantity was 60°, and, as far as the observations
altogether seemed to show, it would appear that the pollen
of many of the meadow-grasses is not readily thrown off at
any temperature below this.

§ 252. Although the amount of pollen gathered was
always lessened by a fall of rain, this decrease, as might
naturally be expected, was generally compensated for soon
after the cessation of rain ; and this was always the more
marked if with the cessation of rain there had been a rise
in the temperature.

As a rule the effect of a fall of rain manifested itself at
once, and so rapidly was the effect produced that often a
fall of five or ten minutes' duration would, for a time, com-
pletely clear the air of pollen as well as of every other kind
of solid matter. The effect of a change of temperature was,
however, generally not seen for some hours after it had
occurred, and this was perhaps a little more noticeable in a
rise than it was in a fall of temperature.

§ 253. The maximum quantity of pollen — 880 — as the
table of curves shows, was obtained on June 28th. The
maximum temperature occurred on June 27th, and was 96°
Fahr. The quantity of pollen given above is, however, only
the mean of the four slides exposed. The highest number
was 1260.* The average temperature of three of the days
in the earliest part of the course, when the pollen began to
manifest its power, was 71*3° Fahr. The average of three
of the days at the termination of the course, and when the

*, Equal to 7870 to the square inch.

160 Experimental Researches on Hay-Fever :

symptoms of hay-fever had all but disappeared, was 73* 3
Fahr.

The facts given above, on the relation of the temperature
to the quantity of pollen collected, point to the conclusion
that, whilst there is a tolerably close connection between
the two, quantity is not entirely dependent upon any given
temperature. It is, in fact, probable that whilst there is a
certain temperature which may be considered the normal
point for the generation of pollen, a certain amount of
variation above or below this may occur without perceptibly
retarding this process.

§ 254. To a hay-fever patient it signifies little which
pollen it is that produces an attack of the disorder so long
as it is produced ; but it is a matter of some importance to
him to know that if he can so regulate his movements as to
avoid certain districts during the flowering period of any
plant which may be grown in quantity in those districts, he
has a chance of escaping the attacks. And it is still more
important for a patient to know that his chance of escape
will be much increased if it is shown that the pollen of one
order of plants is the principal cause of his suffering.

Before the experiments were tried I, in common with
some other authors, had an idea that a fair percentage of
the pollen found in the atmosphere would not be derived
from the Graminacese. I have found it very difficult to
determine the exact proportion. Of the pollens of other
orders a large number are easily distinguished from those
of the Graminacese, but there are some that even when fresh
and when placed side by side with grass pollen are not
easily distinguished from it. This difficulty is also increased
after the pollen grains have been more or less distorted by
being soaked in fluid.

§ 255. So far as I could judge from observation fully
ninety-five per cent, of all that was collected belonged to
the Graminacese. It would, however, not be right to assume
that because in this district I found so large a proportion
of the pollen to come from plants belonging to the last-
named order, it would be the same in every other district.
It is probable that a very different result would be obtained

Atmospheric Experiments. 1C1

in other countries and also in parts of our own country
where plants belonging to other orders grow wild or are
largely cultivated. This remark will particularly apply to
America, where, as we have seen, the Ambrosia artemisice-
folia is very abundant. And here it is important to notice
two facts to which Mr. Darwin kindly drew my attention
in 1873. 1st. Pollens have been divided into two classes,
namely, into coherent and non-coherent. The pollen masses
of the orchids may be taken as a type of the first class,
whilst the pollen of the grasses may be taken as a type of .
the second class. 2nd. Delpino* has also divided plant3
into two classes, according to the mode in which they are
fertilised. In the one case they are fertilised by the agency
of the wind and are termed 'anemophilous ' plants. In the
other they are fertilised through the agency of insects, and
are termed ' entomophilous.' The grasses are examples of
the first class, and the orchids of the second.

§ 256. Coherent pollen is seldom found floating in the
' atmosphere, and cannot therefore be a cause of hay-fever.
The grains of incoherent pollen are almost always found
floating in the atmosphere singly. In no case have I ever
found a number of grass pollen grains massed together or
one grain over-riding another on the exposed slides. It
must, therefore, be that pollen will be distributed in the
same manner on the mucous membranes. Each one will have
its own separate sphere of action in which it can expend its
full power without let or hindrance, and without waste of
power. We cannot with any means we have at present at
command show the exact nature of the action which pollen
has upon the mucous membranes; nor do we know whether
the iiedema which it sets up in the submucous and subcu-
taneous cellular tissues is due to its action upon the capillary
blood-vessels or upon those of the lymphatics. But upon
whichever set of vessels its power is exercised we know that
each individual pollen grain will have its own sphere of
physiological action, and that the quantity of the materies
morbi which operates within this sphere must be exceed-

* Ult. Osservazioni sulla Dicogamia, part ii. fasc. i. 1870 ; and Studtf
sopra un Lignaggio anemq/Uo, etc., 1871.

11

162 Experimental Researches on Hay-Fever:

ingly small. This part of the subject will, however, occupy
our attention in another chapter.

§ 257. In attempting to place a mathematical value upon
the intensity of the symptoms in any disorder, we encounter
one of the greatest difficulties with which we can have to
deal in the study of disease. There is no known method of
t constructing a scale by which the severity of a malady can
be estimated in the same ratio by all physicians. Then,
again, the susceptibility to the action of certain morbid
agents is not often exactly the same in any two individuals,
nor yet in the same individual at different times.

In hay-fever, also, as in many other diseases, there are
many other factors which go to make up the sum total of
those influences which modify the severity of an attack, and
unless we know the degree of susceptibility in any case, and
are acquainted with the nature and mode of action of these
factors, it is impossible to fix an exact value upon a given
dose of the morbid agent. The knowledge of the amount
of the dose furnishes only part of the data required. The
other portion is an unknown quantity.

§ 258. There is also another point to which I think it
necessary to refer before I pass from this part of the subject.
I have, at times, thought that the continued contact with
pollen had a tendency to create a certain degree of tolerance
for it. Towards the end of a season I have occasionally
found that when the quantity of the pollen has been moder-
ately large the symptoms of hay-fever have not been cor-
respondingly severe. Of this, however, I cannot feel very
certain. At the end of a season I have always been too
glad to get quit of the trouble to permit me to think of
lengthening my sufferings by trying if I could exhaust the
susceptibility by the repeated application of pollen. I can
only, therefore, give the above as an impression which has
occasionally arisen — not as an ascertained fact.

§ 259. The study of hay-fever is as much affected by the
difficulties of which I have spoken as that of any other
disease, and in judging of the action of the varying amount
of pollen found in the air we shall have to take these, and
also other disturbing causes to which I have before alluded,
into account.

Atmospheric Experiments. 163

In all the experiments I have tried one fact stands
prominently out, namely, that a certain amount of pollen
may be present in the air without producing, in me, any
appreciable symptoms. Whether other hay-fever patients
would, under the same circumstances, be as free from the
disorder I cannot say, but I am inclined to think that in
this respect the degree of susceptibility will vary in different
individuals, and I also think that any given pollen may be
highly irritating with one person and comparatively mild
with another. This is a point, however, that demands more
investigation.

§ 260. After the grasses begin to flower — which in this
part of the country is generally early in May — pollen may
be found in the air up to the end of September, or even
later, if the season is mild; and occasionally, when the second
crop of grass flowers vigorously, it may for a short time be
found in considerable quantity. Under such circumstances
I have sometimes had a return of the malady for a short
time in the autumn.

If along with a large quantity of hay-grass there is also
a large growth of several of the cereals in any district,
patients who are very susceptible to the action of pollen
will have the symptoms of hay-fever more or less from May
to September. These facts I have no doubt will in many
cases reconcile the discrepancies there are in the statements
which are made with regard to the duration of the disease.

§ 261. In my own case very slight symptoms have been
felt so early as the middle or latter end of May, but these
have generally been too slight to attract attention if I had
not by experience known what they were the forerunners
of. In the year in which the first continuous experiments
were made, the attack commenced in good earnest on the
8th of June, but in the table of curves pollen is shown to be
present from the 28th of May.

In estimating the correspondence there was between the
quantity of pollen and the severity of the symptoms, the
plan pursued was first to note the number of pollen grains
deposited when the disorder began to appear, and then to
make the quantity of pollen and the intensity of the syrap-

11—2

164 Experimental Researches on Hay-Fever:

toms a standard for estimating the probable rise or fall of
those of the following day. Thus, in this way each day
was made to do duty as a standard for the next. In all
cases the day's symptoms were registered before any
attempts were made to ascertain the quantity of pollen
deposited.

§ 262. In pursuing this plan no exact estimate of the
quantity could be formed from the symptoms merely.
Nevertheless, a tolerably correct opinion could generally be
formed as to whether there had been an increase or dimi-
nution in the quantity, and in most cases it was not difficult
to say whether the rise or fall had been very marked.

The time spent in the district in which the experiments
were made varied. Generally not less than four hours
were spent in this district. Sometimes six hours would be
passed in the neighbourhood ; but as I found that it made,
very little difference in the severity of the symptoms which-
ever side of the city I happened to be on — providing I was
an equal distance from town — it mattered very little where
I passed the time* if this was passed in the open air.

§ 263. A few experiments were tried for the purpose of
ascertaining what amount of pollen there is in the air of
a dwelling-house. I found that as a rule there was very
little in this situation even when a large quantity was
collected in the open air. In a room which was seldom
entered no pollen at all was deposited on a glass which was
exposed the usual length of time — twenty-four hours. In
other rooms in which the experiment was several times tried,
and which were in constant use, the highest number of pollen
grains obtained was six. In a room where I purposely kept
a quantity of grass in full flower so that it might throw off its
pollen, only eight grains were found on the cell after this
had been exposed forty-eight hours ; and although I was in
the room frequently for an hour at a time whilst the pollen
was being thrown off, I had no symptoms which could be
fairly attributed to its presence. This result I attribute to
the fact that in an atmosphere in which the air is perfectly
still, and where the direct rays of the sun do not penetrate,
* Except under the circumstances named at § 208.

Atmospheric Experiments. 165

the pollen falls almost perpendicularly to the ground as
soon as it escapes from the anther.

§ 264. The result of these experiments has led me to
conclude that the time spent in a house, unless this is situ-
ated in the midst of grass lands in the open country, is, as
a rule, free from the influence of pollen ; or at any rate,
that this is rarely present in the air of city houses in such
quantity as to give rise to a troublesome degree of hay-fever.
At § 175, an experiment of Dr. Wyman's, of much the
same character as the above, is referred to, and where the
same result was obtained. I have shown above that in a
still air indoors the pollen falls almost perpendicularly from
the anther. This circumstance would, I think, quite ac-
count for the absence of symptoms in Dr. Wyman's case.
When I come to speak of the distribution of pollen in the
upper atmosphere, I shall have to show that in the summer-
time the opposite of this occurs.

§ 265. The highest points in the table of curves corres-
sponded tolerably well with the periods of the greatest
intensity of the disease. On June 8th, when the symptoms
began to be troublesome, the number of pollen grains
obtained was sixty-seven. The entry for this day in my
note-book states that ' I had been in the field only a quarter
of an hour when a smart attack of sneezing came on. This
was followed by one or two others during the day. There
was copious discharge of serum from the nostrils, with
itching of the eyelids and hard palate for some time after
leaving the district.' Again, on June 23rd — the highest
point but one on the table of curves — I find the following
entry : — ' The nostrils have been much inflamed all day, and
have discharged a large quantity of thin watery serum
mixed with puriform mucus. I have also had several violent
attacks of sneezing, with watering and burning of the eyes
during the day; but the heat in the eyes and nostrils,
with the constant discharge of fluid from the latter, are
the most distressing symptoms. The Schneiderian mem-
brane has also been much swollen, but not so as to lead
to complete occlusion of the nasal passages/

§ 266. On the day on which the highest numtax ^S.

16 J Experimental Researches on Hay-Fever:

pollen grains was collected the symptoms were in some
respects not so severe as might have been expected. This
might in part be accounted for by the circumstance that
the constant irritation of the mucous membrane of the
nares had caused the nasal passages to become completely
occluded for the greater part of the day. In this way less
pollen was drawn into the nostrils, and, of course, less
irritation arose ; and as I have found.that the mucous mem-
brane of the buccal cavity is much less sensitive to the
action of pollen than that of the nares, even when respira-
tion is entirely performed through the oral aperture, less
irritation must arise than when the air passes through the
nasal apertures. It is not at all improbable that the slight
amelioration of the symptoms, which sometimes occurred
during the days which comprise the descending scale, may
have been due to the same cause.

What the disorder lacked in intensity in one way, how-
ever, it quite gained in another. On the day in question
the ophthalmic suffering was very severe. The eyelids and
conjunctivse ^were much swollen. There was a constant
discbarge of fluid from the eyes, with intense itching and
slight burning. The tumid state of the conjunctivse also
gave rise to a slight appearance of chemosis. The nasal
apertures remained occluded nearly the whole of the day,
and the symptoms taken as a whole gave rise to an amount
of discomfort which only those who suffer from hay-fever can
fully understand.

§ 267. The lowest points in the scale were not always
marked by a decrease in the severity of the suffering which
corresponded to the quantity of pollen gathered. If the
interval between two high points was not more than two
days, it seemed not to give the mucous membrane sufficient
time to recover from the effect of one before the other was
reached. If, however, the interval was longer than two
days, the effect was very marked. Such an interval
occurred between June 14th and June 21st. On June
18th, five days after a high point had been reached, the
symptoms were very mild. There was no sneezing nor
any irritation of the nostrils or eyes whilst I was on the

Atmospheric Experiments. 167

ground where the instruments were placed, and on the
whole I felt as I do when I am becoming convalescent,
On the 19th I find the following entry in my note-book :
'Have been more free from symptoms during the last
twenty-four hours than at any time since the attack com-
menced.' On the 20th the number of pollen grains, which
on the previous day had gone down to seven, rose to one
hundred and fifty. With this rise the symptoms began
again to be severe, and continued to be so until the highest
point was reached.

§ 268. The remarks made above to a large extent hold
good with regard to the changes which occurred in the
descending scale, but with this difference, that after a sudden
decline in the severity of the symptoms and the quantity of
pollen, these never rose again to the same point they had
been at before the alteration occurred ; and this was always
the case notwithstanding that under such circumstances the
temperature remained very high at times. On July 11th
and 12th, for instance, the temperature was 94° and 90°
Fahr. ; but the number of pollen grains had gone down from
the highest point, 880, to 275 and 260 respectively, and the
symptoms had correspondingly declined in severity.

The facts given above show conclusively that hay-fever
is, in my case, due to the presence of pollen in the air, and
not to heat.

§ 269. In the year 1867 a second set of experiments was
tried near to town. This was done in order to ascertain
the number of pollen grains that would be deposited on
glasses placed on the outskirts of the city, but still within
the boundary of one of the most densely populated parts.

The spot in which the instruments were placed was an
open space to the south-west of Manchester, about eighty
yards long by about eighteen yards wide. This quadrangle
was bounded on three sides by buildings three stories high,
and on the other side by buildings two stories high.

When the wind came in a north-easterly direction it
would have to pass over a dense mass of buildings quite
three miles in extent without coming in contact with a
single yard of grass land in which pollen could be formed.

168 Experimental Researches on Hay-Fever:

In the two directions at right angles to this the distance to
the open country would be from half a mile to a mile. In
the other or south-westerly direction the distance would be
about a third of a mile.

§ 270. Though not in the centre of the city the place
selected for the experiments was a good example of an
average city residence. I have no doubt, however, that if
these could have been made nearer the centre of the city
the results would have been slightly different, and would
have tended to show still more forcibly than they did the
great difference there is to a hay -fever patient between a
residence in the town and in the country during the hay-
season.

In the first set of experiments four glasses were exposed,
and the mean of the four taken. In this series only one
glass was exposed,Jand as this was equally open to the air
on all sides, the quantity of pollen obtained may be taken
to be nearly what was the maximum in the first course.
As in the other case, the symptoms were always registered
before the slide was examined, and the point at which these
first showed themselves was noted; and, as in the former
year's experiments, each day was made a standard for that
which was to follow.

§ 271. The table of curves (Table II.) shows the time at
which pollen first began to appear continuously, and it is
curious to observe that the day on which the first im-
portant rise occurs in the quantity is exactly the same as is
shown in Table I. In like manner, too, there is at the
beginning a period of twelve days, during which the quantity
is very small. The highest point in the scale was, as will
be seen by the table, reached on June 23rd, five days
earlier than in the year before. On this day I find an
entry in my note-book to the following effect: — 'I am
much more severely affected than I have been on any day
since the attack commenced. The eyes are very hot, and
itch intensely, and have a slight burning sensation in the
anterior part of the eyeballs, as if hot fluid of some kind
had been dropped on to them. The nostrils have discharged
freely, and I have had several violent attacks of sneezing.'

Tabta of Om^B centimitre, fifom M«y *8th, to Angwt and, 1S67 ;

M»V JUH 4U%

ff isi-wj/ / 2\. a ,, ,g ,j , y ,„- a, ,,- f/s&s * Jin ,'.;•><; ?7 *?■& M It t i

/M

w

7"

6

J»

-w

" -S

-v^3

J

x;

In the

the op
the otl
about

52;

aelecte
averag
these c
the res
have t
great d
residen
season.

In th
and the
glass w\
on all si
to be r
As in tt
before t
first sh(
year's ei
which yf

§ 271
which p>
curious
portant :
shown i
beginnic
is very f
be seen
earlier 1
entry ib
much m
since tl
itch infa
anterior
had beei
freely, a:

Atmospheric Experiments. 16&

§ 272. The changes which occurred in this season (1867)
were not, as a whole, so sudden nor yet so great, as those of
1866. In the ascending part of the scale they were very
similar in character — making allowance, of course, for the
difference in quantity*— but in the descending part of the
scale the fall was much more gradual. The character of
the symptoms corresponded very closely with these changes.
We had first an absence of symptoms up to the point named
above ; then an increase in the intensity at each rise up to
the highest point; then a continued lessening in severity
until all symptoms disappeared at the end of July.

If we take ten of the days on which the highest number
of pollen grains was obtained in 1866 — the year in which
the experiments were tried in the country — we find the
average for each day to be 472*5. If in the same way we
take ten of the highest numbers for 1867 — the year in
which the experiments were tried in the town — we find the
average to be 46*8 per day; thus showing that a patient
who resides in a large city during the hay season will not
need to come in contact with more than one-tenth of the
quantity of pollen he will have to meet with in the country.
These proportions will of course differ according to the size
of the town and the character of the country around it,
but the experiments given above prove in a very conclusive
manner that hay-fever is less severe in a town because
pollen is much less abundant.

§ 273. A number of experiments were again tried in
1869 behind my own residence. This is just outside the
periphery of the city, and is half a mile nearer to the open
country (where the first observations were made) than the
place selected for the second course. Practically it was a
sort of midway between the two. Grass was grown and
made into hay within a hundred yards ; and as I could be
on the spot quite fourteen hours out of the twenty-four, it
seemed to be an excellent opportunity for trying the experi-

* In a few experiments tried in the country in 1873, the quantity
gathered was generally ten times as much as we had in the city, and
it will be seen that the proportion I give afterwards will be about
the same.

170 Experimental Researches on Hay-Fever:

merits under conditions which were slightly more favourable
for getting exact results than they had been in the former
instances.

In the experiments previously tried the slips of glass
were placed horizontally, but in these the slide was placed
perpendicularly, in the manner shown at figs. 8 and 9.
(Plate V.)

§ 274. In these experiments the same rule was ob-
served as in the first course, so far as regards the registering
of the symptoms each day before the slide was examined.
The results were quite as conclusive as in the first and
second course.

I had here an opportunity of being, during the day-time,
more constantly in the open air, and in close proximity to
the instruments, than I had in the first course. This, I
think, helped to make the symptoms accord more closely
with the quantity of pollen collected than they had done in
the first observations. I also found that it enabled me to
predicate with more confidence the probable rise or fall in
the number of pollen grains on each day.

As I have given the results of the first course of experi-
ments quite fully enough to enable us to see the connection
there is between the quantity of pollen and the intensity of
the symptoms of hay-fever, it would serve no purpose to
enter into the details of this course, and the more especially
so as they would not throw much fresh light upon the facts
already given.

§ 275. In 1875 and 1876 Dr. Marsh, of Paterson, New
Jersey, U.S., made some experiments'* on the presence of
pollen in the atmosphere with prepared slides and instru-
ments, similar to those I have already described as being
used in my own experiments. Dr. Marsh's catarrh com-
menced, as usual, after he had found specimens of the
Ambrosia artemisicefolia in flower. One slide was placed
in Dr. Marsh's own garden in the centre of the city, and
another one just in the outskirts of the city. A few days
after the catarrh commenced pollen began to be found in

° Hay-Fever, or Pollen Poisoning, by Elias J. Marsh, M.D., pp.
15-17.

Fig. 8. — A side view of the instrument represented : a, the
roof or cover ; b, an ordinary microscopic slide ; c, c, sockets
through which the central shaft, i, passes, and which are soldered
to the back of the plate, e;f, one of the aide pillars, which,
with its fellow of the opposite side, supports the roof a ; g, a
socket which fits on to the npper part of a pillar of wood,
which, by its lower extremity, is attached to a hinged tripod.
By this latter the whole apparatus can be so regulated that the
vane, h, will have no bias in any one direction, and the slide, b,
will be exactly perpendicular.

Fig. 9. —A front view of the instrument : a, the roof or cover ;
b, a microscopic glass slide, with a cell one square centimetre
formed in the contre with black varnish ; d, a square hollow
pedestal; e, e, clips which turn over the edges of the glass slide
and keep this in position. These are attached to the back plate to
which the sockets, c, c (shown in fig. 8), are soldered ; g, a socket
which fits on the upper end of a pillar of wood attached to a
hinged tripod ; j, a spring which is bent forward at right angles
to keep the glass slide in position.

Drawn to a seals of jth.

51 „

4 „

(

square
in&tre.

112 „

on a
centi

204 „

310 „

Atmospheric Experiments. 171

both situations, and continued to be present up to the end
of the hay-fever season. In both the years named the
same results were obtained.

As Dr. Marsh was, on account of the severity of his
attacks, obliged to leave home before the season was over,
a non-medical friend carried on the experiments for him.
The following is a specimen of the observations made in
1875:

August 28th, one day's exposure, 80 pollen grains

29th
September 2nd „ „

» 3rd „ „

„ 6th „ „

» 8th „ „

On September 10th this same friend sent a couple of
slides to a friend in New York, with a request that he
would expose them on the window-sills of his house
(Twelfth Street, New York) for two days, and then return
them. When the slides were examined they were found to
contain thirty pollen grains of the Ambrosia on the square
centimetre. On September 8th, a slide placed on the roof
of the gentleman's own house in Paterson collected forty-
nine pollen grains in nine hours ; whilst a slide placed on
the lawn in the garden collected three hundred and ten in
the same time.

276. In addition to those influences which make pollen
more or less capable of fulfilling its own proper function in
the vegetable world, there also seems to be some influence
at work which, independent of quantity and of the condition
of the patient, alters its power of producing hay-fever. That
these alterations are due to one and the same cause I hope
to be able to show, and that there can be no doubt that this
occasionally alters — so far as hay-fever is concerned — the
properties of pollen, whilst at the same time it, in all proba-
bility, renders it less capable of performing its function in
the vegetable world.

It has also two or three times happened that the slide,
instead of having the usual deposit of pollen upon it, has

172 Experimental Researches on Hay-Fever:

had a quantity of the granular matter spread evenly over
the cell ; and this has been distributed in such a manner as
to preclude the idea that it could have been discharged from
the pollen grain after this had been deposited upon the cell.
What had been the cause of this mode of distributing the
granular matter I was not able to ascertain, but I was
certain that it must have floated in the air as free granular
matter.

b Experiments at high altitudes.

§ 277. During the second course of experiments my
attention was drawn to the circumstance that sometimes
when the wind had been blowing right over the city for
nearly the whole of the twenty-four hours during which a
slide was exposed, there was nevertheless a deposit of pollen.
When the wind blew in this direction the nearest point of
land where pollen could be formed would be nearly three
miles distant ; and whatever quantity was deposited at the
spot where the instrument was placed, it would have to rise
to a considerable altitude and cross the dense mass of build-
ings which form part of the city and two of the outlying
townships of Manchester.

§ 278. Darwin and other observers have shown that dust
and organic matter can be carried very long distances by
atmospheric currents * but this has generally been under-
stood to have occurred when strong winds have carried the
dust into the upper atmosphere.^ I had at one time the
impression that in a quiet state of the atmosphere only a
very small quantity of solid matter of any kind would be
found very high up in the air. It had consequently been a
favourite idea with me that if a patient could, during the
hay season, go into a district which lay considerably above
the sea-level, he would have a good chance of escaping
severe attacks of hay-fever — partly for the reasons given

* Journal of Researches in a Voyage Round the World, by Charles
Darwin, M.A., F.R.S. London : Murray, 1845, 2nd edition.

t 'I believe it to be the whirl-pillar which carries up volcanic
ashes into the upper atmospheric currents, in which they are some-
times carried along to great distances.' — Law of Storms and Variable
Winds, by Lieut.-Col. Wm. Reid, C.B., F.R.S.

Expei % vmerd8 at High Altitudes. 173

above, and partly because pollen would not be generated so
plentifully at high altitudes as at places near the sea-level.
Yarious circumstances, however, and especially the influence
of what is known as Hadley's law,* led me subsequently to
believe that the current of air that, according to this law,
must go from the earth's surface to the upper atmosphere,
in all probability carried with it a large number of the
lighter particles of matter that came within its influence. I
was also convinced that this upward current was to some
extent independent of gome of the influences which pro-
duced movement of the air in the horizontal direction, for
the reason that its effects were most observable when little
or no wind was blowing.

§ 279. But beyond the interest which attached to the
question in its connection with hay-fever, it had a still
further interest in the possibility there was of the investi-
gation throwing some little fresh light upon one possible
mode of spreading epidemic and contagious diseases. I,
therefore, determined to investigate the subject as fully as
opportunity would permit.

The problems to be solved were — 1st. How high can
pollen rise in the atmosphere, and to what distance can it
travel ? 2nd. What quantity is to be met with in the
upper strata of the atmosphere as compared with the lower?
3rd. Supposing pollen to be capable of rising to high
altitudes, and of being transported long distances, under
what circumstances or by what causes is it made to deposit
on the earth's surface ? Some of these problems I have
partially solved ; others there are towards the solution of
which I have made little or no approach.

§ 280. Familiarity with the appearance of pollen and its
known presence in the atmosphere at certain seasons
furnished the means of making comparisons such as do not

* According to this law the sun's rays heat the surface of the earth
more at one part than they do at another, and this superior heat is
communicated to the air resting upon this surface. This heated air
expands, rises, and flows over, at some given height, towards the
cooler regions. It then becomes cooled and descends and flows back
at a lower level, as a return current to the warmer regions, there to
undergo the same process.

174 Experimental Researches on Hay -Fever :

exist in any other disease. These comparisons had hitherto,
however, only been made on the deposits got in the lower
strata of air. The question was, by what means should the
upper atmosphere be reached by instruments ? Two modes
presented themselves. One was for the observer to go to
some high mountain range, and there to expose the slips of
glass in the same manner these had been exposed in
the experiments already described. Another method was
to send jip an instrument by a kite, or by a balloon, in the
same district in which the other observations had been
made.

Against the first plan there were several objections. In
the first place, the air on high mountain ranges, such as are
accessible to observers in England, might be at best only a
mixture of the upper and lower strata. If we suppose a
current of air at the earth's surface to pass over a level
country and then to meet with a high mountain range, a
large portion of the air in this lower current must, in
passing, be upraised, and thus we should have a mingling of
the upper and lower strata.

