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THE HARVARD CLASSICS 



The Five-Foot Shelf of Books 




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THE HARVARD CLASSICS 
EDITED BY CHARLES W. ELIOT, LL.D. 



Scientific Papers 

Physiology 

Medicine • Surgery 

Geology 

W?VA Introductions and l^otes 
Yo/ume 38 




P. F. Collier & Son Corporation 



NEW YORK 



Copyright, 1897 
By G. p. Putnam's Sons 

Entered at Stationers' Hall. London 

Copyright, 1861, 1862, 1883, 1889, 1890, 1891 
By Oliver Wendell Holmes 

Copyright, 1892 

By Houghton, Mifflin & Company 

All Rights Reserced 

Copyright, 1910 
By p. F. Collier & Son 

manufactured in u. s. a. 



CONTENTS 

PAGE 

The Oath of Hippocrates 3 

The Law of Hippocrates 4 

Journeys in Diverse Places Ambroise Pare 9 

translated by STEPHEN PAGET 

On the Motion of the Heart and Blood in Animals .... 75 
William Harvey translated by Robert willis 

The Three Original Publications On Vaccination Against 

Smallpox Edward Jenner 145 

The Contagiousness of Puerperal Fever 223 

O. W. Holmes 

On the Antiseptic Principle of the Practice of Surgery . . . 257 

Lord Lister 

The Physiological Theory of Fermentation 275 

Louis Pasteur 

translated by F. FAULKNER AND D. C. ROBB (Rcvised) 

The Germ Theory and its Applications to Medicine and Surgery 

(Revised) Louis Pasteur 364 

translated by H. C. ERNST 

On the Extension of the Germ Theory to the Etiology of Cer- 
tain Common Diseases (Revised) .... Louis Pasteur 371 

translated by H. C. ERNST 

Prejudices which have Retarded the Progress of Geology . . 385 

Sir Charles Lyell 
Uniformity in the Series of Past Changes in the Animate and 

Inanimate World Sir Charles Lyell 398 



INTRODUCTORY NOTE 

Hippocrates, the celebrated Greek physician, was a contemporary of 
the historian Herodotus. He was born in the island of Cos between 470 
and 460 B.C., and belonged to the family that claimed descent from the 
mythical iEsculapius, son of Apollo. There was already a long medical 
tradition in Greece before his day, and this he is supposed to have 
inherited chiefly through his predecessor Herodicus; and he enlarged his 
education by extensive travel. He is said, though the evidence is unsatis- 
factory, to have taken part in the efforts to check the great plague which 
devastated Athens at the beginning of the Peloponnesian war. He died 
at Larissa between 380 and 360 B.C. 

The works attributed to Hippocrates are the earliest extant Greek 
medical writings, but very many of them are certainly not his. Some five 
or six, however, are generally granted to be genuine, and among these 
is the famous "Oath." This interesting document shows that in his time 
physicians were already organized into a corporation or guild, with regu- 
lations for the training of disciples, and with an esprit de corps and a 
professional ideal which, with slight exceptions, can hardly yet be re- 
garded as out of date. 

One saying occurring in the words of Hippocrates has achieved uni- 
versal currency, though few who quote it to-day are aware that it origi- 
nally referred to the art of the physician. It is the first of his "Apho- 
risms": "Life is short, and the Art long; the occasion fleeting; experience 
fallacious, and judgment difficult. The physician must not only be pre- 
pared to do what is right himself, but also to make the patient, the 
attendants, and externals cooperate." 



THE OATH OF HIPPOCRATES 

I SWEAR by Apollo the physician and ^sculapius, and Health, 
and All-heal, and all the gods and goddesses, that, according to 
my ability and judgment, I will keep this Oath and this stipula- 
tion — to reckon him who taught me this Art equally dear to me as 
my parents, to share my substance with him, and relieve his neces- 
sities if required; to look upon his oflspring in the same footing as 
my own brothers, and to teach them this Art, if they shall wish to 
learn it, without fee or stipulation; and that by precept, lecture, and 
every other mode of instruction, I will impart a knowledge of the 
Art to my own sons, and those of my teachers, and to disciples 
bound by a stipulation and oath according to the law of medicine, 
but to none others. I will follow that system of regimen which, 
according to my ability and judgment, I consider for the benefit of 
my patients, and abstain from whatever is deleterious and mis- 
chievous. I will give no deadly medicine to any one if asked, nor 
suggest any such counsel; and in like manner I will not give to a 
woman a pessary to produce abortion. With purity and with holi- 
ness I will pass my life and practice my Art. I will not cut persons 
labouring under the stone, but will leave this to be done by men 
who are practitioners of this work. Into whatever houses I enter, I 
will go into them for the benefit of the sick, and will abstain from 
every voluntary act of mischief and corruption; and, further, from 
the seduction of females or males, of freemen and slaves. Whatever, 
in connection with my professional practice, or not in connection 
with it, I see or hear, in the life of men, which ought not to be spoken 
of abroad, I will not divulge, as reckoning that all such should be 
kept secret. While I continue to keep this Oath unviolated, may it 
be granted to me to enjoy Hfe and the practice of the Art, respected 
by all men, in all times. But should I trespass and violate this Oath, 
may the reverse be my lot. 



THE LAW OF HIPPOCRATES 

MEDICINE is of all the arts the most noble; but, owing to 
the ignorance of those who practice it, and of those who, 
inconsiderately, form a judgment of them, it is at present 
far behind all the other arts. Their mistake appears to me to arise 
principally from this, that in the cities there is no punishment con- 
nected with the practice of medicine (and with it alone) except 
disgrace, and that does not hurt those who are familiar with it. Such 
persons are like the figures which are introduced in tragedies, for 
as they have the shape, and dress, and personal appearance of an 
actor, but are not actors, so also physicians are many in title but very 
few in reality. 

2. Whoever is to acquire a competent knowledge of medicine, 
ought to be possessed of the following advantages: a natural dis- 
position; instruction; a favorable position for the study; early tuition; 
love of labour; leisure. First of all, a natural talent is required; for, 
when Nature leads the way to what is most excellent, instruction in 
the art takes place, which the student must try to appropriate to 
himself by reflection, becoming an early pupil in a place well adapted 
for instruction. He must also bring to the task a love of labour and 
perseverance, so that the instruction taking root may bring forth 
proper and abundant fruits. 

3. Instruction in medicine is like the culture of the productions 
of the earth. For our natural disposition, is, as it were, the soil; the 
tenets of our teacher are, as it were, the seed; instruction in youth 
is like the planting of the seed in the ground at the proper season; 
the place where the instruction is communicated is like the food 
imparted to vegetables by the atmosphere; diligent study is like the 
cultivation of the fields; and it is time which imparts strength to 
all things and brings them to maturity. 

4. Having brought all these requisites to the study of medicine, 
and having acquired a true knowledge of it, we shall thus, in travel- 

4 



THE LAW 5 

ling through the cities, be esteemed physicians not only in name 
but in reality. But inexperience is a bad treasure, and a bad fund 
to those who possess it, whether in opinion or reality, being devoid 
of self-reliance and contentedness, and the nurse both of timidity 
and audacity. For timidity betrays a want of powers, and audacity 
a lack of skill. They are, indeed, two things, knowledge and opinion, 
of which the one makes its possessor really to know, the other to 
be ignorant. 

5. Those things which are sacred, are to be imparted only to 
sacred persons; and it is not lawful to impart them to the profane 
until they have been initiated in the mysteries of the science. 



JOURNEYS IN DIVERSE PLACES 



BY 

AMBROISE PARE 

TRANSLATED BY 
STEPHEN PAGET 



INTRODUCTORY NOTE 

Ambroise Pare was born in the village of Bourg-Hersent, near Laval, 
in Maine, France, about 1510. He was trained as a barber-surgeon at a 
time when a barber-surgeon was inferior to a surgeon, and the profes- 
sions of surgeon and physician were kept apart by the law of the Church 
that forbade a physician to shed blood. Under whom he served his 
apprenticeship is unknown, but by 1533 he was in Paris, where he 
received an appointment as house surgeon at the Hotel Dieu. After three 
or four years of valuable experience in this hospital, he set up in private 
practise in Paris, but for the next thirty years he was there only in the 
intervals of peace; the rest of the time he followed the army. He became 
a master barber-surgeon in 154 1. 

In Fare's time the armies of Europe were not regularly equipped with 
a medical service. The great nobles were accompanied by their private 
physicians; the common soldiers doctored themselves, or used the services 
of barber-surgeons and quacks who accompanied the army as adven- 
turers. "When Pare joined the army," says Paget, "he went simply as a 
follower of Colonel Montejan, having neither rank, recognition, nor 
regular payment. His fees make up in romance for their irregularity: a 
cask of wine, fifty double ducats and a horse, a diamond, a collection of 
crowns and half-crowns from the ranks, other 'honorable presents and of 
great value'; from the King himself, three hundred crowns, and a promise 
he would never let him be in want; another diamond, this time from 
the finger of a duchess: and a soldier once offered a bag of gold to him." 

When Pare was a man of seventy, the Dean of the Faculty of Medicine 
in Paris made an attack on him on account of his use of the ligature 
instead of cauterizing after amputation. In answer. Pare appealed to his 
successful experience, and narrated the "Journeys in Diverse Places" here 
printed. This entertaining volume gives a vivid picture, not merely of 
the condition of surgery in the sixteenth century, but of the military life 
of the time; and reveals incidentally a personality of remarkable vigor 
and charm. Fare's own achievements are recorded with modest satis- 
faction: "I dressed him, and God healed him," is the refrain. Fare died 
in Paris in December, 1590. 



JOURNEYS IN DIVERSE 

PLACES' 

1537-1569 

The Journey to Turin. 1537 

I WILL here shew my readers the towns and places where I 
found a way to learn the art of surgery : for the better instruc- 
tion of the young surgeon. 

And first, in the year 1536, the great King Francis sent a large 
army to Turin, to recover the towns and castles that had been taken 
by the Marquis de Guast, Lieutenant-General of the Emperor. M. 
the Constable, then Grand Master, was Lieutenant-General of the 
army, and M. de Montejan was Colonel-General of the infantry, 
whose surgeon I was at this time. A great part of the army being 
come to the Pass of Suze, we found the enemy occupying it; and 
they had made forts and trenches, so that we had to fight to dis- 
lodge them and drive them out. And there were many killed and 
wounded on both sides, — but the enemy were forced to give way 
and retreat into the castle, which was captured, part of it, by Cap- 
tain Le Rat, who was posted on a little hill with some of his soldiers, 
whence they fired straight on the enemy. He received an arquebus- 
shot in his right ankle, and fell to the ground at once, and then 
said, "Now they have got the Rat." I dressed him, and God healed 
him. 

We entered pell-mell into the city, and passed over the dead 
bodies, and some not yet dead, hearing them cry under our horses' 
feet; and they made my heart ache to hear them. And truly I re- 
pented I had left Paris to see such a pitiful spectacle. Being come 
into the city, I entered into a stable, thinking to lodge my own and 
my man's horse, and found four dead soldiers, and three propped 

' The present translation is taken from Mr. Stephen Paget's "Ambroise Par^ and 
His Times" by arrangement with Messrs. G. P. Putnam's Sons. 



10 AMBROISE PARE 

against the wall, their features all changed, and they neither saw, 
heard, nor spake, and their clothes were still smouldering where 
the gun-powder had burned them. As I was looking at them with 
pity, there came an old soldier who asked me if there were any 
way to cure them. I said no. And then he went up to them and 
cut their throats, gently, and without ill will toward them. Seeing 
this great cruelty, I told him he was a villain: he answered he 
prayed God, when he should be in such a plight, he might find 
someone to do the same for him, that he should not linger in misery. 
To come back to my story, the enemy were called on to surrender, 
which they did, and left the city with only their lives saved, and the 
white stick in their hands; and most of them went off to the Chateau 
de Villane, where about two hundred Spaniards were stationed. 
M. the Constable would not leave these behind him, wishing to 
clear the road for our own men. The castle is seated on a small 
hill; which gave great confidence to those within, that we could 
not bring our artillery to bear upon them. They were summoned 
to surrender, or they would be cut in pieces: they answered that 
they would not, saying they were as good and faithful servants of 
the Emperor, as M. the Constable could be of the King his master. 
Thereupon our men by night hoisted up two great cannons, with 
the help of the Swiss soldiers and the lansquenets; but as ill luck 
would have it, when the cannons were in position, a gunner stupidly 
set fire to a bag full of gunpowder, whereby he was burned, with 
ten or twelve soldiers; and the flame of the powder discovered our 
artillery, so that all night long those within the castle fired their 
arquebuses at the place where they had caught sight of the cannons, 
and many of our men were killed and wounded. Next day, early 
in the morning, the attack was begun, and we soon made a breach 
in their wall. Then they demanded a parley: but it was too late, 
for meanwhile our French infantry, seeing them taken by surprise, 
mounted the breach, and cut them all in pieces, save one very fair 
young girl of Piedmont, whom a great seigneur would have. . . . 
The captain and the ensign were taken alive, but soon afterward 
hanged and strangled on the battlements of the gate of the city, to 
give example and fear to the Emperor's soldiers, not to be so rash 
and mad as to wish to hold such places against so great an army. 



JOURNEYS IN DIVERSE PLACES II 

The soldiers within the castle, seeing our mea come on them with 
great fury, did all they could to defend themselves, and killed and 
wounded many of our soldiers with pikes, arquebuses, and stones, 
whereby the surgeons had all their work cut out for them. Now I 
was at this time a fresh-water soldier; I had not yet seen wounds 
made by gunshot at the first dressing. It is true I had read in John 
de Vigo, first book. Of Wounds in Genercd, eighth chapter, that 
wounds made by firearms partake of venenosity, by reason of the 
powder; and for their cure he bids you cauterise them with oil of 
elder, scalding hot, mixed with a litde treacle. And to make no 
mistake, before I would use the said oil, knowing this was to bring 
great pain to the patient, I asked first before I applied it, what the 
other surgeons did for the first dressing; which was to put the said 
oil, boiling well, into the wounds, with tents and setons; wherefore 
I took courage to do as they did. At last my oil ran short, and I was 
forced instead thereof to apply a digestive made of the yolks of 
eggs, oil of roses, and turpentine. In the night I could not sleep in 
quiet, fearing some default in not cauterising, that I should find the 
wounded to whom I had not used the said oil dead from the poison 
of their wounds; which made me rise very early to visit them, where 
beyond my expectation I found that those to whom I had applied 
my digestive medicament had but little pain, and their wounds 
without inflammation or swelling, having rested fairly well that 
night; the others, to whom the boiling oil was used, I found feverish, 
with great pain and swelling about the edges of their wounds. 
Then I resolved never more to burn thus cruelly poor men wdth 
gunshot wounds. 

While I was at Turin, I found a surgeon famed above all others 
for his treatment of gunshot wounds; into wiiose favour I found 
means to insinuate myself, to have the recipe of his balm, as he 
called it, wherewith he dressed gunshot wounds. And he made me 
pay my court to him for two years, before I could possibly draw the 
recipe from him. In the end, thanks to rtiy gifts and presents, he 
gave it to me; which was to boil, in oil of lilies, young whelps just 
born, and earth-worms prepared with Venetian turpentine. Then 
I was joyful, and my heart made glad that I had understood his 
remedy, which was like that which I had obtained by chance. 



12 AMBROISE PARE 

See how I learned to treat gunshot wounds; not by books. 

My Lord Marshal Montejan remained Lieutenant-General for 
the King in Piedmont, having ten or twelve thousand men in gar- 
rison in the different cities and castles, who were often fighting 
among themselves with swords and other weapons, even with 
arquebuses. And if there were four wounded, I always had three 
of them; and if there were question of cutting off an arm or a leg, 
or of trepanning, or of reducing a fracture or a dislocation, I ac- 
complished it all. The Lord Marshal sent me now here now there 
to dress the soldiers committed to me who were wounded in other 
cities beside Turin, so that I was always in the country, one way 
or the other. 