§ 281. Then another important objection is that no com-
parative experiments could be tried at the same spot at a
lower level. In most cases there must be a difference of
some miles between the base of a mountain range and the
apex. And, further, it would in most instances be found
that the means of making a comparison — the pollen — would
be very scanty in such situations. The only thing that
could be done to give any satisfactory results would be to
make a course of experiments on the plan I have followed
at the lower levels, for two or three seasons, and thus to see
if a patient would escape the disorder in such situations.
This I have not been able to do, and consequently cannot
say from the data obtained by actual experiment that a
patient will to any extent escape the malady by going
into districts considerably above the sea-level in England.
I think it is, however, highly probable that in most
instances he would do so, and that in some particular
situations the immunity will be almost complete. To the
consideration of this I shall return in another chapter.

PLATE VI.

Fig. 10.

Fig. 10. — A front view of the instrument represented. A, A,
microscopic glass slides with cells one centimetre square (aa
shown at d), formed with black varnish ; b, b, springs of thin
brass attached to the back of the frame, c, o ; the ends of these
springs are turned up at right angles, so as to keep the slides in
position ; c, c, a frame of brass which, at each end, is made to
turn over the outside edges of the glass slides in the form of a
hook. Another piece which has a similar construction is at-
tached to the centre of the frame and secures the other edges of
the slides ; e, a tapering brass rod attached to the back of the
frame, c, c. When the instrument is in use this rod is placed
in a socket, which is fastened to the back of the apex of the
kite standard, so that the glasses project a little above the kite.

Drawn to a scale of about $rds.

Experiments at High Altitudes. 175

§ 282. The objections above named induced me to look
for some means of accomplishing the object in view which
would be free from them, and which would at the same time
be easily worked. Partly because of the simplicity of the
plan, and partly because the experiments could be conducted
in any district, I determined to try if a kite could be made
to carry the apparatus required for the observations. For
this purpose I had a kite constructed to carry the instrument
shown at fig. 10 (Plate VI.). For the observations made at
low levels, to compare with those above, I used the instru-
ment shown at figs. 8 and 9 (Plate V.).

A kite would seem, at first sight, to be a very simple
instrument, and capable of being easily worked; in practice,
however, I found it was by no means so easily managed
as was first expected, and that in order to ensure success
it was needful to take every possible precaution. Even
when this had been done I had many failures and dis-
appointments. The kite has, however, some advantages
over a more cumbrous and costly instrument in the shape
of a balloon. It can be used in almost any locality, and
with less expenditure of time and money, than would be the
case if a balloon were used.*

§ 283. The first experiment at a high altitude was tried
on June 17th, 1868. The cells were charged in the usual
way with a drop of the prepared fluid. A slide prepared in
the same manner was fixed in the instrument shown at figs.
8 and 9, and was placed at the ordinary breathing level.
The altitude attained in this first experiment varied from

* The first kite used was six feet in length by three feet in width,
and was made of the usual form, namely, with a central shaft or
* standard/ and a semicircular top or ' bender.' In constructing a
kite for such experiments as these, the great object should be to
attain as high an altitude as possible with as little expenditure of
labour and material as may be. In order to accomplish this, light-
ness, with great strength, are the two principal things to be aimed at.
Thin tissue paper was used for covering the kite, but it was found
necessary to waterproof this by varnishing it with a mixture of boiled
linseed oil and copal varnish. The cord used for raising the kite was
also made waterproof by being soaked in a varnish made with paraffin
dissolved in paraffin oil.

176 Experimental Researclies on Hay-Fever:

300 to 500 feet. The day was very hot, and there was
during the whole of it scarcely a cloud in the sky. The
wind was W.N.W.W., and came from the open county
where a large quantity of hay-grass was growing. I fully
expected that pollen would be found in the upper atmosphere,
but that it would be in smaller quantity than in the lower.
I found, however, in this instance, that the pollen in the
upper strata was very largely in excess of that of the lower
strata. The number of pollen grains obtained with the
lower slide was ten. On the upper slide the number was
one hundred and four. I was considerably surprised at
this result, and felt sure the slides must have been changed
in some accidental way after being taken out of the instru-
ments to be examined under the microscope.

As I had no opportunity of repeating the experiment
during the hay-season of 1868 the matter had to stand over
until the following year, the impression remaining on my
mind that the numbers would be reversed when further
trials were made.

§ 284. In 1869 two other experiments were tried, the
first of these on July 10th. The altitude attained varied,
according to the force of the wind, from 600 to 800 feet.
The experiment occupied six hours. The wind blew all the
time from the east, and consequently would pass over a
large portion of the southern side of the city before it came
in contact with the instrument. The nearest grass-land
would be from two and a half to three miles distant. Five
hundred and eighty-four pollen grains were deposited on
the upper slide in the six hours. Unfortunately the slide
placed on the instrument at the lower level was accidentally
damaged before it had been examined, so that I could not
make any comparison between the two quantities. A slide
exposed, however, for twenty-four hours on the previous
day gave only sixteen pollen grains, whilst the one exposed
on the following day had sixty-four on it.

The second experiment was tried on July 14th. The
weather had been fine for a portion of the day. A tolerably
strong wind was blowing from the north-west, consequently
this did not come much over the town. No rain had fallen

Experiments at High Altitudes. 177

for three or four days. An ascent of four hours — from 3
p.m. to 7 p.m. — gave a deposit on the upper slide of twelve
hundred and twenty-seven pollen grains (= 7663 to the
square inch), whilst the number obtained at the ordinary
level during the same period of time was only eighty.

§ 285. In 1870 nine other experiments at high altitudes
were tried, but five of these only were successful. On
April 27th a very small quantity of pollen was found at
an elevation of 400 feet, but none at the ordinary level.
On May 27th, at an altitude of 1000 feet, forty-six pollen
grains were deposited in four hours, whilst the slide at
the lower level contained only four. On June 20th an
ascent of two hours with an elevation of 600 feet gave four
hundred and forty-six pollen grains, but the slide at the
lower level, exposed for the same period, gave only thirty.
On July 6th, at an altitude of 500 feet, four hundred and
thirty-five pollen grains were collected in four and a half
hours, whilst the lower slide had only thirty-six deposited
upon it.

In an ascent made on August 11th, 1871, the altitude
attained was about 1500 feet.* The wind came in a south-
westerly direction, and consequently would come right over

* The highest altitude that can be attained with a single kite is
about 1000 feet ; but this will depend upon the character of the wind.
At the suggestion of a friend who assisted me in nearly all the ex-
periments at high altitudes, I tried if one kite could be attached to
another after the first had attained a moderate elevation. With a
little management and care it was found that the plan was quite
practicable. It was by this arrangement that the above altitude was
obtained. There is, in fact, no limit to the elevation that may be
attained by this method ; more than two kites cannot, however, be
manipulated very well by the hands alone. If more are sent up a
small reel or windlass must be used.

Several other experiments with the two kites were tried, but were
unsuccessful. In some of these it was curious to observe the differ-
ence there was in the direction of the upper and lower currents of air.
In some cases the upper kite would be 15° or 18° (taken horizontally)
out of the line formed by the cord of the lower one. The difference
in the direction of the two currents must have been considerably
more than this, since each kite had a tendency to keep the other in
its own line.

178 Experimental Researches on Hay-Fever :

the centre of the county of Cheshire. The number of
pollen grains obtained on the upper slide was fifty -eight, on
the lower slide four only.

§ 286. Other observations by means of the kite were
made at Filey Bay in 1870. Only one of these was
successful. In the former experiments at high altitudes
my object was to see what the difference was between
the pollen floating in the upper and lower strata of the
atmosphere. Here, however, I had a slightly different
object in view ; I was wishful in this case to ascertain if
the upper part of the atmosphere contained any pollen, or
any other form of organic matter after passing over about
four hundred miles of ocean, and also, if possible, I was
wishful to get to know at what altitude it ceased to be
present.

It was not entirely on account of the important connec-
tion this phase of the subject had with the study of hay-
fever that I was wishful to throw a little more light upon
it; but, as I have previously intimated, partly for the
explanation it might help to give of the way in which the
causes of disease may be conveyed from one continent to
another. Ifc was not without interest, however, in its con-
nection with those attacks of hay-fever which are said to
have come on whilst the patients have been out at sea. If
it can be shown that pollen will cross large tracts of ocean,
it is not at all difficult to believe that at times it will
descend to the lower part of the atmosphere and be de-
posited on board any ship that comes in its way. In this
manner some of those anomalous cases of hay-fever which
are said to have occurred out at sea may be reasonably
accounted for.

§ 287. The instrument shown at figs. 11 and 12 (Plate
VII.) was devised specially to assist this form of the investi-
gation, and is so constructed that it can be got up to any
required altitude before pollen is allowed to come in contact
with the squares of thin glass which it is made to carry. It
consists of a thin brass case which contains an arrangement
of wheel-work, much like that of an ordinary watch, and
which is driven by a spring in a similar manner.

Fig. 11.— A view of the instrument with the cap H (shown in
fig. 12) removed, a, a cue of thin metal in which the wheel-
work is placed, b, a disc of metal attached by the nut o
to the central pivot of the instrument, D, D, cells of thin metal
made to hold the amall platea of glass r, v. On two of
the cells the springs which keep the glass plates in position
are raised to show their attachment, e, e, rods of metal screwed
into the disc B, and attached to the back of the celts o, j>. v, v,
plates of thin microscopic glass bordered with black varnish so
as to enclose a space of one centimetre square. These cells are
charged with the prepared fluid, aa in alt the other atmospheric
experiments, o, small rings attached to the case A. Through
these passes the piece of cord that is attached to the Hoe used
to raise the kite. The dial plate ia marked so that each division
ropassents a period of fifteen minutes when the central arm ia
moving.

Fig. 12. — A view of the instrument with the cap a in the
position it is in when in use.

Drawn to a scale of about |rds.

Experiments at High Altitudes. 179

In the former case the instrument (Fig. 10) was placed at
the head of the kite. In this case it was attached to the
cord about one hundred feet below the kite. The pivot
which carries the arm b was made to revolve once in twelve
hours, so that the glass d would be three hours in passing
the opening shown in the cap /at fig. 12. By varying the
size of this opening the time during which the square of
thin glass would be exposed to the wind would vary accord-
ingly. Whatever length of time is necessary to get the
kite up to the required altitude before the glass becomes
exposed, it is necessary to place the cap / in such a position
that the arm will travel that length of time before the
glass emerges from under it.

§ 288. The only successful experiment with this instru-
ment was tried at Filey in July, 1870. The wind was
blowing from the sea in an easterly direction, ahd had been
blowing, more or less, from the same quarter for twelve or
fifteen hours. The altitude attained was nearly one thousand
feet. The place selected for the experiment was the narrow
slip of land on the cliffs* close to the reef rocks,f and
was as near to the sea as it was possible to get and allow
room to work. Grass- was growing on the land, but as this
was used for pasture, and was kept closely cropped by sheep
and cattle, little or no pollen was formed. The experiment
was continued for three hours, and during this time a
stiffish sea-breeze was blowing. A glass exposed at the
margin of the water showed no pollen or any form of
organic matter.J The glass exposed in the instrument at
the altitude named above had a deposit of eighty pollen
grains upon it.

§ 289. It would, however, not be right to conclude that
pollen or any other form of organic matter would always, at
certain seasons, be found at high altitudes in the air which
has crossed long stretches of ocean, but this experiment has
shown that living germs may be carried by the upper at-
mospheric currents long distances across the sea, whilst the
lower strata of air may be perfectly free from them. Thus
one question I had proposed was answered.

* The Car Naze, t The brig. % Or any solid matter whatever.

12—2

180 Experimental Researches on Hay-Fever:

If we take an average of the quantities where pollen was
present at both levels, we find that whilst the average for
the ordinary level was 24 only, for each experiment, that
for the high altitudes was 472*33 ; or in other words, more
than nineteen times tfce quantity was present in the upper
strata of air as compared with the lower. Some allowance,
however, must be made for the difference there is in the
velocity of the air at various altitudes. According to some
authorities, this is as tvjo for the lower strata to seven in
the upper;* but even after we have made due allowance for
this difference there still remains a great preponderance in
favour of the upper strata of air, and it leaves the fact that
organic matter is present in such large quantity in the
upper regions still unexplained.

§ 290. In some of the experiments slips of ozone test-
paper were sent up with the kite. In most cases ozone was
altogether absent ; in others it was present in small quan-
tity, but never to a higher degree than 2" of Schonbein's
scale.

In the earlier part of my observations I have shown that
ozone is present in many situations where hay-fever patients
are free from the attacks of the disorder. I had at one time
an idea that, possibly, ozone might have the power of alter-
ing or controlling the action of pollen in producing hay-
fever, especially if this was long subjected to the influence
of currents of air which contained a full quantity of ozone.
I have, as I have shown, had many opportunities of testing
the action of both substances. Pollen has often been tested
after it had been for some time subjected to the influence of
a sea-breeze which contained a large amount of ozone, but
never in any instance have I found this substance to have
any tendency to alter the action of pollen.-} -

* In some balloon experiments tried by M. Duprey de Lome during
the Franco-German war, the wind in the upper atmosphere blew at
the rate of forty- two miles per hour, whilst the anemometer at the
Montsaurin Observatory showed a rate of only twelve miles per hour.

Mr. Glaisher had also previously ascertained that ground anemo-
meters do not give nearly the full value of aerial currents.

t From other experiments I have made with the spores of some of
the cryptogams I do not think that, in the quantity usually present

Experiments at High Altitudes. 181

§ 291. I have hitherto in these atmospheric experiments
confined my attention solely to the consideration of the
amount of pollen in the air ; it might therefore be imagined
by some that this was the only organic matter met with.
This, however, would be a great mistake ; in no instance, in
which pollen was present, could I say that there were not
also germs or spores of some other kind to be found. Gene-
rally these were present in much larger quantity than
pollen. In many cases the number of spores seemed to be
governed by the quantity of pollen, but in others there
seemed to be no very close connection between the two.

With the form of some of the spores I was tolerably
familiar, but there were others which were quite strange.
It would be foreign to my object to enter here into a de-
scription of all that was met with in addition to pollen, and
it must suffice, at present, to say that the species were very
numerous. The number of spores and germs of all kinds
combined was often so great that it was very difficult to
form a correct estimate of the quantity.

§ 292. If the advocates of spontaneous generation, who
call so persistently for proofs of the existence of large
numbers of germs in the air,* will adopt the plan followed
in these observations, they will have no lack of evidence
that they are at times present in very large quantities. In
one experiment which lasted about four hours, and in which
the number of pollen grains collected at an altitude of 1000

in the atmosphere, ozone can lessen the vitality of living germs of
any kind.

* The late M. Pouchet, who was one of the chief advocates of
spontaneous generation, in one of his later works on this subject says :
' On a vue que, contrairement k ce que pre*tendent les chimistes, lair
ne contenait normalement ni oeufs ni semences, et que toutes leurs
experiences, h vaisseaux clos, dtaient frappes de nullite, puisque dans
leur appareils, Ingenhous, Mantegazza, Joly, Musset et Wyman
obtenaient, ainsi que nous, des animaux et des plantes dans l'air
calcine^ et mime dans Pair artificiel ou de l'oxygene ; et cela avec
des liquides qui avaient subi une Ebullition des plusieurs heures,
meme sous une pression de deux atmospheres.' — JNouvelles Expert"
ences sur la Generation spontanSe et la R&sistance vitale, par F. A,
Pouchet : Paris, 1864, p. 207.

182 Experimental Researches on Hay-Fever:

feet, was over twelve hundred, the spores of one of the
cryptogams* were so numerous that I could not count
them. At a rough estimate, however, there could not have
been fewer than six to seven thousand on the slide
(= 30,000 to 40,000 to the square inch). This experiment,
I think, furnishes a fair answer to those who ask for evidence
of the presence of germs in the air ; and in answer to those
who will insist that these atmospheric germs ought to have
an appreciable weight,+ 1 shall, as I proceed, be able to show
that, although they do ' weigh something/ the balance and
the test-tube are, in some instances, quite incapable of
demonstrating their existence even when present in con-
siderable numbers.

§ 293. At § 278 it was stated that Darwin and other
observers had shown that dust and organic matters can be
carried long distances by atmospheric currents. It will not
be out of place here to give some examples of what has been
stated by these observers. In referring to this subject in
his ' Narrative of the Voyage of the Beagle,' Mr. Darwin
says : + ' I have found no less than fifteen different accounts
of dust having fallen on vessels when far out on the Atlantic.
From the direction of the wind, whenever it has fallen, and
from its always having fallen during those months when the

* Probably they were the spores of the Ustilago segetum, or of
several species closely resembling these.

t Professor Wanklyn, in a letter to the editor of Nature, says :
1 Great difficulties are involved in the assumption that the atmosphere
constitutes a storehouse of germs of all kinds ready to burst out into
life on the occurrence of suitable conditions. However small these
germs may be, still they must weigh something ; and there must be
very many of them, seeing that there must be an immense number of
kinds of germs, if a volume of air is to supply to any given infusion
precisely the right kinds of germs suitable to the conditions provided
by the infusion. Now, chemists are in possession of data showing
that the possible amount of organic nitrogenous matter in common
clear water and common good air is remarkably small— so small,
indeed, that the question may fairly be asked, is it large enough to
admit of the requisite number of germs the existence of which the
vitalists assume in water and airT — Vide Nature, July 21st, 1870.
„ X Journal of Researches in a Voyage Round the World, by Charles
Darwin, F.R.S. London : Murray, 1845, second edition.

Experiments at High Altitudes. 183

harmattan is known to raise clouds of dust high into the
atmosphere, we may feel very sure that it all comes from
Africa. It is, however, a very singular fact that, although
Professor Ehrenberg knows many species of infusoria pecu-
liar to Africa, he finds none of these in the dust which I
sent him : on the other hand, he finds in it two species
which hitherto he knows as living only in South America.
The dust falls in such quantity as to dirty everything on
board, and to hurt people's eyes ; vessels have even run on
shore owing to the obscurity of the atmosphere. It has
often fallen on ships when several hundred and even more
than a thousand miles from the coast of Africa, and at
points sixteen hundred miles distant in a north and south
direction.'

§ 294. Lieutenant-Colonel Reid, from whose work I have
previously quoted, in speaking of the cause of whirlwinds,
says : * 'It is now a well-ascertained fact that whirlpillars
are developed in the midst of storms ; and being small whirl-
winds turning in either direction, they may cause unex-
pected shifts of wind dangerous to ships. ... I believe it
to be the whirlpillar which carries up volcanic ashes into
the upper atmospheric currents in which they are sometimes
earned along to great distances.' In quoting Red field on
Aerial Currents, Colonel Reid says, further: 'We learn
from Humboldt that in the great eruption of Jorullo, a
volcano of Southern Mexico, which is 2100 feet above the
sea, in lat. 18° 45', long. 161° 30', the roofs of the houses in
Queretaro, more than 150 miles from the volcano, were
covered with the volcanic dust. In January, 1835, an
eruption took place in the volcano of Cosiguina, on the
Pacific Coast of Central America, in lat. 13° N., and having
an elevation of 3800 feet, the ashes from which fell on the
Island of Jamaica, distant 730 miles N., 60* E., from the
volcano. . . . Few facts in meteorology are more worthy
of our attention than the stratiform character of the vast
horizontal extension of the aerial currents in different
portions of the globe.'

* Law of Storms and Variable Winds, by Lieut. -Col. Wm. Reid,
C.B., F.RS. j (London: 1849.

184 Experimental Researches on Hay-Fever:

§ 295. Mr. Darwin, in speaking of the distribution of
pollen,* says : ' The amount of pollen produced by anemo-
philous plants, and the distance to which it is often trans-
ported by wind, are both surprisingly great. . . . Bucketful^
of pollen, chiefly of coniferse and graminse, have been swept
off the decks of vessels near the North American shore ;.
and Mr. Riley has seen the ground near St. Louis in
Missouri, covered with pollen, as if sprinkled with sulphur \
and there is good reason to believe that this had been
transported from the pine-forests at least 400 miles to the
south. Kerner has seen snow-fields on the higher Alps
similarly dusted/

Then we had last year (1879^ some extraordinary
examples of the way in which pollen may be carried by
wind. ' A remarkable shower of pollen grains fell on the
north-eastern part of Pensylvania on the morning of March
17th, which covered an area of more than 2500 square
miles. It is believed to be chiefly the pollen of the Pinu»
Australia of the Southern States, and that it had been
carried a distance of 500 miles.' - !-

We have also, at times, similar showers of pollen in
England. A local paper gives the following: 'During the
heavy storms at the commencement of last week there fell
with the rain in the Windsor county a yellowish powder,
having all the appearance of powdered brimstone. At the
town gas-works it collected on the exterior of the gasometer
and by the side of the rails on the Great Western Railway.
The deposit remained visible for days in some places. The
fall appears to have been general about Windsor, Eton,,
Chalvey, Slough, and Datchet/J A correspondent of Science
Gossip (Mr. H. G. Wheeler) examined this deposit under the
microscope, and found it to be the pollen of the Pinus
Australia^

§ 296. The examples just given are instances of the

° The Effects of Cross and Self-Fertilisation in the Vegetable
Kingdom by Charles Darwin, M.A., F.R.S., etc., pp. 405, 406.
f Science Gossip, June 2nd, 1879.
X Manchester Evening Mail, June 19th, 1879.
§ Science Gossip, August 1st, 1879.

Experiments at High Altitudes. 185

deposit of pollen which were visible to the naked eye. In
England daring the hay season, and in America during the
critical seasons, and also in other countries, similar pheno-
mena will occur. There will generally, however, be this
difference — namely, that the phenomenon is seldom visible
to the naked eye. In all my atmospheric experiments the
air, during the hay-fever season, has appeared quite as clear
as at other times, and the keenest eye, unaided by the
microscope, would have failed to discover anything unusual
in the common dust of the roads. It is, however, certain
that during the summer time this dust must be largely
impregnated with pollen, and that whenever those who are
susceptible to the action of this body come in contact with
the dust so constituted it will give rise to the symptoms of
hay-fever ; but I need hardly point out that it is not the
dust, but the pollen which it contains, which is the active
agent. It is the want of a due appreciation, or the want of
the knowledge of such facts as are given above, that has
caused some authors to persist in regarding dust as one of
the most potent causes of the malady.

§ 297. Notwithstanding that pollen, as I have shown, rises
to high altitudes, my first idea, that patients might escape
it by going to places far above the sea level seems, from the
experience of American subjects of hay-fever, to have been
the correct one. We find that, as a rule, patients in that
country escape the attacks by going to the mountainous
districts, and it would appear that the greater the altitude
the more certain the immunity. There are, however, some
places that give relief at one season and not at another. It
is not easy to explain satisfactorily the reason of this, but
seeing that pollen does rise to high altitudes and travels
long distances by atmospheric currents, I think it is not
impossible for these accidental showers of pollen to occur,
and to give rise to attacks of the malady in districts that
are usually free from it. It is, however, a question that can
only be settled by actual experiment.

§ 298. Another point I must notice here is the inter-
ference with Hadley's law, which occurs under some circum-
stances. As has been previously stated, the action of this

186 Experimental Researches on Hay-Fever:

law is to cause an upward current in the atmosphere
wherever the sun's rays are powerful enough to heat the
surface of the earth and the layer of air next to it more
than in other parts. On dull and cloudy days this upward
current must, as a matter of course, be either rendered very-
feeble or be absent altogether for the time being. As a
consequence of this, less pollen will be carried into the air,
and hay-fever patients will, as a result, have the symptoms
in a milder form. Many patients confirm this statement,
and say that a dull grey day restores them for a time to
comparative health.

This brings me also to another point I must notice. Dr.
Wyman tells us he had a plant of the Ambrosia throwing
off its pollen in his sleeping-room, but he had no catarrh
whilst it was doing so. Precisely the same thing has
occurred with me frequently. I have many times had the
grasses, and once or twice the Artemisia vulgare (a plant
nearly allied to the Ambrosia) 9 throwing off their pollen in a
room in which I spent several hours a day, but unless the
plants wera disturbed mechanically, I had no symptoms of
hay-fever. The reason of this is clear and simple. Where
the sun's rays do not penetrate directly, and where there is
no artificial heat, there are no currents to speak of, and the
pollen, if liberated at all, falls straight to the ground, or to
the next surface on which it can find a resting-place.
Under such circumstances it cannot be inhaled, and cannot
produce hay-fever.

§ 299. There is also another phase of the question which,
although it is not closely connected with my subject, I
must not neglect to touch upon before I pass on to other
matters. I have shown that, at times, the granular matter
of the pollen grain has escaped from the sac before this has
been deposited on the slide, thus showing that the former
must have floated in the air as free granular matter.

Many of the multitudinous forms of germs and spores
which float in the atmosphere have, like pollen, a cellular
form, and also — like pollen — have granular contents. If
many of these should resemble pollen in its capacity for
absorbing water and discharging its granular matter, we

Experiments at High Altitudes. 187

may have a form of finely divided vegetable and animal
matter thrown into the air, which the best modern instru-
ments would fail to discover the origin and nature of, but
which might, nevertheless, be a powerful cause of disease.
That the granular matter of pollen can and does so act at
times I am well satisfied. Such, perhaps, is the state of the
active cause of cholera. Of the nature and origin of this
latter I shall not at present offer an opinion.

§ 300. I must now bring this portion of my experimental
inquiry to a close. During its course I have shown that
pollen of all kinds will give rise to some of the symptoms
of hay-fever, and that all the other so-called causes have
little or nothing to do with generating the disease. I have
also shown that the actual attacks of the disorder, as they
•occur in the summer, are caused by the pollen which floats
in the atmosphere at this time. We have also seen that
pollen rises to high altitudes, and is carried very long dis-
tances by atmospheric currents ; but the most remarkable
t part of the phenomena exhibited by this course of investi-
gation is the circumstance that there seems to be a zone of
atmosphere, commencing some distance above the earth,
which contains a much larger number of germs and spores
than is found in the lower portion of the atmosphere. How
high does this zone extend ? How far can germs be carried
by the currents which prevail in the upper regions ? What
is the nature of the force which keeps these germs in the
higher regions ? Under what circumstances do they descend
again ? Can atmospheric currents convey the active causes
• of disease from one continent to another ? These and many
other questions are suggested by the results brought out by
these experiments. Future investigations only can answer
them. At present the upper atmosphere is almost an un-
.known region.

188

CHAPTER V.

ON THE GREATER PREVALENCE OF HAY-FEVER, AND ON
THE INCREASE OF ITS PREDISPOSING AND EXCITING
CAUSES,

§ 301. It would seem that hay-fever has, of late years,
been considerably on the increase. The fact of my atten-
tion having been closely directed to the disorder, for many
years past, has probably brought more cases under mjr
notice than formerly, and it is therefore possible that the
increase has not really been so marked as it has appeared
to me to be. But even if some allowance be made for this
probability, I am still strongly impressed with the idea that
the disease was less frequently seen fifteen or twenty years
ago, and that it is at the present time largely on the increase.
There is no possibility now of determining the exact time
at which the disorder first showed itself; but, for reasons
which will presently be given, it is probable that it was not
only very rare, but that it was, in early times, almost, if not
entirely, unknown.

§ 302. Every writer on hay-fever has recognised the-
existence of a peculiar condition of the constitution which
gives a proclivity to attacks of the malady. This pecu-
liarity is generally regarded as extremely curious, and as
one which stands, as it were, outside the pale of those
constitutional conditions which give a liability to other
forms of disease. Why it should be so regarded is, how-
ever, not easy to explain. Probably the yearly recurrence
of the disorder and its regular departure at a given time
have, more than any other circumstance, led to its being
regarded in this light. If its causes had been as inscrutable

On the Increase of its Causes. 139

as those of some of the more fatal disorders, and had mani-
fested their power at irregular periods; and, more especially
if death had been the not unfrequent result of an attack, we
should probably cease to look upon the predisposition as a
thing which is out of the usual course.

§ 303. Another point upon which most writers are agreed
is the fact of hay-fever being, as has been before stated, a
disorder which is almost wholly confined to the educated
classes. Some exceptions there are to this rule, but there
can be no doubt that that condition of the nervous system
which mental training generates is one which is especially
favourable to the development of the disorder ; and if this
view of the predisposing cause be the correct one, we have
an explanation of the greater prevalence of the disease
amongst the educated classes.

Of forty-eight patients that have come more or less
directly under my own notice, six are clergymen, three are
relations of clergymen, four are medical men, one is
the son of a medical man, three are military officers, one
is the widow of a military ojjieer, one is a school in-
spector, two are lawyers, one is a professor of music, four
are merchants, five are manufacturers, one is the son of a
manufacturer, one is a farmer, and five are engaged in
mercantile pursuits which cannot be referred to any of the
above classes. The remainder cannot be distinctly classi-
fied, but all belong more or less to the educated class.

In a table given by Dr. Wytnan* we also find the
educated to preponderate very largely. Amongst fifty- five
patients whose occupations are given, we find that forty-
nine belong to the educated class, but, somewhat different
to my own experience, Dr. Wyman has amongst his patients
three farmers, one gardener, one butcher, and one carpenter,
who, I presume, may be said to belong to the working class.
The proportion of those who belong to the labouring class,
as given by Dr. Beard, is very different to those of Dr
Wyman and myself. Of a total of one hundred and sixty-
five patients, fifty-three were either artisans, farmers, or
housekeepers.

* Autumnal Catarrh, by Morrill Wyman, M.D., p. 81.

190 Experimental Researches on Say-Fever:

§ 304. These statistics of the occupations of hay-fever
patients bring out prominently the very curious circum-
stance that the persons who are most subjected to the
action of pollen belong to a class which furnishes the fewest
cases of the disorder, namely, the farming class. This
remarkable fact may be accounted for in two different ways :
it may, on the one hand, be due to the absence of the pre-
disposition which mental culture generates ; or, on the
other hand, it may be that in this disease there is a possi-
bility of a patient being rendered insusceptible to the
action of pollen by continued exposure to its influence. If
this latter hypothesis be correct, it shows that, in one case
at least, the enjoyment of health does not merely depend
upon a high state of vitality, but also, to some extent, upon
the acquisition of a certain degree of insusceptibility to the
action of the exciting cause of the disease. Tn this instance
I believe that the immunity enjoyed is as much due to the
latter influence as it is to the absence of that predisposition
which education brings. How then has the disorder arisen,
and why has it become more common in England in these
later times ? A glance at the state of education and at the
condition of the town and rural population five or six
hundred years ago, as well as at a few of the changes which
have since taken place, may throw some light on the subject,
and may partially answer these questions.

§ 305. There was a time in the history of this country
when education, such as it was, was for the most part
confined to the members of the various monastic orders ;
and even amongst these it was very unequally distributed.
With the nobility also learning was not by any means
general, and in the class which stood between these and the
working classes education was as much the exception as it is
now the rule, whilst for the latter class it could scarcely be
said to have any existence. If, therefore, it is true that
the condition which mental training induces act3 as a pre-
disponent to attacks of hay-fever, we should expect that at
this early period this predisposition would be very sparingly
developed.

§ 306. But even if we admit the existence of a certain

On the Increase of its Causes. 191

amount of the predisposition in these early times, there
were other causes at work which would help to make the
disease comparatively rare. One of these causes was the
smallness of the area of land under cultivation. But not
only was there less land under cultivation, but upon that
which was in use less hay-grass would be raised than is
now obtained from the same breadth of land ; whilst on
some of the land vegetable products of quite another kind
were sometimes grown as food for cattle. Buckwheat
(Polygonum fago^yvum) was one of the plants formerly
grown for this purpose in several of the English counties *
Gerarde, who wrote in the early part of the 17th century,
mentions the fact,t and states that buckwheat was not only
grown as food for cattle, but in times of scarcity — which in
those times were not unfrequent — the seeds were mixed
with other grain, and ground and made into bread. J The
anthers of buckwheat are very much smaller than those of
the cereals and most of the grasses; and if this plant was

* Some years ago, when the branch line of railway was being made
between Eccles and Tyldesley (near Manchester), whilst passing a por-
tion of the cutting, my attention was drawn to the exceedingly luxu-
riant growth of the Polygonum there was at this spot. Along a portion
of the embankment where the soil had been turned up a few months
before from a depth of twenty to twenty-five inches, the plants were as
closely set as if they had been planted there for some special purpose.
Another remarkable example of this same thing occurred near to my
own residence. A field, which had been used for more than a hun-
dred years only for grazing and the growth of hay-grass, was one
year deeply ploughed and was sown with potatoes. The season was
a wet one and the potatoes proved a failure, but in their place there
came up a dense crop of the Polygonum persicaria ; so dense indeed
was it that it looked as if it had been sown over the entire field
on purpose. It is probable these were relics of the old Lancashire
husbandry, and that in the process of cultivation the seeds had by
some chance been buried too deep in the soil to permit them to ger-
minate. In this position they must have lain dormant for two or
three hundred years.

t The Herball, or General Historie of Plants, gathered by John
Gerarde, of London, Master in Chirurgerie. Very much Enlarged
and Amended by Thomas Johnson, Citizen and Apothecarye.
London, 1633.

X Withering also mentions the same facts.

192 Experimental Researches on Hay-Fever:

at all extensively cultivated in lieu of the grasses, a much
smaller quantity of pollen would be generated than would
be formed by the growth of hay-grass on the same breadth
of land. Thus, whilst on the one hand, there was a dearth
of those influences which lead to a predisposition to hay-
fever, there was, on the other, a comparatively small
quantity of the exciting cause of the disorder produced.

§ 307. But there were also other influences at work
which brought about important changes. Some of these,
for a time, checked the development of the disorder, but
others not only tended to increase the aggregate quantity
of pollen produced at certain seasons, but also caused this
increase to occur for the most part in comparatively limited
areas. Some of these influences had also the effect of
increasing the number of persons susceptible to the action
of pollen.

In very early times the cultivation of the soil was the
principal occupation of a large portion of the people, but at
the same time the ability to take part in the manufacture
of some of the simple fabrics then in use was much more
general than it is now. The two pursuits were often so
blended together that if, for a time, the manufacturing
occupation predominated, the individuals so occupied were
seldom entirely removed from the influence of a country
life. As time passed on, however, there was a tendency
for the various arts and manufactures to be taken up as
separate occupations, and for the workers in these to locate
themselves in the towns. This tendencj 7 had a great
impetus given to it in the reign of Edward III. During
this reign a number of Flemish weavers, skilled in the
manufacture of the finer sorts of woollen cloth, came over
and settled in various towns in England, and for greater
security the manufacture was principally carried on in
walled towns.* But in these times some of the largest
towns would not be larger than many of our villages and
smallest country towns are now; and even when the division
of labour had been carried so far as to cause a considerable

* Wade's History of the Middle, and Working Classes. Edinburgh :
W. and R. Chambers, 1842.

On the Increase of its Causes. 193

number of the people to be specially devoted to trades and
to manufactures, whatever happened to be the nature of
their occupation, these would be subject to the atmospheric
conditions which prevail in the country to a far greater
extent than the inhabitants of our towns are at the present
day.

§ 308. After a time the domestic manufacture of woollen
cloth as an article of sale began to grow, and it was not
unusual for the cultivation of the soil and the manufacture
of some kind of woollen cloth to be followed by the same
individual. At this period, too, a system sprung up, which
has continued more or less to our own time. It was the
custom for the clothier, who at that time occupied the
place of the mill-owner of the present day, to deliver to the
weaver a certain weight of wool to be made into cloth at
his own home in the country. This system of domestic
manufacture was pretty equally distributed over the whole
country. The consequence of all this would be that, with
one part of our population the life would be essentially
rural, whilst with the other, or town population, the condition
would, so far as atmospheric influences are concerned, very
closely approximate to that of the country manufacturer of
a later time.

§ 309. In the early history of the linen, cotton, and silk
manufactures a similar system prevailed. It was at this
period not unusual in some of the northern counties of
England to see the business of the farmer and small manu-
facturer combined, and for the workmen employed by the
latter to give a helping hand at farming operations at
certain seasons if required. As in the case of the woollen
manufacture, it was quite common for many of the work-
people engaged in the cotton, linen, and silk trades to follow
their occupation at their own homes in the country. In
those days the click of the shuttle of the hand-loom weaver
could be heard almost daily in most of the villages of Lan-
cashire, Yorkshire, and parts of Cheshire, as well as in other
parts of the country which have since become manufac-
turing centres. Attached to each cottage there was gene-
rally a patch of ground, the cultivation of which furnished

13

194 Experimental Researches on Hay-Fever:

occupation to the inmates in their leisure hours and when
work was scarce. Now the whole thing is changed. The
farmer and the manufacturer have formed two distinct classes ;
or if the occupation of the farmer is still retained by the
manufacturer, it is as a small addition to the business of the
latter ; and seldom are the workers in one employed in the
other. Although the practice of following their occupation,
at their own homes still lingers among the workpeople in
some branches of trade, it is now rarely seen. The hand-
loom weaver has almost died out. His place, as well as
that of many other outside workers, has been taken by the
mill-hand. Thus a large portion of the rural population
has been transferred from the country cottage to the mills
and workshops of onr towns.

§ 310. Whilst these changes have been going on educa-
tion has been spreading. Not only does it permeate more
completely all grades of society, but in every grade it is of
a higher quality than in former days. Competitive exami-
nations are now the rule where they were formerly the
exception. At all the examining boards in the United
Kingdom the standard of excellence has been raised, and
there can be no doubt that it now requires a much greater
amount of book-learning to reach certain positions in the
social scale than it formerly did. Whether all this forcing
is an unmixed good is a question I need not enter upon
here.

It is true there are parts of the country where some of
these changes have not taken place, but these are parts where
the population has not increased very rapidly, and which
have been, and still remain, purely agricultural ; but even
here the surplus population has been to a large extent
drafted off to feed the ever-increasing demand in the large
towns, and in this way also a considerable number of indi-
viduals have been withdrawn from the preservative influence
which a rural or semi-rural life exercises, and have been
placed under conditions which are favourable to the develop-
ment of the predisposition to hay- fever.

§ 311. In addition to the spread of that kind of education
which consists of regular training and book-learning, there

On the Increase of its Causes. 195

has been a vast advance made in another kind of education ;
and although this latter is not capable of being formulated
or of having its quantity estimated in the way that of the
former can be, it is nevertheless of immense value to the
country. It is in fact a hidden, but perhaps irregular and
somewhat fitful, stream of true technical education which
affects, more or less, all below a certain grade in society.
The immense progress which has of late years been made in
every department of trade and manufacture, and the greater
complication and intricacy which have been introduced into
these, have led to a demand for skilled labour which was
not dreamed of in former times. This kind of labour has
had, to a large extent, to be formed out of the raw material
furnished by the unskilled labourer. In this process of
training, faculties which would otherwise have lain dormant
have been called into play. Intellect of a certain kind has
been developed, and, although there may not be many
instances of the possession of extraordinary acquirements,
there are not wanting examples of remarkable success in
various walks of life, amongst those who have had only this
irregular kind of training; and there can be no doubt that
by this alone the intellectual capacity of the nation has
been raised several degrees, and that the constant tendency
has been for a certain number of the individuals belonging
to this class to be transferred to the educated class, and
thus to increase the relative proportion of the latter.

§ 312i Along with all these changes there has been an
immense increase in the population of the country at large,
and especially in that of our large towns and cities.* This,

* At the close of the seventeenth century the population of England
and Wales was about 5,500,000. London had a population a little over
half a millon. Manchester at this time contained only 6000 inhabi-
tants, and is said to have had neither printing-press nor hackney-
coach in it. Leeds had a population of 7000, whilst Sheffield had
only 2000 inhabitants.

At the present time the population of England and Wales is over
23,000,000. That of London is ten times as great as it was in 1700,
whilst that of Manchester is sixty times as great as it was at the
period named. Leeds at the present time contains above 260,000 in-
habitants—more than thirty-eight times the number it had in it in

13—2

196 Experimental Researches on Hay-Fever:

combined with the growth of commerce and the general
increase of wealth and luxury, must have led to a very large
demand for the article upon the growth of which the pre-
sence of the active cause of hay-fever depends, namely,
pollen. These circumstances must not only have led to an
increased aggregate production of hay-grass, but also to a
large local production. In ordinary times it does not pay
to carry hay very long distances, and whatever increase
there happens to be in the local demand there must to some
extent be an increase in the local production * Thus it must
be that in the neighbourhood of all large towns there will
be a greater amount of pollen generated than will be found
in other parts ; and in estimating the relative frequency of
cases of hay-fever at the present day, it should be borne in
mind that this increase occurs for the most part close to the
places where a relatively large number of persons susceptible
to the influence of pollen are to be found.

§ 313. We have thus seen that at one time the influences
which lead to a predisposition to hay-fever were very scanty,
and that the production of the exciting cause was at its
lowest point. We have also seen that at a later period a
large proportion of the population was subjected to the pro-
tective influence which a rural occupation seems to afford,
and I have shown that large numbers of the people have
been transferred from the country to the workshops and
mills of the towns, and have thus been placed in circum-
stances where the predisposition to hay-fever would be most
rapidly developed in those who rise to a place amongst the
educated class. And lastly, I have shown that the produc-

1700. Sheffield seems to have far exceeded other towns in the rate of
its increase. At the present time it contains more than 240,000 in-
habitants, or above one hundred and twenty times the number it had
in the year 1700.

° One of the largest farmers in my own neighbourhood tells me
that the growth of hay-grass has, on his own farm — nearly three hun-
dred acres in extent —in creased immensely during the time he and
his father have occupied the farm. The reason for this, he says, is :
1st, the increased local demand for hay ; and 2nd, the abundant
supply of cheap manure near at hand.

On the Increase of its Causes. 197

tion of the exciting cause has of late years been largely
increased.

Taking all these circumstances into account, it is highly
probable that hay-fever was at one time altogether unknown,
and it is tolerably certain that it has not only been much
more frequent of late, but that, as population increases and
as civilisation and education advance, the disorder will
become more common than it is at the present time.

198

CHAPTER VI.

ON THE NATURE AND SYMPTOMS OF HAY-FEVER.

§ 314. Beyond the circumstance of the predisposition to
hay-fever being more common amongst the educated than
it is amongst the illiterate, we have scarcely anything to
guide us in forming an opinion as to the class of persons, or
the kind of individuals, most likely to be affected by the
malady. In this respect it does not much differ from many
other diseases. If a number of individuals belonging to any
class of society were taken promiscuously and examined, it
would, without some knowledge of their proclivities, be im-
possible to say beforehand whether, and to what extent,
they would be liable to be affected by any disease with the
exciting causes of which they might be brought in contact.
It is precisely the same in hay-fever : we have no marks by
which the liability to the malady can be recognised, nor do
we know of any signs by which the severity of the attacks
can be foretold. The disease seems to affect persons of all
temperaments and all kinds of constitutions, but if there is
one temperament which more than another predisposes to
attacks of hay-fever, it is the nervous temperament. Upon
this point, however, sufficient evidence to base a conclusive
opinion upon has not yet been obtained.

§ 315. Age exercises some influence upon the commence-
ment of the attacks. According to a table given by Dr.
Phoebus * showing the ages of thirty-nine patients at the
time the first attack came on :

<

* Der Typische FriiJisommer Katarrh oder das sogenannte Heufieber
Heu-Asthma, von Philipp Phoebus, M.D., etc., Giessen, 1862, p. 71.

On the Nature and Symptoms of the Disorder. 199

11 commenced before they were 10 years of age.
9 » » 20 „

11

»

n

so

»

8

»

19

40

«

39

One of these patients was only five years and three months
old when the first attack occurred, and in no case did the
age exceed forty years.

Dr. Wyman also gives a table showing the age of seventy-
two patients at the time the disorder first commenced.* Of
these :

11 had their first attack when under 10 years of age.

15 „ „ 20

2d „ „ 30 „

8 „ „ 40 „

11 w „ oO „

2 „ „ 60

72

§ 316. Dr. Beard gives a table containing a total of one
hundred and eighty-eight patients.f Of these :

34 had their first attack when under 30 years of age.
56 „ „ 40 „

65 „ „ 50 „

33 „ „ 60

»

188

Fully two-thirds of the patients I have mentioned as

coming under my own notice had their first attack when

between fifteen and thirty years of age. Several cannot

remember the exact time at which the disorder first showed

itself, and as it was not a matter to which I gave close

attention at the commencement of my investigations, I have

not been able to classify the ages of the patients. One of

my patients, however, was below five years of age when

•
° Autumnal Catarrh, by Dr. Wyman, p. 81.

t Hay-Fever, by Dr. Beard, p. 45.

200 Experimental Researches on Hay-Fever:

the first attack came on, and one of my correspondents, as-
we have seen (§ 91), has stated that he knows of one patient
who was sixty years of age when the malady first began
to trouble him.

From these statistics it would seem that the disease may
begin at a very early age, and, whilst a very advanced time
of life is not exempt from the possibility of attacks, there is-
the greatest susceptibility to them between the fifteenth
and forty-fifth years.

§ 317. Hay-fever is without doubt strongly hereditary
in its character. It is to Dr. Wyman that the credit of
having first investigated this part of the subject is due.*
Six members of his own family are sufferers from the malady.
In another family consisting of six individuals, five had
either autumnal catarrh or June cold. Seventy-seven
cases are recorded (in the table), and in fifteen of these
more than one member of the same family was affected.

In the statistics relating to this question more than one-
third of the patients from whom Dr. Beard obtained replies
are stated to have had relatives who suffer from some form
of hay-fever.f In some cases the patients have as many
as five relatives who are sufferers.

In my own investigations this question has not been lost
sight of, but only in three cases have I met with patients
who have had relations who were affected with hay-fever;
but I have no doubt that when the question comes to be
more closely inquired into, we shall find this tendency to be
almost as strongly marked in England as it is in America.

§ 318. No information that can be relied upon has yet
been obtained upon the effect which attacks of other diseases
have upon those of hay-fever. In one case a mild attack of
gastric fever, attended with congestion of the lungs, seemed
to cause the attacks of hay-fever which followed it to be
milder in character than they usually were ; but, as no expe-
riments on the quantity of pollen in the atmosphere were
made at the time, no inference of any value can be drawn from
this case. In a certain number of pases patients who suffer

° Autumnal Catarrh, by Dr. Wyman, p. 83.
t Hay-Fever, by Dr. Beard, p. 46.

On the Nature and Symptoms of the Disorder. 201

from hay-fever are also affected with urticaria, but generally
at times of the year when the former is absent. The number
of those who do thus suffer is relatively larger than we find
in those affected with any other disease. From this it
would appear that there was some connection between the
two disorders, but as we find that many persons who suffer
from urticaria are not affected with hay-fever, and that many
who are victims to the latter are entirely free from the former,
it is not probable that there is any close connection between
the two. Nevertheless it is not improbable that it may be
found that some diseases have considerable influence in pre-
venting or in predisposing to attacks of hay-fever. One
circumstance, however, should never be lost sight of when
considering the influence which attacks of other maladies
have upon those of hay-fever. I allude to the fact that in
most instances where a patient is suffering from an acute
attack of any kind during the hay season, he will, for the
time being, be almost free from contact with pollen because
of the close confinement the acute attack will necessitate.

§ 319. If the chemical investigation into the nature of
pollen had been fully carried out it might possibly help us
to form some notion of the general character and scope of
the symptoms produced by it ; but unless it can be shown
that pollen contains some powerful substance of the nature
of one of the poisonous alkaloids, or of some other equally
powerful class of bodies, the investigation will not help us
much. It is in fact probable that, like many other dis-
ease-producing substances, pollen is a body with qualities
essentially mil generis; and that these depend not merely
upon the number and nature of the elements which form it,
but also upon the mode in which they are combined and
upon the relation which the body itself has to the organs
whose healthy action it is able to disturb. If the above
view of the case be correct, it is obvious that, as has been
before intimated, any investigation which disturbs this mode
of combination will alter this relation and may at once destroy
the disease-producing property of the body.* As, however,

* In a few experiments with the spectroscope, kindly undertaken
for me by Mr. Thomas Harrison, of Manchester, two metals— sodium

202 Experimental Researches on Hay-Fever:

no such investigation has taken place, we are left to the
observation of the effects which pollen produces in attacks of
hay-fever and when used in the way of experiment. The
question of the vitality of this body need not trouble us here,
as our present object is to ascertain the nature and extent
of the derangement which it produces, but not to determine
the nature of the power which causes that derangement.
This may be due to the vitality — or at least may be partly
due to it — or may possibly depend upon the presence of some
substance which may yet be isolated. The settlement of this
question will have to be left to future investigations, but is
not without interest in the bearing it has upon the study of
the nature and mode of action of other causes of disease.

§ 320. First attacks of hay-fever are often milder and
less persistent than they are after a patient has suffered for
some years : this is no doubt due to the fact that the sus-
ceptibility to the action of pollen is not so marked on its
first appearance as it is at a subsequent time. There is also
in some cases a tendency for the disorder to take on the
asthmatic form in later years. In the case of the young
patient I have mentioned, although he lives in the country
the attack only came on when he was in the midst of a
meadow of hay-grass in full bloom. In my own case, when
the attacks first commenced they were induced only when
I was in the immediate neighbourhood of hay-grass in full
flower ; now it is sufficient for me to be anywhere outside
the city to have the symptoms unpleasantly severe at any
time during the hay season.

Whether the actual attacks increase the susceptibility, or
whether this increase is due to other causes, cannot at present
be determined; but whatever may be the cause, there does,
in most cases, appear to be a tendency for the susceptibility
to become more marked in each succeeding year. It should,
however, be borne in mind that, for the reasons already given

and barium — were found in the pollen of Lolium perenne, and also in
the pollen of Secale cereale. So far as a few experiments of this
nature could show, they corroborated the remarks made above on the
difficulties that must attend the investigation of the properties of
pollen by chemical tests.

On ilie Nature and Symptoms of the Disorder. 203

(§ 312), there must be a continued increase in the quantity
of pollen produced, and that by making the attacks more
severe this may cause an apparent increase in the suscep-
tibility. But even if we make considerable allowance for
this circumstance, there will still remain an undoubted
tendency for the susceptibility to become more marked as
time passes on. One case, however, has come under my
notice where the attacks have entirely disappeared after
recurring regularly at the usual time for some years.

§ 321. Dr. Phoebus divides the symptoms into six groups :
viz., into the head group ; the eye group ; the nose group ;
the throat and mouth group; the chest group; and the
general symptoms. Useful as this classification may occa-
sionally be, there is, in most cases, no necessity for this
minute subdivision. For all practical purposes the simple
•division into the catarrhal and the asthmatic forms of the
■disorder will answer quite as well as the elaborate classifica-
tion given above. If any other arrangement is necessary it
would be better to have one which is not only founded on
the differences in the structure and function of the parts
affected, but that would also throw the symptoms into fewer,
but at the same time well-marked, groups. Such a classifi-
cation as this would give us four groups : viz. — 1st. The
symptoms caused by the action of pollen on the mucous
membranes of the nares, fauces, and buccal cavity; 2nd.
Those caused by its action on the lining membranes of the
larynx, trachea and bronchial tubes ; 3rd. Those caused by
its action on the conjunctiva and the structures adjoining;
4th. General symptoms.

§ 322. A patient may suffer from one or from all the
phases of the disorder, but whatever difference there may
be in the symptoms the malady is one and the same, and due
to the same cause. In a very large number of instances
the disease is purely local, and whatever may be the function
of the part affected we shall find that we generally have
one special morbid condition present, and that this condition
in each case gives a peculiar character to the symptoms.
Whatever classification we adopt, the symptoms will tend
to form themselves into the two groups spoken of above,

204 Eocperimental Researches on Hay-Fever :

and will exhibit themselves in this way to the eye of a
casual observer. In one form of the disorder — the
catarrhal form — we have not much pain and scarcely any
dangerous symptoms. In the other, or asthmatic form,
though there is very little actual pain, the distress and
suffering is often very great, and frequently the attacks
appear to be very dangerous.

§ 323. Hay-fever is said by some writers to have pre-
monitory symptoms : these are said to consist of a feeling of
weakness, languor, repugnance to food, coated-tongue, con-
stipation alternating with diarrhoea, sleeplessness, irritability
of temper, and a feeling of exhaustion when the weather is
hot.

Dr. Phoebus gives three stages of the disorder: — 1st.
The stage of development; 2nd. The paroxysmal stage;,
and 3rd. The stage of convalescence. In speaking of the
first he does not seem to view it as a true premonitory stage.
' It lasts,' he says ' only a few days at most/ and as a
rule even a less time than this ; sometimes not more than
an hour elapses before the paroxysm shows itself, and in
some cases the latter comes on at once. In one case which
Dr. Phoebus mentions the attack came on immediately
when bunches of ripe grass and wild flowers were brought
to the patient by some friends.

§ 324. If there are premonitory symptoms in hay-fever
these must be produced, either by the causes of the disorder
itself, or by causes which have no necessary connection with
it. If produced by the former they must be of the same
nature as those of the acute stage of the disorder, differing
only in degree. But if produced by the latter they may
be more or less different in character, and since they may
thus differ and are produced by unlike causes, they cannot
be a necessary and invariable antecedent to attacks of the
genuine disease.

This view of the case is supported by the fact that the
malady can, by the application of the requisite quantity of
pollen, be brought on at any time without the development
of premonitory symptoms ; and especially by the fact that,
however often and however slowly or rapidly these arti-

On the Nature and Symptoms of the Disorder. 205

fieial attacks may be produced, they are never preceded by
symptoms such as have been spoken of. In the case men-
tioned by Dr. Phoebus the attack came on suddenly and
without any such symptoms ; and in the experiments cited
by Dr. Wyman (§ 174) the symptoms of hay-fever showed
themselves immediately the pollen was applied. The same
thing occurred also in Dr. Marsh's experiments (§ 176). In
all my own experiments, where pollen was applied arti-
ficially, no premonitory symptoms were observed, and, as
has been previously stated, I have several times had sudden
attacks, without any warning symptoms of any kind, when
brought accidentally into contact with pollen.

§ 325. In order to test this question of premonitory
symptoms more fully, a series of observations was made on
the temperature and on the pulse of a hay-fever patient
during two months of the year 1867. The observations
were commenced. on the 28th of April — six weeks before the
attacks of hay-fever usually came on — and were continued
to June 28th, this being the period at which the quantity
of pollen collected was generally at its highest point, and,
as a matter of course, the time at which the attacks were
also at their highest degree of intensity. The time was
divided into two equal periods, viz., one comprising the days
occurring between the 28th of April and the 28th of May,
and the other those between the 28th of May and the 28th
of June. In the first period we have generally, in this part
of the country, no symptoms of hay- fever showing them-
selves. In the second, the disorder commences and goes on
from its lowest to its highest point. The average tempera-
ture observed, during the first period was 97*0°, the maximum
being 080°, and the minimum 95*4°. In the second period
the average temperature was 97*4°, the maximum being
exactly the same as in the first period, viz., 980°, whilst the
minimum was 95*7°. In all cases the temperature was
obtained by placing the thermometer in the axilla. The
pulse varied relatively almost as little as the temperature.
In the fitst period the average was 70*22 beats per minute ;
the maximum being 78, and the minimum 60. In the
second period the average was 68*8, the maximum 78, and

20(5 Experimental Research on Hay-Fever:

the minimum 64. These experiments, along with the facts
previously given, show that in some cases, at least, there
are no premonitory symptoms, and that these cannot there-
fore be a condition essential to the proper development of
hay-fever. I have, as I have stated above, watched the
development of the disease in my own case and also in the
cases of the patients I have had under my care, and in
no instance have I seen it to be commonly preceded by
phenomena such as those referred to at § 323.

§ 326. In some few cases, however, premonitory symptoms
may be seen,but only in a few. From the time that pollen first
comes in contact with the mucous membranes of a patient,
during the ordinary attacks of the disorder, there must be
some action going on, but it i3 not certain that this can be
perceived by the patient in all cases. In my own case I
found that if the deposit on the glass slide (§ 235) did not
amount to more than an average of ten pollen grains in the
twenty-four hours, the disturbance in the action of the mucous
membranes was not perceptible to me. In some instances
I do not doubt that the insusceptibility may reach a much
higher point. Probably in these cases a portion of the
deposit is rapidly thrown off, just as other foreign matters
are, and that up to a certain quantity the membranes are
able to tolerate its presence without their action being in
any way disturbed ; but once let this point be passed and
we have all the phenomena of direct and reflex action
exhibited which pollen is capable of producing.