M. the Marshal sent to Milan, to a physician of no less reputation 
than the late M. le Grand for his success in practice, to treat him 
for an hepatic flux, whereof in the end he died. This physician was 
some while at Turin to treat him, and was often called to visit the 
wounded, where always he found me; and I was used to consult 
with him, and with some other surgeons; and when we had re- 
solved to do any serious work of surgery, it was Ambroise Pare 
that put his hand thereto, which I would do promptly and skilfully, 
and with great assurance, insomuch that the physician wondered 
at me, to be so ready in the operations of surgery, and I so young. 
One day, discoursing with the Lord Marshal, he said to him: 

"Signor, tu hai un Chirurgico giovane di anni, ma egli e vecchio 
di sapere e di esperientia: Guardalo bene, perche egli ti fara servicio 
et honore." That is to say, "Thou hast a surgeon young in age, but 
he is old in knowledge and experience: take good care of him, for 
he will do thee service and honour." But the good man did not 
know I had lived three years at the Hotel Dieu in Paris, with the 
patients there. 

In the end, M. the Marshal died of his hepatic flux. He being 
dead, the King sent M. the Marshal d'Annebaut to be in his place: 
who did me the honour to ask me to live with him, and he would 
treat me as well or better than M. the Marshal de Montejan. Which 
I would not do, for grief at the loss of my master, who loved me 
dearly; so I returned to Paris. 



JOURNEYS IN DIVERSE PLACES I3 

The Journey to Marolles and Low Brittany. 1543 

I WENT to the Camp of Marolles, with the late M. de Rohan, as 
surgeon of his company; where was the King himself. M. d'Estam- 
pes. Governor of Brittany, had told the King how the English had 
hoist sail to land in Low Brittany; and had prayed him to send, to 
help him, MM. de Rohan and de Laval, because they were the 
seigneurs of that country, and by their help the country people would 
beat back the enemy, and keep them from landing. Having heard 
this, the King sent these seigneurs to go in haste to the help of their 
country; and to each was given as much power as to the Governor, 
so that they were all three the King's Lieutenants. They willingly 
took this charge upon them, and went off posting with good speed, 
and took me with them as far as Landreneau. There we found every 
one in arms, the tocsin sounding on every side, for a good five or 
six leagues round the harbours, Brest, Couquet, Crozon, le Fou, 
Doulac, Laudanec; each well furnished with artillery, as cannons, 
demi-cannons, culverins, muskets, falcons, arquebuses; in brief, all 
who came together were well equipped with all sorts and kinds of 
artillery, and with many soldiers, both Breton and French, to hinder 
the English from landing as they had resolved at their parting from 
England. 

The enemy's army came right under our cannons: and when we 
perceived them desiring to land, we saluted them with cannon-shot, 
and unmasked our forces and our artillery. They fled to sea again. 
I was right glad to see their ships set sail, which were in good num- 
ber and good order, and seemed to be a forest moving upon the sea. 
I saw a thing also whereat I marvelled much, which was, that the 
balls of the great cannons made long rebounds, and grazed over 
the water as they do over the earth. Now to make the matter short, 
our English did us no harm, and returned safe and sound into 
England. And they leaving us in peace, we stayed in that country 
in garrison until we were assured that their army was dispersed. 

Now our soldiers used often to exercise themselves with running 
at the ring, or with fencing, so that there was always some one in 
trouble, and I had always something to employ me. M. d'Estampes, 
to make pastime and pleasure for the Seigneurs de Rohan and de 



14 AMBROISE PARE 

Laval, and other gentlemen, got a number of village girls to come 
to the sports, to sing songs in the tongue of Low Brittany: vs^herein 
their harmony was like the croaking of frogs when they are in love. 
Moreover, he made them dance the Brittany triori, without moving 
feet or hips : he made the gentlemen see and hear many good things. 

At other times they made the wrestlers of the towns and villages 
come, where there was a prize for the best: and the sport was not 
ended but that one or other had a leg or arm broken, or the shoulder 
or hip dislocated. 

There was a little man of Low Brittany, of a square body and 
well set, who long held the credit of the field, and by his skill and 
strength threw five or six to the ground. There came against him a 
big man, one Dativo, a pedagogue, who was said to be one of the 
best wrestlers in all Brittany: he entered into the lists, having thrown 
off his long jacket, in hose and doublet: when he was near the little 
man, it looked as though the little man had been tied to his girdle. 
Nevertheless, when they gripped each other round the neck, they 
were a long time without doing anything, and we thought they 
would remain equal in force and skill: but the little man suddenly 
leaped beneath this big Dativo, and took him on his shoulder, and 
threw him to earth on his back all spread out like a frog; and all 
the company laughed at the skill and strength of the little fellow. 
The great Dativo was furious to have been thus thrown to earth 
by so small a man: he rose again in a rage, and would have his 
revenge. They took hold again round the neck, and were again a 
good while at their hold without falling to the ground: but at last 
the big man let himself fall upon the little, and in falling put his 
elbow upon the pit of his stomach, and burst his heart, and killed 
him stark dead. And knowing he had given him his death's blow, 
took again his long cassock, and went away with his tail between 
his legs, and eclipsed himself. Seeing the little man came not again 
to himself, either for wine, vinegar, or any other thing presented to 
him, I drew near to him and felt his pulse, which did not beat at 
all: then I said he was dead. Then the Bretons, who were assisting 
at the wrestling, said aloud in their jargon, "Andraze meuraquet 
enes rac un bloa so abeudeux henelep e barz an gouremon enel ma 
boa engoustun." That is to say, "That is not in the sport." And 



JOURNEYS IN DIVERSE PLACES 1 5 

someone said that this great Dative was accustomed to do so, and 
but a year past he had done the same at a wrestHng. I must needs 
open the body to know the cause of this sudden death. I found 
much blood in the thorax. .... I tried to find some internal open- 
ing whence it might have come, which I could not, for all the dili- 
gence that I could use. . . . The poor litde wrestler was buried. I 
took leave of MM. de Rohan, de Laval, and d'Estampes. M. de 
Rohan made me a present of fifty double ducats and a horse, M. de 
Laval gave me a nag for my man, and M. d'Estampes gave me a 
diamond worth thirty crowns: and I returned to my house in Paris. 

The Journey to Perpignan. 1543 

Some while after, M. de Rohan took me with him posting to the 
camp at Perpignan. While we were there, the enemy sallied out, 
and surrounded three pieces of our ardllery before they were beaten 
back to the gates of the city. Which was not done without many 
killed and wounded, among the others M. de Brissac, who was then 
grand master of the artillery, with an arquebus-shot in the shoulder. 
When he retired to his tent, all the wounded followed him, hoping 
to be dressed by the surgeons who were to dress him. Being come 
to his tent and laid on his bed, the bullet was searched for by three 
or four of the best surgeons in the army, who could not find it, but 
said it had entered into his body. 

At last he called for me, to see if I could be more skilful than 
they, because he had known me in Piedmont. Then I made him 
rise from his bed, and told him to put himself in the same posture 
that he had when he was wounded, which he did, taking a javelin 
in his hand just as he had held his pike to fight. I put my hand 
around the wound, and found the bullet. . . . Having found it, I 
showed them the place where it was, and it was taken out by M. 
Nicole Lavernault, surgeon of M. the Dauphin, who was the King's 
Lieutenant in that army; all the same, the honour of finding it be- 
longed to me. 

I saw one very strange thing, which was this: a soldier in my 
presence gave one of his fellows a blow on the head with a halbard, 
penetrating to the left ventricle of the brain; yet the man did not 
fall to the ground. He that struck him said he heard that he had 



1 6 AMBROISE PARE 

cheated at dice, and he had drawn a large sum of money from him, 
and was accustomed to cheat. They called me to dress him; which 
I did, as it were for the last time, knowing that he would die soon. 
When I had dressed him, he returned all alone to his quarters, 
which were at the least two hundred paces away. I bade one of his 
companions send for a priest to dispose the affairs of his soul; he 
got one for him, who stayed with him to his last breath. The next 
day, the patient sent for me by his girl, dressed in boy's apparel, to 
come and dress him; which I would not, fearing he would die under 
my hands; and to be rid of the matter I told her the dressing must 
not be removed before the third day. But in truth he was sure to 
die, though he were never touched again. The third day, he came 
staggering to find me in my tent, and the girl with him, and prayed 
me most affectionately to dress him, and showed me a purse wherein 
might be an hundred or sixscore pieces of gold, and said he would 
give me my heart's desire; nevertheless, for all that, I put off the 
removal of the dressing, fearing lest he should die then and there. 
Certain gentlemen desired me to go and dress him; which I did at 
their request; but in dressing him he died under my hands in a 
convulsion. The priest stayed with him till death, and seized his 
purse, for fear another man should take it, saying he would say 
masses for his poor soul. Also he took his clothes, and everything 
else. 

I have told this case for the wonder of it, that the soldier, having 
received this great blow, did not fall down, and kept his reason to 
the end. 

Not long afterward, the camp was broken up from diverse causes: 
one, because we were told that four companies of Spaniards were 
entered into Perpignan: the other, that the plague was spreading 
through the camp. Moreover, the country folk warned us there 
would soon be a great overflowing of the sea, which might drown 
us all. And the presage which they had, was a very great wind from 
sea, which rose so high that there remained not a single tent but 
was broken and thrown down, for all the care and diligence we 
could give; and the kitchens being all uncovered, the wind raised 
the dust and sand, which salted and powdered our meats in such 
fashion that we could not eat them; and we had to cook them in 



JOURNEYS IN DIVERSE PLACES 1 7 

pots and other covered vessels. Nor was the camp so quickly moved 
but that many carts and carters, mules and mule drivers, were 
drowned in the sea, with great loss of baggage. 
When the camp was moved I returned to Paris. 

The Journey to Landresy. 1544 

The King raised a great army to victual Landresy. Against him 
the Emperor had no fewer men, but many more, to wit, eighteen 
thousand Germans, ten thousand Spaniards, six thousand Walloons, 
ten thousand English, and from thirteen to fourteen thousand horse. 
I saw the two armies near each other, within cannon-shot; and we 
thought they could not withdraw without giving battle. There were 
some foolish gentlemen who must needs approach the enemy's 
camp; the enemy fired on them with light field pieces; some died 
then and there, others had their arms or legs carried away. The 
King having done what he wished, which was to victual Landresy, 
withdrew his army to Guise, which was the day after All Saints, 
1544; and from there I returned to Paris. 

The Journey to Boulogne. 1545 

A LITTLE while after, we went to Boulogne; where the English, 
seeing our army, left the forts which they were holding, Moulam- 
bert, le petit Paradis, Monplaisir, the fort of Chastillon, le Portet, the 
fort of Dardelot. One day, as I was going through the camp to 
dress my wounded men, the enemy who were in the Tour d'Ordre 
fired a cannon against us, thinking to kill two men-at-arms who had 
stopped to talk together. It happened that the ball passed quite 
close to one of them, which threw him to the ground, and it was 
thought the ball had touched him, which it did not; but only the 
wind of the ball full against his corselet, with such force that all the 
outer part of his thigh became livid and black, and he could hardly 
stand. I dressed him, and made diverse scarifications to let out the 
bruised blood made by the wind of the ball; and by the rebounds 
that it made on the ground it killed four soldiers, who remained 
dead where they fell. 

I was not far from this shot, so that I could just feel the moved 
air, without its doing me any harm save a fright, which made me 



1 8 AMBROISE PARE 

duck my head low enough; but the ball was already far away. The 
soldiers laughed at me, to be afraid of a ball which had already 
passed. Mon petit maistre, I think if you had been there, I should 
not have been afraid all alone, and you would have had your share 
of it. 

Monseigneur the Due de Guise, Francois de Lorraine, was 
wounded before Boulogne with a thrust of a lance, which entered 
above the right eye, toward the nose, and passed out on the other 
side between the ear and the back of the neck, with so great violence 
that the head of the lance, with a piece of the wood, was broken 
and remained fast; so that it could not be drawn out save with 
extreme force, with smith's pincers. Yet notwithstanding the great 
violence of the blow, which was not without fracture of bones, 
nerves, veins, and arteries, and other parts torn and broken, my lord, 
by the grace of God, was healed. He was used to go into battle 
always with his vizard raised: that is why the lance passed right out 
on the other side. 

The Journey to Germany. 1552 

I WENT to Germany, in the year 1552, with M. de Rohan, captain 
of fifty men-at-arms, where I was surgeon of his company, as I have 
said before. On this expedition, M. the Constable was general of 
the army; M. de Chastillon, afterward the Admiral, was chief 
colonel of the infantry, with four regiments of lansquenets under 
Captains Recrod and Ringrave, two under each; and every regiment 
was of ten ensigns, and every ensign of five hundred men. And 
beside these were Captain Chartel, who led the troops that the 
Protestant princes had sent to the King (this infantry was very fine, 
and was accompanied by fifteen hundred men-at-arms, with a 
following of two archers apiece, which would make four thousand 
five hundred horse) ; and two thousand light horse, and as many 
mounted arquebusiers, of whom M. d'Aumalle was general; and a 
great number of the nobility, who were come there for their pleasure. 
Moreover, the King was accompanied by two hundred gentlemen of 
his household, under the command of the Seigneurs de Boisy and de 
Canappe, and by many other princes. For his following, to escort 
him, there were the French and Scotch and Swiss guards, amounting 



JOURNEYS IN DIVERSE PLACES I9 

to six hundred foot soldiers; and the companies of MM. the Dauphin, 
de Guise, d'Aumalle, and Marshal Saint Andre, amounting to four 
hundred lances; which was a marvellous thing, to see such a multi- 
tude; and with this equipage the King entered into Toul and Metz. 

I must not omit to say that the companies of MM. de Rohan, the 
Comte de Sancerre, and de Jarnac, which were each of them of fifty 
horse, went upon the wings of the camp. And God knows how 
scarce we were of victuals, and I protest before Him that at three 
diverse times I thought to die of hunger; and it was not for want 
of money, for I had enough of it; but we could not get victuals save 
by force, because the country people collected them all into the towns 
and castles. 

One of the servants of the captain-ensign of the company of M. de 
Rohan went with others to enter a church where the peasants were 
retreated, thinking to get victuals by love or by force; but he got 
the worst of it, as they all did, and came back with seven sword- 
wounds on the head, the least of which penetrated, to the inner table 
of the skull; and he had four other wounds upon the arms, and one 
on the right shoulder, which cut more than half of the blade-bone. 
He was brought back to his master's lodging, who seeing him so 
mutilated, and not hoping he could be cured, made him a grave, 
and would have cast him therein, saying that else the peasants would 
massacre and kill him. I in pity told him the man might still be 
cured if he were well dressed. Diverse gentlemen of the company 
prayed he would take him along with the baggage, since I was 
willing to dress him; to which he agreed, and after I had got the 
man ready, he was put in a cart, on a bed well covered and well 
arranged, drawn by a horse. I did him the office of physician, apothe- 
cary, surgeon, and cook. I dressed him to the end of his case, and 
God healed him; insomuch that all the three companies marvelled 
at this cure. The men-at-arms of the company of M. de Rohan, the 
first muster that was made, gave me each a crown, and the archers 
half a crown. 

The Journey to Danvilliers. 1552 

On his return from the expedition against the German camp, 
King Henry besieged Danvilliers, and those within would not 



20 AMBROISE PAKE 

surrender. They got the worst of it, but our powder failed us; so 
they had a good shot at our men. There was a culverin-shot passed 
through the tent of M. de Rohan, which hit a gentleman's leg who 
was of his household. I had to finish the cutting off of it, which I 
did without applying the hot irons. 

The King sent for powder to Sedan, and when it came we began 
the attack more vigorously than before, so that a breach was made. 
MM. de Guise and the Constable, being in the King's chamber, 
told him, and they agreed that next day they would assault the 
town, and were confident they would enter into it; and it must be 
kept secret, for fear the enemy should come to hear of it; and each 
promised not to speak of it to any man. Now there was a groom of 
the King's chamber, who being laid under the King's camp-bed to 
sleep, heard they were resolved to attack the town next day. So he 
told the secret to a certain captain, saying that they would make 
the attack next day for certain, and he had heard it from the King, 
and prayed the said captain to speak of it to no man, which he 
promised; but his promise did not hold, and forthwith he disclosed 
it to a captain, and this captain to a captain, and the captains to 
some of the soldiers, saying always, "Say nothing." And it was just 
so much hid, that next day early in the morning there was seen the 
greater part of the soldiers with their boots and breeches cut loose 
at the knee for the better mounting of the breach. The King was 
told of this rumour that ran through the camp, that the attack was 
to be made; whereat he was astonished, seeing there were but three 
in that advice, who had promised each other to tell it to no man. 
The King sent for M. de Guise, to know if he had spoken of this 
attack; he swore and affirmed to him he had not told it to anybody; 
and M. the Constable said the same, and told the King they must 
know for certain who had declared this secret counsel, seeing they 
were but three. Inquiry was made from captain to captain. In the 
end they found the truth; for one said, "It was such an one told me," 
and another said the same, till it came to the first of all, who declared 
he had heard it from the groom of the King's chamber, called 
Guyard, a native of Blois, son of a barber of the late King Francis. 
The King sent for him into his tent, in the presence of MM. de 
Guise and the Constable, to hear from him whence he had his 



JOURNEYS IN DIVERSE PLACES 21 

knowledge, and who had told him the attack was to be made; and 
said if he did not speak the truth he would have him hanged. Then 
he declared he lay down under the King's bed thinking to sleep, 
and so having heard the plan he revealed it to a captain who was 
a friend of his, to the end he might prepare himself with his sol- 
diers to be the first at the attack. Then the King knew the truth, 
and told him he should never serve him again, and that he de- 
served to be hanged, and forbade him ever to come again to the 
Court. 

The groom of the chamber went away with this to swallow, and 
slept that night with a surgeon-in-ordinary of the King, Master 
Louis of Saint Andre; and in the night he gave himself six stabs 
with a knife, and cut his throat. Nor did the surgeon perceive it 
till the morning, when he found his bed all bloody, and the dead 
body by him. He marvelled at this sight on his awaking, and feared 
they would say he was the cause of the murder; but he was soon 
relieved, seeing the reason, which was despair at the loss of the 
good friendship of the King. 

So Guyard was buried. And those of DanvilUers, when they saw 
the breach large enough for us to enter, and our soldiers ready to 
assault them, surrendered themselves to the mercy of the King. 
Their leaders were taken prisoners, and their soldiers were sent away 
without arms. 

The camp being dispersed, I returned to Paris with my gentleman 
whose leg I had cut off; I dressed him, and God healed him. I sent 
him to his house merry with a wooden leg; and he was content, 
saying he had got off cheap, not to have been miserably burned to 
stop the blood, as you write in your book, mon petit maistre. 

The Journey to Chateau le Comte. 1552 

Some time after. King Henry raised an army of thirty thousand 
men, to go and lay waste the country about Hesdin. The King of 
Navarre, who was then called M. de Vendosme, was chief of the 
army, and the King's Lieutenant. Being at St. Denis, in France, 
waiting while the companies passed by, he sent to Paris for me to 
speak with him. When I came he begged me (and his request was 
a command) to follow him on this journey; and I, wishing to make 



22 AMBROISE PARE 

my excuses, saying my wife was sick in bed, he made answer there 
were physicians in Paris to cure her, and he, too, had left his wife, 
who was of as good a house as mine, and he said he would use me 
well, and forthwith ordered I should be attached to his household. 
Seeing this great desire he had to take me with him, I dared not 
refuse him. 

I went after him to Chateau le Comte, within three or four 
leagues of Hesdin. The Emperor's soldiers were in garrison there, 
with a number of peasants from the country road. M. de Vendosme 
called on them to surrender; they made answer that he should never 
take them, unless it were piecemeal; let him do his worst, and they 
would do their best to defend themselves. They trusted in their 
moats, which were full of water; but in two hours, with plenty of 
faggots and casks, we made a way for our infantry to pass over, 
when they had to advance to the assault; and the place was attacked 
with five cannons, and a breach was made large enough for our 
men to enter; where those within received the attack very valiantly, 
and killed and wounded a great number of our men with arque- 
buses, pikes, and stones. In the end, when they saw themselves 
overpowered, they set fire to their powder and ammunition, whereby 
many of our men were burned, and some of their own. And they 
were almost all put to the sword; but some of our soldiers had 
taken twenty or thirty, hoping to have ransom for them: and so 
soon as this was known, orders were given to proclaim by trumpet 
through the camp, that all soldiers who had Spaniards for prisoners 
must kill them, on pain of being themselves hanged and strangled: 
which was done in cold blood. 

Thence we went and burned several villages; and the barns were 
all full of grain, to my very great regret. We came as far as Tourna- 
han, where there was a large tower, whither the enemy withdrew, 
but we found the place empty: our men sacked it, and blew up 
the tower with a mine of gunpowder, which turned it upside down. 
After that, the camp was dispersed, and I returned to Paris. And 
the day after Chateau le Comte was taken, M. de Vendosme sent a 
gentleman under orders to the King, to report to him all that had 
happened, and among other things he told the King I had done very 
good work dressing the wounded, and had showed him eighteen 



JOURNEYS IN DIVERSE PLACES 23 

bullets that I had taken out of their bodies, and there were many 
more that I had not been able to find or take out; and he spoke 
more good of me than there was by half. Then the King said he 
would take me into his service, and commanded M. de Goguier, his 
first physician, to write me down in the King's service as one of his 
surgeons-in-ordinary, and I was to meet him at Rheims within ten 
or twelve days: which I did. And the King did me the honour to 
command me to live near him, and he would be a good friend to 
me. Then I thanked him most humbly for the honour he was 
pleased to do me in appointing me to serve him. 

The Journey to Metz. 1552 

The Emperor having besieged Metz with more than an hundred 
and twenty thousand men, and in the hardest time of winter, — it is 
still fresh in the minds of all — and there were five or six thousand 
men in the town, and among them seven princes; MM. le Due de 
Guise, the King's Lieutenant, d'Enghien, de Conde, de la Mont- 
pensier, de la Roche-sur-Yon, de Nemours, and many other gentle- 
men, with a number of veteran captains and officers: who often 
sallied out against the enemy (as I shall tell hereafter), not without 
heavy loss on both sides. Our wounded died almost all, and it was 
thought the drugs wherewith they were dressed had been poisoned. 
Wherefore M. de Guise, and MM. the princes, went so far as to beg 
the King that if it were possible I should be sent to them with a 
supply of drugs, and they believed their drugs were poisoned, seeing 
that few of their wounded escaped. My belief is that there was no 
poison; but the severe cutlass and arquebus wounds, and the extreme 
cold, were the cause why so many died. The King wrote to M. the 
Marshal de Saint Andre, who was his Lieutenant at Verdun, to find 
means to get me into Metz, whatever way was possible. MM. the 
Marshal de Saint Andre, and the Marshal de Vielleville, won over 
an Italian captain, who promised to get me into the place, which he 
did (and for this he had fifteen hundred crowns). The King having 
heard the promise that the Italian captain had made, sent for me, 
and commanded me to take of his apothecary, named Daigne, so 
many and such drugs as I should think necessary for the wounded 
within the town; which I did, as much as a post-horse could carry. 



24 AMBROISE PARE 

The King gave me messages to M. de Guise, and to the princes and 

the captains that were in Metz. 

When I came to Verdun, some days after, M. the Marshal de 
Saint Andre got horses for me and for my man, and for the Itahan 
captain, who spoke excellent German, Spanish, and Walloon, beside 
his own mother-tongue. When we were within eight or ten leagues 
of Metz, we began to go by night only; and when we came near 
the enemy's camp I saw, more than a league and a half off, fires 
lighted all round the town, as if the whole earth were burning; and 
I believed we could never pass through these fires without being 
discovered, and therefore hanged and strangled, or cut in pieces, or 
made to pay a great ransom. To speak truth, I could well and gladly 
have wished myself back in Paris, for the great danger that I fore- 
saw. God guided our business so well, that we entered into the 
town at midnight, thanks to a signal the captain had with another 
captain of the company of M. de Guise; to whom I went, and found 
him in bed, and he received me with high favour, being right glad 
at my coming. 

I gave him my message as the King had commanded me, and 
told him I had a little letter for him, and the next day I would not 
fail to deliver it. Then he ordered me a good lodging, and that I 
should be well treated, and said I must not fail next morning to be 
upon the breach, where I should find all the princes and seigneurs, 
and many captains. Which I did, and they received me with great 
joy, and did me the honour to embrace me, and tell me I was 
welcome; adding they would no more be afraid of dying, if they 
should happen to be wounded. 

M. le Prince de la Roche-sur-Yon was the first who entertained 
me, and inquired what they were saying at the Court concerning 
the town of Metz. I told him all that I chose to tell. Forthwith 
he begged me to go and see one of his gentlemen named M. de 
Magnane, now Chevalier of the Order of the King, and Lieutenant 
of His Majesty's Guards, who had his leg broken by a cannon-shot. 
I found him in bed, his leg bent and crooked, without any dressing 
on it, because a gentleman promised to cure him, having his name 
and his girdle, with certain words (and the poor patient was weep- 
ing and crying out with pain, not sleeping day or night for four 



JOURNEYS IN DIVERSE PLACES 25 

days past). Then I laughed at such cheating and false promises; 
and I reduced and dressed his leg so skilfully that he was without 
pain, and slept all the night, and afterward, thanks be to God, he 
was healed, and is still living now, in the King's service. The Prince 
de la Roche-sur-Yon sent me a cask of wine, bigger than a pipe of 
Anjou, to my lodging, and told me when it was drunk, he would 
send me another; that was how he treated me, most generously. 

After this, M. de Guise gave me a list of certain captains and 
seigneurs, and bade me tell them what the King had charged me to 
say; which I did, and this was to commend him to them, and give 
them his thanks for the duty they had done and were doing in hold- 
ing his town of Metz, and that he would remember it. I was more 
than eight days acquitting myself of this charge, because they were 
many. First, to all the princes; then to others, as the Duke Horace, 
the Count de Martigues, and his brother M. de Bauge, the Seigneurs 
de Montmorency and d'Anville, now Marshal of France, M. de la 
Chapelle aux Ursins, Bonnivet, Carouge, now Governor of Rouen, 
the Vidame de Chartres, the Count de Lude, M. de Biron, now 
Marshal of France, M. de Randan, la Rochefoucault, Bordaille, 
d'Estres the younger, M. de Saint Jean en Dauphine, and many 
others whom it would take too long to name; and also to many 
captains, who had all done their duty well for the defence of their 
lives and of the town. Afterward I asked M. de Guise what it pleased 
him I should do with the drugs I had brought with me; he bade 
me distribute them to the surgeons and apothecaries, and principally 
to the poor wounded soldiers, who were in great numbers in the 
Hospital. Which I did, and can truly say I could not so much as 
go and see all the wounded, who kept sending for me to visit and 
dress them. 

All the seigneurs within the town asked me to give special care, 
above all the rest, to M. de Pienne, who had been wounded, while 
on the breach, by a stone shot from a cannon, on the temple, with 
fracture and depression of the bone. They told me that so soon as 
he received the blow, he fell to the ground as dead, and cast forth 
blood by the mouth, nose, and ears, with great vomiting, and was 
fourteen days without being able to speak or reason; also he had 
tremors of a spasmodic nature, and all his face was swelled and 



26 AMBROISE PARE 

livid. He was trepanned at the side of the temporal muscle, over the 
frontal bone. I dressed him, with other surgeons, and God healed 
him; and to-day he is still living, thank God. 

The Emperor attacked the town with forty double cannons, and 
the powder was not spared day or night. So soon as M. de Guise saw 
the artillery set and pointed to make a breach, he had the nearest 
houses pulled down and made into ramparts, and the beams and 
joists were put end to end, and between them faggots, earth, beds, 
and wool-packs; then they put above them other beams and joists as 
before. And there was plenty of wood from the houses in the 
suburbs; which had been razed to the ground, for fear the enemy 
should get under cover of them, and make use of the wood; it did 
very well for repairing the breach. Everybody was hard at work 
carrying earth to repair it, day and night; MM. the princes, the 
seigneurs, and captains, lieutenants, ensigns, were all carrying the 
basket, to set an example to the soldiers and citizens to do the like, 
which they did; even the ladies and girls, and those who had not 
baskets, made use of cauldrons, panniers, sacks, sheets, and all such 
things to carry the earth; so that the enemy had no sooner broken 
down the wall than they found behind it a yet stronger rampart. 
The wall having fallen, our men cried out at those outside, "Fox, 
fox, fox," and they vented a thousand insults against one another. 
M. de Guise forbade any man on pain of death to speak with those 
outside, for fear there should be some traitor who would betray 
what was being done within the town. After this order, our men 
tied live cats to the ends of their pikes, and put them over the wall 
and cried with the cats, "Miaut, Miaut." 

Truly the Imperials were much enraged, having been so long 
making a breach, at great loss, which was eighty paces wide, that 
fifty men of their front rank should enter in, only to find a rampart 
stronger than the wall. They threw themselves upon the poor cats, 
and shot them with arquebuses as men shoot at the popinjay. 

Our men often ran out upon them, by order of M. de Guise; a 
few days ago, our men had all made haste to enroll themselves in 
sallying-parties, chiefly the young nobility, led by experienced cap- 
tains; and indeed it was doing them a great favour to let them 
issue from the town and run upon the enemy. They went forth 



JOURNEYS IN DIVERSE PLACES "T] 

always an hundred or six score men, well armed with cutlasses, 
arquebuses, pistols, pikes, partisans, and halbards; and advanced as 
far as the trenches, to take the enemy unawares. Then an alarum 
would be sounded all through the enemy's camp, and their drums 
would beat plan, plan, ta ti ta, ta ta ti ta, tou touf touj. Likewise 
their trumpets and clarions rang and sounded. To saddle, to saddle, 
to saddle, to horse, to horse, to horse, to saddle, to horse, to horse. 
And all their soldiers cried, "Arm, arm, arm! to arms, to arms, to 
arms! arm, to arms, arm, to arms, «rw";— like the hue-and-cry after 
wolves; and all diverse tongues, according to their nations; and you 
saw them come out of their tents and little lodgings, as thick as 
little ants when you uncover the ant-hills, to bring help to their 
comrades, who were having their throats cut like sheep. Their 
cavalry also came from all sides at full gallop, patati, patata, patati, 
patata, pa, ta, ta, patata, pata, ta, eager to be in the thick of the 
fighting, to give and take their share of the blows. And when our 
men saw themselves hard pressed, they would turn back into the 
town, fighting all the way; and those pursuing them were driven 
back with cannon-shots, and the cannons were loaded with flint- 
stones and with big pieces of iron, square or three-sided. And our 
men on the wall fired a volley, and rained bullets on them as thick 
as hail, to send them back to their beds; whereas many remained 
dead on the field: and our men also did not all come back with 
whole skins, and there were always some left behind (as it were a 
tax levied on us) who were joyful to die on the bed of honour. And 
if there was a horse wounded, it was skinned and eaten by the 
soldiers, instead of beef and bacon; and if a man was wounded, I 
must run and dress him. Some days afterward there were other 
sallies, which infuriated the enemy, that we would not let him 
sleep a little in safety. 