§ 327. In some cases, however, it is probable that, after
the pollen grain has burst in the manner described at § 188,
somo of the most finely divided portions of the granular
matter make their way through the walls of the capillaries
into the blood-current, but just as we find a certain degree
of tolerance for the action of pollen when in contact with
the mucous membranes, so we may have a similar degree of
tolerance for the presence of the granular matter in the
blood. Then again not only the power of resistance varies
in different individuals, but the power of elimination also
varies. In some cases the granular matter may be thrown
out of the circulation quite as quickly as it enters, and so
long as this is the case no symptoms can be noticed ; but

On the Nature and Symptoms of the Disorder. 207

where the power of elimination does not equal the rate of
absorption, an accumulation must take place and, sooner or
later, constitutional disturbance may be set up; and this
disturbance may, in some cases, be seen before any local
symptoms have been manifested. In this way premonitory
symptoms and a stage of development may be produced,
but in no case are these absolutely essential to attacks of
hay-fever; and if any such action as that which occurs
during the period of incubation in zymotic diseases is to be
understood, we must refuse to accept the definition, because
I shall be able to show that pollen has not the usual pro-
perties of a ferment. As I have before observed, the pre-
monitory stage will be seen in very few cases; why it
should not be seen in all it is not possible to say, any more
than it is to say why the exciting causes of other diseases
do not affect all who suffer from them in the same way and
to the same extent.

§ 328. In most cases, and especially in the earlier years
of the disease, the action of pollen seems to be most marked
in the nasal passages ; next to these come the eyes ; then
the buccal cavity and the fauces, and lastly the larynx
trachea, and bronchial tubes. This order is, however, sub-
ject to much variation in different patients ; and although
the symptoms brought on by the affection of the parts last
named are often very prominent, and apparently very
dangerous, it is not from the greater amount of irritation
set up in the parts, but principally because of the import-
ance of the function which they discharge.

The first symptom of the presence of pollen is generally
itching of the parts with which it is first brought in con-
tact. This is sometimes so mild as scarcely to be perceptible,
but it may go on to a degree which is very severe, and
which has more or less of a burning feeling with it. Gene-
rally this itching is first felt in the fauces, in the Eustachian
tubes, and the nostrils ; then in a severer form in the eyes
and nostrils, and lastly in the bronchial tubes, in those who
are liable to the asthmatic form of the malady. If the wind
is moderately strong the irritation may be felt in the eyes
before any other part has become affected ; and if the wind

208 Experimental Researches on Hay-Fever:

is at all cool the patient may imagine that this latter has
been the principal cause of the derangement, whereas it is
mainly due to the extra quantity of pollen which the in-
creased velocity of the wind brings into contact with the
conjunctiva.

§ 329. When once the production of pollen has, during
the Lay-season, passed beyond a certain point, the quantity
may increase so rapidly that in twenty-four hours, or even
in less time, the attack may pass from its milder form to
the true catarrhal stage. This is characterised by the dis-
charge of thin watery serum from the nostrils, by violent
attacks of sneezing, and in many cases by swelling of the
eyelids and severe lacbrymation. Generally the violent
attacks of sneezing precede the discharge from the nostrils,
but the coryza in a mild form may be the first symptom of
an attack. In the earliest stage of the disorder the fits of
sneezing are not very long nor very severe, but when the
malady has become fully developed they become so violent
and seem to take such entire possession of the patient, when
they do come on, that, for the time being, he loses all con-
trol over himself. In some cases the patient will sneeze
twenty or thirty times in succession, and whatever he may
be occupied with when the fit comes on he is obliged to set
it aside and resign himself to the paroxysm until it is over.
In some instances also a profuse cold sweat will break out
at the termination of each of the violent attacks of sneezing.

§ 330. After the attack has lasted for a short time the
submucous tissue in the nasal passages begins to swell, and
if the quantity of pollen in the air becomes moderately large
this will go on increasing so rapidly that in a short time no
air whatever can be drawn through the nostrils. This
swelling and stoppage in the nares often alters in a very
curious and apparently unaccountable manner. After both
passages have been equally closed for a time, if the patient
gets into a recumbent position, so as to lie on one side, the
nasal passage which is uppermost becomes after a short time
quite open, whilst the lower one becomes still more com-
pletely occluded. This change is caused by the fluid in the
submucous tissue gravitating towards the lowest part, and

On the Nature and Symptoms of the Disorder. 209

as often as the position is changed this alteration in the
•condition of the two passages will take place.

§ 331. During the hay-season most patients have paroxysms
•of sneezing not only in the day, but frequently also during
the night, and especially when the disorder is just arriving
at its highest point of intensity. I have myself had such
attacks often, and knowing that pollen was seldom present
in the air of a bedroom in quantity sufficient to bring them
on, I was not able to account for them. After closely ob-
serving the phenomenon some time, however, I noticed that
"these attacks only came on when the nasal passages had
been more or less occluded for a time, and that so long as
there was no change in the condition of the two when they
were swollen, the sneezing in the night did not occur by any
means so often as it did when one of the nares suddenly be-
came permeable to air. On trying the experiment it was
found that the paroxysms of sneezing could be brought on
by changing from side to side whilst in the recumbent
posture, so as to give time for the fluid in the submucous
tissue to gravitate and close the lower passage whilst the
upper one became patent. It seems as if the sensibility of
the Schneiderian membrane becomes lessened by the pressure
of the fluid, and as soon as this pressure is removed by the
gravitation of the fluid, not only does the normal amount of
sensibility return, but for a short time some degree of hyper-
esthesia is acquired. In this way some of the violent attacks
of sneezing which occur in the night may be accounted for.

§ 332. So long as the supply of pollen is kept up, the
sneezing and discharge of serum continue ; but the frequency
and severity of these do not in all stages of the disease
entirely depend upon the quantity of pollen inhaled. The
degree of occlusion in the nasal passages varies in the day
as well as in the night, but not to the same extent. If the
occlusion has been tolerably complete in one or both nostrils
for some hours, and by any chance suddenly lessens, the
patient may for the reasons I have just adduced have a
violent attack of sneezing, notwithstanding that he may be
inhaling a very small quantity of pollen at the time. If the
average quantity is large, however, the swelling of the sub-

14

210 Experimental Researches on Hay-Fever:

mucous tissue continues — subject to the variations above al-
luded to — and the ate nasi, as well as the lining membrane of
the nares, become tender and inflamed, and have a tendency
to bleed slightly if rubbed. Under these circumstances
the patient frequently finds that air can only be drawn
through the oral aperture, and if he sleeps he finds on
awaking that the tongue and the whole buccal cavity are-
more or less parched. As the disorder progresses the dis-
charge from the nostrils becomes more inspissated and puri-
form, especially early in the morning. This is found by
many patients to be more marked in the descending scales,,
shown in Tables I. and II., than in the ascending scales, and
when once convalescence has fairly set in the symptoms will
closely resemble those of the subsiding stage of ordinary coryza*

§ 333. When pollen is brought into contact with the eye
the phenomena exhibited are very marked, and in one of its*
symptoms very characteristic of its mode of action. Gener-
ally, however, these show themselves later than the other
symptoms do ; the reason for this I shall refer to presently.

In addition to phenomena of a purely physiological
character we have also some which are due to mechanical
irritation. Whilst the quantity of pollen is small, the ordi-
nary fluid secretions of the eye will be sufficient to clear it
away by the natural channel — the nasal duct — just as they
do other foreign matters deposited by the atmosphere^
When, however, the quantity of pollen becomes large, it will
not be so readily cleared away, and a portion will get be-
tween the ocular and palpebral layers of the conjunctiva*
and thus severe irritation may be set up ; and this will be
all the more likely to be the case after the patient has been
out in a tolerably strong wind during the height of the hay-
season. The difference there is between the quantity of
pollen inhaled and that which is thrown against the eyeball
by the force of the wind, may be judged of by the results of
the experiments which will presently be given. In one
sense it is a fortunate thing for the patient that this differ-
ence does exist, for if the same quantity of pollen that is.
inhaled came in contact with the eyeball, his condition
would be almost unbearable. This difference will also, as I

On tlte Nature and Symptoms of the Disorder. 211

have stated above, account for the fact that the eye symp-
toms are, generally, later than the nasal symptoms in
showing themselves.

§ 334. In the eyes, as in the other regions, the first symp-
tom of a commencing attack is itching. At first it is very
mild, but as the hay-season progresses it becomes very
troublesome, and is frequently attended by a slight burning
sensation, which extends to the deeper parts of the eyeball.
When the disease is fully developed the lachrymal canals
and nasal ducts become almost entirely closed by the swell-
ing of their submucous tissue, but I have never been able
to decide whether the irritation which causes this occlusion
commences above or below, or, in other words, whether it
is begun by the pollen which passes down the nasal duct
from the eyeball, or by that which is deposited in the nostril
in the process of respiration. It is, however, probable that
both causes operate to produce the effect, and it is also pro-
bable that some portion of the derangement of the structures
surrounding the eyeball is due to the reflex action of the
irritation which is set up in the nasal passages. At which-
ever point it commences the effect is the same, namely, a
partial or total occlusion of the nasal ducts, and, as a conse-
quence of this, a constant tendency to lachrymation ; but
there is no doubt that the secretion of the lachrymal gland
is also increased by the presence of pollen on the surface of
the eyeball.

§ 335. A short time after pollen first comes in contact
with the eye the conjunctival vessels become injected, and
generally the larger capillaries show the first ; but occasion-
ally when the patient has been much exposed to the wind
whilst the quantity of pollen in the air is large, the anterior
surface of the eyeball may be covered with a pale crimson
or pink tinge from congestion of the smallest capillaries.
After a time the itching and burning become so troublesome
that the patient finds it difficult to resist the temptation to
be constantly rubbing the eyes, but the relief this gives is
very transient, and, in the end, adds much to the irritation.
Occasionally shooting pains of a neuralgic character are felt
in the back part of the orbit and in the eyeball, and when

14—2

212 Experimental Researches on Hay-Fever:

the attack has been very severe or long continued, slight
chemosis may be seen ; this latter symptom, however, will
be seen in very sensitive patients only, or when the
quantity of pollen in the air is at its maximum. In very
severe attacks also the eyelids become oedematous, and this
is often more observable in the morning than it is in the
latter part of the day, but in some cases this condition will
be seen at all parts of the day.

§ 386. When the disorder has lasted some time there is
with some patients a considerable amount of photophobia,
and this may be sufficiently severe to cause the patient to
be glad to seek the shade rather than the broad sunlight.
In my own case, however, I have never found it necessary
to remain in a darkened room, nor yet to avoid a moderate
degree of sunlight. Even after being exposed to the action
of pollen and strong sunlight for six or eight hours in the
day, and when, as a consequence, the conjunctivae have been
very much congested, I have frequently worked at the
microscope for two or three hours in the evening without
causing any additional irritation or inconvenience. In this
case, as in every other, I found that if I could get beyond the
reach of pollen the symptoms, whatever they were, were
sure to improve. I have also in my own case sometimes
thought that, for a short period at the height of the disorder,
the sight has been obscured as if from an alteration in the
normal convexity of the cornea ; but when tested by placing
small print before the eyes, I have never been able to discover
any marked alteration in the focal distance at the time the
test has been used.

§ 337. The eyeball and its appendages seem to be as
sensitive to the action of pollen as any organ with which it
comes into contact, and if the irritation in the eye were to
be kept up by a large quantity of pollen being constantly
applied, it is highly probable that mischief to the deeper-
seated structures would be the result ; but what would be
the nature and extent of the derangement it is not possible
at present to say. In ordinary attacks of hay-fever the
mischief seems not to extend beyond the subconjunctival
cellular tissue. In no case have I ever seen any sign of

On the Nature and Symptoms of the Disorder. 213

effusion between the layers of the cornea, nor have I ever
seen the sclerotic coat to be affected ; although I think it is
quite possible that it may be in some cases.

The discharge which comes from the eye, like that which
comes from the nostrils, is at first thin and watery, and no
doubt largely consists of the secretion of the lachrymal gland.
After a time, however, it becomes more inspissated ; and
although it rarely happens that it contains any considerable
quantity of pus, this may sometimes be the case ; and often
when the effused fluid seems to the naked eye to be tolerably
transparent, pus-cells may be detected in it by the aid of the
microscope.

§ 338. When once the quantity of pollen in the air has
risen to its maximum and begins to decline, a very marked
change in the condition of the eye will soon be seen. The
improvement will not, however, be always steady and
gradual ; but, like all the other symptoms of hay-fever, will
be influenced by the sudden changes in the quantity of
pollen. There will at times be a rapid improvement ; the
congestion of the conjuctival vessels will quickly lessen ; the
itching and burning will subside, and the oedema of the eye-
lids will disappear. Often, however, the patient finds after
a few days of improvement that a relapse comes on ; but
there is this peculiarity in the attacks which occur in the
latter part of the season (from the latter end of June to the
beginning of August*), namely, that they rarely attain to
the same degree of severity they have in what I call the
ascending part of the scale.

§ 339. The last symptoms to disappear are the oedema of
the eyelids and the chemosis (when present) ; but the changes
above alluded to do not take place in the same order nor in
the same time in all cases. The experiment cited at § 168
shows that, even after the disturbance had been much more
severe than it is in an ordinary attack of hay-fever, the con-
gestion had almost disappeared at the end of eighteen hours,
and that after thirty-two hours had elapsed all traces of the

* This remark applies, of course, only to the part of the country
where my experiments have been made ; more south the time will be
earlier, and more north later.

214 Experimental Researches on Hay-Fever:

derangement were gone. A single night, even in the height
of the disease, will in most cases bring about some improve-
ment, for the simple reason that during the night-time the
patient does not come in contact with pollen, and in this
way it may seem to some that the malady has somewhat of
a remittent character. Taking the eye symptoms as a whole,
I believe they disappear rather sooner than the nasal symp-
toms ; that is to say, the nasal mucous membrane is longer
in recovering its healthy condition than the conjunctiva is,
but in this respect as well as in others there will be some
difference in different cases.

§ 340. With some patients who are extremely sensitive to
the action of pollen, the skin of the face and neck will oc-
casionally show signs of irritation. There is no doubt that
all the subjects of hay-fever are liable to have the normal
condition of the skin disturbed, but it is only under some
circumstances that this disturbance is severe enough to
attract notice. My attention was forcibly drawn to this
phase of the subject on several occasions, and with results
that somewhat puzzled me for a time. On most days when
the quantity of pollen in the air was very considerable
I had no itching of the skin of the face ; but on other
days I occasionally had considerable irritation, although the
quantity of pollen was not greater than when the face was
free from irritation. For some time I was not able to account
for the difference, and was at first inclined to believe that it
was due to a difference in the power of the sun's rays render-
ing the skin more sensitive at times. The problem was solved
for me in an accidental and very simple manner, and in a way
that showed that the sun had no direct influence in producing
the irritation.

§ 341. Happening, during the summer of 187-4, to be called
away a distance from town into a neighbourhood where I
found a field of Secale cereale in full bloom, I gathered a
large bunch of this plant for the purpose of experimenting
with the pollen in a way I shall speak of presently. Having
nothing to wrap it in, it was placed carefully in the hat. The
day was hot, and having some distance to walk, profuse
perspiration soon came on. In a short time that portion

On the Nature and Symptoms of tlie Disorder. 215

•of the scalp not covered by hair began to itch intensely;
and by the time I arrived in Manchester, an eruption much
like that of Lichen papillaris covered the entire portion
of the skin which was exposed to the influence of the
pollen. At the same time the face itched rather unplea-
santly, but the irritation was not by any means as severe
as that of the scalp.

The quantity of pollen that came in contact with the
scalp was very large, and this, coupled with the abundant
supply of moisture that the profuse perspiration brought
out, would quite account for the severity of the symptoms.
We had, in fact, on a large scale, a reproduction of that
which occurs on a small scale, in the nostrils and other por-
tions of the mucous membranes. The absence of irritation
in the face on some occasions was no doubt due to the absence
•of perspiration at such times.

§ 342. The mucous membranes of the fauces and of the
buccal cavity do not seem to be as sensitive to the action of
pollen as that of the nares. This may, however, be more
apparent than real. If swelling of the submucous tissue
does occur, it will not be so much seen on account of the
structures being soft and yielding; and if fluid is thrown
off by the mucous follicles, this will be much diluted by the
ordinary glandular secretions of the buccal cavity, and will be
rapidly carried off. Nevertheless some degree of congestion of
the mucous membrane and swelling of submucous tissue do
occur, but not by any means to the extent they do in the nares.

The symptoms caused by the contact of pollen with the
lining membrane of the pharynx are itching and slight burn-
ing or pricking; with these there is sometimes a sensation
as if there was a thin film of some delicate substance stretched
across the pharynx in places. Occasionally there is a little
hoarseness, but this is not often present. The itching is'
generally felt to be very severe in the hard palate, in the
upper part of the pharynx, and in the Eustachian tubes ;
and not unfrequently it extends to the meatus externus.
Sometimes there is slight dulness of hearing, but this may
be so slight that the patient will scarcely notice it unless his
attention is specially drawn to the circumstance. ' *

216 Experimental Researches on Hay-Fever:

§ 343. Deglutition is very rarely interfered with, bub-
there is occasionally a sense of dryness and obstruction in
the throat on awaking in the morning. If we examine the-
throat in the earliest stage of the disease very little change
will be seen, but later on there may be rednes3 and swelling
of the mucous membrane. There is also in the daytime a
little extra secretion going on, and especially when the
attack is getting near to its highest point of intensity ; but,,
as I have before intimated, this is so intermixed with the
ordinary glandular secretions that it is difficult to arrive at
any precise notion of its quantity or its character. And on
account of the tendency there is for the effusion in the sub-
mucous tissues to diffuse itself, it is not easy to distinguish
it or to say whether it is much or little. The throat symp-
toms, like those of the buccal cavity, to which, indeed, they
really belong, vary much in intensity in different individuals ;
they may in a few cases be somewhat severe, but generally
they will be very mild.

§ 344. The asthmatic symptoms of hay-fever are by far
the mast important of any of the groups, because they are
the most troublesome and the most dangerous. Like all the
other derangements caused by pollen, they vary in intensity
in different individuals and in different seasons. In some
cases there is only a very slight sense of obstruction in the
breathing; in others the derangement may cause great
suffering and at times may seem to endanger life. The
symptoms are, as I think I shall be able to show, principally
due to the obstruction caused by the altered condition of the
submucous cellular tissue of the larynx, trachea and bronchial
tubes, for effusion into the connective tissue of any one of
these will give rise to the asthmatic symptoms.

In many of its symptoms hay-asthma closely resembles
ordinary asthma ; and unless we know the exact history of
the case we may be investigating, we shall find it always
difficult and sometimes impossible to decide which species
the case belongs to. In both there is the same sense of
tightness across the breast at the commencement, and as the
disease advances there is the same loud wheezing and slow
inspiration and expiration. There is also at first dry cough

On the Nature and Symptoms of the Disorder. 21T

or cough with scanty expectoration in both forms of the
disorder, and as the breathing becomes more and more diffi-
cult the face may be pale and anxious-looking. If the
dyspnoea still increases, in both phases of the disorder the
face will become livid and turgid, the patient will seem as.
if threatened with suffocation, and will try to fix himself
in such a position that the respiratory muscles can act with
the greatest vigour, and this will almost invariably be in the
upright position, with the arms and hands firmly fixed on
some article of furniture. In both cases too the voiding of
a thin frothy sputum may be one of the first signs of ap-
proaching relief, but this latter is not so much the case in
hay-asthma as it is in ordinary asthma.

§ 345. There are, however, some points in which the two
disorders differ, and which it is important for us to notice.
In ordinary asthma the attack usually comes on in the
night, and is often preceded by a long-continued fit of
dyspepsia. In hay-asthma the first attack of the season
generally comes on in the daytime after the patient has-
been exposed to the influence of pollen, and although dis-
order of the stomach may be present and may help to make
the malady more severe when it does come on, it is usually
quite independent of dyspepsia. In hay-asthma the first
attack of the season may and often does come on in the open
air, but in ordinary asthma it generally comes on in the
house. In the one case the occurrence of the disease is en-
tirely dependent upon the inhalation of pollen ; in the other
it is, so far as we know at present, entirely independent of
it. Another very important point of distinction is that
unless the patient is brought accidentally into contact with
pollen, hay-asthma only comes on during the hay-season,
whilst ordinary asthma may come on at any time of the
year, and is most common in winter.

There is also another important difference between the
two forms of the disorder. In ordinary asthma there are
paroxysms with intervals of perfect freedom, at least in the
early and less confirmed state. In hay-asthma this scarcely
ever occurs in so marked a degree as in ordinary asthma ;
there may be remissions and sometimes even distinct inter-

"218 Experimental Researches on May-Fever:

missions for short periods, but the tendency is for the dis-
order to continue with more or less severity during the
whole of the hay-season if the patient pursues his ordinary
•avocations and is thereby exposed to the influence of pollen.
And lastly, if coryza does accompany an attack of common
asthma it is rarely as severe as it is in hay-asthma, and we
scarcely ever see the conjunctivae affected as they are in the
latter disorder.

§ 346. In most instances the coryza and eye symptoms
will show themselves before any difficulty of breathing is
■noticed, but occasionally the reverse may be the case ; some-
times, however, they will come on together. The first
symptom of an asthmatic attack will most commonly be the
sense of tightness and weight across the chest of which I
have previously spoken. In some few instances, the ex-
pectoration may be copious from the commencement, and if
this is the case the dyspnoea does not generally become so
severe as it is when the expectoration is scanty.

In the eariy stage of the disorder the difficulty of breath-
ing is not very great, and if the patient lives in the centre
•of a large town he will often escape with comparatively little
suffering unless he comes accidentally into contact with a
large quantity of pollen. In cases where the patient is
extremely susceptible to the action of pollen he may have
the symptoms pretty fully developed even in a large town,
but this is not often the case.

§ 347. When the disorder is at its height, and when the
«usceptibility is very marked, the patient will have most of
the severe symptoms described above ; and in some instances
the dyspnoea becomes so urgent if the recumbent position is
attempted that for several nights in succession he will not
be able to lie down. In one case I have had under my care,
the dyspnoea was so severe in the early years of the attacks
that the patient had to sit up for twelve or fourteen nights
in succession during the hay-season. At this time the
patient (a lady) lived in the country: during the latter
years of her life she lived in a thickly populated suburb of
Manchester, and although she had an attack of hay-fever
every summer, the dyspnoea was never very severe.

On the Nature and Symptoms of the Disorder. 219

Generally the obstruction to the breathing attains its
maximum degree of severity during the night, but may be
somewhat severe during the latter part of the day after
the patient has been inhaling pollen for some hours. It
will, however, often vary in an apparently unaccountable
manner.

§ 348. There is in all the asthmatic cases of hay-fever
more or less cough present in one or other stage of the dis-
order. It usually, however, comes on after the catarrhal
stage has been in existence some time. It varies in character
and severity in different individuals as much as any other
symptom. In some cases it may be dry and spasmodic, and
at the same time very troublesome ; whilst iu others it will
be moist, and will give comparatively little trouble through-
out the whole attack. In some instances it is most severe
in the daytime, in others in the night, and is attended with
a varying amount of expectoration, the quantity of which
seems to depend more upon the susceptibility of the mucous
membrane to the influence of pollen tlian it does on any
other circumstance ; that is to say, changes of temperature,
or a dry or moist condition of the atmosphere, do not
seem to have much influence upon the quantity which is
voided. In some cases also we shall have severe coughing
fits if, after the asthmatic symptoms have been fully deve-
loped, the patient is brought into contact with some of
those agents that have been thought by some authors to
he amongst the most active of the exciting causes of the
malady, such as smoke and indoor dust. There is, however,
this important difference between the disturbance caused by
these secondary causes and that which is brought about by
pollen, namely, that in cases of genuine hay-fever the former
•cannot set up the disease de novo, and can only exert their
influence after pollen has produced a certain amount of
•derangement on the mucous membranes of the air passages.
Another important point is that pollen will give rise to
«very phase of the malady although the patient may not
•come into contact with any of the agents that produce
■exacerbations when once the disease has been set up.
. § 349. The sputa will at first be thin and frothy, and

220 Experimental Researches on Hay-Fever :

may or may not be got up with difficulty. If the quantity-
of pollen should rise by a sort of regular progression the-
sputa will gradually increase, but not always in the same
ratio. In the discharge from the nares the quantity seems
to be governed by the quantity of pollen inhaled ; it is not-
so, however, in the asthmatic phase of the disorder., The
reason for this difference I have never been able satisfactorily
to make out, but I believe it is highly probable that it is
often due to the presence of the accidental causes to which
allusion has been made above.

There is also another change which occurs in the discharge
from the nares in a much more marked degree than it does
in that from the trachea and bronchial tubes. In the de-
clining stage of the disorder, or even when the quantity of
pollen becomes suddenly lessened for more than a couple of
days, there is a marked tendency for the discharge from the
nostrils to become puriform ; but if by chance the patient
becomes again exposed to a large quantity of pollen, the-
discharge of thin serum will commence again and will be
mingled, or alternated, with the muco-pus. In the asthmatic
form of the disorder the same thing is seen, but by no means.
to the same extent, and very often some portion of the sputa
will come up in the shape of small pellets of semi-transparent
starchy-looking material.

§ 350. It has been shown at § 299 that at times the
granular matter of the pollen escapes from the pollen sac-
and floats in the air as free granular matter. There is reason
to believe that when this is the case this matter will, when
inhaled, penetrate much farther into the bronchial tubes,
than the entire pollen grain will, and that it causes less-
catarrh but more severe asthmatic symptoms than the pollen
does. I have never, for obvious reasons, been able to-
demonstrate this very clearly, and can only therefore give it
as an opinion which I have not as yet been able to verify ;.
but if the opinion is correct, it will help us partly to account
for the differences we find in the severity of the asthmatic
symptoms at various times, and which the quantity of pollen
in the air does not always quite account for.

The duration of these symptoms will be found to differ^

On the Nature and Symptoms of the Disorder. 221

much in different cases, and although a rapid improvement
may often take place up to a certain point, some degree of
obstruction in the breathing is apt to remain after most of
the other symptoms have disappeared, and I believe that
this is more likely to be the case when free granular matter
has been inhaled than it is under other circumstances. So
much, however, depends upon accidental conditions, of the
precise nature of which we have not yefc a full knowledge,
that no rule can, at present, be laid down.

§ 351. Dr. Phoebus, Dr. Wyman, and other writers, speak
of very decided head symptoms, which the former places in
a separate group. These are said to consist of fulness of
the head, with heaviness and pains behind the ears, and a
feeling as of a band passing round the head above the eyes.*
So far as I have observed in the cases that have come under
my own notice, symptoms of this kind have not been com-
mon. There are occasionally shooting pains in the head, but
I think these are, in character, closely allied to the neuralgic
pains occurring in the eyeball and orbit. I have never seen
any symptoms which had the appearance of being caused by
•congestion of the meninges of the brain or of the brain sub-
stance. There is in some cases a considerable amount of
tinnitus aurium : what the exact cause of this is, I have
never been able clearly to make out ; but I do not think it
is due to derangement of any part of the nerve-centres. It
is probably caused by irritation of some portion of the
tympanum or membrana tympani, or possibly to reflex
action. The neuralgic disturbance commonly departs with
the other symptoms, but the tinnitus may remain for some
weeks or even months.

§ 352. The constitutional symptoms of hay-fever are
differently stated by different authors. As it rarely
happens that all that may occur are present in any one
case, this may account for the different statements made.
In some instances they are almost entirely wanting, and I
cannot but think the symptoms described by some patients
have been due to influences which have no connection with
hay-fever. When general symptoms are present they are

° Autumnal Catarrh, by Morrill Wyman, M.D., p, 29.

222 Experimental Researches on Hay-Fever:

partly due to derangement of the nervous system, and
partly to a disturbance in the circulation. Amongst these
are low spirits, gloomy forebodings, a dislike to mental and
physical exertion, with a feeling of relaxation and weak-
ness, and a tendency to palpitation of the heart on making-
violent exertion. In some cases there are pains of a neu-
ralgic or rheumatic character in various parts of the body,
such as I have already alluded to as occurring in the
eyeballs, orbit, and within the cranium.