M. de Guise played a trick upon them: he sent a peasant, who 
was none of the wisest, with two letters to the King, and gave him 
ten crowns, and promised the King would give him an hundred 
if he got the letters to him. In the one letter M. de Guise told the 
King that the enemy shewed no signs of retreating, and had put 
forth all their strength and made a great breach, which he hoped 
to defend, even at the cost of his own life and of all who were in 



28 AMBROISE PARE 

the town; and that the enemy had planted their artillery so well 
in a certain place (which he named) that it was with great difficulty 
he could keep them from entering the town, seeing it was the 
weakest place in the town; but soon he hoped to rebuild it well, so 
that they should not be able to enter. This letter was sewed in the 
lining of the man's doublet, and he was told to be very careful not 
to speak of it to any person. And the other letter was given to him, 
wherein M. de Guise told the King that he and all those besieged 
with him hoped to guard the town well; and other matters which 
I leave untold here. He sent out the man at night, and he was 
taken by the enemy's guard and brought to the Duke of Alva, that 
the Duke might hear what was doing in the town; and the peasant 
was asked if he had any letters. He said "Yes," and gave them the 
one; and they having seen it asked him if he had not another. He 
said "No." Then he was searched, and they found on him that 
which was sewed in his doublet; and the poor messenger was hanged 
and strangled. 

The letters were taken to the Emperor, who called his council, 
where it was resolved, since they had been unable to do anything at 
the first breach, the artillery should forthwith be set against the 
place which they thought weakest, where they put forth all their 
strength to make a fresh breach; and they sapped and mined the 
wall, and tried hard to make a way into the Hell Tower, but dared 
not assault it openly. 

The Duke of Alva represented to the Emperor that every day 
their soldiers were dying, to the number of more than two hundred, 
and there was so little hope of entering the town, seeing the time 
of year and the great number of our soldiers who were in it. The 
Emperor asked what men they were who were dying, and whether 
they were gentlemen and men of mark; answer was made to him 
"They were all poor soldiers." Then said he, "It was no great loss 
if they died," comparing them to caterpillars, grasshoppers, and 
cockchafers, which eat up the buds and other good things of the 
earth; and if they were men of any worth they would not be in his 
camp at six livres the month, and therefore it was no great harm 
if they died. Moreover, he said he would never depart from the 
town till he had taken it by force or by famine, though he should 



JOURNEYS IN DIVERSE PLACES 29 

lose all his army; because of the great number of princes who were 
shut up in It, with the greater part of the nobility of France, who 
he hoped would pay his expenses four times over; and he would go 
yet again to Paris, to see the Parisians, and to make himself King 
of all the kingdom of France. 

M. de Guise, with the princes, captains, and soldiers, and in 
general all the citizens of the town, having heard the Emperor's 
resolve to exterminate us all, forbade the soldiers and citizens, and 
even the princes and seigneurs, to eat fresh fish or venison, or par- 
tridges, woodcocks, larks, francolines, plovers, or other game, for 
fear these had acquired any pestilential air which could bring infec- 
tion among us. So they had to content themselves with the fare of 
the army; biscuit, beef, salt cow-beef, bacon, cervelas, and Mayence 
hams; also fish, as haddock, salmon, shad, tunny, whale, anchovy, 
sardines, herrings; also peas, beans, rice, garlic, onions, prunes, 
cheeses, butter, oil, and salt; pepper, ginger, nutmegs and other spices 
to put in our pies, mostly of horses, which without the spice had a 
very bad taste. Many citizens, having gardens in the town, had 
planted them with fine radishes, turnips, carrots, and leeks, which 
they kept flourishing and very dear, for the extreme necessity of the 
famine. Now all these stores were distributed by weight, measure, 
and justice, according to the quality of the persons, because we knew 
not how long the siege would last. For after we heard the Emperor's 
words, how he would not depart from before Metz, till he had taken 
it by force or by famine, the victuals were cut down; and what they 
used to distribute to three soldiers was given to four; and it vras 
forbidden to them to sell the remains which might be left after 
their meals; but they might give them to the rabble. And they 
always rose from table with an appetite, for fear they should be 
subject to take physick. 

And before we surrendered to the mercy of the enemy, we had 
determined to eat the asses, mules, and horses, dogs, cats, and rats, 
even our boots and collars, and other skins that we could have 
softened and stewed. And, in a word, all the besieged were resolved 
to defend themselves valiantly with all instruments of war; to set 
the artillery at the entry of the breach, and load with balls, stones, 
cart-nails, bars and chains of iron; also all sorts and kinds of arti- 



3© AMBROISE PARE 

ficial fires, as barricadoes, grenades, stink-pots, torches, squibs, fire- 
traps, burning faggots; with boiUng water, melted lead, and lime, 
to put out the enemy's eyes. Also, they were to make holes right 
through their houses, and put arquebusiers in them, to take the 
enemy in flank and hasten his going, or else give him stop then and 
there. Also they were to order the women to pull up the streets, and 
throw from their windows billets, tables, trestles, benches, and 
stools, to dash out the enemy's brains. Moreover, a little within 
the breach, there was a great stronghold full of carts and palisades, 
tuns and casks; and barricades of earth to serve as gabions, interlaid 
with falconets, falcons, field-pieces, crooked arquebuses, pistols, arque- 
buses, and wild-fires, to break their legs and thighs, so that they 
would be taken from above and on the flank and from behind; and 
if they had carried this stronghold, there were others where the 
streets crossed, every hundred paces, which would have been as bad 
friends to them as the first, or worse, and would have made many 
widows and orphans. And if fortune had been so hard on us that 
they had stormed and broken up our strongholds, there would yet 
have been seven great companies, drawn up in square and in tri- 
angle, to fight them all at once, each led by one of the princes, for 
the better encouragement of our men to fight and die all together, 
even to the last breath of their souls. And all were resolved to bring 
their treasures, rings, and jewels, and their best and richest and most 
beautiful household stuffs, and burn them to ashes in the great 
square, lest the enemy should take them and make trophies of them. 
Also there were men charged to set fire to all the stores and burn 
them, and to stave in all the wine-casks; others to set fire to every 
single house, to burn the enemy and us together. The citizens thus 
were all of one mind, rather than see the bloody knife at their 
throats, and their wives and daughters ravished and taken by the 
cruel savage Spaniards. 

Now we had certain prisoners, who had been made secretly to 
understand our last determination and desperation; these prisoners 
M. de Guise sent away on parole, who being come to their camp, 
lost no time in saying what we had told them; which restrained the 
great and vehement desire of the enemy, so that they were no longer 
eager to enter the town to cut our throats and enrich themselves 



JOURNEYS IN DIVERSE PLACES 3 1 

with the spoils. The Emperor, having heard the decision of this 
great warrior, M. de Guise, put water in his wine, and restrained 
iiis fury; saying that he could not enter the town save with vast 
butchery and carnage, and shedding of much blood, both of those 
defending and of those attacking, and they would be all dead 
together, and in the end he would get nothing but ashes; and 
afterward men might say it was a like destruction to that of the 
town of Jerusalem, made of old time by Titus and Vespasian. 

The Emperor thus having heard our last resolve, and seeing how 
little he had gained by his attack, sappings, and mines, and the 
great plague that was through all his camp, and the adverse time 
of the year, and the want of victuals and of money, and how his 
soldiers were disbanding themselves and going off in great com- 
panies, decided at last to raise the siege and go away, with the 
cavalry of his vanguard, and the greater part of the artillery and 
engines of war. The Marquis of Brandebourg was the last to budge 
from his place; he had with him some troops of Spaniards and 
Bohemians, and his German regiments, and there he stopped for 
a day and a half, to the great regret of M. de Guise, who brought 
four pieces of artillery out of the town, which he fired on him this 
side and that, to hurry him off: and off he went, sure enough, and 
all his men with him. 

When he was a quarter of a league from Metz, he was seized with 
a panic lest our cavalry should fall upon his tail; so he set fire to his 
store of powder, and left behind him some pieces of artillery, and a 
quantity of baggage, which he could not take along with him, 
because their vanguard and their great cannons had broken and torn 
up the roads. Our cavalry were longing with all their hearts to issue 
from the town and attack him behind; but M. de Guise would never 
let them, saying on the contrary we had better make their way 
smooth for them, and build them gold and silver bridges to let them 
go; like the good pastor and shepherd, who will not lose one of 
his sheep. 

That is how our dear and well-beloved Imperials went away from 
Metz, which was the day after Christmas Day, to the great content 
of those within the walls, and the praise of the princes, seigneurs, 
captains, and soldiers, who had endured the travail of this siege for 



32 AMBROISE PARE 

more than two months. Nevertheless, they did not all go: there 
wanted more than twenty thousand of them, who were dead, from 
our artillery and the fighting, or from plague, cold, and starvation 
(and from spite and rage that they could not get into the town to 
cut our throats and plunder us) : and many of their horses also died, 
the greater part whereof they had eaten instead of beef and bacon. 
We went where their camp had been, where we found many dead 
bodies not yet buried, and the earth all worked up, as one sees in 
the Cemetery of the Holy Innocents during some time of many 
deaths. In their tents, pavilions, and lodgings were many sick people. 
Also cannon-shot, weapons, carts, waggons, and other baggage, with 
a great quantity of soldier's bread, spoiled and rotted by the snows 
and rains (yet the soldiers had it but by weight and measure). Also 
they left a good store of wood, all that remained of the houses they 
had demolished and broken down in the villages for two or three 
leagues around; also many other pleasure-houses, that had belonged 
to our citizens, with gardens and fine orchards full of diverse fruit- 
trees. And without all this, they would have been benumbed 
and dead of the cold, and forced to raise the siege sooner than they 
did. 

M. de Guise had their dead buried, and their sick people treated. 
Also the enemy left behind them in the Abbey of Saint Arnoul 
many of their wounded soldiers, whom they could not possibly take 
with them. M. de Guise sent them all victuals enough, and ordered 
me and the other surgeons to go dress and physick them, which we 
did with good will; and I think they would not have done the like 
for our men. For the Spaniard is very cruel, treacherous, and 
inhuman, and so far enemy of all nations : which is proved by Lopez 
the Spaniard, and Benzo of Milan, and others who have written the 
history of America and the West Indies: who have had to confess 
that the cruelty, avarice, blasphemies, and wickedness of the Span- 
iards have utterly estranged the poor Indians from the religion that 
these Spaniards professed. And all write that they are of less worth 
than the idolatrous Indians, for their cruel treatment of these Indians. 

And some days later M. de Guise sent a trumpet to Thionville 
to the enemy, that they could send for their wounded in safety: 



JOURNEYS IN DIVERSE PLACES 33 

which they did with carts and waggons, but not enough. M. de 
Guise gave them carts and carters, to help to take them to Thionville. 
Our carters, when they returned, told us the roads were all paved 
with dead bodies, and they never got half the men there, for they 
died in their carts: and the Spaniards seeing them at the point of 
death, before they had breathed their last, threw them out of the 
carts and buried them in the mud and mire, saying they had no 
orders to bring back dead men. Moreover, our carters said they had 
found on the roads many carts stuck in the mud, full of baggage, 
for which the enemy dared not send back, lest we who were within 
Metz should run out upon them. 

I would return to the reason why so many of them died; which 
was mostly starvation, the plague, and cold. For the snow was more 
than two feet deep upon the ground, and they were lodged in pits 
below the ground, covered only with a little thatch. Nevertheless, 
each soldier had his camp-bed, and a coverlet all strewed with stars, 
glittering and shining brighter than fine gold, and every day they 
had white sheets, and lodged at the sign of the Moon, and enjoyed 
themselves if only they had been able, and paid their host so well 
over night that in the morning they went off quits, shaking their 
ears: and they had no need of a comb to get the down and feathers 
out of their beards and hair, and they always found a white table- 
cloth, and would have enjoyed good meals but for want of food. Also 
the greater part of them had neither boots, half-boots, slippers, hose, 
nor shoes: and most of them would rather have none than any, 
because they were always in the mire up to mid-leg. And because 
they went bare-foot, we called them the Emperor's Apostles. 

After the camp was wholly dispersed, I distributed my patients 
into the hands of the surgeons of the town, to finish dressing them : 
then I took leave of M. de Guise, and returned to the King, who 
received me with great favour, and asked me how I had been able 
to make my way into Metz. I told him fully all that I had done. 
He gave me two hundred crowns, and an hundred which I had 
when I set out: and said he would never leave me poor. Then I 
thanked him very humbly for the good and the honour he was 
pleased to do me. 



34 AMBROISE PARE 

The Journey to Hesdin. 1553 

The Emperor Charles laid siege to the town of Theroiienne; and 
M. le Due de Savoie was General of his whole army. It was taken 
by assault: and there was a great number of our men killed and 
taken prisoners. 

The King, wishing to prevent the enemy from besieging the 
town and castle of Hesdin also, sent thither MM. le Due de Bouillon, 
le Due Horaee, le Marquis de Villars, and a number of eaptains, and 
about eighteen hundred soldiers: and during the siege of The- 
roiienne, these Seigneurs fortified the castle of Hesdin, so that it 
seemed to be impregnable. The King sent me to the Seigneurs, 
to help them with my art, if they should come to have need of it. 

Soon after the capture of Theroiienne, we were besieged in Hesdin. 
There was a clear stream of running water within shot of our cannon, 
and about it were fourscore or an hundred of the enemy's rabble, 
drawing water. I was on a rampart watching the enemy pitch their 
camp; and, seeing the crowd of idlers round the stream, I asked M. 
du Pont, commissary of the artillery, to send one cannon-shot among 
this canaille: he gave me a flat refusal, saying that all this sort of 
people was not worth the powder would be wasted on them. Again 
I begged him to level the cannon, telling him, "The more dead, the 
fewer enemies;" which he did for my sake: and the shot killed 
fifteen or sixteen, and wounded many. Our men made sorties 
against the enemy, wherein many were killed and wounded on both 
sides, with gunshot or with fighting hand to hand; and our men 
often sallied out before their trenches were made; so that I had my 
work cut out for me, and had no rest either day or night for 
dressing the wounded. 

And here I would note that we had put many of them in a 
great tower, laying them on a little straw: and their pillows were 
stones, their coverlets were cloaks, those who had any. When the 
attack was made, so often as the enemy's cannons were fired, our 
wounded said they felt pain in their wounds, as if you had struck 
them with a stick : one was crying out on his head, the other on his 
arm, and so with the other parts of the body: and many had their 
wounds bleed again, even more profusely than at the time they were 



JOURNEYS IN DIVERSE PLACES 35 

wounded, and then I had to run to staunch them. Mon petit 
maistre, if you had been there, you would have been much hindered 
with your hot irons; you would have wanted a lot of charcoal to 
heat them red, and sure you would have been killed like a calf for 
your cruelty. Many died of the diabolical storm of the echo of these 
engines of artillery, and the vehement agitation and severe shock 
of the air acting on their wounds; others because they got no rest for 
the shouting and crying that were made day and night, and for want 
of good food, and other things needful for their treatment. Mon 
petit maistre, if you had been there, no doubt you could have given 
them jelly, restoratives, gravies, pressed meats, broth, barley-water, 
almond-milk, blanc-mange, prunes, plums, and other food proper for 
the sick; but your diet would have been only on paper, and in fact 
they had nothing but beef of old shrunk cows, seized round Hesdin 
for our provision, salted and half-cooked, so that he who would 
eat it must drag at it with his teeth, as birds of prey tear their food. 
Nor must I forget the linen for dressing their wounds, which was 
only washed daily and dried at the fire, till it was as hard as parch- 
ment: I leave you to think how their wounds could do well. There 
were four big fat rascally women who had charge to whiten the 
linen, and were kept at it with the stick; and yet they had not 
water enough to do it, much less soap. That is how the poor patients 
died, for want of food and other necessary things. 

One day the enemy feigned a general attack, to draw our soldiers 
into the breach, that they might see what we were like: every man 
ran thither. We had made a great store of artificial fires to defend 
the breach; a priest of M. le Due de Bouillon took a grenade, think- 
ing to throw it at the enemy, and lighted it before he ought: it 
burst, and set fire to all our store, which was in a house near the 
breach. This was a terrible disaster for us, because it burned many 
poor soldiers; it even caught the house, and we had all been burned, 
but for help given to put it out; there was only one well in the castle 
with any water in it, and this was almost dry, and we took beer to 
put it out instead of water; afterward we were in great want of 
water, and to drink what was left we must strain it through napkins. 