In the experiments cited at §§ 170 — 173, when the arm
and leg were inoculated with pollen, no pain was felt ; but
in some experiments subsequently tried, sharp neuralgic
pains were felt in the thumb and index-finger of the limb
operated upon, and also along the course of the radial nerve.

§ 353. Dr. Phoebus says : ' Dr. Cornaz mentions a lady
who felt such violent pains, resembling those of rheumatism,
that she was obliged to keep in bed. These were felt first
in the right abdomen, then in the chest, and, in the back
part of the head, especially close to the ears : these symp-
toms lasted the whole of the day, and produced during the
time a strong nervous tension in the head, back, and legs,
with a difficulty of keeping the eyes open/

In some cases the imagination seems to be very powerful.
In one case, quoted by Dr. Phoebus, the patient had an
attack of sneezing, with other symptoms of hay-fever,
'whilst looking at a beautiful picture of a hay-field/
Another patient ' on thinking of the disease, and seeing his
swollen face in the glass, had all the symptoms/* I have*
myself never seen a patient with such extreme susceptibility
of the nervous system as is here described, and can, there-
fore, only give these cases on the authority of the writers
mentioned by Dr. Phoebus.

§ 354. A feverish condition is rarely seen in any but
the asthmatic form of the disorder; except when produced
artificially by inhaling pollen-f- or by inoculating with it, I

* Der Typische Frulisommer Katarrh oder das sogennannte Ileujieber,
Heu~ Asthma, p. 30.

t In these cases it was only when the pollen of one of the Amen-
taceae was used that feverish symptoms came on.

On tlte Nature and Symptoms of the Disorder. 223>

have myself never had any feverish symptoms. It is highly
probable that this is dependent on the quantity of pollen
inhaled, and also to some extent on the kind of pollen.
When it does come on there is a frequent and full pulse,
with more or less shivering ; hot dry skin, with a bruised
feeling in various parts of the body ; sleeplessness from a
crowd of ideas which will rush through the mind in spite of
the patient's efforts to quiet himself and sink off to resL
These symptoms usually pass off with a profuse perspiration
which may last for some hours. In the long and violent
attacks of sneezing, which occur just before the hay-grass
commences to be cut, the pulse will rise, the face will flush,,
and the respiration will quicken; but these symptoms are
only temporary ; in a few minutes at most they usually pass
away, and do not reappear until the next paroxysm of
sneezing comes on. A fit of this sort generally ends with
slight shivering, and with the patient being bathed all over
with cold perspiration.

Although I have stated that feverish symptoms do not
usually come on in the catarrhal form of the disorder, it
is only right to say that I do not consider that sufficient
evidence has yet been gathered on this point to enable us
to say under what precise circumstances they'do or do not
come on. Not only is there a different amount of suscep-
tibility in different individuals, but, if ever the matter is
more closely investigated, different pollens will probably be
found to have different powers in respect to the intensity of
the feverish symptoms they may produce.

§ 355. After the disease has lasted some three or four
weeks — varying in time according to the kind of season and
the susceptibility of the patient — it begins to decline. If
the season is a very favourable one for haymaking it will
decline rapidly, and this, as everyone knows, is generally
the most favourable with a very high temperature. When
any of the cereals happen to be in bloom at the time hay-
making is about finishing in any district, patients residing
in this district will find their attacks to be prolonged, and
if it happens that a second crop of grass comes into flower
before the harvest is over, the attack may seem almost con*
tinuous from May to September.

524 Experimental Researches on Hay-Fever:

When once the stage of convalescence has set in, if the
patient keeps free from the influence of pollen, the recovery
is very rapid. This may, however, appear to set in two or
three times in the course of a season. If there is a fall of
rain for three or four days in succession, and especially if
this is tolerably continuous, the symptoms moderate so
quickly that the patient may think the stage of convales-
cence has commenced. Unless the hay has been got in, how-
ever, he may generally expect a return of the disorder before
the season is over.

§ 35G. When the patient does get fairly from under the
influence of pollen, the change is very marked. A single
night is sufficient to produce a very agreeable alteration.
However profuse the discharge from the nostrils may have
been, it rapidly lessens and becomes more inspissated and
puriform. The swelling of the submucous tissue subsides,
the heat and tenderness of the alas nasi and of the lining
membrane of the nares lessens, and in the course of three
or four days the patient considers himself quite well.
•Generally, however, the convalescence is much more slow
than this, for the reason that in most seasons the quantity
of pollen diminishes slowly. So much depends upon acci-
dental circumstances that no rule can be laid down. A
rapid growth of hay-grass with a very favourable hay-
making season will make a short — though it may be sharp
— attack, and vice versd.

§ 357. One important matter which influences the severity
of the attacks I must not omit to notice here, although in a
brief manner. If active exercise is taken when the disorder
has become fully established, the irritation in the hard palate,
the nostrils, and the fauces will become very marked. The
fits of sneezing also will become more violent and prolonged,
and if the patient suffers from the asthmatic form of the
complaint the breathing will become very laboured. When
we remember that the quantity of air inhaled in violent
exercise is three to four times the quantity we take in in a
state of rest, it is easy to see that rest and exercise must
make a wide difference in the severity of the symptoms.
Many patients have thought that exposure to the heat of

On tlie Nature and Symptoms of the Disorder. 225

the sun has made their attacks more severe, but the real
reason has been that whilst they have been taking active
exercise in the open air they have been inhaling a much
larger quantity of pollen than they would have inhaled in
3. state of rest. It was for this reason that Bostock had the
symptoms more severely developed whenever he ventured
into the open air whilst residing at Ramsgate.

§ 358. Dr. Phoebus notices that exercise — especially that
of a fatiguing nature — causes exacerbations; but this he
says is often ' only by causing the patient to be heated, or
rather by getting cold after being heated/ The great dif-
ference between the amount of air inspired in a state of rest
and during active exercise seems here to be completely lost
sight of, as are also other important facts. Active exercise,
if indulged in for any length of time, is generally taken in
the open air, whilst rest is usually taken in a house; and I
have shown that the quantity of pollen in the air of an
ordinary dwelling-house is as a rule very small, whilst that
in the open air may be very large.

At the commencement of an attack of hay-fever the dif-
ference between the amounts of the pollen inhaled under
the two conditions will not be very marked, but when the
disorder is getting near to its height the difference in the
gross quantity is much greater than at the commencement.
To the consideration of this important question I shall
return when I come to speak of the quantity of pollen
necessary to produce hay-fever.

§ 359. Almost all authors agree in the opinion that hay-
fever leaves no perceptible effects behind. It may dis-
appear slowly in some cases; in some it may terminate
with a somewhat troublesome attack of diarrhoea, and in
others by a fit of constipation; but after the disease has
once fairly passed away, no sign of organic changers seen
in the parts which have been affected. The eye, which
may be considered one of the most highly endowed and
sensitive of all the organs attacked, recovers its healthy
condition almost as quickly as any, and never, so far as I am
aware, exhibits any trace of organic change in any part of
its structure. Even in those cases where the asthmatic

15

226 Experimented Researches on Hay-Fever:

•

attacks have been very severe, and after they have occurred
periodically for years, emphysema of the lung, which is so
apt to come on in the course of long-continued attacks of
ordinary asthma, is rarely, if ever, seen to follow hay-
asthma. These considerations bring us to other important
points in the investigation of the character and nature of
this curious malady.

§ 360. In studying the nature of hay- fever and in observ-
ing the changes which the affected parts undergo in its
course, one of the questions which naturally occurs is as to
whether the disease is, at its onset, really inflammatory. In
considering this question we shall have to look at the mode
in which pollen affects different tissues. Its leading and
principal action is to produce effusion, but that this cannot
always be considered inflammatory I think I shall be able
to show.

When a part is inflamed and ' when liquor sanguinis is
exuded, it generally coagulates and constitutes a foreign
body in the texture of the parts affected, which it becomes
the object of nature to remove from the system, or so to
modify that its presence may be rendered conducive to the
wants of the economy. In order to accomplish this, two
kinds of changes may take place — 1st, the exudation serves
as, a blastema in which new vital structures originate and
aj-e . developed ; 2nd, it exhibits no power of becoming
organised, and the exuded matters, together with the
textures involved in them, die.'*

§ 361. In the experiments on the action of pollen on the
abraded skin, as we have seen, neither of these events came
to pass. The exudation probably consists only of serum ; and
as pollen does not, unless applied artificially in very large
quantitv, give rise to either pain, heat, or redness, and leaves
no mark of its presence behind it after the exudation has
been absorbed, it cannot be considered inflammatory in the
proper sense of the term at its commencement. It is a re-
markable fact, too, that when pollen is applied only in small
quantity to the abraded skin, the capillaries of the corium —

* Clinical Lectures on the Principles and Practice of Medicine, by
John Hughes Bennett, M.D., F.R.S.E., Edinburgh, 1858, p. 133.

On five Nature and Symptoms of Hie Disorder. 227

the part to which the pollen is directly applied — escape its
action altogether, the whole of its power being concentrated
on the capillaries of the cellular tissue underneath. It is
this power of dilating, and of causing exudation from, the
capillary vessels of the connective tissue that constitutes one
of the great peculiarities in the action of pollen.

§ 362. When pollen comes in contact with the mucous
membranes, we have not only exudation into the submucous
tissue, but also a largely increased secretion on the surface
of the membrane and in its follicles. As previously inti-
mated, the first contact of pollen with the Schneiderian mem-
brane does not, so far as my experiments enable me to
decide, seem to produce any inflammatory action ; it is only
when the discharge of serum has gone on for a time that
redness and excoriation are seen. It is true that a different
effect is seen when pollen is applied to the eye, but this is
partly due to mechanical irritation. If it were possible to
apply pollen to the mucous membrane of the nares without
producing a discharge of serum, I believe that, although we
might have sneezing, and also infiltration into the cellular
tissue, we should have no inflammatory action at the com-
mencement. On several occasions effusion into the sub-
mucous tissue has been produced by the application of
pollen which had been reduced to a pulp by being rubbed
up with water ; but in these cases there was little or no
sneezing at the commencement, and scarcely any discharge
from the nostrils, whilst at the same time there was neither
redness nor excoriation seen in any of the experiments. But
whatever may be the effect which pollen has in the majority
of cases when first applied, there can be no doubt that the
effect of a constant discharge of fluid, upon the mucous mem-
brane and skin over which it passes, is to produce redness
and excoriation.

§ 363. The exudation in the nares at first consists of a
thin serum. This contains a large number of minute
granules which may generally be seen to have a vigorous
molecular motion. Some part of the molecules are, no
doubt, derived from the pollen grains. Interspersed with
these are a number of bodies which to me look like enlarged

15—2

228 Experimental Researches on Hay-Fever :

free nuclei from pus-cells. In some of these the outline is
irregular, as if there was some attempt at division, but in
others the outline is circular. If dyed (on Beale's method)
with an ammoniacal solution of carmine, or with a weak
alcoholic solution of chloride of aniline, they are very dis-
tinctly seen, on account of the avidity with which they seize
upon the colouring matter ; in this respect they closely re-
semble the nuclei of pus-cells. After the exudation has
continued for a short time, cells which are not easily dis-
tinguished from the white cells of the blood are intermingled
with the nuclei. Still later perfect pus-cells are present,
but these are at first very few in number. In the earliest
stage epithelial cells may be seen here and there, and,
generally, these are of the ciliated kind.

After the irritation has been kept up for a length of time
oy the constant inhalation of pollen, very few cells of any
kind will be seen in the effused fluid, the principal ingre-
dient being the granular matter of which I have just spoken.
It should be observed, however, that a single drop of the
exudation will make three or four microscopic cells — each
containing about 700 ' fields '— and that, as the character of
the exuded fluid varies at different parts of the day, it
would require a much greater amount of time than I could
spare to enable me to say definitely what its constituents
are.

§ 364. When the pollen in the air begins to diminish, the
number of pus-cells in a given quantity of the effusion in-
creases, but whether it is because they are formed more
rapidly, or because they are carried away less rapidly by
the diminished discharge, it is impossible to say ; but certain
it is that, relatively to the amount of the discharge, they
continue to increase until the patient becomes nearly well.
It is a singular circumstance, too, that in all my examina-
tions of the effused fluid by the microscope I have seen very
few perfect pollen grains, and, compared with the number
inhaled, very few empty ones. Whether this must be attri-
buted to the solvent power of the serum, or to the fact that
they are to a large extent carried away by it, cannot be
determined ; but if I had depended upon my examinations

On the Nature and Symptoms of the Disorder. 229

of the exuded fluid for a knowledge of the exciting causes
of hay-fever, I should have been a long time in getting
any clear notion of their nature.

§ 365. The condition of the mucous membrane of the
nares during attacks of hay-fever is not very easily ascer-
tained, because that part of it with which the great bulk
of the pollen comes in contact is out of sight, and this
particular part is that which is most sensitive to its action.
The part that can be seen is not at first reddened, but,
as I have before observed, when the discharge has con-
tinued for a time, a diffused blush of redness may be seen,
and if the quantity of pollen increases, the redness and
irritation may increase, until the membrane becomes very
tender to the touch, from the fact of its being partially
denuded of its epithelium, and also from the circumstance
that the membrane itself becomes swollen and inflamed.
It is said that, in severe attacks of common coryza, flakes
of epithelium may often be found in the effused fluid.
This is not the case in catarrhus aestivus, so far, at any rate,
as my examinations have enabled me to decide. The quan-
tity of the fluid effused, and the length of the time that this
comes awav, are such that it would take an enormous
quantity of epithelium if only a very small amount must
be present in each portion of the exudation. No doubt epi-
thelium is formed and carried off again in some stages of
the disorder, but I do not think it ever comes away in the
form it is said to do in ordinary catarrh.

§ 366. One part of the effect produced by pollen is due to
its direct action, and another to its indirect or reflex action.
The discharge of serum in the nares is an example of the first
kind, whilst the effusion into the subcutaneous cellular tissue
is au example of the second kind of action. In the con-
gestion of the vessels of the conjunctiva we may have both
kinds of action. The reflex mode of action may be ex-
hibited by any irritant being applied to the mucous mem-
brane of the nostrils. Every aurist knows that the intro-
duction of the catheter to the Eustachian tube will give rise
to a flow of tears and to congestion of the conjunctival
vessels ; and I have frequently seen the amplication of pollen

230 Experimental Researches on Hay-Fever:

to the nares produce slight redness of the eyeball, but this
has generally been when a tolerably large quantity of pollen
has been applied. Another way in which reflex action may
manifest itself is when the irritation in the nostril is trans-
ferred to the bronchial tubes, and produces slight asthmatic
symptoms ; this, also, I have experienced on two occasions.

§ 367. In attempting to classify hay-fever, a different
position has been given to it by different authors. In the
excellent article on hay-fever written by Dr. Zuelzer, of
Berlin, for Ziemssen's Cyclopaedia,* it is placed amongst the
acute infectious diseases. If we accept this classification, it
will be necessary to bear in mind the distinction which has
been made between the terras miasm and contagium by
Professor Leibermeister in his admirable introduction to the
papers on typhus and typhoid fever. Infectious diseases, he
says, may be divided into miasmatic and contagious ; —

' Miasm, in the original and broadest sense, is the name
for any material contained in the air that can produce

disease It is usual now to speak of contagium as a

specific excitant of disease, which originates in the organism
suffering from the specific disease; while miasm, on the
other hand, is used of a specific excitant of disease, which
propagates itself outside of, and disconnected from, a pre-
viously diseased organism. Contagion can be conveyed by
contact from a diseased person to a sound one, produce the
disease in him, and then again reproduce itself. Miasm ori-
ginates from without ; taken up into the body, it can call a
specific disease into action, but it cannot spread the disease
any further by conveying it from a diseased to a sound
person/f

The exciting cause of hay-fever answers to this definition
of the term miasm admirably. The disease is generated by
an agent which originates outside the susceptible organism,
and floats in the atmosphere, and the malady to which it
gives rise cannot be conveyed from one susceptible person
to another.

* Cyclopaedia of the Practice of Medicine, edited by Dr. H. Von
Ziemssen. London : Sampson Low and Co. Vol. ii. pp. 539 — 552.
t Ibid. vol. i. p. 25.

On live Nature and Symptoms of the Disorder. 231

§ 368. Dr. Beard places hay-fever amongst the neuroses.*
On what logical and scientific grounds the malady can be
placed among diseases of the nervous system it is not, from
the reasoning of the author, easy to make out. It is true
that the condition of the nervous system is an important
factor in the predisposition which all hay-fever patients
must have, and also that the nervous system is very distinctly
affected in attacks of hay-fever. But the same things may
be said of a host of other diseases that no one ever thinks of
classing with the neuroses. In hay-fever, as in many of the
diseases alluded to, we have on the one hand a certain amount
of susceptibility in the individual who suffers from the
malady, and, on the other, the presence of a given agent,
which is known to be the exciting cause. The two are
brought into contact, and disease follows. This is precisely
what happens in all infectious diseases ; and if we must
place hay-fever amongst the neuroses, we ought to do the
same thing for the great majority of the maladies which are
dependent for their manifestation upon the presence of the
two conditions named — a susceptible person and an exciting
cause. The unsoundness of such a mode of reasoning I
hardly need point out to my medical readers.

§ 369. Hay-fever is said to be made up of two principal
forms of derangement of healthy action, namely, catarrh and
spasm ; the former affecting all the raucous membranes with
which pollen comes in contact, the latter only the muscular
apparatus of the bronchial tubes. Dr. Phoebus, when refer-
ring to the asthmatic form of the disease, calls it a ' laryngo-
bronchio catarrh.' Dr. Barclay speaks of it as a catarrh
which ' has nothing of the paroxysmal character.^

Dr. Thorowgood also places hay -asthma amongst the
neuroses, and believes that the wheezing and bronchial rales
are ' due to spasm and not to inflammation.^ The name
given to the disease by Dr. Phoebus is not inappropriate ;

* Hay-Fever , by Dr. Beard, p. 77.

f A Manual of Medical Diagnom y by A. W. Barclay, M.D., London,
1870, p. 354.

X Notes mi Asthma, by Jno. C. Thorowgood, M.D., London, 1870.
p. 127.

232 Experimental Researches on Hay-Fever:

but although most writers on hay-fever have attributed the
dyspnoea which occurs in the asthmatic form of the disorder
to spasm of the circular muscles of the bronchial tubes, I
shall, I think, be able to show that there is no necessity for
believing in the constant presence of spasm to account for
the dyspnoea.

§ 370. If we breathe through a tube which has the same
diameter as the trachea, we find that air enters the lungs
freely, and that there is apparently a certain amount of
surplus space in the tube. This is proved by the circum-
stance that we can breathe through tubes of a much less
diameter than that of the trachea without producing any
unpleasant difficulty of breathing. If, instead of using a
single tube the size of the trachea, we use two tubes the
diameter of the bronchial tubes which form the first division
of the trachea, we find the same rule holds good. If we
carry the experiment still further and use tubes of a
gradually decreasing diameter, we find that to bring on the
amount of dyspnoea which occurs in hay-asthma, tubes of a
very small diameter would have to be used ; and that conse-
quently, if such a diminution in the size of the bronchial
tubes is brought about, the circular muscles must act
with a force which they cannot reasonably be supposed to
possess.

§ 371. The free transmission of air through the trachea
and bronchial tubes is the one prime condition necessary to
the proper fulfilment of their function, and wherever this is
interfered with to any great extent, we have another im-
portant factor in the production of dyspnoea brought into
play, namely /the imperfect oxygenation Of the blood. What
proportion of the effect may be due to this cause in hay-
* asthma or in ordinary asthma, it is impossible to say ; but
whatever the proportion may be, it is quite certain that
whether the imperfect supply of air is brought about by
the spasm of the bronchial muscles, or in the way I am
endeavouring to prove, the prime factor is the deficient
supply of air. But even if we grant that the circular
muscles have some power, it is difficult to understand what
purpose they could serve if they could contract the bronchial.

On the Nature and Symptoms of the Disorder. 233

tubes down to a diameter sufficiently small to produce the
dyspnoea of hay-asthma; and whatever may be the end these
circular fibres are destined to serve in the economy of respir-
ation, I am satisfied that their contraction is not necessary
for the production of the dyspnoea of hay-asthma.

§ 372. I have shown that the peculiar and distinctive
action of pollen is seen in the oedema which it produces in
the cellular tissue of any part to which it is applied. This
I believe is the true cause of the dyspnoea ; and I am also
inclined to think that when all the phenomena of ordinary
asthma have been thoroughly investigated, a similar con-
dition may often be found to be partly, if not wholly, the
cause of the dyspnoea in the latter disease also.* How,
then, are we to account for the sudden diminution which
sometimes occurs, in the difficulty of breathing in hay-
asthma — the so-called relaxation of the spasm? I will
endeavour to answer this question. It has been seen that
one of the most marked symptoms of the catarrhal form of
hay-fever is closure of the nasal passages by the effusion of
fluid into the submucous tissue, and that at times the
occlusion has been so complete that no air whatever could
be drawn through the passages. So complete, indeed, has
the stoppage sometimes been, in the experiments described,
that if respiration could only have been kept up by the air
which could be made to pass through the nasal apertures,
death from asphyxia must have been the result.

§ -373. In those instances in which partial occlusion oc-
curred it was only necessary to attempt, for a time, to
breathe through the nares in order to produce the true
asthmatic condition, so far as the dyspnoea is concerned.
How, then, is the relaxation of the so-called spasm brought
about ? I have shown that when a patient has been in a

* When the above sentence was written for the first edition of this
work, I had the impression that I stood almost, if not entirely, alone
in the expression of the above opinion. I now find, however, that
some well-known German authors (Weber, Wintrich, and others) are
opposed to the idea that bronchial spasm is the sole cause of the
dyspnoea of asthma. Weber believes it to be due simply to tumefac-
tion of the bronchial mucous membrane. Vide Ziemssen's Cych-
pcedia of the Practice of Medicine, pp. 536 — 546.

234 Experimental ResearcJces on Hay-Fever:

recumbent position for a time, a change from one side to
the other would close the nasal aperture on the lower side,
and at the same time open the upper one ; but, curiously
-enough, if the patient? placed himself on bis back when the
passage of fluid from one nostril to the other was only half
•completed, the closure of both would be almost complete, and
in this state he would find it impossible to pass sufficient
air through the nostrils to keep up healthy respiration. I
have again and again tried the experiment of attempting to
breathe through the nostrils only when tbey have been in
this condition, and have always found that I could produce
all the distress of a true asthmatic attack by keeping up the
experiment for a few minutes only.

§ 374. The same swelling of the submucous tissue is
present in the larynx and trachea, and probably also in the
larger bronchial tubes ;* and we have only to suppose that
the same changes which occur in the nares take place in the
larynx or at the bifurcation of the trachea, and we have
all the conditions necessary for the production of a fit of
asthma, apparently by spasm, and for its relief by the so-
-called relaxation.

Then again, when once the disease has been fairly com-
menced, exacerbations of an asthmatic attack may often
occur in the night ; and sometimes when the day has been
comparatively free from difficulty of breathing a sudden
attack may come on in the night. This also I believe is
often due to a change in the position and quantity of fluid
in particular parts of the cellular tissue of the air passages,
nor do I think it always necessary for the bronchial tubes
themselves to be affected in order to produce an asthmatic
seizure. If the fluid in the cellular tissue of the buccal
cavity and pharynx should gravitate towards the larynx and
upper part of the trachea, this, in addition to the fluid which
may already be present in these parts, would be quite suf-
ficient to bring on severe dyspnoea. Such an alteration as

*

* It is not probable that any great quantity of pollen penetrates to
the smaller bronchial tubes, because, if this were the case, such an
amount of oedema would bo produced that fatal consequences must
•often speedily ensue.

On the Nature and Symptoms of the Disorder. 235

that described above would be most likely to occur after
the patient had placed himself in the recumbent position.

§ 375. In support of the above opinions, it may be ob-
served that position is with an asthmatic patient a very
important condition. In some mild attacks of hay-asthma,
produced artificially, I found that an alteration in the posi-
tion always produced a change in the breathing, which was
better or worse according to circumstances. Knowing that
such alterations must cause an accumulation of the effused
fluid in certain spots, it is easy to see that this may give
rise to dyspnoea, which will vary in severity and duration
according to the quantity and position of the fluid ; but if
spasm is the sole cause of the dyspnoea, it is difficult to
perceive how position can affect it in the way it does.

§ 376. Hitherto the disorder has had a name applied to
it which was adopted when it was supposed that the ema-
nation from hay, in the process of being made, was the
principal cause of it. This notion we have seen to be
erroneous, and it cannot be too distinctly stated that it is
not merely the hay-making, but the flowering of the hay-
grass, that is the cause of hay-fever in England.* We have
also seen that wherever flowering plants can grow in suffi-
cient numbers to throw off a large quantity of pollen, hay-
fever may be produced. It would therefore be better to
designate it by the name of the agent which is known to
produce it in every country in which it has yet been seen,
namely, by the terms pollen catarrh and pollen asthma.

In suggesting these names, as well as in describing the
investigations I have made on this subject, I have been
desirous of strictly confining my attention to the phenomena
of the disorder which is brought on by pollen. There are,
no doubt, other agents which may produce symptoms not
unlike those of hay-fever ; but cases arising from contact
with such causes will, so far as a tolerably lengthened ex-
perience enables me to decide, form an exceedingly small
percentage of the whole, whilst the total number of those

* Some of my reviewers have made the mistake of supposing the
disease to depend on hay-making only.

23C Experimental Besearclies on Hay-Fever:

that suffer from pollen asthma and pollen catarrh is a rela-
tively large and an increasing number.

§ 377. The preceding observations on the nature and
symptoms of hay-fever have applied principally to the
disease as we see it in England. In America, if one may
judge by the descriptions given, they have the malady in a
much more severe form than we have it in this country.
Not only are the symptoms more severe as a whole, but,
amongst those who do suffer, there appears to be a larger
proportion who are affected by the asthmatic form of the
malady. But there can be no doubt that it is essentially
the same disease. The total number of patients in America
seems also, in proportion to the population, to be greater
than in England. It is said there are at least 50,000 people
who suffer from one or other form of the malady in America.*

It is highly probable that this relatively large number of
patients may be partly accounted for by the fact that the
two plants (the Indian corn and the Roman wormwood)
which are said to be the principal causes of the malady in
America flower exactly at the time that autumnal catarrh
comes on, and thus furnish a double supply of pollen.

§ 378. If it were possible for us to have thrown into the
atmosphere, from another source, as much pollen as that fur-
nished by the growth of the hay-grass, and at the same time
of the year, we can easily imagine that hay-fever in England
would be much more severe in each individual case than we
now have it. It is also highly probable that it would not
only be more severe in each case, but that a larger propor-
tion of the people would suffer from it. We have, however,

■ * So numerous do the patients seem to have become of late, that an
Association of those who suffer from the malady has been formed under
the title of * The United States Hay-fever Association ;' its head-
quarters being at Bethlehem, New Hampshire. The object of the
Association is to collect and to diffuse information on the subject of
hay-fever. Article V. of the Association strikes one as somewhat
singular in the wording of the latter part of it. It is as follows : — ' It
shall be the duty of each member to report to the recording secretary
the discovery of any remedy, source of relief, or exempt district which
may come to his or her knowledge during their natural life, and after-
wards, if permitted.'

On the Nature mid Symptoms of ilie Disorder. 237

no data to enable us to form an estimate of the exact pro-
portion of the population that are victims to hay-fever in
England, nor does it appear that any such data have been
collected in America ; and it is therefore impossible to say
with certainty what are the exact causes of the apparent
difference in the severity of the disease in the two countries.
One thing that would help to determine the c^use of this
difference would be to have observations made in different
years, in one or more of the hay-fever districts of America,
on the plan I have pursued for the purpose of ascertaining
the amount of pollen in the atmosphere, and its relation to
the severity of the symptoms in different patients. Dr.
Marsh is, so far as I know, the only one in America who has
made the attempt, and he unfortunately was, as we have
seen (§ 176), obliged by the severity of his attacks to aban-
don the attempt. It is to be regretted that no American
physician or scientific man has thought it worth while to
follow out the inquiry in a thorough and systematic manner.