The enemy, seeing the explosion and violence of the fires, which 
made a wonderful flame and thundering, thought we had lit them 



36 AMBROISE PARE 

on purpose to defend the breach, and that we had many more of 
them. This made them change their minds, to have us some other 
way than by attack : they dug mines, and sapped the greater part of 
our walls, till they came near turning our castle altogether upside 
down; and when the sappers had finished their work, and their 
artillery was fired, all the castle shook under our feet like an earth- 
quake, to our great astonishment. Moreover, they had levelled five 
pieces of artillery, which they had placed on a little hillock, so as 
to have us from behind when we were gone to defend the breach. 
M. le Due Horace had a cannon-shot on the elbow, which carried 
off his arm one way and his body the other, before he could say a 
single word; his death was a great disaster to us, for the high rank 
that he held in the town. Also M. de Martigues had a gun-shot 
wound which pierced his lungs: I dressed him, as I shall tell here- 
after. 

Then we asked leave to speak with the enemy; and a trumpet was 
sent to the Prince of Piedmont to know what terms he would give 
us. He answered that all the leaders, such as gentlemen, captains, 
lieutenants, and ensigns, would be taken prisoners for ransom, and 
the soldiers would leave the town without their arms; and if we 
refused this fair and honest offer, we might rest assured they would 
take us next day, by attack or otherwise. 

A council was held, to which I was called, to know if I would 
sign the surrender of the town; with many captains, gentlemen, and 
others. I answered it was not possible to hold the town, and I 
would sign the surrender with my own blood, for the little hope 
I had we could resist the enemy's forces, and for the great longing 
I had to be out of this hell and utter torture; for I slept neither 
night nor day for the great number of the wounded, who were 
about two hundred. The dead were advanced in putrefaction, piled 
one upon the other like faggots, and not covered with earth, because 
we had none. And if I went into a soldier's lodging, there were 
soldiers waiting for me at the door when I came out, for me to dress 
others; it was who should have me, and they carried me like the 
body of a saint, with my feet off the ground, fighting for me. I 
could not satisfy this great number of wounded: nor had I got what 
I wanted for their treatment. For it is not enough that the surgeon 



JOURNEYS IN DIVERSE PLACES 37 

do his duty toward his patients, but the patient also must do his; 
and the assistants, and external things, must work together for him : 
see Hippocrates, Aphorism the First. 

Having heard that we were to surrender the place, I knew our 
business was not prospering; and for fear of being known, I gave 
a velvet coat, a satin doublet, and a cloak of fine cloth trimmed with 
velvet, to a soldier; who gave me a bad doublet all torn and ragged 
with wear, and a frayed leather collar, and a bad hat, and a short 
cloak; I dirtied the neck of my shirt with water mixed with a little 
soot, I rubbed my hose with a stone at the knees and over the heels, 
as though they had been long worn. I did the same to my shoes, 
till one would have taken me for a chimney-sweep rather than a 
King's surgeon. I went in this gear to M. de Martigues, and prayed 
him to arrange I should stop with him to dress him; which he 
granted very willingly, and was as glad I should be near him as 
I was myself. 

Soon afterward, the commissioners who were to select the prison- 
ers entered the castle, the seventeenth day of July, 1553. They took 
prisoners MM. le Due de Bouillon, le Marquis de Villars, de Roze, 
le Baron de Culan, M. du Pont, commissary of the artillery, and 
M. de Martigues; and me with him, because he asked them; and 
all the gentlemen who they knew could pay ransom, and most of 
the soldiers and the leaders of companies; so many and such prisoners 
as they wished. And then the Spanish soldiers entered by the breach, 
unresisted; our men thought they would keep their faith and agree- 
ment that all lives should be spared. They entered the town in a 
fury to kill, plunder, and ravage everything: they took a few men, 
hoping to have ransom for them. ... If they saw they could not 
get it, they cruelly put them to death in cold blood. . . . And they 
killed them all with daggers, and cut their throats. Such was their 
great cruelty and treachery; let him trust them who will. 

To return to my story : when I was taken from the castle into the 
town, with M. de Martigues, there was one of M. de Savoie's gentle- 
men, who asked me if M. de Martigues's wound could be cured. 
I told him no, that it was incurable: and off he went to tell M. le 
Due de Savoie. I bethought myself they would send physicians and 
surgeons to dress M. de Martigues; and I argued within myself if I 



38 AMBROISE PARE 

ought to play the simpleton, and not let myself be known for a 
surgeon, lest they should keep me to dress their wounded, and in 
the end I should be found to be the King's surgeon, and they would 
make me pay a big ransom. On the other hand, I feared, if I did 
not show I was a surgeon and had dressed M. de Martigues skilfully, 
they would cut my throat. Forthwith I made up my mind to show 
them he would not die for want of having been well dressed and 
nursed. 

Soon after, sure enough, there came many gentlemen, with the 
Emperor's physician, and his surgeon, and those belonging to M. de 
Savoie, and six other surgeons of his army, to see M. de Martigues's 
wound, and to know of me how I had dressed and treated it. The 
Emperor's physician bade me declare the essential nature of the 
wound, and what I had done for it. And all his assistants kept their 
ears wide open, to know if the wound were or were not mortal. I 
commenced my discourse to them, how M. de Martigues, looking 
over the wall to mark those who were sapping it, was shot with an 
arquebus through the body, and I was called of a sudden to dress 
him. I found blood coming from his mouth and from his wounds. 
Moreover, he had a great difficulty of breathing in and out, and air 
came whistling from the wounds, so that it would have put out a 
candle; and he said he had a very great stabbing pain where the 
bullet had entered. ... I withdrew some scales of bone, and put in 
each wound a tent with a large head, fastened with a thread, lest 
on inspiration it should be drawn into the cavity of the chest; which 
has happened with surgeons, to the detriment of the poor wounded; 
for being fallen in, you cannot get them out; and then they beget 
corruption, being foreign bodies. The tents were anointed with a 
preparation of yolk of egg, Venice turpentine, and a little oil of 
roses. ... I put over the wounds a great plaster of diachylum, 
wherewith I had mixed oil of roses, and vinegar, to avoid inflam- 
mation. Then I applied great compresses steeped in oxycrate, and 
bandaged him, not too tight, that he might breathe easily. Next, I 
drew five basons of blood from his right arm, considering his youth 
and his sanguine temperament. . . , Fever took him, soon after he 
was wounded, with feebleness of the heart. . . . His diet was barley- 
water, prunes with sugar, at other times broth: his drink was a 



JOURNEYS IN DIVERSE PLACES 39 

ptisane. He could lie only on his back. . . . What more shall I say ? 
but that my Lord de Martigues never had an hour's rest after he 
was wounded. . . . These things considered, Gentlemen, no other 
prognosis is possible, save that he will die in a few days, to my 
great grief. 

Having finished my discourse, I dressed him as I was accustomed. 
When I displayed his wounds, the physicians and surgeons, and 
other assistants present, knew the truth of what I had said. The 
physicians, having felt his pulse and seen that the vital forces were 
depressed and spent, agreed with me that in a few days he would 
die. Then they all went to the Due de Savoie, and told him M. de 
Martigues would die in a short time. He answered them, "Possibly, 
if he had been well dressed, he might have escaped death." Then 
they all with one voice said he had been very well dressed and 
cared for altogether, and it could not be better, and it was impossi- 
ble to cure him, and his wound was of necessity mortal. Then 
M. de Savoie was very angry with them, and cried, and asked them 
again if for certain they all held his case hopeless: they answered, 
yes. 

Then a Spanish impostor came forward, who promised on his 
life to cure him; and if he did not, they should cut him in an 
hundred pieces; but he would have no physicians, nor surgeons, nor 
apothecaries with him : and M. le Due de Savoie forthwith bade the 
physicians and surgeons not go near M. de Martigues; and sent a 
gentleman to bid me, under pain of death, not so much as to touch 
him. Which I promised, and was very glad, for now he would not 
die under my hands; and the impostor was told to dress him, and 
to have with him no other physicians or surgeons, but only himself. 
By and bye he came, and said to M. de Martigues, "Senor Cavallero, 
M. de Savoie has bid me come and dress your wound. I swear to 
God, before eight days I will set you on horseback, lance in hand, 
provided none touch you but I alone. You shall eat and drink what- 
ever you Uke. I will be dieted instead of you; and you may trust 
me to perform what I promise. I have cured many who had worse 
wounds than yours." And the Seigneurs answered him, "God give 
you His grace for it." 

He asked for a shirt of M. de Martigues, and tore it in little 



40 AMBROISE PARE 

strips, which he laid cross-wise, muttering and murmuring certain 
words over the wounds: having done this much for him, he let him 
eat and drink all he would, saying he himself would be dieted in 
his stead; which he did, eating but six prunes and six morsels of 
bread for dinner, and drinking only beer. Nevertheless, two days 
later, M. de Martigues died: and my friend the Spaniard, seeing him 
at the point of death, eclipsed himself, and got away without good- 
bye to any man. And I believe if he had been caught he would have 
been hanged and strangled, for the false promise he made to M. le 
Due de Savoie and many other gentlemen. M. de Martigues died 
about ten o'clock in the morning; and after dinner M. de Savoie 
sent the physicians and surgeons, and his apothecary, with a store 
of drugs to embalm him. They came with many gentlemen and 
captains of his army. 

The Emperor's surgeon came to me, and asked me in a very 
friendly way to make the embalmment; which I refused, saying that 
I was not worthy to carry his instrument-box after him. He begged 
me again to do it to please him, and that he would be very glad 
of it. . . . Seeing his kindness, and fearing to displease him, I then 
decided to show them the anatomist that I was, expounding to them 
many things, which would here be too long to recite. . . . Our dis- 
course finished, I embalmed the body; and it was placed in a coffin. 
Then the Emperor's surgeon drew me aside, and told me, if I 
would stop with him, he would treat me well, and give me a new 
suit of clothes, and set me on horseback. I gave him many thanks, 
and said I had no wish to serve any country but my own. Then he 
told me I was a fool, and if he were a prisoner as I was, he would 
serve a devil to get his freedom. In the end I told him flat I would 
not stop with him. The Emperor's physician then went back to 
M. de Savoie, and explained to him the causes of M. de Martigues' 
death, and that it was impossible for all the men in the world to 
have cured him; and assured him again I had done all that was to 
be done, and besought him to take me into his service; saying much 
more good of me than there was. He having been persuaded to 
do this, sent to me one of his stewards, M. du Bouchet, to tell me, 
if I would serve him, he would use me well; I sent back my very 
humble thanks, and that I had decided not to take service under any 



JOURNEYS IN DIVERSE PLACES 4I 

foreigner. When he heard my answer he was very angry, and said 
I ought to be sent to the galleys. 

M. de Vaudeville, Governor of Graveline, and colonel of seventeen 
ensigns of infantry, asked him to send me to him, to dress an old 
ulcer on his leg, that he had had for six or seven years. M. de Savoie 
said he was willing, so far as I was concerned; and if I used the 
cautery to his leg, it would serve him right. M. de Vaudeville 
answered, if he saw me trying it, he would have my throat cut. 
Soon after, he sent for me four German halberdiers of his guard; 
and I was terrified, for I did not know where they were taking me : 
they spoke no more French than I German. When I was come to 
his lodging, he bade me welcome, and said, now I belonged to him; 
and so soon as I had healed him, he would let me go without ransom. 
I told him I had no means to pay any ransom. He called his 
physician and his surgeon-in-ordinary, to show me his leg; and 
when we had examined it, we withdrew into a room, where I began 
my discourse to them. . . . Then the physician left me with the 
surgeon, and went back to M. de Vaudeville, and said he was sure 
I could cure him, and told him all I had decided to do; which pleased 
him vastly. He sent for me, and asked if I thought I could cure 
him; I said yes, if he were obedient to what was necessary. He 
promised to do only what I wished and ordered; and so soon as he 
was healed, he would let me go home without ransom. Then I 
asked him to make better terms with me, saying it was too long to 
wait for my liberty: in fifteen days I hoped his ulcer would be less 
than half its present size, and give no pain; then his own surgeon 
and physician could finish the cure. He granted this to me. Then 
I took a piece of paper to measure the size of the ulcer, and gave it 
to him, and kept another by me; I asked him to keep his promisej 
when I had done my work; he swore by the faith of a gentleman 
he would. Then I set myself to dress him properly, after the manner 
of Galen. . . . He wished to know if it were true, what I said of 
Galen, and bade his physician look to it, for he would know it for 
himself; he had the book put on the table, and found that what I 
said was true; so the physician was ashamed, and I was glad. Within 
the fifteen days, it was almost all healed; and I began to feel happy 
about the compact made between us. He had me to eat and drink at 



42 AMBROISE PARE 

his table, when there were no more great persons than he and I only. 
He gave me a big red scarf which I must wear; which made me 
feel something like a dog when they give him a clog, to stop him 
eating the grapes in the vineyards. His physician and surgeon took 
me through the camp to visit their wounded; and I took care to 
observe what our enemy was doing. I found they had no more great 
cannons, but only twenty-five or thirty field-pieces. 

M. de Vaudeville held prisoner M. de Bauge, brother of M. de 
Martigues who died at Hesdin. M. de Bauge was prisoner at Cha- 
teau de la Motte au Bois, belonging to the Emperor; he had been 
captured at Theroiienne by two Spanish soldiers; and M. de Vaude- 
ville, when he saw him there, concluded he must be some gentleman 
of good family: he made him pull off his stockings, and seeing his 
clean legs and feet, and his line white stockings, knew he was one 
to pay a good ransom. He told the soldiers he would give them 
thirty crowns down for their prisoner: they agreed gladly, for they 
had no place to keep him, nor food for him, nor did they know his 
value: so they gave their man into his hands, and he sent him off at 
once, guarded by four of his own soldiers, to Chateau de la Motte 
au Bois, with others of our gentlemen who were prisoners. 

M. de Bauge would not tell who he was; and endured much hard- 
ship, living on bread and water, with a little straw for his bed. When 
Hesdin was taken, M. de Vaudeville sent the news of it to him and 
to the other prisoners, and the list of the killed, and among them 
M. de Martigues: and when M. de Bauge heard with his own ears 
his brother was dead, he fell to crying, weeping, and lamentation. 
His guards asked him why he was so miserable: he told them, for 
love of M. de Martigues, his brother. When he heard this, the 
captain of the castle sent straight to tell M. de Vaudeville he had a 
good prisoner: who was delighted at this, and sent me next day with 
four soldiers, and his own physician, to the castle, to say that if M. 
de Bauge would pay him fifteen thousand crowns ransom, he would 
send him home free: and he asked only the security of two Antwerp 
merchants that he should name. M. de Vaudeville persuaded me I 
should commend this offer to his prisoner: that is why he sent me 
to the castle. He told the captain to treat him well and put him in a 
room with hangings, and strengthen his guard : and from that time 



JOURNEYS IN DIVERSE PLACES 43 

onward they made a great deal o£ him, at the expense of M. de 
Vaudeville. 

M. de Bauge answered that he could not pay his ransom himself: 
it depended on M. d'Estampes his uncle, and Mile, de Bressure his 
aunt: he had no means to pay such a ransom. I went back with my 
guards, and gave this answer to M. de Vaudeville; who said, 
"Possibly he will not get away so cheap": which was true, for they 
knew who he was. Then the Queen of Hungary and M. le Due de 
Savoie sent word to M. de Vaudeville that this mouthful was too 
big for him, and he must send his prisoner to them (which he did), 
and he had other prisoners enough without him. The ransom paid 
was forty thousand crowns, without other expenses. 

On my way back to M. de Vaudeville, I passed by Saint Omer, 
where I saw their great cannons, most of which were fouled and 
broken. Also I passed by Theroiienne, where I saw not one stone 
left on another, save a vestige of the great church: for the Emperor 
ordered the country people for five or six leagues round to clear 
and take away the stones; so that now you may drive a cart over 
the town : and the same at Hesdin, and no trace of castle and fortress. 
Such is the evil that wars bring with them. 

To return to my story; M. de Vaudeville soon got the better of 
his ulcer, and was nearly healed: so he let me go, and sent me by a 
trumpet, with passport, as far as Abbeville. I posted from here, and 
went to find my master. King Henry, at Aufimon, who received me 
gladly and with good favour. He sent MM. de Guise, the Constable, 
and d'Estres, to hear from me the capture of Hesdin; and I made 
them a true report, and assured them I had seen the great cannons 
they had taken to Saint Omer: and the King was glad, for he had 
feared the enemy would come further into France. He gave me 
two hundred crowns to take me home: and I was thankful to be 
free, out of this great torment and thunder of the diabolical artillery, 
and away from the soldiers, blasphemers and deniers of God. I 
must add that after Hesdin was taken, the King was told I was not 
killed but taken prisoner. He made M. Goguier, his chief physician, 
write to my wife that I was living, and she was not to be unhappy, 
and he would pay my ransom. 



44 AMBROISE PARE 

Battle of Saint Quentin. 1557 

After the battle of Saint Quentin, the King sent me to La Fere 
en Tartenois, to M. le Marechal de Bourdillon, for a passport to 
M. le Due de Savoie, that I might go and dress the Constable, who 
had been badly wounded in the back with a pistol-shot, whereof he 
was like to die, and remained prisoner in the enemy's hands. But 
never would M. le Due de Savoie let me go to him, saying he would 
not die for want of a surgeon; that he much doubted I would go 
there only to dress him, and not rather to take some secret informa- 
tion to him; and that he knew I was privy to other things besides 
surgery, and remembered I had been his prisoner at Hesdin. M. le 
Marechal told the King of this refusal: who wrote to M. le Mare- 
chal, that if Mme. the Constable's Lady would send some quick- 
witted man of her household I would give him a letter, and had also 
something to say to him by word of mouth, entrusted to me by the 
King and by M. le Cardinal de Lorraine. Two days later there came 
one of the Constable's gentlemen of the bedchamber, with his shirts 
and other linen, to whom M. le Marechal gave a passport to go to 
the Constable. I was very glad, and gave him my letter, and instruc- 
ted him what his master must do now he was prisoner. 

I thought, having finished my mission, to return to the King; but 
M. le Marechal begged me to stop at La Fere with him, to dress a 
very great number of wounded who had retreated there after the 
battle, and he would write to the King to explain why I stopped; 
which I did. Their wounds were very putrid, and full of worms, 
with gangrene, and corruption; and I had to make free play with 
the knife to cut off what was corrupt, which was not done without 
amputation of arms and legs, and also sundry trepannings. They 
found no store of drugs at La Fere, because the surgeons of the 
camp had taken them all away; but I found the waggons of the 
artillery there, and these had not been touched. I asked M. le Mare- 
chal to let me have some of the drugs which were in them, which 
he did; and I was given the half only at one time, and five or six 
days later I had to take the rest; and yet it was not half enough to 
dress the great number of wounded. And to correct and stop the 



JOURNEYS IN DIVERSE PLACES 45 

corruption, and kill the worms in their wounds, I washed them with 
iEgyptiacum dissolved in wine and eau-de-vie, and did all I could 
for them; but in spite of all my care many of them died. 

There were at La Fere some gentlemen charged to find the dead 
body of M. de Bois-Dauphin the elder, who had been killed in the 
battle; they asked me to go with them to the camp, to pick him out, 
if we could, among the dead; but it was not possible to recognize 
him, the bodies being all far gone in corruption, and their faces 
changed. We saw more than half a league round us the earth all 
covered with the dead; and hardly stopped there, because of the 
stench of the dead men and their horses; and so many blue and 
green flies rose from them, bred of the moisture of the bodies and the 
heat of the sun, that when they were up in the air they hid the sun. 
It was wonderful to hear them buzzing; and where they settled, 
there they infected the air, and brought the plague with them. Mon 
petit maistre, I wish you had been there with me, to experience the 
smells, and make report thereof to them that were not there. 

I was very weary of the place; I prayed M. le Marechal to let me 
leave it, and feared I should be ill there; for the wounded men stank 
past all bearing, and they died nearly all, in spite of everything we 
did. He got surgeons to finish the treatment of them, and sent me 
away with his good favour. He wrote to the King of the diligence 
I had shown toward the poor wounded. Then I returned to Paris, 
where I found many more gentlemen, who had been wounded and 
gone thither after the battle. 

The Journey to the Camp at Amiens. 1558 

The King sent me to Dourlan, under conduct of Captain Gouast; 
with fifty men-at-arms, for fear I should be taken by the enemy; and 
seeing we were always in alarms on the way, I made my man get 
down, and made him the master; for I got on his horse, which 
carried my valise, and could go well if we had to make our escape, 
and I took his cloak and hat and gave him my mount, which was a 
good little mare; he being in front, you would have taken him for 
the master and me for the servant. The garrison inside Dourlan, 
when they saw us, thought we were the enemy, and fired their 



46 AMBROISE PARE 

cannon at us. Captain Gouast, my conductor, made signs to them 
with his hat that we were not the enemy; at last they ceased firing, 
and we entered Dourlan, to our great relief. 

Five or six days before this, a sortie had been made from Dourlan; 
wherein many captains and brave soldiers had been killed or 
wounded: and among the wounded was Captain Saint Aubin, 
vcdllant comme I'espee, a great friend of M. de Guise: for whose 
sake chiefly the King had sent me there. Who, being attacked with 
a quartan fever, yet left his bed to command the greater part of his 
company. A Spaniard, seeing him in command, perceived he was 
a captain, and shot him through the neck with an arquebus. Captain 
Saint Aubin thought himself killed: and by this fright I protest to 
God he lost his quartan fever, and was forever free of it. 1 dressed 
him, with Antoine Portail, surgeon-in-ordinary of the King; and 
many other soldiers. Some died, others got off with the loss of an 
arm or a leg or an eye, and said they had got off cheap, to be alive at 
all. Then, the enemy having broken up their camp, I returned to 
Paris. 

I say nothing here of mon petit maistre, who was more comfort- 
able in his house than I at the wars. 

The Journey to Bourges. 1562 

The King with his camp was but a short time at Bourges, till those 
within the walls should surrender; and they came out with their 
goods saved. I know nothing worth remembering, but that a boy 
of the King's kitchen, having come near the walls of the town before 
the agreement had been signed, cried with a loud voice, "Huguenot, 
Huguenot, shoot here, shoot here," having his arm thrown up and 
his hand spread out; a soldier shot his hand right through with a 
bullet. When he was thus shot, he came to find me to dress him. 
And the Constable seeing the boy in tears, with his hand all bloody, 
asked who had wounded him : then a gentleman who had seen him 
shot said it served him right, because he kept calling "Huguenot, 
hit here, aim here." And then the Constable said this Huguenot 
was a good shot and a good fellow, for most likely if he had chosen 
to fire at the boy's head, he would have hit it even more easily than 
his hand. I dressed the kitchen boy, who was very ill. He recovered, 



JOURNEYS IN DIVERSE PLACES 47 

but with no power in his hand: and from that time his comrades 
called him "Huguenot": he is still living now. 

The Journey to Rouen. 1562 

Now, as for the capture of Rouen, they killed many of our men 
both before and at the attack: and the very next day after we had 
entered the town, I trepanned eight or nine of our men, who had 
been wounded with stones as they were on the breach. The air was 
so malignant, that many died, even of quite small wounds, so that 
some thought the bullets had been poisoned: and those within the 
town said the like of us; for though they had within the town all 
that was needful, yet all the same they died like those outside. 

The King of Navarre was wounded, some days before the attack, 
with a bullet in the shoulder. 1 visited him, and helped to dress 
him, with one of his own surgeons. Master Gilbert, one of the chief 
men of Montpellier, and others. They could not find the bullet. I 
searched for it very accurately, and found reason to believe it had 
entered at the top of the arm, by the head of the bone, and had 
passed into the hollow part of the bone, which was why they could 
not find it; and most of them said it had entered his body and was 
lost in it. M. le Prince de la Roche-sur-Yon, who dearly loved the 
King of Navarre, drew me aside and asked if the wound were 
mortal. I told him yes, because all wounds of great joints, and 
especially contused wounds, were mortal, according to all those who 
have written about them. He asked the others what they thought 
of it, and chiefly Master Gilbert, who told him he had great hope 
his Lord the King would recover; which made the Prince very glad. 

Four days later, the King, and the Queen-mother, and M. le 
Cardinal de Bourbon, his brother, and M. le Prince de la Roche- 
sur-Yon, and M. de Guise, and other great persons, after we had 
dressed the King of Navarre, wished us to hold a consultation in 
their presence, all the physicians and surgeons together. Each of 
them said what he thought, and there was not one but had good 
hope, they said, that he would recover. I persisted always in the 
contrary. M. le Prince, who loved me, drew me aside, and said I 
was alone against the opinion of all the others, and prayed me not to 
be obstinate against so many good men. I answered. When I shall 



48 AMBROISE PARE 

see good signs of recovery, I will change my mind. Many consulta- 
tions were held, and I never changed what I said, and the prognosis 
I had made at the first dressing, and said always the arm would fall 
into a gangrene, which it did, for all the care they could give to it; 
and he rendered his spirit to God the eighteenth day after his wound. 
M. le Prince, having heard of it, sent to me his surgeon, and his 
physician, one Lefevre, now physician-in-ordinary to the King and 
Queen-mother, to say he wished to have the bullet, and we were to 
look for it, to see where it was. Then I was very glad, and assured 
them I should quickly find it; which I did in their presence, with 
many other gentlemen: it was just in the very middle of the bone. 
M. le Prince took and showed it to the King and to the Queen, 
who all said that my prognosis had come true. The body was laid 
to rest at Chateau Gaillard: and I returned to Paris, where I found 
many patients, who had been wounded on the breach at Rouen, and 
chiefly Italians, who were very eager I should dress them: which I 
did willingly. Many of them recovered: the rest died. Mon petit 
maistre, I think you were called to dress some, for the great number 
there was of them. 

The Battle of Dreux. 1562 

The day after the battle of Dreux, the King bade me go and 
dress M. le Comte d'Eu, who had been wounded in the right thigh, 
near the hip-joint, with a pistol-shot: which had smashed and broken 
the thigh-bone into many pieces: whereon many accidents super- 
vened, and at last death, to my great grief. The day after I came, 
I would go to the camp where the battle had been, to see the dead 
bodies. I saw, for a long league round, the earth all covered: they 
estimated it at twenty-five thousand men or more; and it was all 
done in less than two hours. I wish, mon petit maistre, for the love 
I bear you, you had been there, to tell it to your scholars and your 
children. 

Now while I was at Dreux, I visited and dressed a great number 
of gentlemen, and poor soldiers, and among the rest many of the 
Swiss captains. I dressed fourteen all in one room, all wounded with 
pistol-shots and other diabolical firearms, and not one of the four- 
teen died. M. le Comte d'Eu being dead, I made no long stay at 



JOURNEYS IN DIVERSE PLACES 49 

Dreux. Surgeons came from Paris, who fulfilled their duty to the 
wounded, as Pigray, Cointeret, Hubert, and others; and I returned 
to Paris, where I found many wounded gentlemen who had retreated 
thither after the battle, to have their wounds dressed; and I was not 
there without seeing many of them. 

The Journey to Havre de Grace. 1563 

And I will not omit to tell of the camp at Havre de Grace. When 
our artillery came before the walls of the town, the English within 
the walls killed some of our men, and several pioneers who were 
making gabions. And seeing they were so wounded that there was 
no hope of curing them, their comrades stripped them, and put them 
still living inside the gabions, which served to fill them up. When 
the English saw that they could not withstand our attack, because 
they were hard hit by sickness, and especially by the plague, they 
surrendered. The King gave them ships to return to England, very 
glad to be out of this plague-stricken place. The greater part of them 
died, and they took the plague to England, and they have not got 
rid of it since. Captain Sarlabous, master of the camp, was left in 
garrison, with six ensigns of infantry, who had no fear of the 
plague; and they were very glad to get into the town, hoping to 
enjoy themselves there. Mon petit maistre, if you had been there, 
you would have done as they did. 

The Journey to Bayonne. 1564 

I WENT with the King on that journey to Bayonne, when we were 
two years and more making the tour of well-nigh all this kingdom. 
And in many towns and villages I was called in consultation over 
sundry diseases, with the late M. Chapelain, chief physician to the 
King, and M. Castellan, chief physician to the Queen-mother; 
honorable men and very learned in medicine and surgery. During 
this journey, I always inquired of the surgeons if they had noted 
anything rare in their practices, so that I might learn something 
new. While I was at Bayonne, two things happened worthy of 
remark by young surgeons. The first is, I dressed a Spanish gentle- 
man, who had a great and enormous swelling of the throat. He 
had lately been touched by the deceased King Charles for the king's 



50 AMBROISE PARE 

evil. I opened his swelling. ... I left him in the hands of a surgeon 
of the town, to finish his cure. M. de Fontaine, Knight of the Order 
of the King, had a severe continued pestilent fever, accompanied 
with many inflammatory swellings in sundry parts of the body. He 
had bleeding at the nose for two days, without ceasing, nor could 
we staunch it: and after this haemorrhage the fever ceased, with 
much sweating, and by and bye the sweUings suppurated, and he 
was dressed by me, and healed by the grace of God. 

Battle of Saint Denis. 1567 

As for the battle of Saint Denis, there were many killed on both 
sides. Our wounded withdrew to Paris to be dressed, with the 
prisoners they had taken, and I dressed many of them. The King 
ordered me, at the request of Mme. the Constable's Lady, to go to 
her house to dress the Constable: who had a pistol-shot in the 
middle of the spine of his back, whereby at once he lost all feeling 
and movement in his thighs and legs . . . because the spinal cord, 
whence arise the nerves to give feeling and movement to the parts 
below, was crushed, broken, and torn by the force of the bullet. Also 
he lost understanding and reason, and in a few days he died. The 
surgeons of Paris were hard put to it for many days to treat all the 
wounded. I think, man petit maistre, you saw some of them. I 
beseech the great God of victories, that we be never more employed 
in such misfortune and disaster. 

Voyage of the Battle of Moncontour. 1569 

During the battle of Moncontour, King Charles was at Plessis-les- 
Tours, where he heard the news of the victory. A great number of 
gentlemen and soldiers retreated into the town and suburbs of Tours, 
wounded, to be dressed and treated; and the King and the Queen- 
mother bade me do my duty by them, with other surgeons who 
were then on duty, as Pigray, du Bois, Portail, and one Siret, a 
surgeon of Tours, a man well versed in surgery, who was at this 
time surgeon to the King's brother. And for the multitude of bad 
cases we had scarce any rest, nor the physicians either. 

M. le Comte de Mansfeld, Governor of the Duchy of Luxem- 
bourg, Knight of the Order of the King, was severely wounded in 



JOURNEYS IN DIVERSE PLACES 5 1 

the battle, in the left arm, with a pistol-shot which broke a great 
part of his elbow; and he withdrew to Borgueil near Tours. Then 
he sent a gentleman to the King, to beg him to send one of his 
surgeons, to help him of his wound. So they debated which surgeon 
they should send. M. le Marechal de Montmorency told the King 
and the Queen that they ought to send him their chief surgeon; and 
urged that M. de Mansfeld had done much toward the victory. 

The King said flat he would not have me go, and wished me to 
stop with himself. Then the Queen-mother told him I would but 
go and come back, and he must remember it was a foreign lord, 
who had come, at the command of the King of Spain, to help him. 
Then he let me go, provided I came back very soon. So he sent for 
me, and the Queen-mother with him, and bade me go and find the 
Lord de Mansfeld, wherever he should be, to do all I could for him 
to heal his wound. I went to him, with a letter from Their Majesties. 
When he saw it, he received me with good-will, and forthwith dis- 
missed three or four surgeons who were dressing him; which was 
to my very great regret, because his wound seemed to me incurable. 