238

CHAPTER VII.

ON THE QUANTITY OF POLLEN NECESSARY TO PRODUCE

HAY-FEVER,

§ 379. Before I could hope to deal successfully with the
treatment and prevention of hay-fever, I found it necessary
to get to know the actual weight of pollen in the atmosphere
that sufficed to commence and to sustain the attacks of the
malady throughout its course. The solution of this problem
was one of the most difficult of any with which I had had
to deal, and it was only by the alow accumulation of small,
and in some cases apparently unimportant, facts, as well as
by persistent effort in getting at the more important ones,.
that success was at last attained. The whole matter hinged
upon the average weight of single pollen grains. If this
could be ascertained, the rest would be comparatively easy.
Again and again attempts had been made to weigh on the
balance a number of pollen grains, such as could be counted
under the microscope, but again and again I had failed. The
largest number that could be counted accurately in a space
of one square centimetre was three thousand, but this num-
ber did not affect a balance (one of Oertling's) that turns
easily with one two-hundredth of a grain. I began to think
I should have to give up the task without accomplishing
anything more ; but I did not like to acknowledge this, and
still persevered in my efforts, and, by the aid of the micro-
scope, the balance, and the instrument shown in fig. 13, I
have, I think, been enabled to solve the problem satis-
factorily.

§ 380. The first step in the process was to note the num-

Quantity of Pollen necessary to Produce Hay-Fever. 239

ber of pollen grains that were collected daily before the
disease began to show any symptoms by which it could be
recognised in the earliest part of the hay -fever season, and
specially the number present when the disturbance was first
perceived. It is important here to note this distinction (the
earliest part of the hay-fever season), because I have reason
to believe that occasionally the mucous membranes will bear
the contact of a greater amount of pollen at the beginning
than at the height of the hay season.

By a reference to Table I., it will be seen that pollen was
found in the air from the 28th of May, and that on all the
days between this and the 7th of June it was present in
small quantity only. On the 30th of May the number found
on the slide was twenty-five, and with this number there
were perceptible but not troublesome symptoms produced.
On the 8th of June the number rose to seventy-six ; and
had they remained at this point, I think it is highly pro-
bable the mucous membranes, and especially the conjunctiva,
would have borne the contact of this quantity for some days,
without showing any very annoying amount of irritation.
On the 11th of June, however, the number of pollen grains
rose to a little over two hundred and eighty, and it was at
this date that I began to have unmistakable signs of the
commencement of my summer attack in a really trouble-
some form.

§ 381. In 1872, a young patient, who had been sent to
me by one of my colleagues, made some valuable obser-
vations for me near to St. Mary's Loch, Selkirkshire, Scot-
land. The patient had been a sufferer from the catarrhal
form of hay-fever for some years, and, on the approach of
the flowering season, had generally gone to the district
referred to, until the hay-time was over in the neighbour-
hood of Liverpool, where he resided. He had always been
free from his attacks whilst in Scotland ; and it occurred
to me that it probably might give me a chance of deter-
mining, in another case than my own, what was the
minimum amount of pollen that could produce symptoms
of the malady in a tolerably sensitive patient. As it hap-
pened, the circumstances were admirably adapted for the

i

240 Experimental liesearcltes on Hay-Fever:

purpose. A small patch of land near to the cottage occu-
pied by the patient had this year been sown with the
seeds of rye-grass, which was allowed to get into flower,
and when the wind was in a southerly direction, it came
directly to the spot he occupied. Twenty-four experi-
ments were tried under exactly the same regulations as
those described in my own case (§ 235), the temperature,
the wind, the rain, and the appearance of the sky, as far as
possible, being all noted. The slides were sent to me by
post, the patient making a record of his symptoms each day
in the meantime. Each slide was examined under the micro-
scope before the record of symptoms was seen by me, and in
this way afforded a fair test of the extent to which one may
be enabled to predict the appearance of symptoms by know-
ing the quantity of pollen floating in the air.

§ 382. The experiments commenced on the 24th of June,
and ended on the 17th of July. Pollen was found on the
slides on twenty-three days, the highest number being sixty-
six and the lowest number one. The patient had slight
symptoms of hay-fever on four days only, and on these days
the numbers collected were twenty-five,thirty4wo,fifty-fowr f
and sixty-six. The object of the experiments was not men-
tioned to the patient, and it is perhaps as well to note here
that he had no means of knowing how far the quantity of
pollen agreed with the symptoms recorded. As we have
seen, the smallest number that produced symptoms was
twenty-five. On two other days, when no disturbance was
noticed, the numbers were respectively eighteen and twenty.
When I come to show what the average weight of the pollen
grain is, it will be seen how exceedingly small is the quan-
tity that will give rise to symptoms, and also how marvel-
lously narrow is the margin between the quantity that can
produce perceptible disturbance, and that which is free from
it. By referring again to Table I. it will be seen that the
highest number collected at the height of the season was
eight hundred and eighty. We have thus the numbers
which produced the mildest form of the symptoms, and
also the quantity that gave rise to the most severe attacks
of the season.

Quantity of Pollen necessary to Produce Hay+Fever. 241

§ 383. The next step was to determine the 'relation that
exists between the quantity deposited on the slide, in the
way we have seen, and the quantity inhaled in any given
period. Another point that was especially noticed in these
experiments, was the difference in the quantity of pollen
inhaled in a state of rest and during moderate exercise.
The observations were made by the aid of the instrument
shown at Figs. 3, 4, and 5 (Plates II. and III.). Three trials
were made at different periods of the day : Iri the first trial '
500 inspirations, made in thirty minutes, whilst the operator
was perfectly still, gave a deposit of 115 pollen grains on a
space of one square centimetre. During the same time
thirty pollen grains were deposited on the glass placed in
the instrument shown at Figs. 8 and 9. In another experi-
ment, in which the operator was walking at the rate of tw<*
miles per hour, 500 inspirations gave 140 pollen grains';
whilst in the same space of time twenty-eight were cot-
lected on the glass placed on the vane (Figs. 8 and 9). In
the third experiment 1000 inspirations, made whilst the
patient was walking at the rate of three miles per hour,
gave a deposit of 253 pollen grains. During the same time
the glass placed on the vane gave fifty-eight only.

In these three experiments we have a total of 508 pollen
grains obtained by 2000 inspirations : in these the air was
made to pass over a space <of one square centimetre of the
prepared glass at a rate varying from seventeen to twenty-
eight respirations per minute, each inspiration taking in
from thirty to forty cubic inches of air. The total of the
deposits obtained on the slides placed on the vane was
115. Comparing these quantities, we find that we have 4'4»
pollen grains inhaled for each one that is deposited on the
glass.

§ 384. If we institute a similar comparison to that made
on the deposits obtained in the ordinary way, we shall find
that the difference between the number of respirations, and
consequently of the quantity of pollen inhaled whilst in a
state of rest, and during violent exercise,is very considerable.
Ten hours passed in the open air in a state of rest would
give a deposit of 2300 pollen grains ; but if we suppose that

16

242 Experimental Researches on Hay-Fever :

three times the quantity would be inhaled during violent
exercise, the number would be 6900 ; or, in other words, we
should have an extra deposit of 4G00 on the same space of
mucous membrane. This number is rarely, if in any case,
reached, because it seldom happens that a patient passes
ten hours consecutively in the open air, and very rarely
does it come to pass that violent exercise is taken for so
long a period. In proportion, however, to the amount of
exercise taken and the length of time passed in the open air
during the period the grasses are in flower, so will be the
approach to the results here given ; and if we make an exact
estimate of the difference between the number of respira-
tions and the volume of air taken into the lungs, during
active exercise and in a state of rest, we shall find that the
percentage of increase given above, large as it is, will be
rather under than over the mark. The inevitable con-
sequence of this must be that exercise in the open air must,
during the hay-season, increase the severity of the attacks
of hay-fever.

§ 385. We are now in a position to determine the actual
weight of pollen that suffices to produce the attacks of hay-
fever in their mildest as well as their severest form. The
first step in the process was to weigh on the balance l-100th
of a grain of pollen, and to use the instrument figured on
Plate VIII. in the manner described below.* On this plan

* In using this instrument the screws K k k are first adjusted so
that the points are about one line below the mouth of the graduated
tube (equal to four turns of the screws). The screw i is now turned
down until the compressor J has driven the air from the india-rubber
tube. We now take 1 -100th of a grain of pollen and place it in one
hundred grains of a fluid composed of six parts of alcohol- (proof
spirit) two of glycerine and two of distilled water. After this has
been well shaken so as to distribute the pollen evenly through
the liquid, the bottle is placed under the tube c and raised until
the point fairly dips into the liquid. The screw J is now turned
up until the fluid rises to the uppermost mark of the graduated
tube. If the screw is now turned gently down again until the upper
surface of the fluid has passed five divisions, a drop of the fluid
equal to one-fourth of a grain will hang from the mouth of the
tube. This drop will contain 0*000,025 of a grain of the pollen. A
microscopic slide with a circular cell of varnish upon it, half an inch

PLATE VIII.
Fra. 13.

Fig. 13. — a, abroad flat pillar of wood, to which is attached th«
foot-piece b. c, a glass tube with an internal diameter of about
i^th of an inch, and graduated so that each division will contain
■j> th of a grain of distilled water, d, a brass not, into the pos-
terior portion of which is inserted the small brass tnbe which
carries the graduated tube c. The nut and the tnbe are slit
perpendicularly, so as to permit- the glass tnbe to be clamped by
the screw e. f, a caoutchouc tube attached by one extremity to
the graduated tnbe C, and closed at the other by a glass plug.
s, a brass box open at each end for the passage of the compres-
sor j. To the top of the box a is attached the nut h, through
which posses the tcrew I which acta upon the compressor J.
E E E, three screws which pass through nuts cut in the bars L L.
Two nuts are seen in the posterior bar and one in the anterior
one. These ecrewa are used for regulating the distance of the
microscopic slide from the mouth of the graduated tube c. On
the upper part of the screws E E E are seen three lock-nuts M,
used to fasten the screws in any given position, n, the fluid
containing the pollen, o, a flat plate of brass into which is
riveted the nut d. This plate is screwed to the edge of tha
pillar A. The lower part of the graduated tnbe is ground with
fine emery powder, so as to canse a constant amount of capillary
attraction. The ring of black varnish shown at the lower end
of the tube prevents the fluid from rising beyond the lower
margin of the ring. The screws rc k k and I are cut with fifty
threads to the inch, and the heads are graduated with twenty
divisions on each, so that each degree gives a rise or fall of
l-1000th of an inch.

Drawn to a scale of about £th.

1

i! I

il :

^

I

I"

'■:\

Quantity of Pollen necessary to Produce Hay-Fever. 243

the average weight of the pollen grains of several species of
plants was ascertained. In each case ten slides were counted,
in order to neutralise possible errors. Ten slides of the
pollen of Lolvwm perennb had an average of 150*8 on each
slide ; thus it was found that one grain, by weight, of this
pollen would contain 6,032,000. Ten slides of the pollen of
Plantago lanceolata contained 253*1 on each slide, so that
it would require 10,124,000 to make up one grain by weight.
Ten slides of the pollen of Scirpus lacustris gave an average
of 620*5. Thus one grain by weight would contain 24,820,000
pollen grains. The pollen of the Vacoa (an exotic) contained
37,888,000 in one grain.

§ 386. It is necessary to remark here that the weight of
the single pollen grain differs in different years. In a
number of experiments tried in 1874, one grain of the Loliu/m
perennb was found to contain 4,400,000 .* At § 276 I
remark, that € in addition to those influences which make
pollen more or less capable of fulfilling its own proper
function in the vegetable world, there also seems to be some
influence at work which, independent of the quantity of the
materies morbi, or condition of the patient, alters its power
of producing hay-fever.' I believe now that this difference
is mainly owing to the difference in the size of the pollen
grain, and that this again is dependent upon the kind of
season. In late and cold seasons, such as we had last year
(1879), we shall have ill-developed pollen. In warm
seasons we shall, on the contrary, have large and vigorous

in diameter, is now made to touch the points of the screws k k k, and
the fluid will at once be distributed over the surface of glass within
the ring of varnish. The slide is now placed in the horizontal position,
and kept at a temperature of 100° or 120° Fahr. until the alcohol and
water have evaporated and the glycerine is left as a thin and smooth
layer. By placing the slide under the microscope with a good J in. or
| in. objective of moderate angle, the pollen grains can easily be
counted on any microscope that has a mechanical stage attached to
it, if the method described at p. 155 is followed.

* In an article sent to Dr. Zuelzer of Berlin (in 1876), and from
which I believe some extracts were published in the new edition of
the second volume of Ziemssen's Cyclopaedia of the Practice of Medi-
cine, the calculations were based on these numbers (4,400,000).

16—2

244 Experimental Researches on Hay-Fever:

pollen ; and just in the same proportion will the intensity of
the symptoms vary in any given year. The calculations
which follow are based on the results of experiments speci-
ally made in the summer of 1876.

§ 387. We are now in a position to determine the weight
of pollen necessary to bring on the malady. For this we
have already some data collected. We know for example
that the quantity of pollen deposited, as compared with
that inhaled, in a period of twenty-four hours is as 1*0
to 4*4. But as a patient is not in the open air exposed to
pollen more than eight hours out of the twenty-four, it will
be necessary to reduce the 4*4 to 20, or less than one half.

The quantity of pollen collected on the day when the

disorder was fairly commencing was 74, and if we multiply

this by 2*0 we have 148 as the product. The pollen of

Lolium perenne contains 6,032,000 in one grain by weight,

and as this is a fair average of the size of the pollens of the

English meadow grasses, we may take it as a standard. If

the number inhaled be divided by the number contained in

one grain of this pollen, we get the exact weight of pollen

148
that will bring on the disorder. Thus n ^ oc> ^^

° 0,UoZ,UOO =

•0,000,245 gr., or in other words less than l-40,000th of a
grain inhaled in each twenty-four hours suffices to bring on
the malady in its mildest form. But we have seen that so
small a quantity as twenty-five pollen grains, inhaled in each
twenty-four hours, sufficed to produce perceptible symptoms
in the case of the young patient in Scotland, as well as in
my own case, so that the first indications of the advent of
the malady may be produced by the inhalation of about
the l-120,000th of a grain of pollen.

§ 388. When the quantity of pollen in the atmosphere
was the largest, and the symptoms of the disorder were the
most severe of any day in the season,the deposit was 880 in the

1 *7fiO

twenty-four hours ; 880 x 2 = 1760 ; and - ■ =

00029 grain. Thus rather less than l-3427th of a grain
of pollen inhaled in each twenty-four hours will keep up
hay-fever in its severest form.

Quantity of Pollen necessary to Produce Hay -Fever. 245

Small as pollen grains are, they are much larger than
some other organic bodies that float in the atmosphere. It
was shown at § 292 that a large number of the spores of
one of the cryptogams was, upon one occasion, found upon
the slide. Since this experiment was made, I have weighed
the spores of several of the cryptogams. In the case of one
of these, of a kind closely allied to that alluded to above,
the weight of each single spore was rather less than the
l-500,000,000th of a grain. These, however, are more than
ten times as large as some I have attempted to weigh, but
have not yet succeeded with. Then these, again, are im-
mensely larger than the germs of some of the infusoria.*
For those who claim that atmospheric germs must have an
appreciable weight, it would, in some respects, be a useful
task to try to determine the exact weight of say ten thou-
sand of these last-named germs.

* In the admirable researches of the Kev. W. H. Dallinger and
Dr. J. Drysdale on the * Life-History of the Monads/ it is shown that
even whilst working with a l-50th of an inch objective and a No. 3
eye-piece, the sporules of one of the monads in their earliest form
appeared as a mere nebula under this immense magnifying power.
('Further Researches into the Life-History of the Monads/ by W. H.
Dallinger, F.K.M.S., and J. Drysdale, M.D., Transactions of the Royal
Microscopical Society, 1873, pp. 245—247).

246

CHAPTER VIII.

ON THE TREATMENT AND PREVENTION OF HAY-FEVER.

§ 389. We come now to discuss what will be considered by
sufferers from hay-fever the most interesting and important
part of our subject, namely, the treatment and prevention
of the malady. During the earlier years of my attacks,
many different modes of treatment were tried, and, amongst'
these, baths of various kinds occupied a prominent place.
The daily use of the cold plunge or the cold shower-bath
was first tried, then the hot-air and the vapour baths. After
these the Turkish bath was tried for a short period. In no
case did baths of any kind seem to have a beneficial effect
upon the attacks of hay-fever in the early part of the season ;
nor did they, so far as I could perceive, lessen the suscep-
tibility to the action of pollen. I believe, however, that the
Turkish bath is serviceable in lessening the prostration which
most hay-fever patients complain of at one part of the
season or another.

In the earlier years, also, a large number of drugs were
tried, in doses varying from the purely infinitesimal to a
more or less full dose. Amongst the remedies used may be
mentioned : Aconite ; Arsenic (in various forms) ; Asarum
Europseum; Arum maculatum; Ammonium carbonicum;
Belladonna; Bryonia; Camphor; Causticum; Calcareacar-
bonica ; Euphrasia officinalis ; Mercury (in various forms) ;
Ipecacuanha ; Nux vomica ; Iodide of potassium ; Bichro-
mate of potash; Chlorate of potash; Quinine; Scillamaritima;
Senega ; Stramonium ; Sulphur ; Strychnia, etc.

§ 390. The foregoing list by no means makes up a full

The Treatment and Prevention of the Malady. 247

record of all the drugs tested ; but it will serve to show that
a fair number of remedies were tried. In some cases these
seemed to do good, but often a relapse came on whilst the
drug was still in use ; and in some instances, when a full
dose was taken, the unpleasant effects of this were worse to
bear than the .hay- fever. This was especially the case with
quinine, and, to a smaller extent, with arsenic and some
others. On the whole, the treatment was very unsatis-
factory ; and, at the time alluded to, the erratic character
of the malady was very perplexing. Ultimately, all treat-
ment was, with very rare exceptions, for the time being
abandoned, and the time was, so far as professional duties
would permit, devoted to the investigation of the causes of
the malady. With what results these investigations were
attended, my readers have already seen.

It will readily be understood, by my professional brethren
at least, that during the time some of the most important
of these researches were in progress, no systematic experi-
ments on the treatment of hay-fever could be made, because
any success that had attended this treatment would have
lessened the value of experiments tried with the supposed
causes. And it must be confessed that the experience gained
on the inefficacy of treatment did not give any great hope
of being able to cope with the disease successfully until the
exact nature of the cause was thoroughly understood.

§ 391. These investigations have revealed some facts, too,
that probably do not exist in connection with any other
known disease, as well as some that may be common to
other maladies. We have seen that the exciting cause of
hay-fever is at the commencement of the attacks present
only in small quantity, and that, up to a certain point, it
goes on steadily increasing, and again declines in a similar
manner. It is this increase of the dose of the exciting cause
that constitutes the great peculiarity of hay-fever, and at
the same time presents one of the greatest difficulties in the
way of its successful treatment. If we could imagine the
case of a patient who is suffering from any other disease — due
to a miasmatic cause — being subjected to the action of a
daily and constantly increasing dose of the poison, for

i

248 Experimental Researches on Hay-Fever:

fifteen or twenty days in succession, and that the largest
dose of this should be fully twenty times the quantity that
sufficed to produce the first symptoms, we could easily con-
ceive that the complete control of the disease in such a case
would be very difficult, if not impossible. And yet this
rapid increment of the dose is, as we have seen, exactly the
condition with which we have to deal in the treatment
of hay-fever.

The steady diminution of the dose of pollen in the
latter half of the critical season is also another difficulty
that has often prevented us from forming a correct esti-
mate of the value of a remedy ; and in the hands of
some physicians, who are but imperfectly acquainted with
the aetiology and the natural history of hay-fever, reme-
dies have ,been credited with effects which were due
simply to the diminution of the quantity of the exciting
cause.

§ 392. The treatment and prevention of hay-fever may
be looked at from different points of view, and our choice
of the means to be used will be largely influenced by the
amount of success which is possible with any one or more
of the methods we contemplate using. No doubt the
most desirable mode of dealing with a patient would be
to rid him of the susceptibility altogether; but, although
I do not give up the hope that this may one day be
accomplished, there is, so far as can now be seen, not
much likelihood of this being done without a consider-
able amount of careful experimentation. We must, there-
fore, look to more readily practicable methods of dealing
with the subjects of hay-fever. These methods may be
said to divide themselves naturally into the prophylactic,
the preventive, the curative, and the palliative. As we
proceed, it will be seen what is intended to be understood
by each of these terms.

§ 393. During the trials made with the drugs named in
the list just given, and also with some not specified, not-
withstanding the general want of success, I was impressed
with the idea that some of the drugs exercised a perceptible
control upon the severity of the symptoms up to a certain

The Treatment and Prevention of the Malady. 249

point. At the time alluded to, there were no means of
ascertaining either the positive or relative value of any
drug used as a therapeutic agent, because there was no
known method of determining the quantity of the exciting
cause present at any given time. After the experiments
had been successfully carried out, this difficulty no longer
existed, and at any time during the hay-season the quantity
of pollen floating in the atmosphere could be ascertained.

By this and also by another method of measuring the
amount of pollen that is brought into contact with the
mucous membranes (to which I shall have to refer pre-
sently), the value of any given therapeutic agent could be
estimated at least approximatively.

But apart from any special experiments tried for this
purpose, long practice enabled me to form a tolerably correct
opinion of the quantity of pollen that ought to be present
at any given part of the season ; and it occurred to me that
it would be well to re-test some of the drugs that had been
previously used, and thus if possible to determine their
value.

§ 394 The remedies I shall first speak of are such as
may properly come under the term 'prophylactic, although
some of them may also be used in a curative way. These
remedies were of course used with a view of delaying the
commencement of the attacks, and specially to determine
how much larger a number of pollen grains could be borne
in contact with the mucous membranes with the use of the
drug than without it. This was almost always determined
with more or less certainty by the time eight or ten days of
the hay-season had gone over. If one remedy failed, the
use of another was immediately commenced. In using the
drug, the plan adopted was to commence using it some two
or three weeks before the hay-season began, and to continue
its use until I was satisfied it had no beneficial effect.

§ 395. In comparing the quantity of pollen with the
severity of the symptoms whilst the remedies were being
used, two methods were followed. In one case the deposit
was taken in the ordinary way, by exposing a glass in the
open air, in the manner described in the chapter on atmo-

250 Experimental Researches on Hay-Fever:

spheric experiments. In the other case, a small cell, similar
to the one shown at Fig. 12 (Plate VII.) was fixed to some
prominent part of the dress of the patient, and was worn
by him during the day-time. The amount of the deposit
was ascertained at the end of each day, and the severity of
the symptoms was compared with the amount of pollen
gathered.* The great difficulty in using these two methods
was that they were essentially different in their results, and
had to be judged of by different standards. The pollen
collected by exposing the slides in the open country always
gave an aggregate quantity much above that obtained by
fixing the glass to the dress of the patient. The reason of
this difference was that the latter was either wholly or par-
tially beyond the reach of pollen often for several hours in
the day. By testing the drugs separately on each method,
tolerably correct estimates of their value could be formed.

§ 396. The drugs tried on these different plans were:
Arsenic ; Arsenite of Quinine ; Arsenite of Potash (Sol Fow-
lerii); Iodide of Arsenic; Bromide of Potassium; Iodide of
Potassium ; Iodide of Mercury cum Iodide of Potassium (a
double salt) ; Quinine ; Salicyn and Sulphur.

Quinine proved, in my hands, an entire failure ; and as I
have met with other patients to whom it had been pre-
viously administered without any benefit, I conclude that
it has no power to modify the attacks of hay-fever when
given internally. In two different years it was also used
on Professor Helmholtz's plan, which is to inject a saturated
solution of the drug into the nostrils several times a day.
In the case of two patients for whom it was prescribed, it
did not give the slightest relief; and in my own case the
nostrils were more irritated after the use of the solution than
before it, and after two or three days' trial of it, I was glad to

* Another method which was tried was to distribute a certain
weight of pollen in the air of a room containing a given cubic
space. This was inhaled after being tested by the instrument shown at
Plates II. and III. This method promises to be the most thoroughly
scientific of any yet adopted ; but as the trials have not been numer-
ous, I cannot speak of it with any certainty. Of another important
use I have made of this method, I shall have to speak further on.

The Treatment and Prevention of the Malady. 251

omit its use. Salicylic acid and Salicylate of Soda were
also found to be failures.

Bromide of Potas&iumh&d some influence in delaying the
attacks, but it was very feeble ; and had it not been that I
was able to measure the quantity of pollen in the atmo-
sphere, it would not have seemed to have any control.

Iodide of Potassium and Iodide of Mercury evidently
possessed some control, and enabled me to bear the contact
of a greater number of pollen grains with the mucous
membranes than could have been borne without them ; but
the relief they gave was only perceptible at the commence-
ment of a season, and on attempting to push their use beyond
a moderate dose, an amount of disturbance was produced
that was as bad to bear as the mild degree of hay-fever they
saved a patient from.

§ 397. Arsenite of Quinine and Arsenite of Potash stood
next in degree in their prophylactic power, and it was
whilst re-testing these drugs that I began to have some
hope of being able to exercise a little control over my
annual attacks. The dose of Arsenite of Qwmine first used
was gr. j. of the third decimal trituration four times a day
(=l-1000th of a grain of the crude drug). This dose was
gradually increased to gr. x. four times a day, and at this
point I was obliged to stop, because any dose beyond this
produced in me some rather unpleasant symptoms, in the
shape of a mild degree of cinchonism, with slight disturb-
ance of the stomach. This drug had a very beneficial effect
upon the prostration which is so marked a feature in some
cases of hay-fever. The dose of Arsenite of Potash varied
from the l-100th of a minim of the officinal preparation to
one minim given four times a day.

After my own trials of the Arsenite of Quinine it was
prescribed for three other patients, and in each case they
reported favourably of it.

§ 398. Arsenic, in trituration and in solution, was also
tried. The dose varied from l-5000th to l-200th of a grain
of the crude drug, administered three to four times a day.
Although the physiological action of arsenious acid differs
somewhat from that of the arsenite of potash, the power of

252 Experimental Researches on Hay-Fever:

the two in controlling the action of pollen does not seem to
differ very materially, and for the purpose we have in view
the two may be classed together. Sulphur was found to
stand next in its prophylactic power, and, if used continu-
ously for a short time before the commencement of the hay-
season, will, I believe, considerably modify the attacks of
the malady during the early part of them. The dose of
Sulphur varied from gr. x. of the third decimal trituration to
gr. x. of the first decimal (=l-100th, and to gr. j. of the crude
drug respectively), administered four or six times a day.

§ 399. Of all the remedies I have had an opportunity
of testing, I must give the palm to the Iodide of Arsenic for
its prophylactic properties in the early stage of hay-fever,
both in my own case and in those of other patients. It is,
however, a powerful drug, and will not bear using in any-
thing like the same dose in which some of the other drugs
named can be given. The dose I used varied from gr. j. to
gr. v. of the third decimal trituration administered three
times a day (=l-1000th and l-200th of a grain respectively).

One patient who lives in a part of the country where the
disease makes its appearance earlier than it does with us,
tried the last-named drug (Iodide of Arsenic) in two succes-
sive years. The administration of the remedy was com-
menced at the latter end of April, and after being continued
for a month the patient, in reporting his condition, says : —
4 1 am certainly better than I have been at this time of the
year for many years past.' Again, in the succeeding year
he says : — ' I do not think I have been so well at this season
of the year for many years/ (The date of the letter is June
2nd.) These results accorded perfectly with those obtained
in my own trials, as well as with those of other patients
upon whom the drug was tried.

Some trials were also made with a double salt — Iodide of
Mercury cum Iodide of Potassium. This drug seemed, so
far as I could judge by the few trials I had an opportunity
of giving it, to promise excellent results ; but as these can-
not be considered a sufficient test of its value, it will not be
well to speak too confidently of it.