Now many gentlemen had retreated to Borgueil, having been 
wounded: for they knew that M. de Guise was there, who also had 
been badly wounded with a pistol-shot through the leg, and they 
were sure that he would have good surgeons to dress him, and 
would help them, as he is kindly and very generous, and would 
relieve their wants. This he did with a will, both for their eating 
and drinking, and for what else they needed: and for my part, they 
had the comfort and help of my art: some died, others recovered, 
according to their wounds. M. le Comte Ringrave died, who was 
shot in the shoulder, like the King of Navarre before Rouen. M. de 
Bassompierre, colonel of twelve hundred horse, was wounded by a 
similar shot, in the same place, as M. de Mansfeld: whom I dressed, 
and God healed. God blessed my work so well, that in three weeks 
I sent them back to Paris: where I had still to make incisions in 
M. de Mansfeld's arm, to remove some pieces of the bones, which 
were badly splintered, broken, and carious. He was healed by the 
grace of God, and made me a handsome present, so I was well 
content with him, and he with me; as he has shown me since. He 
wrote a letter to M. le Due d'Ascot, how he was healed of his 



52 AMBROISE PARE 

wound, and also M. de Bassompierre of his, and many others whom 
I had dressed after the battle of Moncontour; and advised him to 
ask the King of France to let me visit M. le Marquis d'Auret, his 
brother: which he did. 

The Journey to Flanders. 1569 

M. le Dug d' Ascot did not fail to send a gentleman to the King, 
with a letter humbly asking he would do him so much kindness and 
honour as to permit and command his chief surgeon to visit M. le 
Marquis d'Auret, his brother, who had received a gunshot wound 
near the knee, with fracture of the bone, about seven months ago, 
and the physicians and surgeons all this time had not been able to 
heal him. The King sent for me and bade me go and see M. d'Auret, 
and give him all the help I could, to heal him of his wound. I told 
him I would employ all the little knowledge it had pleased God 
to give me. 

I went off, escorted by two gentlemen, to the Chateau d'Auret, 
which is a league and a half from Mons in Hainault, where M. le 
Marquis was lying. So soon as I had come, I visited him, and told 
him the King had commanded me to come and see him and dress 
his wound. He said he was very glad I had come, and was much 
beholden to the King, who had done him so much honour as to 
send me to him. 

I found him in a high fever, his eyes deep sunken, with a mori- 
bund and yellowish face, his tongue dry and parched, and the whole 
body much wasted and lean, the voice low as of a man very near 
death: and I found his thigh much inflamed, suppurating, and 
ulcerated, discharging a greenish and very offensive sanies. I probed 
it with a silver probe, wherewith I found a large cavity in the middle 
of the thigh, and others round the knee, sanious and cuniculate: 
also several scales of bone, some loose, others not. The leg was 
greatly swelled, and imbued with a pituitous humor . . . and bent 
and drawn back. There was a large bedsore; he could rest neither 
day nor night; and had no appetite to eat, but very thirsty. I was 
told he often fell into a faintness of the heart, and sometimes as in 
epilepsy: and often he felt sick, with such trembling he could not 
carry his hands to his mouth. Seeing and considering all these great 



JOURNEYS IN DIVERSE PLACES 53 

complications, and the vital powers thus broken down, truly I was 
very sorry I had come to him, because it seemed to me there was 
little hope he would escape death. AH the same, to give him courage 
and good hope, I told him I would soon set him on his legs, by the 
grace of God, and the help of his physicians and surgeons. 

Having seen him, I went a walk in a garden, and prayed God 
He would show me this grace, that he should recover; and that 
He would bless our hands and our medicaments, to fight such a 
comphcation of diseases. I discussed in my mind the means I must 
take to do this. They called me to dinner. I came into the kitchen, 
and there I saw, taken out of a great pot, half a sheep, a quarter of 
veal, three great pieces of beef, two fowls, and a very big piece of 
bacon, with abundance of good herbs: then I said to myself that 
the broth of the pot would be full of juices, and very nourishing. 

After dinner, we began our consultation, all the physicians and 
surgeons together, in the presence of M. le Due d' Ascot and some 
gentlemen who were with him. I began to say to the surgeons that 
I was astonished they had not made incisions in M. le Marquis' 
thigh, seeing that it was all suppurating, and the thick matter in it 
very foetid and offensive, showing it had long been pent up there; 
and that I had found with the probe caries of the bone, and scales 
of bone, which were already loose. They answered me: "Never 
would he consent to it"; indeed, it was near two months since they 
had been able to get leave to put clean sheets on his bed; and one 
scarce dared touch the coverlet, so great was his pain. Then I said, 
"To heal him, we must touch something else than the coverlet of 
his bed." Each said what he thought of the malady of the patient, 
and in conclusion they all held it hopeless. I told them there was 
still some hope, because he was young, and God and Nature some- 
times do things which seem to physicians and surgeons impossible. 

To restore the warmth and nourishment of the body, general 
frictions must be made with hot cloths, above, below, to right, to left, 
and around, to draw the blood and the vital spirits from within out- 
ward. . . . For the bedsore, he must be put in a fresh, soft bed, 
with clean shirt and sheets. . . . Having discoursed of the causes 
and complications of his malady, I said we must cure them by their 
contraries; and must first ease the pain, making openings in the 



54 AMBROISE PARE 

thigh to let out the matter. . . . Secondly, having regard to the 
great swelling and coldness of the limb, we must apply hot bricks 
round it, and sprinkle them with a decoction of nerval herbs in 
wine and vinegar, and wrap them in napkins; and to his feet, an 
earthenware bottle filled with the decoction, corked, and wrapped 
in cloths. Then the thigh, and the whole of the leg, must be fomented 
with a decoction made of sage, rosemary, thyme, lavender, flowers 
of chamomile and melilot, red roses boiled in white wine, with a 
drying powder made of oak-ashes and a little vinegar and half a 
handful of salt. . . . Thirdly, we must apply to the bedsore a large 
plaster made of the desiccative red ointment and of Unguentum 
Comitissae, equal parts, mixed together, to ease his pain and dry 
the ulcer; and he must have a little pillow of down, to keep all 
pressure off it. . . . And for the strengthening of his heart, we 
must apply over it a refrigerant of oil of water-lilies, ointment of 
roses, and a little saffron, dissolved in rose-vinegar and treacle, 
spread on a piece of red cloth. For the syncope, from exhaustion of 
the natural forces, troubling the brain, he must have good nourish- 
ment full of juices, as raw eggs, plums stewed in wine and sugar, 
broth of the meat of the great pot, whereof I have already spoken; 
the white meat of fowls, partridges' wings minced small, and other 
roast meats easy to digest, as veal, kid, pigeons, partridges, thrushes, 
and the like, with sauce of orange, verjuice, sorrel, sharp pome- 
granates; or he may have them boiled with good herbs, as lettuce, 
purslain, chicory, bugloss, marigold, and the like. At night he can 
take barley-water, with juice of sorrel and of water-lilies, of each 
two ounces, with four or five grains of opium, and the four cold 
seeds crushed, of each half an ounce; which is a good nourishing 
remedy and will make him sleep. His bread to be farm-house 
bread, neither too stale nor too fresh. For the great pain in his head, 
his hair must be cut, and his head rubbed with rose-vinegar just 
warm, and a double cloth steeped in it and put there; also a forehead- 
cloth, of oil of roses and water-lilies and poppies, and a little opium 
and rose-vinegar, with a little camphor, and changed from time to 
time. Moreover, we must allow him to smell flowers of henbane 
and water-lilies, bruised with vinegar and rose-water, with a little 
camphor, all wrapped in a handkerchief, to be held some time to 



JOURNEYS IN DIVERSE PLACES 55 

his nose. . . . And we must make artificial rain, pouring water 
from some high place into a cauldron, that he may hear the sound 
of it; by which means sleep shall be provoked on him. As for the 
contraction of his leg, there is hope of righting it when we have 
let out the pus and other humors pent up in the thigh, and have 
rubbed the whole knee with ointment of mallows, and oil of lihes, 
and a little eau-de-vie, and wrapped it in black wool with the grease 
left in it; and if we put under the knee a feather pillow doubled, 
little by little we shall straighten the leg. 

This my discourse was well approved by the physicians and 
surgeons. 

The consultation ended, we went back to the patient, and I made 
three openings in his thigh. . . . Two or three hours later, I got a 
bed made near his old one, with fair white sheets on it; then a 
strong man put him in it, and he was thankful to be taken out of 
his foul stinking bed. Soon after, he asked to sleep; which he did 
for near foiir hours: and everybody in the house began to feel 
happy, and especially M. le Due d' Ascot, his brother. 

The following days, I made injections, into the depth and cavities 
of the ulcers, of .^gyptiacum dissolved sometimes in eau-de-vie, 
other times in wine. I applied compresses to the bottom of the 
sinuous tracks, to cleanse and dry the soft spongy flesh, and hollow 
leaden tents, that the sanies might always have a way out; and above 
them a large plaster of Diacalcitheos dissolved in wine. And I 
bandaged him so skilfully that he had no pain; and when the pain 
was gone, the fever began at once to abate. Then I gave him wine 
to drink moderately tempered with water, knowing it would restore 
and quicken the vital forces. And all that we agreed in consultation 
was done in due time and order; and so soon as his pains and fever 
ceased, he began steadily to amend. He dismissed two of his sur- 
geons, and one of his physicians, so that we were but three with him. 

Now I stopped there about two months, not without seeing many 
patients, both rich and poor, who came to me from three or four 
leagues round. He gave food and drink to the needy, and com- 
mended them all to me, asking me to help them for his sake. I 
protest I refused not one, and did for them all I could, to his great 
pleasure. Then, when I saw him beginning to be well, I told him 



56 AMBROISE PAHi. 

we must have viols and violins, and a buffoon to make him laugh: 
which he did. In one month, we got him into a chair, and he had 
himself carried about in his garden and at the door of his chateau, 
to see everybody passing by. 

The villagers of two or three leagues round, now they could have 
sight of him, came on holidays to sing and dance, men and women, 
pell-mell for a frolic, rejoiced at his good convalescence, all glad to 
see him, not without plenty of laughter and plenty to drink. He 
always gave them a hogshead of beer; and they all drank merrily 
to his health. And the citizens of Mons in Hainault, and other 
gentlemen, his neighbours, came to see him for the wonder of it, as 
a man come out of the grave; and from the time he was well, he 
was never without company. When one went out, another came 
in to visit him; his table was always well covered. He was dearly 
loved both by the nobility and by the common people; as for his 
generosity, so for his handsome face and his courtesy: with a kind 
look and a gracious word for everybody, so that all who saw him 
had perforce to love him. 

The chief citizens of Mons came one Saturday, to beg him let me 
go to Mons, where they wished to entertain me with a banquet, 
for their love of him. He told them he would urge me to go, which 
he did; but I said such great honour was not for me, moreover they 
could not feast me better than he did. Again he urged me, with 
much affection, to go there, to please him: and I agreed. The next 
day, they came to fetch me with two carriages: and when we got 
to Mons, we found the dinner ready, and the chief men of the town, 
with their ladies, who attended me with great devotion. We sat 
down to dinner, and they put me at the top of the table, and all 
drank to me, and to the health of M. le Marquis d'Auret: saying 
he was happy, and they with him, to have had me to put him on 
his legs again; and truly the whole company were full of honour 
and love for him. After dinner, they brought me back to the Chateau 
d'Auret, where M. le Marquis was awaiting me; who affectionately 
welcomed me, and would hear what we had done at our banquet; 
and I told him all the company had drunk many times to his health. 

In six weeks he began to stand a little on crutches, and to put on 
fat and get a good natural colour. He would go to Beaumont, his 



JOURNEYS IN DIVERSE PLACES 57 

brother's place; and was taken there in a carrying-chair, by eight 
men at a time. And the peasants in the villages through which we 
passed, knowing it was M. le Marquis, fought who should carry 
him, and would have us drink with them; but it was only beer. 
Yet I believe if they had possessed wine, even hippocras, they would 
have given it to us with a will. And all were right glad to see him, 
and all prayed God for him. 

When we came to Beaumont, everybody came out to meet us 
and pay their respects to him, and prayed God bless him and keep 
him in good health. We came to the chateau, and found there more 
than fifty gentlemen whom M. le Due d' Ascot had invited to come 
and be happy with his brother; and he kept open house three whole 
days. After dinner, the gentlemen used to tilt at the ring and play 
with the foils, and were full of joy at the sight of M. d'Auret, for 
they had heard he would never leave his bed or be healed of his 
wound. I was always at the upper end of the table, and everybody 
drank to him and to me, thinking to make me drunk, which they 
could not; for I drank only as I always do. 

A few days later, we went back; and I took my leave of Mdme. 
la Duchesse d' Ascot, who drew a diamond from her finger, and 
gave it me in gratitude for my good care of her brother: and the 
diamond was worth more than fifty crowns. M. d'Auret was ever 
getting better, and was walking all alone on crutches round his 
garden. Many times I asked him to let me go back to Paris, telling 
him his physician and his surgeon could do all that was now wanted 
for his wound: and to make a beginning to get away from him, I 
asked him to let me go and see the town of Antwerp. To this he 
agreed at once, and told his steward to escort me there, with two 
pages. We passed through Malines and Brussels, where the chief 
citizens of the town begged us to let them know of it when we re- 
turned; for they too wished, like those of Mons, to have a festival 
for me. I gave them very humble thanks, saying I did not deserve 
such honour. I was two days and a half seeing the town of Antwerp, 
where certain merchants, knowing the steward, prayed he would 
let them have the honour of giving us a dinner or a supper: it was 
who should have us, and they were all truly glad to hear how well 
M. d'Auret was doing, and made more of me than I asked. 



58 AMBROISE PARE 

On my return, I found M. le Marquis enjoying himself: and five 
or six days later I asked his leave to go, which he gave, said he, with 
great regret. And he made me a handsome present of great value, 
and sent me back, with the steward, and two pages, to my house in 
Paris. 

I forgot to say that the Spaniards have since ruined and demol- 
ished his Chateau d'Autet, sacked, pillaged, and burned all the 
houses and villages belonging to him: because he would not be of 
their wicked party in their assassinations and ruin of the Nether- 
lands. 

I have published this Apologia, that all men may know on what 
footing I have always gone: and sure there is no man so touchy not 
to take in good part what I have said. For I have but told the 
truth; and the purport of my discourse is plain for all men to see, 
and the facts themselves are my guarantee against all calumnies. 



ON THE MOTION OF THE HEART 
AND BLOOD IN ANIMALS 



BY 
WILUAM HARVEY 

TRANSLATED BY 
ROBERT WILLIS 

AND REVISED BY 
ALEXANDER BOWIE 



INTRODUCTORY NOTE 

William Harvey, whose epoch-making treatise announcing and 
demonstrating the circulation of the blood is here printed, was born at 
Folkestone, Kent, England, April i, 1578. He was educated at the 
King's School, Canterbury, and at Gonville and Caius College, Cam- 
bridge; and studied medicine on the Continent, receiving the degree of 
M.D. from the University of Padua. He took the same degree later at 
both the English universities. After his return to England he became 
Fellow of the College of Physicians, physician to St. Bartholomew's 
Hospital, and Lumleian lecturer at the College of Physicians. It was in 
this last capacity that he delivered, in 161 6, the lectures in which he first 
gave public notice of his theories on the circulation of the blood. The 
notes of these lectures are still preserved in the British Museum. 

In 1 61 8 Harvey was appointed physician extraordinary to James I, and 
he remained in close professional relations to the royal family until the 
close of the Civil War, being present at the battle of Edgehill. By man- 
date of Charles I, he was, for a short time. Warden of Merton College, 
Oxford (1645-6), and, when he was too infirm to undertake the duties, 
he was offered the Presidency of the College of Physicians. He died on 
June 3, 1657. 