§ 400. The important point we have now to consider is

The Treatment and Prevention of the Malady. 253

the extent of protection afforded to the patient by the use
of the drugs named above. This is exceedingly difficult to
determine with that amount of accuracy that one would
desire. Our results can for the present therefore be con-
sidered only approximative ; but they are, as far as they go
in this direction, trustworthy. We have seen (§ 387)
that twenty-five pollen grains inhaled in each twenty-four
hours gave unmistakable though not unpleasant evidence
of their presence. By the weakest of the drugs, that
showed any controlling action at all, the amount of toler-
ance seemed to be doubled, but by the use of the iodide of
arsenic the degree of tolerance was apparently raised to
about six times the amount ; in other words, if twenty-five
pollen grains inhaled in each twenty-four hours produced
perceptible symptoms without the use of the drug, it would
require one hundred and fifty to produce the same amount
of disturbance whilst the drug was being administered, and
so far as I could judge, the influence of the remedy was felt
more or less throughout the whole of the attack. Arsenic,
Arsenite of Potash, and Sulphur occupied a position
about midway between the extreme points taken by the
remedies alluded to above.*

§ 401. It is important to notice here that it is probable
that some of the drugs which seemed, with some patients, to
have very little prophylactic properties might be found to
possess them when used for other patients, and it cannot be
too strongly impressed upon the minds of those who would
treat cases of hay-fever, that individual peculiarities have
an important bearing upon the selection of remedies.

How far prophylaxis can be carried it is at present im-
possible to say ; and, although the experiments just quoted
*are in themselves important, they are only the first instal-
ment of a method of investigation that should, if carefully

* In addition to the remedies enumerated above, there were some
with which only fragmentary trials were made. These, and also
others which were not tested, would be well worthy of a trial, both as
prophylactic and as curative agents. Amongst such may be mentioned
Arum maculatum, Antim. pot. tart, Eucalyptus globulus, Zinci
chlorid, Zinci sulph., Lycopodium, Cyclamen Europseum, etc., etc.

254 Experimental Researches on Hay -Fever:

followed out, lead to valuable results. One important result
will be, that not only may the really trustworthy remedies
be singled out, but also that the worthless ones may be
eliminated. If this could be done in the case of some
other diseases, it would be a great boon to the art of
medicine.

§ 402. With a view of determining whether it would be
possible to exhaust the susceptibility to the action of pollen
in any given part of the integument, by inoculating the
part with pollen in the manner described at § 170, experi-
ments were tried during the winter of 1875-6. A second-
ary object of the experiments also was, to ascertain if pollen
had any zymotic properties. Judging from the experience
gained by the yearly attacks, it did not seem likely that
pollen had anything of this character ; but as it had only
been applied to the abraded skin on two occasions, it was
quite possible that, under some circumstances, the system
might resist the influence of one or two applications, whilst
a larger number might produce a different result.

Twenty applications in all were made to abraded spots
on one forearm, on a surface about an inch square ; 1-1 00th
of a grain of pollen was applied each time, and the appli-
cations followed each other at intervals of twenty-four to
thirty-six hours. The effect did not differ at all from
that described in the former experiments, and apparently
the susceptibility was just as great at the conclusion of
the experiments as at the beginning. No constitutional
symptoms were developed, so that it is not at all probable
that pollen has any zymotic properties.

§ 403. In the investigations described in the preceding
pages the exact quantity of pollen that came in contact with
the eyeball, as compared with that which entered the nares,
had never been determined; consequently no correct esti-
mate could be formed of the part which each organ took in
the production of the -whole effect. Experience showed that
pollen in contact with the nasal mucous membrane would
inflame the conjunctiva, and, on the other hand, that pollen
collected on the eyeball passed into the nasal duct and the
nostril, and caused imitation there ; but how much or how

The Treatment and Prevention of the Malady. 255

little of the irritation was due to the pollen directly imping-
ing on each part was not known.

The quantity of pollen brought into contact with the eye-
ball was not difficult to determine. For this purpose the
following plan was adopted : A pair of neutral-tint spec-
tacles had lines engraved on one of the glasses so as to
enclose a space of one centimetre square. After these lines
had been filled in with black varnish the enclosed space, or
cell, was charged with the prepared fluid (§ 235). The
glass so charged was worn during the hay-season for a short
time on the days when it was desired to make an experi-
ment,* and at the termination of this the number of pollen
grains was counted by the aid of the microscope. By
making a comparison between the space exposed on the
eyeball and that on the cell, a tolerably correct estimate of
the quantity of pollen brought into contact with the eye-
ball could be made. These observations were made simul-
taneously with those described in the following paragraphs.
But so far as the special object in view was concerned they
were, for reasons presently to be given, almost useless. They
showed, however, how important a gathering ground for
atmospheric germs the exposed part of the eyeball is, and
also how easy it is for these when deposited on this surface
to make their way to the alimentary canal, and from this
point to permeate the system.

§ 404. The determination of the precise quantity of pollen
passing into the nares was by no means easy. In the early
part of the investigation, when it became certain that pollen
was the exciting cause of hay-fever, the idea naturally
occurred that any intercepting medium placed in the
nostrils would, so far as these latter were concerned, get rid
of the trouble. The attempt had consequently been many
times made to wear plugs of various kinds of fibrous
material in the nostrils. These, however, gave rise to such
a degree of irritation that the attempt had always to be
quickly abandoned. The presence of any kind of fibrous

* The steel frame of the spectacles was fitted with a screw, on one
side, which allowed the glass to be taken out and examined under the
microscope.

25G Experimental Researches on Hay-Fever :

material in the nostrils generally brought on a discharge
of serum, and sometimes attacks of sneezing ; and, on
the whole, the annoyance and irritation were almost as
bad to bear as that occasioned by moderate quantities of
pollen.

With this experience there was not much hope of being
able to train the sensitive mucous membranes to bear the
contact of any solid body. I determined, however, to try
to make them to bear the contact of an apparatus suitable
for intercepting pollen for at least a short period. I had no
expectation of doing more than to make a few short experi-
ments on some one or two of the days when the largest
quantity of pollen was present in the atmosphere.

§ 405. The first idea that presented itself was to make a
metal case to fit each nostril, and to place in this a layer of
wire gauze of a texture sufficiently close to intercept the
pollen at one operation, as it were.

My first care was to take an exact cast of each nasal
cavity from the margin of the ala nasi and septum narium
to the inferior turbinated bone, taking care to avoid any
entanglement with either of the turbinated bones — an acci-
dent which is very likely to occur, unless great care is
exercised. From these casts I constructed, by the aid of
the galvanic battery, cases of silver that fitted every depres-
sion of the mucous membrane of the nares. Into the upper
part of each case was fitted a layer of fine wire gauze, and
the instrument was then ready for use. When tried, how-
ever, it was found that the great amount of debris floating
in the atmosphere quickly stopped the openings in the
gauze, so much as to make the respiration difficult. But,
independently of this, there was another cause that pre-
vented the method being workable. Each opening in the
wire gauze was really a transverse section of a very small
capillary tube/* and, after being in use for a short time,

* 4 The diameter of the pollen grains of the grasses (in their dried
state) varies from 0*001 to 0*0015 of an inch in their longest diameter,
and from 0*0007 to 0*001 of an inch in their shortest diameter. To
insure their being intercepted by a wire gauze, the openings in this
would have to be rather less than l-1500th of an inch in diameter.

The Treatment and Prevention of the Malady. ?57

these became filled with the condensed vapour from the
lung, and also in more prolonged experiments with the
mucus from the nostrils. The resistance thus offered to the
passage of air made it necessary to adopt some method that
would, as far as possible, get rid of the capillary arrange-
ment.

§ 406. The next plan that was tried was to arrange
several layers of platinum wire in a partially regular, and a
partially irregular, manner in the silver case. The thick-
ness of the platinum wire varied from 0001 to 0*007 of an
inch. In so limited a space, it was extremely difficult to
arrange this, so that it would intercept the pollen without
interfering too much with the respiration. But apart from
this difficulty, the attempt proved a failure, so far as con-
cerned the estimation of the quantity of pollen passing into
the nares. The plan was to make a certain number of
inspirations through the nares, with the silver cases in situ,
on some of the days when the hay-grass was fully in flower.
The cases, with the intercepting sieves, were then washed
in one hundred grains of the prepared fluid (§ 235), and the
quantity of pollen they contained was ascertained by using
the instrument shown on Plate VIII. In this way it was
easy to determine the number of pollen grains contained in
the fluid ; but, even with the most careful washing, it was
not possible to know how many remained in the intercepting
sieve. Thus the experiment was, for the purpose it was
intended to serve, an entire failure. But although a failure
in this respect, it led me to contemplate the accomplishment
of a much more important thing, namely, the permanent
interception of so much of the pollen as would, with the
help of some of the drugs named, rob hay-fever of a great
part of its severity.

§ 407. In attempting to accomplish all that was contem-
plated there were many difficulties that were not met with
in the short experiments described above. In the first place
it was necessary to fit the apparatus into a very small space
— the nasal cavity — in such a way that it would not be
seen by ordinary observers ; and, whilst maintaining perfect
freedom of respiration at a moderate walking speed, to make

VI

258 . Experimental Researches on Hay-Fever:

it capable of intercepting a very large percentage of the
floating pollen. And lastly, before this could be of any use,
it was necessary to train the sensitive mucous membrane to
bear the daily contact of the instrument for eight or ten
hours at a time during the whole of the hay-season. The
accomplishment of these objects taxed my patience, and
perseverance very considerably, and I am free to confess
that had it not been for the self-interest that was thrown
into the scale, in the shape of a hope of controlling my own
attacks of the malady, I should more than once have given
up the attempt. In two successive years, however, there
had been some signs of the disorder taking on the asthmatic
form with me ; and as this, if allowed to go on, would pro-
bably have compelled me to be absent from professional duty
for at least a tenth part of each year, this prospect of
enforced idleness perhaps gave a little persistence to my
efforts.

§ 408. Strange as it may seem, it is nevertheless true,
that the smallness of the quantity, combined with the
extreme minuteness of each separate particle of the exciting
cause, constituted one of the great difficulties in the way of
barring its ingress to the mucous membranes. A more
bulky agent and a larger quantity would have been more
easily managed, and, in order to overcome the difficulties
spoken of, it was found necessary to deal with the subject
in a thoroughly systematic manner. The first thing to be
done was to ascertain how much of the actual breathing-
space in the nares could be taken up with the intercepting
sieve, or in other words, what size of opening would, with a
given circumference of the thorax, allow of a fair amount of
freedom in breathing. It was found that with a chest cir-
cumference of thirty-three inches (measured on a level with
the nipples), a circular opening in each nostril of four milli-
mUres in diameter was sufficient to maintain respiration
with moderate freedom whilst walking at the rate of two to
three miles per hour.*

* It was also found that in order to produce the distress of a severe
asthmatic attack, the breathing space in each nostril must be reduced
to a circular aperture of one millimetre in diameter (=l-2Sth of an
inch).

The Treatment and Prevention of ifie Malady. 259

§ 409. The plan now pursued was to attach to an aspirator
that contained a given quantity of water, a metal plate with
a circular opening of four millimetres in diameter in it.
The aspirator was now allowed to empty itself, and the time
taken in doing so was carefully noted. The instrument was
again filled with water, and one of the silver cases with its
intercepting sieve in situ, was put into the position previ-
ously occupied by the metal plate. The aspirator was then
again allowed to empty itself. In the first experiment the
air passed into the instrument through the opening in the
metal plate ; but in the second it passed through the inter-
cepting sieve, and the density and thickness of this latter
was regulated so as to make the time occupied by each
operation exactly the same.

§ 410. The next and the most important step of all was
to test the apparatus, and to see how far it answered the
main object — the interception of the pollen. To accomplish
this the following plan was adopted. A given weight of
pollen (1-100 th of a grain) was distributed in the atmosphere
of a room that had 1,000,000 cubic inches of space in it.
Whilst the pollen was still floating, one of the silver cases
was attached by an india-rubber tube to the instrument
shown at Plates II. and III. By inhaling through this it
was at once seen to what extent it was pollen-proof in a
given number of inspirations. By these means the relation
that exists between the freedom of respiration and the power
of intercepting pollen could be determined and regulated
with the greatest delicacy ; but it was found that it was not
possible to secure perfect freedom of breathing and complete
interception of the pollen at one and the same time.

There was also this curious circumstance in connection
with these trials, namely, that in the first few inhalations,
all the pollen was retained, whilst the later ones allowed
some to pass, and a very strong inspiration would drive a
larger number through. I determined, however, to try the
method during an entire hay-season, securing the intercep-
tion of as much pollen as was possible with a moderate
freedom of respiration.

§ 411. Some imperfect trials were made in 1877, but it

17—2

260 Experimental Besearches on Hay-Fever:

was found necessary to give more time than had been
allowed for the mucous membrane of the nares to become
accustomed to the contact of the silver cases the time
required*

In 1878 the first fair trial was made, and the experiments
were commenced earlier. By placing the silver cases in sitvu
a short time each day for some weeks before the hay-season
came on, and by using the ointment, the formula for which
is given below, f the cases were easily borne in position the
whole of the day by the time the grass began to be fully in
flower. The administration of the Iodide of Arsenic had
been commenced at the latter end of Mav, and was continued
to the beginning of July (gr. iij. 3rd dec. trit. quater in die).
The Arsenite of Quinine was then taken to the termination
of the season (gr. v. 3rd dec. trit. quater in die). Euphrasia
officinalis was, however, taken in alternation with the above
during the middle part of the season (gtt. v. 1st dec. atten.
quater in die).

The experiments were fairly commenced on the 12th of
June, and as I was anxious to see what part the eyes took
in the total amount of irritation produced, no glasses were
worn during the first seven days. Each day my professional
work called me more or less into the midst of the hay-
making districts. During this time, i.e. from the 12th to
the 19th of June, there was scarcely any sneezing ; but there
was a slight though continuous drip from the nostrils, with
some itching of the eyes, and slight engorgement of the
vessels of the conjunctiva.

§ 412. On the 20th of June the glasses with the cell one
centimetre square upon one of them began to be worn ; the
wire gauze guards which had been attached to them fitted

° Vulcanised india-rubber, and also vulcanite, cases were tried, but
did not answer any better than the silver cases.

t R ZinciOx. 3j.

Ac. Tannici, gr. x.
Ung. Cer. Alb. Jj.

Misce ut fiat unguent.

A small portion to be applied to the mucous membrane of each
nostril two or three times a day.

The Treatment and Prevention of the Malady* 261

very imperfectly, however. Nevertheless, as the opportunity
offered, I determined to put this method of prevention to
the severest test I could find. Two fields of rye-grass which
were coming rapidly into flower had been kept under
observation, and on the day the grass commenced to be
mowed and made into hay, I went into the midst of it, and
stayed some time whilst the men were at work. Previous
to this experiment being tried, I had no conception of the
immense quantity of pollen that can be thrown off from
grass in favourable seasons, because I had never before dared
to put myself in a position to see it. It is no exaggeration to
say that the pollen came away in small clouds as the
mowing-machine in one field passed through the grass ; and
as the ' tedding-machine ' in another field threw up the grass
that had been already mowed, the pollen that came from it
looked like a thin yellow haze in the atmosphere.

§ 413. Previously to going to the hay-field, the cell on
the spectacle-glass had been charged with the prepared
fluid. In examining this under the microscope in the
evening, sixteen hundred pollen grains were found upon
the surface of one square centimetre. This number
was gathered with about seven hours' exposure in various
districts (including three quarters of an hour in the hay-
field), and when we remember that twelve hundred was the
highest number obtained in the experiments of 1866, where
the slide was exposed for twenty-four hours at a time, we
may conclude that the number in this latter experiment was
relatively very large. In referring to the entry in my note-
book for this day I find the following : — ' The test to-day
has been the most severe I have ever tried, and on the
whole I have stood it remarkably well. No sneezing whilst
in the field : there was a little discharge from the nostrils,
and these felt somewhat warm, and itched a little. After
walking a mile, had one very mild attack of sneezing ; in an
hour had another similar attack, and a third one in the
evening after being out in the neighbourhood of the hay-
field. The whole, however, did not make up a twentieth
part of the suffering I usually have at this part of the
season/

262 Experimental Researches on Hay-Fever:

§ 414. On June 22nd the experiment was reversed by
my going about the whole of the day without any means of
protection in the shape of glasses and nasal respirators.
The entry in my note-book for this day is as follows:
* Made one journey of six miles by rail into the country,
and then went four miles in the opposite direction in the
early part of the day. • Had violent attacks of sneezing on
each occasion, with profuse discharge of serum from the
nostrils. The conjunctivae were congested, and the eyes
itched and burned severely/ The contrast here was very
marked ; but taken altogether the suffering was not quite
so severe as it usually was with the same amount of ex-
posure at this part of the season, and with the same kind
of weather. The 23rd was again warm and sunny — just
such a day as would produce severe suffering with hay-
fever patients. On this day the glasses and the respirators
were again used when in the open air, and were so con-
tinued to the end of the season, the intercepting sieve
being moistened with a mixture of glycerine and water.
The entry in my note-book for this day gives the follow-
ing : ' No sneezing, and very little irritation in the eyes ;
slight drip from the nostrils, which are still a little swollen
from yesterday's experiment.' For six or eight days the
symptoms took on this mild character. After this a rapid
improvement occurred, so that complete convalescence was
established at a much earlier date than in former years*
On looking over my list of visits, it was found that from the
12th of June to the 20th of July, fifty visits had been
made in districts in which an enormous quantity of hay-
grass is grown. Under ordinary circumstances this would
have led to severe suffering, which happily for me had been
to a large extent escaped, thus showing that the improve-
ment on the former state of things was very considerable.

§ 415. Before the season of 1879 commenced, one or two
important changes were made in the methods adopted. At
§ 191 we have seen that when pollen comes in contact
with the vapour exhaled from the lungs, it bursts and dis-
charges its granular matter onto the surface of the mucous
membranes. This change no doubt depends upon the vitality

The Treatment and Prevention of the Malady. 263

which pollen in its active condition possesses ; and if this
could be destroyed before the pollen reaches the mucous
membrane, a part of the mischief it sets up would be pre-
vented.

With a view of destroying this vitality, experiments were
made with solutions of Arsenic, Carbolic acid, Sulphate of
Copper, Sulpliate of Zinc, etc. Dilutions of Alcohol, Chloro-
form, and of some vegetable infusions were also tried. A
one per cent solution of any of the metallic salts named
above, quickly destroyed the vitality of the pollen, but
irritated the mucous membranes, if it by chance came in
contact with them. A one-tenth per cent, solution of most
of the above-named agents destroyed the vitality of ninety-
five per cent, of the pollen grains, but did not disturb the
mucous membranes.* Carbolic acid was eventually selected,
and one or two drops of the solution of this agent was used
to moisten the intercepting sieve at the commencement of
each day's experiment.

§ 416. Another precaution that was taken, was to have
models made that followed exactly the curves of the margin
of each orbit, and from these to have wire gauze guards
constructed, so that when attached to the spectacles and
placed in situ, any pollen that came in contact with the
eyeball must pass through the gauze. When in use the
gauze guard was sprinkled with the carbolic acid solution,
with of course the same intention as in the last experiments
named.

The observations were commenced on the 1st of June ;
the glasses with the cell of one centimetre square on one
of them being worn each day. These were examined under

* It was interesting to watch the effect that a higher dilution had
when applied to a large number of pollen grains. One fourth of a
grain of a one-fifteenth per cent, solution (1 in 1500) was sufficient to
saturate several thousand pollen grains. When applied, the smaller
and weaker of these seemed to succumb first. In some instances the
granular matter would crowd suddenly to the end of the pollen grain
at which the pore is situated, just as it does when pure water is
applied ; but the process would in most cases be arrested there. It
seemed as if the solution had acted first as a stimulant, and then as a
poison.

264 Experimental Researches on Hay-Fever:

the microscope at the end of each day's experimentation.
The administration of the Iodide of Arsenic had been com-
menced in the middle of May, and was continued to the
25th of June. The Iodide of Mercury cum Iodide of Po-
tassium was then taken for ten days (gr. iij. 3rd dec. trit.
quater in die). After this the Arsenite of Quinine was
taken to the end of the season. In the middle portion of
the time, however, lincture of Euphrasia officinalis was
taken in alternation with one or other of the above medicines
(gtt. v. 1st dec. atten. quater in die).

§ 417. The early part of the summer was exceptionally
cold and wet in this part of the country. No pollen grains
were found in the atmosphere until the 25th, and then only
four were found on the cell. It will be seen by a reference
to the table of curves (No. I.) that in these experiments
where a slide was exposed each twenty-four hours in the
open country, the number had, before this date (25th of
June), reached six hundred and sixty. Usually the 25th
is within three days of the highest point of the season, show-
ing in a very conclusive manner how remarkably late the
season of 1879 was. On the 26th also, four pollen grains
were found on the glass. On the 27th, the number suddenly
rose to one hundred and sixteen/* and on the 28th to one
hundred and forty. From this date to the 20th of July,
the number varied from twenty to one hundred. During
this time I was almost entirely free from my usual attacks,
and it is here important to observe that the average ex-
posure of the glass, on which the pollen was deposited, was
not more than one-third of the time occupied in the experi-
ments of 1866 and '67 when the slide was exposed in the
open air.

On the 10th of July, the experiment of going into the
midst of a hay-field, whilst the mowing and hay-making

* On this day five patients, whose cases were mentioned to me,
commenced with their usual symptoms in a severe form. On many
of the days in the early part of the season the sky was overcast, and
the temperature was much below 60° Fahr. In examining the anthers
of the grasses on these days scarcely any were found open, thus show-
ing that a low temperature prevents pollen from escaping.

The Treatment and Prevention of the Malady. 265

were going on, was repeated. Five hundred pollen grains
were found on the cell at the termination of the experiment,
which had lasted an hour and a half. During this time
there was no sneezing, and the eyes were perfectly clear
and easy.

§ 418. After several such trials the process was on the
16th of July repeated, in as severe a form as it was possible
to devise. In three-quarters of an hour seven hundred and
seventy pollen grains were collected. If the experiment had
been continued for eight hours (about the usual time a
patient is abroad in each twenty-four hours), the enormous
number of eight tltousand would have been deposited on the
glass (=50,000 to the square inch).

During the greater part of the time these trials were
being made, there was so little irritation and inconvenience
generated that, had I not had my attention called to the
symptoms by the fact of making the experiments, I should
not much have noticed them. On the day when the severest
trial was made, the following entry occurs in my note-
book : ' Have had a very small amount of discharge from
the nostrils. The eyes itch slightly, but are not uncom-
fortable ; otherwise I am remarkably well.' Some idea of
the severity of the test may be gained in another way also.
A slide with the usual size of cell upon it (one centimetre
square) was held under one portion of the clothing that
had been worn in the hay-field. The cloth was gently
rubbed so as to disturb the pollen that had deposited upon
it, and this was allowed to settle upon the slide. When
placed under the microscope, the cell was found to contain
sixteen hundred pollen grains.

The experiments were continued to the end of the season
with much the same result — an almost perfect freedom from
unpleasant symptoms. It was evident that a great improve-
ment had been made, and it was the first time in the history
of my attacks that I had felt that I need not in future
dread the summer time coming on.*

* With our present imperfect knowledge of the nature of most of
the exciting causes of miasmatic diseases, it would be unwise to make
any positive statements on the applicability of this method of preven-

266 Experimental Researches on Hay-Fever:

§ 419. The measures I have just described are no doubt
more applicable to the catarrhal than to the asthmatic form
of hay-fever, but from the fact that> during all the experi-
ments of 1878-9, there was no return of the indications I
had previously had of the malady taking on the asthmatic
form, the means used must be more or less beneficial in all
asthmatic cases.

To a very considerable extent the irritation in the eyes is
reflex in character, and it has for this reason been found
exceedingly difficult to determine how much of the irrita-
tion of the conjunctiva is due to the pollen that comes into
actual contact with it. Judging from all the evidence
gathered from the experiments made, I should say that
fully eighty per cent, of the irritation is due to the pollen
that passes into the nares ; and it is also highly probable
that some portion of the asthmatic condition is due to the
reflex action from the nares. However this may be, there
can be no doubt that where pollen is intercepted in the
manner I have shown, to a similar extent will the asthmatic
symptoms be kept in abeyance, if the respiration is princi-
pally performed through the nostrils.

§ 420. Of all the methods of prevention, the removal of
the patient to some place beyond the reach of pollen is the
most effective ; and the open ocean is, as .1 have shown, the
most free from the presence of this agent. Where a patient
can spare the time, a sea-voyage is an unfailing remedy in
ninety-nine cases out of a hundred. Failing this, a residence
at the seaside is the next best thing, if the place is well-
selected. A place situated on the extreme point of a
peninsula will in some instances be almost as efficacious as
a voyage. But the more the place selected approaches the
character of a deeply indented bay, the smaller will be the
patient's chance of escaping his attacks, if hay-grass is
largely grown in the district. Where, however, the land is

tion to other forms of these maladies, but I cannot help believing that,
in some at least, it may be found to be helpful. The extreme
subtlety of some of the miasmata may make it difficult to deal with
them on this plan. Influenza is, however, one of the diseases that will
probably one day be dealt effectively with on this same method.

The Treatment and Prevention of tlte Malady. 267

used principally for grazing (as in some parts of the Western
Highlands), the liability will be correspondingly diminished.
In America the patients obtain great relief, if not complete
immunity for the time being, by having a sojourn in the
mountainous districts during the critical season.

§ 421. Patients who live in the centre of a large town, and
who are unable or unwilling to adopt the means of prevention
I have previously spoken of, may almost entirely escape the
most troublesome symptoms of hay-fever by taking one or
other of the prophylactic remedies I have mentioned, and
by remaining indoors during a few of the most critical days.
For those patients who live in the outskirts of a town or in
the country, the following additional precautions will be
necessary in order to escape any considerable amount of
suffering. In the first place a patient must make up his
mind to remain in one room during fourteen or eighteen
days of the worst part of the season, and this room must be
protected from the ingress of pollen in the following ways :
Outside the room door a curtain of thin calico should be
hung, so as to cover the door and the architraves com-
pletely ; ingress and egress to and from the room being had
by turning the curtain aside. When in use the curtain
should be kept sprinkled with water which has had ten
grains of carbolio acid dissolved in each pint. In addition
to this, it is well to have a frame of thin wood made to fit
the upper or the lower part of the window of the room.*
This, when covered with two folds of muslin (black muslin),
acts as a ventilator and percolator, and keeps out the pollen
whilst it lets in the air. Wherever the patient is, it is of
the highest importance that he should not 9 whilst the grasses
or cereals are in flower, have a constant current of air
passing through his room without some means of intercepts
ing the pollen. Pollen in a still atmosphere indoors will

° This frame should be about six inches deep, and one inch from
back to front On each side it should be covered with black muslin
(book muslin). When in position it is kept from moving by a thin
wedge being pushed between the window-frame and this frame. Apart
from its use by hay-fever patients, it is an excellent ventilator. The
stream of air comes into the room very gently, and the dust and the
smoke are kept out.

268 Experimental Researches on Hay-Fever:

fall to the floor, but if the air is constantly renewed the
supply of pollen is kept up, and a certain amount of it must
be inhaled by those who come in contact with it.

§ 422. To attempt to give all the details of the effects of
the remedies tried in the earlier years of my attacks would
be a profitless task, because I had then no means of deter-
mining their value. In addition, however, to those that
have been referred to as having been used in a prophylactic
way, it will be necessary to speak of some that have been
found useful in various ways in recent years. It will also
be well to notice the conditions that help to prevent the
disorder coming on, as well as some circumstances that have
a favourable or unfavourable influence upon its progress.
And first I shall speak of the great importance there is in
a patient attending carefully to the condition of the stomach
and bowels, before the time for hay-fever comes on. De-
rangement of the functions of either of these organs, if it
comes on at a time when hay-fever is occurring, will help
to make it more severe than it would otherwise be. In the
asthmatic form of the complaint especially, an attack of
dyspepsia is sure to make the suffering more acute than it
would be without it.

Some patients have imagined that their attacks were
partly due to weakness, and that it was on this account
necessary to take a more plentiful supply of nutriment
during the hay season than at other times. This is a great
mistake. Although it is not necessary to live on what is
technically termed ' low diet/ it is important that the diet
should not be too generous. In the asthmatic form of the com-
plaint especially, a patient should not as a rule take animal
food more than once a day, and never in the evening.

§ 423. Another important point is the avoidance of
sudden changes of temperature, or, to speak more correctly,
a sudden lowering of the temperature. This is very apt to
occur if the patient allows himself to get into a profuse per-
spiration, and then remains still in the open air or where
there is a strong current of cool air. In such circumstances
the already irritated mucous membranes of the air passages
are very apt to take on some degree of inflammatory action,

The Treatment and Prevention of the Malady. 269

and in this way to render the patient an easier prey to the
floating pollen.

For a similar reason, a patient should as much as possible
avoid the inhalation of dust or irritating vapours. The
action of pollen is to clear away a portion of the natural
protector of the mucous membrane — the epithelium — thus
rendering the membrane exceedingly sensitive to the contact
of foreign bodies. Under such circumstances, the inhalation
of matters that are at other times quite innocent, will often
give rise to violent attacks of sneezing and to difficulty of
breathing.

The occurrence of such attacks has led some authors and
also some patients to believe that these secondary causes of
paroxysms, are the primary causes of the disease in many
cases. They are, however, easily distinguished by the fact
that they have no disturbing influence at other seasons.

§ 424. One excellent method of relieving the irritation
in the eyes and face, is to bathe these first in tepid, then in
cold water several times a day, taking care to include in the
process those parts of the hair that are exposed to the
atmosphere. The hair forms a very efficient gathering
ground for pollen, and there is no doubt that when this is
disturbed it will give rise to irritation if it comes in contact
with the eyeball.

In addition to the above, the use of a collyrium of some
kind was found to be beneficial in allaying the irritation of
the eyes; several of the various forms of collyrium in
common use were tried at one time or another; but the two
to which I give the preference are the following : —

ft Cupri sulph. gr. x.
Aquae rosse, Jiij.
Aquse dist. ad, ^xij.

Misce ut fiat collyr.

The eyes are to be bathed three or four times a day with
a small quantity of the collyrium.

ft Zinci sulph. gr. v.

Infus. Euphras. offic, 3j.
Aquae dist. ad, Jxij.

Misce ut fiat collyr.

270 Experimental Researches on Hay-Fever:

The eyes are to be bathed in a small portion of the
collyrium three or four times a day.

§ 425. Another important precaution I advise all hay-
fever patients to adopt, is to wear a loosely-fitting overcoat
(or cloak), of very thin material, when out in the open air,
and always to have this taken off and well shaken or
brushed after being out. To wear the same article of cloth-
ing, indoor and outdoor, during the whole of the hay-
season, is to carry a very effective means of infection about
with one. If a patient, however, lives in a large town, and
does not venture into the country much in the hay-season,
this precaution is not so necessary unless he has to come
much into contact with those who go often into the hay-
grass districts. For those patients who live in the midst
of the hay-making districts, the precautionary measures
spoken of at § 421 will be found very necessary, and at the
same time very valuable. If carefully and persistently
carried out, they will often enable the patient to dispense
with the necessity of leaving home for some weeks. With
patients who are at other times strong and healthy, the
confinement to the house which this method of prevention
involves is exceedingly irksome ; but I have met with some
cases in which it has been a matter of the most vital im-
portance that they should be able to remain at home, and
almost equally so that they should escape the hay-fever as
much as possible.

§ 426. We must now notice some of the remedies that
have been found beneficial, in one way or another, under
circumstances that often accompany attacks of hay-fever.

For those patients who suffer from habitual constipation,
or from a tendency to haemorrhoids, the use of Nux vomica
(gtt. v. to gtt. x. 2nd dec. atten. ter vel quater in die), in
alternation with one of the remedies I have previously
spoken of as prophylactic in their action, will be found very
useful; and in cases where there is much dyspepsia com-
bined with the constipation, it will often give great relief.
Sulphur is a drug that is useful, not only as a prophylactic,
but also in cases where there are haemorrhoids and chronic

The Treatment and Prevention of the Malady. 271

constipation. It may be given in alternation with Nux
vomica (gr. v. to gr. x. 2nd dec. trit. quater in die).

In other cases where dyspepsia is one of the leading
symptoms, 'and where there is Jieadache and a confused
feeling in the head, with a disinclination for mental labour,
and especially where there is at the same time a slight
tendency to the asthmatic form of the complaint, Chamo-
milla matricaria, in the form of the mother tincture (gtt. j.
ad gtt. v. quater vel sexter in die), may be given with great
advantage. Where the force of the malady seems to be
concentrated largely in the eye and its surroundings,
Euphrasia officinalis is an exceedingly valuable remedy,
and may be administered in doses of five to ten minims of
the 1st dec. atten. four or six times in the day. It is also
useful as a collyrium, either alone, or in the combination
given at § 424. One of the leading indications for the
administration of Euphrasia, is severe itching and burning
at the margins of the eyelids, with swelling of these parts.
It is also useful in the earlier stages of the disease, when
the fluent coryza and the violent sneezing are just com-
mencing.

§ 427. The asthmatic form of hay-fever is, as every
patient who suffers from it knows, a much more distressing
phase of the malady than the catarrhal form, and unfortu-
nately it is not more amenable to treatment than the latter.
Nevertheless, something may be done to lessen the force of
the attacks by the aid of drugs. In some few cases the
cough, which almost always accompanies this form of the
complaint, assumes a distinctly paroxysmal character, as if
it had something of the nature of whooping-cough combined
with it. At the same time the asthmatic symptoms are not
in these instances as severe as in other cases. In such
instances the administration of the tincture of Drosera
rotumdifolia (gtt. j. ad gtt. jv. 1st dec. atten. quater vel
sexter in die) will help to mitigate the severity of these
paroxysmal attacks. In this phase of the malady Bella-
donna, may also be given in alternation with Drosera (gtt.
v. 2nd dec. atten. quater in die). It is most useful where
the conjunctiva is severely congested, and where the severity

272 Experimental Researches on Hay-Fever :

of the cough seems to produce sharp cutting pains in the
head.

In cases where the pulse increases in frequency, and where
the temperature rises, AgonUe is the principal remedy.
The chief indications for its administration are: — Slight
congestion of the fauces, with a constrictive sensation at the
back of the throat : photophobia, and a feeling as if there
was sand in the eyes. Another important indication is
where there is slight discharge of blood, both from the nose
and the larynx, after the violent attacks of sneezing, and
especially where this is accompanied with a peculiar feeling
of numbness in the back part of the throat. With any, or
all of these symptoms, there is generally a loud, dry, hard
cough preceding, or following, the attacks of sneezing, if
Aconite is suitable.

§ 428. In that form of hay-fever in which asthma is the
leading symptom from the commencement of the attack, the
early administration of Sulphur (gr. x. 3rd dec. trit. quater
in die) is important. It is most useful where the patient is
troubled with occasional attacks of Urticaria at other times
of the year, and when the sneezing in his hay-fever attacks
is apt to be most troublesome on first awaking in the
morning, or on first lying down in the evening. Another
indication for the administration of Sulphur is the occur-
rence of profuse perspiration after the fits of sneezing or
coughing. As I have previously stated, Sulphur may be
given in alternation with Nux vomica, where there is a
tendency to constipation, accompanied with haemorrhoids.
Another indication for the use of Kux vomica in alternation
with Sulphur in the asthmatic form of hay-fever, is the
occurrence of violent paroxysms of coughing in the evening
after lying down, and especially if the expectoration is
absent, or scanty and tenacious.

§ 429. One of the most valuable remedies in the asthmatic
form of the malady is Ipecacuanha. Given alone (gtt. j. ad
gtt. v. 1st dec. atten. sexter in die), or in alternation with
Arsenic, or Nux vomica, or Sulphur, it moderates the force of
the terrible paroxysms of difficult breathing that characterise
the attacks of hay-fever in the height of the season. One

The Treatment and Prevention of the Malady. 273

of the leading indications for its use is. the occurrence of
long-continued exhaustive fits of coughing, which are accom-
panied with fits of suffocation that take on almost a con-
vulsive character, and where the patient obtains no respite
on account of the attacks coming on in such rapid succession.
Another indication for the use of Ipecacuanha is the occur-
rence of long-continued perspiration after the violent fits of
<30Ughing, especially in the night.

In a few cases Lobelia infiata (gtt. v. 2nd dec. atten. ter
in die) may be advantageously given in alternation with
Arsenic, or with Nux vomica, after Ipecacuanha has been
administered for a short time. It is more particularly
applicable to those cases where there is a dull, heavy pain
that passes round the forehead from one temple to the other.

§ 430. The Datura Stramonium, and the Datura tatula
are two drugs that have been largely used in the treatment
of both hay-asthma and ordinary asthma, especially in what
is called the spasmodic form of these diseases. The mode in
which they are ordinarily used is to smoke them as a tobacco,
either alone, or in combination with ordinary tobacco. In
this mode of administration they are often far too powerful.
In the case of delicate and nervous hay-fever patients, who
are not accustomed to smoking, the remedy, administered in
this way, has an effect almost as unpleasant and injurious
as that of pollen. The plan I have adopted in this mode of
administering Stramonium is a combination of two favourite
methods of dealing with asthmatic patients. The plan is as
follows: — A sheet of blotting-paper of medium thickness
is first saturated with a decoction of Stramonium (Sj. of the
herb to 3xx. of water) ; and after this has been allowed to
dry, it is again saturated with a solution of Nitrate of
Potash (Jvij. to gxx. of water).* If one or two strips of

* In preparing this paper, the best plan is to lay half a sheet of
the paper on a plate of glass placed slightly out of the horizontal
position ; then to pour gently over the surface of the paper as much
of the decoction as will suffice to saturate it. After being drained for
a few minutes it is placed in the horizontal position and allowed to
dry. It is then treated exactly in the same manner with the Nitrate
of Potash solution, and after being dried it is cut into strips an inch
wide. If it is desired to increase the quantity of the Stramonium in

18

274 Experimental Researches on Hay-Fever:

this paper are burned in the room where the patient usually
sits, it will be found, in those cases that are amenable to
the action of Stramonivm in this form, to give almost as
much relief as the smoking of it, but without the unpleasant
effects of the latter. It is, in fact, as I have intimated
above, a combination of the two favourite remedies in
desperate cases of ordinary asthma; but the quantity of
Stramonium inhaled can be regulated in a much more
exact manner than by the other method.

§ 431. Stramonivm is also useful when given internally
in the later stages of the disease. When the conjunctiva
becomes injected after the slightest exposure to a current of
air, and when occasional fits of hard dry cough come on,
although the quantity of pollen is rapidly declining, Stra-
monium may be given with great advantage (gtt. v. 2nd
dec. atten. quater vel sexter in die).

Opium is a remedy that often does good service in the
asthmatic form of hay-fever when paroxysms of suffocation
come on during sleep, and when these are apt to be followed
by violent fits of dry racking cough that are relieved for a
time by drinking a glass of water. Another indication for
the administration of opium is the tendency to severe and
long-continued constipation. Gtt. ij. ad gtt. v. 1st dec.
atten. may be given. In the later stages of the disease,
when there is a copious discharge of thick puriform mucus,
or when the nostrils are stopped in the morning by plugs of
hardened mucus, and when the aire nasi remain tender and
swollen, the administration of Nitric acid (gtt. jv. 3rd dec.
atten. sexter in die) will give marked relief.

For the prostration which is present in many cases of
hay-fever, and especially in the middle and later periods of
the disease, the Arsenite of Quinine is, as I have before
intimated, the principal remedy; but in some cases the
Phosphate of Quinine will be found more useful.

§ 432. I have thus briefly reviewed the principal remedies

the paper, it may be saturated twice or three times before it is finally-
saturated with the Nitrate of Potash, By increasing or diminishing
the strength of the Nitrate solution, the paper may be made to burn
more or less slowly, as circumstances may require.

The Treatment and Prevention of the Malady. 275

that have; in my hands, had a beneficial influence on the
treatment of hay-fever. In doing so I have, as much as
possible, adhered to the plan first adopted, namely, to give
only such facts as my own experience taught me to be really
valuable. What has been accomplished by the use of drugs
simply is, as I have previously intimated, only a first instal-
ment of a method of investigation that is in some respects
new. With extended opportunities the experience already
gained may be made much wider, and the results more exact
and valuable. If, as I hope to do, I get the help of a larger
number of patients than have hitherto been found willing
to test the remedies for hay- fever, it is not at all improbable
that we may yet find a specific for it. In the meantime, we
have at our disposal a method of controlling it and robbing
it of a great part of its virulence. So far, however, as
concerns the cause of hay-fever, I think I may say that I
have now completed the task I set myself when I com-
menced my investigations. Upon the result of the inquiry
the reader can now form his own opinions. To my own
mind, the investigation has furnished conclusive evidence
that in this country the exciting cause of the malady, as it
occurs in summer, is principally the pollen of the grasses ;
and that where pollen of any kind is thrown into the
atmosphere in large quantities, it will give rise to hay-
fever.

§ 433. I am, as I have before intimated, quite aware that
other agents may be found to produce symptoms not unlike
those of hay- fever. Amidst the great number of bodies
there are with functions similar to those of pollen, it would
not be surprising if we should find some that have a similar
kind of action; and it is not improbable that among these
we may find the exciting causes of some diseases which are
far more formidable than hay-fever. To have attempted an
inquiry into the nature and mode of action of even a few
of these would, in addition to the work already undertaken,
have made the task too formidable to permit me to have a
chance of completing it. I have therefore preferred to keep
my attention fixed upon that part of the subject which I
felt was fairly within my grasp. I cannot, however, but

18—2

276 Experimental Researches on Hay-Fever.

think that for those who have the courage to enter this path
of investigation, as well as the patience and the perseverance
necessary to pursue it steadily, there is a rich harvest of
facts waiting to be gathered.

With one solitary exception in the matter of the genesis
of hay-fever, I have tried to avoid forming hypotheses. I
have simply endeavoured to interrogate Nature, and as faith-
fully as I could to record her answers. I might now legiti-
mately draw, what seem to me, important conclusions from
the facts I have given, but this I will not attempt to do,
because I feel sure that each individual mind will be able
to do this for itself in a more forcible and suitable manner
than I can hope to do, and I shall therefore leave each one
to draw such lessons as the facts seem best calculated to
teach.

INDEX.

Aberystwith, influence of, in hay-
fever, 55

Aconite in hay-fever, 272 •

Age, influence of, in the produc-
tion of hay-fever, 199

Ambrosia arteniesicefolia, a cause
of hay-fever, 106—109

Animal emanations, effects of,
58

Anthoxanthum odoratum, a cause
of hay-fever, 16, 17, 21, 34

Antozone, 80

Arsenic, as a prophylactic in hay-
fever, 251

Arsenite of potash, as a prophy-
lactic in hay-fever, 251

Arsenite of quinine in hay-fever,
251, 260

Arternesia vulgaris, action of
pollen of, 186

Ascaris megalocephala, supposed
effects of, 37, 63

Asthma of hay-fever, 216, 217

, symptoms of, in hay-
fever, 216—218

Atmospheric experiments, 143 —
187 (see Experiments).

Atropa bellaaona, 112 (see Bella-
dona).

Author's experiments, commence-
ment of, 8 (see Experiments).

Barclay, Dr., on hay-asthma, 231
Bastian, Dr., on the supposed

effects of the emanations from

the Ascaris megalocephala, 37,

63
Baths, use of, 246
Beale, Dr., 128, 223
Bean-field in bloom, a cause of

hay-fever, 48
Beard, Dr., on hay-fever, 5, 40,

41,65
Belladonna, 112

Benzoic acid, experiments with,

in the production of hay-fever,

71
Binz, Prof., on the action of

quinine in curing hay-fever,

44
Blackley, Dr., quoted by Dr,

Patton, 45
Blackpool, as a place of resort

for nay-fever patients, 48
Blane, Sir Gilbert, remarks by, 3
Bostock, Dr., on the cause of

hay-fever, 3, 14, 15, 60, 134
Breathing space in natural and in

asthmatic respiration, 258
Brimstone matches, a supposed

cause of hay-fever, 43
Bromide of potassium in hay-
fever, 251
Buccal cavity, action of pollen

on, 215

Calendula officinalis, 115
Camphor, experiments with, 42
Carbolic acid, experiments with,

on the vitality of pollen, 267
Cases of hay-fever, 22, 23, 24, 28,

46—59
Causes of disease, importance of

investigating, 1
Chcetomium datum, effects of

odour of, 77
Chamomiltamatricaria, effects of

odour of, 77
Chemosis, in hay-fever, 212
Circular of inquiry, 40
Classification of hay-fever, 230
Coherent pollen not a cause of

hay-fever, 161
Cold summer, influence of a, in

retarding the development of

hay-fever, 264
Collyria, use of, in hay-fever,

269

278 Experimental Researches on Hay-Fever.

Comaz, Dr., on hay-fever, 26

Gorylua avellana, effects of pol-
len of, 100.

Coryza, case of, mistaken for
hay-fever, 68

Cullen, Dr., 3

Dacti/lit gfomeroia, Patton's ex-
periments with pollen of, 46

Dallinger'a experiments on the
life-History of the monads, 245

Darwin on the distances to which
dust and pollen are carried by
atmospheric currents, 161, 172,
182

Datchet, shower of pollen at,
184

Datura stramonium in hay-fever,
273

Decaisne on hay-fever, 41

Delpino on entomophilous and
anemophilous plants, 161

Drysdale s researches on the life-
history of the monads, 245

Dust as a supposed cause of hay-
fever, 13, 19, 22, 43, 90

Dyspncea of hay-asthma, 19, 218

Education, influence of, in pro-
ducing a predisposition to hay-
fever, 189
Etliotson on the cause of hay-
fever, 16, 17, 60
Eton, shower of pollen at, 164 i
Euphrasia officinalis in hay-
fever, 264, 269, 271
Exercise, influence of, in in-
creasing the severity of hay- i
fever, 224, 225
Experiments with the presumed

causes of hay-fever, 70 — 142 i
Experiments, atmospheric, 143 —

187
Experiments, atmospheric, at

high altitudes, 172—187
Experiments at Blackpool, 85

■ at Filey Bay, 86

at Grange, 84

at Llandudno, 87

at Moffatt, 87, 239

at Oban, 87, 239

at Southport, 85

by Kirkman, 38

by Marsh, 107

by Patton, 45

by Wyman, 106

by inoculation with

' pollen, 104, 254

Experiments on the quantity of

Sollen inhaled and deposited
nring the same time, 241
Experiments on the average

weight of the pollen grain,

243
Experiments on the action of

pollen on the skin, 214
Experiments on the vitality of

pollen, 263
Experiments on the amelioration

of hay-fever, 269, 270
Experiments on the action of

ozone, 79—90
Experiments on the prevention oi

hay-fever, £46, 256, 266
Experiments on the premonitory

symptoms of hay-fever, 204
Experiments on the prophylactic

properties of some drugs, 243
Experiments on the treatment of

hay-fever, 246
Experiments with pollen, 95—

129, 214
Experiments with benzoic acid,

71
Experiments with coumarin, 73
■ with Rpectroscope,

301
Extine, 114
Ex-intine, 114
Exudation in the connective

tissue, 227
Exudation on the mucous mem-

branes, 227

Fauces, action of pollen on the,

215
Festucapratensit, effect of pollen

of, when inhaled, 46
Feverish condition in hay-fever,

, Filey Bay, 178—179 {see Experi-
I ments at).

I Fowler's solution in hay-fever,
250
Fox on ozone and antozone, 80

j Geneva, 49

I Germ theory, bearing of re-
searches on hay-fever on, 2
j Gtadiolw, action at pollen of, 103
Gordon on the cause of hay-fever,
4, 16
■ Granular matter of pollen, 116
Grass in flower a cause of hay-
fever, 47, 49

Gream on the cause of hay-fever,

19
Greater prevalence of hay-fever,

188
Gull, Sir Win., on the action of

vibriones in hay-fever, 37

Hadley'a law, 173

Hartshorn (ammonia), a supposed
cause of hay-fever, 42

Hastings on hay-fever, 20

Hay, a supposed cause of hay-
fever, 29, 33, 36

Hay-fever : A supposed neurosis,
43 ; American forms of 39 ;
asthmatic form of, 316; ca-
t:i.rrli;il farm of, 208 ; character
of exudation in, 226 ; chemosis
in, 212; constitutional symp-
t inn* -f. ii:i : i'l;i:-*ili!-.ii!.>n of,
230 ; casus of, 22. i?:i : 24, 28,
46—50 ; duration of, 43 ; eye
symptoms of, 211 ; first symp-
toms of, 207 ; grouping of
symptoms of, 203 ; greater
prevalence of, 188 ; hereditary
character of 30 200 ; in India,
46, 47 ; influence of education
in the production of, 189—
196; nature of , 202 ; neuralgic
condition in, 222 ; nomencla-
ture of, 26; cedema in, BlS;
phases of, 203; photophobia
in, 212 j premonitory syn>]>-

: toms in, 204 ; prevention of,
257 — 266 ; prophylactic treat-
ment of, 2*> I — 234 ; static* of.
204; skin symptoms of, 214:
symptoms of. 207—221* ; treat-
ment of, 249

Hay-fever, causes of : Bean-field
in flower. 48 ; greenhouses,
17 ; hay, 42 ; pollenin general,
1 :>„ 2 1 , 4"i, 4G, 52, 95 ; pollen of
Ato/warnis jiratensi/, 97, 99;
Ambrosia artemtBusfolia, 40,
42, 43, 106, 107, 108 ; Zea
mays, 109 ; Anthoxantkum,
odoratuta, 16, 17 ; Hotcus odo-
ratut, 34 ; of Ifordeum dis-
tichnm, 90; Sam'tua'.* ai^i,
48 ; Stcale cereale, 45, 97, 98.

Hay-fever, supposed causes of :
Animal emanations, 37— G3,

128; AsCiiris uie.^lIiH/qiil-illil-,

37, 43 ; benzoic acid, 34, 71 ;
brimstone matches, 42 ; cam-

!. 279

phor, 42 ; cinders, 43 ; chills,

42 ; dust, 13, 19, 22, 43 ;"fniitj
42 ; foul air, 42 ; hartshorn,
42 ; heat, 12, 25, 61 ; indiges-
tion, 42 ; light, 129 : odours,
13 ; over- exertion, 42 ; ozone,
71, 79—90 ; perfumes, 42 ;
smoke, 42 ; sunshine, 22, 43 ;
first heats of summer, 32

Hay-making, 235

Head symptoms in fcsy-fcr,
221

Heat, a supposed cause of haj-
fever, 12,25,61

Helmholtz, on the supposed
action of vibriones, 44

High altitudes, quantity of pollen
at, 180

High altitudes, experiments at,
172—187

Himalaya Mountains, hay-fever
on the, 46

JIolcin odontitis, 34

Hooker on the grasses of the
Himalayas, 139

Incoherent pollen, 161

India, bay-fever in, 136

, influence of climate of,

138

Indigestion, effects of, in hay-
fever, 42

Intine, 114

Inoculation with pollen, 105, 254

Intercepting sieve, 256

Iodide of arsenic in hay-fever,
252, 260

Iodide of potassium cum iodide
of mercury in hay-fever, '252,
265

King, T. W-, on hay-fever, 18
Kirkmau, experiment with pol-
len, 21
Kurrachee, climate of, 47

Labosse on hay-fever, 27
Laforgue on hay-fever, 27
Light, influence of, 33, 34, 129
Literature of hay-fever, 4

Lbiifluilim, L'xpwiments at, 48
LiMiii iitjUtt'i in u;iy-fever, 273
LongueviUe on hay-fever, 27

280 Experimental Researches on Hay-Fever.

Macculloch on the cause of hay-
fever, 4
Marsh on hay-fever, 43, 107
Martin, Sir J. Ranald, on heat in

India and on sun-fever, 140
Miasmatic nature of cause of

hay-fever, 230
Molecular motion, 117
Moore on hay-fever, 3, 36, 137

Nasal respirators, 256
Natural orders of pollens experi-
mented with, 95 (note)
Nature and symptoms of hay-
fever, 198—237
Neuralgia in hay-fever, 222
Night-air, influence of, 21, 42
Nux vomica inhay-f ever, 270 — 272

Odours, influence of, 13
(Edema in hay-fever, 213
Opium in hay-fever, 274
Over-exertion, effect of, 42, 242
Ozone, action of, 12, 29, 33

, experiments with, 79 —

90

Pasteur's mode of experimenting,
146

Patton on hay-fever, 45, 67

Penictilium glaucum, effects of
odour of, 77

-Pennsylvania, showers of pollen
in, 184

Pharynx, action of pollen on the,
215

Phases of hay-fever, 12

Phoebus on hay fever, 5, 25, 32,
61, 144, 158

Photophobia in hay-fever, 212

Pickering on the distribution of
Artemisise in America, 109

Pirrie on hay-fever, 136

Plants, anemophilous, 161
, entomophilous, 161

Poa nemoralis, effects of pollen
of, 57

Pollen, 13, 45, 46, 52, 70.

, action of granular matter,

206 ; action of, when inhaled,
95 — 129, 214 ; average weight
of pollen grains, 243 ; coherent,
161 ; collection of, 162—182 ;
incoherent, 161 ; in a dwelling-
house, 164, 186; experiments
with, 95—129, 214 ; increase
of quantity of, in the atmos-

phere, 196 ; kinds of, that dis-
turb the action of the mucous
membrane, 95; Mr. Wm. W.
Wilson on the action of, 123,
124 ; on the quantity of, in-
haled as compared with that
brought into contact with the
eyeball, 235 ; on the quantity
of, inhaled as compared with
that deposited, 241 ; on the
quantity of, passing into the
nares, 255 ; on the quantity of,
at high altitudes, 180 ; showers
of, 184; pollen to which English
hay-fever is due, 160; pollen
to which American hay-fever
is due, 109

Polygonum persicaria, luxuriant
growth of, 191

Position, influence of, in produc-
ing paroxysms of difficult
breathing, 235

Pouchet on the absence of germs
in the air, 181 (note)

Prater, case of hay-fever, 4

Predisposition, 13, 39

Premonitory symptoms, 204

Prophylactic remedies, 250

Quinine in hay-fever, 246 — 250

Rabbit, effects of odour of, 59
eating flesh of,

59
Rain, influence of, in mitigating

attacks, 20, 49
Ramadge on hay-asthma, 20
Riley, on shower of pollen in

America, 184
Roses, pollen of, 33, 47
Rye, pollen of, 33
Ryde, 50

Salicyn in hay-fever, 250

Sambucus nigra, pollen of, 48

Schonbein, 80

Science Gossip, 184

Sea-air, influence of, 47, 48, 53,

55, 57, 133
Season, influence of kind of, 156
Secale cereale, pollen of, 45
Slough, shower of pollen at, 184
Smith on hay-fever, 34, 62, 134,

135
Solanum tuberosum, pollen of,

112
Solar heat, effects of, 61

Index.

281

Southern States, influence of cli-
mate of, on hay-fever, 138
Spectacles, use of, in hay-fever,

255
Stramonium in hay-fever, 273

paper in hay-fever,

273, 274
Sulphur as a prophylactic and

curative remedy, 250 — 253
Sunshine, 22, 43
Sunstroke, symptoms of, 141
Symptoms, grouping of, 31 (note)

of nay-fever, 203 —

257

Temperature, 111

Tilia media, pollen of, 100

Thorowgood on the nature of

hay-asthma, 231
Trades and professions, influence

of, 189

Valparaiso, influence of climate

of, 138
Ventilators, 267
Vibriones, supposed action of, 44,

118

Walshe on hay-fever, 21
Watson, Sir Thos., on hay-fever,

21
Wet summer, influence of, 264
Wheeler, H. G., 184
Wilson on the action of pollen,

38
Windsor, shower of pollen at,

184
Wire gauze guards, 256, 263
Wyman on autumnal catarrh, 5,

40, 63, 106, 138

Zea mays, 109

THE END.

BAILLIKRE, TINDALL & COX, 20, KINO WILLIAM STREET, STRAND.

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