Harvey's famous "Exercitatio Anatomica de Motu Cordis et San- 
guinis in Animalibus" was published in Latin at Frankfort in 1628. The 
discovery was received with great interest, and in his own country was 
accepted at once; on the Continent it won favor more slowly. Before his 
death, however, the soundness of his views was acknowledged by the 
medical profession throughout Europe, and "it remains to this day the 
greatest of the discoveries of physiology, and its whole honor belongs 
to Harvey." 



TO 

THE MOST ILLUSTRIOUS AND INDOMITABLE 

PRINCE 

CHARLES 

king of great britain, france, and ireland 
defender of the faith 

Most illustrious Prince! 

The heart of animals is the foundation of their life, the sovereign of 
everything within them, the sun of their microcosm, that upon which 
all growth depends, from which all power proceeds. The King, in like 
manner, is the foundation of his kingdom, the sun of the world around 
him, the heart of the republic, the fountain whence all power, all grace 
doth flow. What I have here written of the motions of the heart I am 
the more emboldened to present to your Majesty, according to the custom 
of the present age, because almost all things human are done after 
human examples, and many things in a King are after the pattern of 
the heart. The knowledge of his heart, therefore, will not be useless to a 
Prince, as embracing a kind of Divine example of his functions, — and it 
has still been usual with men to compare small things with great. Here, 
at all events, best of Princes, placed as you are on the pinnacle of human 
affairs, you may at once contemplate the prime mover in the body of 
man, and the emblem of your own sovereign power. Accept therefore, 
with your wonted clemency, I most humbly beseech you, illustrious 
Prince, this, my new Treatise on the Heart; you, who are yourself the 
new light of this age, and indeed its very heart; a Prince abounding 
in virtue and in grace, and to whom we gladly refer all the blessings 
which England enjoys, all the pleasure we have in our lives. 
Your Majesty's most devoted servant, 

William Harvey. 
London, 1628. 



DEDICATION 

TO HIS VERY DEAR FRIEND, 

DOCTOR ARGENT, THE EXCELLENT AND 

ACCOMPLISHED PRESIDENT OF THE ROYAL COLLEGE OF PHYSICIANS, 

AND TO OTHER LEARNED PHYSICIANS, HIS 

MOST ESTEEMED COLLEAGUES. 

I HAVE already and repeatedly presented you, my learned friends, with 
my new views of the motion and function of the heart, in my anatomical 
lectures; but having now for more than nine years confirmed these 
views by multiplied demonstrations in your presence, illustrated them 
by arguments, and freed them from the objections of the most learned 
and skilful anatomists, I at length yield to the requests, I might say 
entreaties, of many, and here present them for general consideration in 
this treatise. 

Were not the work indeed presented through you, my learned friends, 
I should scarce hope that it could come out scatheless and complete; for 
you have in general been the faithful witnesses of almost all the instances 
from which I have either collected the truth or confuted error. You 
have seen my dissections, and at my demonstrations of all that I main- 
tain to be objects of sense, you have been accustomed to stand by and 
bear me out with your testimony. And as this book alone declares the 
blood to course and revolve by a new route, very different from the 
ancient and beaten pathway trodden for so many ages, and illustrated 
by such a host of learned and distinguished men, I was greatly afraid 
lest I might be charged with presumption did I lay my work before the 
public at home, or send it beyond seas for impression, unless I had first 
proposed the subject to you, had confirmed its conclusions by ocular 
demonstrations in your presence, had replied to your doubts and objec- 
tions, and secured the assent and support of our distinguished President. 
For I was most intimately persuaded, that if I could make good my 
proposition before you and our College, illustrious by its numerous body 
of learned individuals, I had less to fear from others. I even ventured 
to hope that I should have the comfort of finding all that you had granted 
me in your sheer love of truth, conceded by others who were philosophers 
like yourselves. True philosophers, who are only eager for truth and 

62 



DEDICATION 63 

knowledge, never regard themselves as already so thoroughly informed, 
but that they welcome further information from whomsoever and from 
wheresoever it may come; nor are they so narrow-minded as to imagine 
any of the arts or sciences transmitted to us by the ancients, in such a 
state of forwardness or completeness, that nothing is left for the ingenuity 
and industry of others. On the contrary, very many maintain that all 
we know is still infinitely less than all that still remains unknown; nor 
do philosophers pin their faith to others' precepts in such wise that they 
lose their liberty, and cease to give credence to the conclusions of their 
proper senses. Neither do they swear such fealty to their mistress An- 
tiquity, that they openly, and in sight of all, deny and desert their friend 
Truth. But even as they see that the credulous and vain are disposed at 
the first blush to accept and believe everything that is proposed to them, 
so do they observe that the dull and unintellectual are indisposed to see 
what lies before their eyes, and even deny the light of the noonday sun. 
They teach us in our course of philosophy to sedulously avoid the fables 
of the poets and the fancies of the vulgar, as the false conclusions of the 
sceptics. And then the studious and good and true, never suffer their 
minds to be warped by the passions of hatred and envy, which unfit 
men duly to weigh the arguments that are advanced in behalf of truth, 
or to appreciate the proposition that is even fairly demonstrated. Neither 
do they think it unworthy of them to change their opinion if truth and 
undoubted demonstration require them to do so. They do not esteem 
it discreditable to desert error, though sanctioned by the highest antiquity, 
for they know full well that to err, to be deceived, is human; that many 
things are discovered by accident and that many may be learned indif- 
ferently from any quarter, by an old man from a youth, by a person of 
understanding from one of inferior capacity. 

My dear colleagues, I had no purpose to swell this treatise into a large 
volume by quoting the names and writings of anatomists, or to make 
a parade of the strength of my memory, the extent of my reading, and 
the amount of my pains; because I profess both to learn and to teach 
anatomy, not from books but from dissections; not from the positions 
of philosophers but from the fabric of nature; and then because I do not 
think it right or proper to strive to take from the ancients any honor 
that is their due, nor yet to dispute with the moderns, and enter into 
controversy with those who have excelled in anatomy and been my 
teachers. I would not charge with wilful falsehood any one who was 
sincerely anxious for truth, nor lay it to any one's door as a crime that 
he had fallen into error. I avow myself the partisan of truth alone; and 



64 DEDICATION 

I can indeed say that I have used all my endeavours, bestowed all my 
pains on an attempt to produce something that should be agreeable to 
the good, profitable to the learned, and useful to letters. 
Farewell, most worthy Doctors, 

And think kindly of your Anatomist, 
William Harvey. 



INTRODUCTION 

As we are about to discuss the motion, action, and use of the heart 
and arteries, it is imperative on us first to state what has been thought 
of these things by others in their writings, and what has been held by 
the vulgar and by tradition, in order that what is true may be confirmed, 
and what is false set right by dissection, multiplied experience, and 
accurate observation. 

Almost all anatomists, physicians, and philosophers up to the present 
time have supposed, with Galen, that the object of the pulse was the 
same as that of respiration, and only differed in one particular, this being 
conceived to depend on the animal, the respiration on the vital faculty; 
the two, in all other respects, whether with reference to purpose or to 
motion, comporting themselves alike. Whence it is affirmed, as by 
Hieronymus Fabricius of Aquapendente, in his book on "Respiration," 
which has lately appeared, that as the pulsation of the heart and arteries 
does not suffice for the ventilation and refrigeration of the blood, there- 
fore were the lungs fashioned to surround the heart. From this it appears 
that whatever has hitherto been said upon the systole and diastole, or 
on the motion of the heart and arteries, has been said with especial 
reference to the lungs. 

But as the structure and movements of the heart differ from those of 
the lungs, and the motions of the arteries from those of the chest, so it 
seems likely that other ends and offices will thence arise, and that the 
pulsations and uses of the heart, likewise of the arteries, will differ in 
many respects from the heavings and uses of the chest and lungs. For 
did the arterial pulse and the respiration serve the same ends; did the 
arteries in their diastole take air into their cavities, as commonly stated, 
and in their systole emit fuliginous vapours by the same pores of the 
flesh and skin; and further, did they, in the time intermediate between 
the diastole and the systole, contain air, and at all times either air or 
spirits, or fuliginous vapours, what should then be said to Galen, who 
wrote a book on purpose to show that by nature the arteries contained 
blood, and nothing but blood, and consequently neither spirits nor air, 
as may readily be gathered from the experiments and reasonings con- 
tained in the same book? Now, if the arteries are filled in the diastole 
with air then taken into them (a larger quantity of air penetrating when 

65 



66 INTRODUCTION 

the pulse is large and full), it must come to pass that if you plunge into 
a bath of water or of oil when the pulse is strong and full, it ought forth- 
with to become either smaller or much slower, since the circumambient 
bath will render it either difficult or impossible for the air to penetrate. 
In like manner, as all the arteries, those that are deep-seated as well as 
those that are superficial, are dilated at the same instant and with the 
same rapidity, how is it possible that air should penetrate to the deeper 
parts as freely and quickly through the skin, flesh, and other structures, 
as through the cuticle alone? And how should the arteries of the foetus 
draw air into their cavities through the abdomen of the mother and the 
body of the womb? And how should seals, whales, dolphins, and other 
cetaceans, and fishes of every description, living in the depths of the sea, 
take in and emit air by the diastole and systole of their arteries through 
the infinite mass of water? For to say that they absorb the air that is 
present in the water, and emit their fumes into this medium, were to 
utter something like a figment. And if the arteries in their systole expel 
fuliginous vapours from their cavities through the pores of the flesh and 
skin, why not the spirits, which are said to be contained in those vessels, 
at the same time, since spirits are much more subtile than fuliginous 
vapours or smoke? And if the arteries take in and cast out air in the 
systole and diastole, like the lungs in the process of respiration, why do 
they not do the same thing when a wound is made in one of them, as 
in the operation of arteriotomy? When the windpipe is divided, it is 
sufficiently obvious that the air enters and returns through the wound 
by two opposite movements; but when an artery is divided, it is equally 
manifest that blood escapes in one continuous stream, and that no air 
either enters or issues. If the pulsations of the arteries fan and refrigerate 
the several parts of the body as the lungs do the heart, how comes it, as 
is commonly said, that the arteries carry the vital blood into the different 
parts, abundantly charged with vital spirits, which cherish the heat of 
these parts, sustain them when asleep, and recruit them when exhausted ? 
How should it happen that, if you tie the arteries, immediately the parts 
not only become torpid, and frigid, and look pale, but at length cease 
even to be nourished? This, according to Galen, is because they are 
deprived of the heat which flowed through all parts from the heart, as 
its source; whence it would appear that the arteries rather carry warmth 
to the parts than serve for any fanning or refrigeration. Besides, how 
can their diastole draw spirits from the heart to warm the body and its 
parts, and means of cooling them from without? Still further, although 
some affirm that the lungs, arteries, and heart have all the same offices. 



INTRODUCTION 67 

they yet maintain that the heart is the workshop of the spirits, and that 
the arteries contain and transmit them; denying, however, in opposition 
to the opinion of Columbus, that the lungs can either make or contain 
spirits. They then assert, with Galen, against Erasistratus, that it is the 
blood, not spirits, which is contained in the arteries. 

These opinions are seen to be so incongruous and mutually subversive, 
that every one of them is justly brought under suspicion. That it is 
blood and blood alone which is contained in the arteries is made manifest 
by the experiment of Galen, by arteriotomy, and by wounds; for from a 
single divided artery, as Galen himself affirms in more than one place, 
the whole of the blood may be withdrawn in the course of half an hour 
or less. The experiment of Galen alluded to is this: "If you include a 
portion of an artery between two ligatures, and slit it open lengthwise 
you will find nothing but blood"; and thus he proves that the arteries 
contain only blood. And we too may be permitted to proceed by a like 
train of reasoning: if we find the same blood in the arteries as in thb 
veins, after having tied them in the same way, as I have myself re- 
peatedly ascertained, both in the dead body and in living animals, we 
may fairly conclude that the arteries contain the same blood as the veins, 
and nothing but the same blood. Some, whilst they attempt to lessen the 
difficulty, affirm that the blood is spirituous and arterious, and virtually 
concede that the office of the arteries is to carry blood from the heart into 
the whole of the body, and that they are therefore filled with blood; for 
spirituous blood is not the less blood on that account. And no one denies 
the blood as such, even the portion of it which flows in the veins, is 
imbued with spirits. But if that portion of it which is contained in the 
arteries be richer in spirits, it is still to be believed that these spirits are 
inseparable from the blood, like those in the veins; that the blood and 
spirits constitute one body (like whey and butter in milk, or heat in hot 
water), with which the arteries are charged, and for the distribution of 
which from the heart they are provided. This body is nothing else than 
blood. But if this blood be said to be drawn from the heart into the 
arteries by the diastole of these vessels, it is then assumed that the arteries 
by their distension are filled with blood, and not with the surrounding 
air, as heretofore; for if they be said also to become filled with air from 
the ambient atmosphere, how and when, I ask, can they receive blood 
from the heart? If it be answered: during the systole, I take it to be 
impossible: the arteries would then have to fill while they contracted, to 
fill, and yet not become distended. But if it be said: during diastole, 
they would then, and for two opposite purposes, be receiving both blood 



68 INTRODUCTION 

and air, and heat and cold, which is improbable. Further, when it is 
affirmed that the diastole of the heart and arteries is simultaneous, and 
the systole of the two is also concurrent, there is another incongruity. 
For how can two bodies mutually connected, which are simultaneously 
distended, attract or draw anything from one another? or being simul- 
taneously contracted, receive anything from each other? And then it 
seems impossible that one body can thus attract another body into itself, 
so as to become distended, seeing that to be distended is to be passive, 
unless, in the manner of a sponge, which has been previously compressed 
by an external force, it is returning to its natural state. But it is difficult 
to conceive that there can be anything of this kind in the arteries. The 
arteries dilate, because they are filled like bladders or leathern bottles; 
they are not filled because they expand like bellows. This I think easy 
of demonstration, and indeed conceive that I have already proved it. 
Nevertheless, in that book of Galen headed "Quod Sanguis continetur 
in Arteriis," he quotes an experiment to prove the contrary. An artery 
having been exposed, is opened longitudinally, and a reed or other 
pervious tube is inserted into the vessel through the opening, by which 
the blood is prevented from being lost, and the wound is closed. "So 
long," he says, "as things are thus arranged, the whole artery will pul- 
sate; but if you now throw a ligature about the vessel and tightly com- 
press its wall over the tube, you will no longer see the artery beating 
beyond the ligature." I have never performed this experiment of Galen's 
nor do I think that it could very well be performed in the living body, 
on account of the profuse flow of blood that would take place from the 
vessel that was operated on; neither would the tube effectually close the 
wound in the vessel without a ligature; and I cannot doubt but that the 
blood would be found to flow out between the tube and the vessel. Still 
Galen appears by this experiment to prove both that the pulsative prop- 
erty extends from the heart by the walls of the arteries, and that the 
arteries, whilst they dilate, are filled by that pulsific force, because they 
expand like bellows, and do not dilate as if they are filled like skins. 
But the contrary is obvious in arteriotomy and in wounds; for the blood 
spurting from the arteries escapes with force, now farther, now not so 
far, alternately, or in jets; and the jet always takes place with the diastole 
of the artery, never with the systole. By which it clearly appears that 
the artery is dilated with the impulse of the blood; for of itself it would 
not throw the blood to such a distance and whilst it was dilating; it 
ought rather to draw air into its cavity through the wound, were those 
things true that are commonly stated concerning the uses of the arteries. 



INTRODUCTION 69 

Do not let the thickness of the arterial tunics impose upon us, and lead 
us to conclude that the pulsative property proceeds along them from the 
heart. For in several animals the arteries do not apparently differ from 
the veins; and in extreme parts of the body where the arteries are mi- 
nutely subdivided, as in the brain, the hand, etc., no one could distinguish 
the arteries from the veins by the dissimilar characters of their coats: the 
tunics of both are identical. And then, in the aneurism proceeding from 
a wounded or eroded artery, the pulsation is precisely the same as in the 
other arteries, and yet it has no proper arterial covering. To this the 
learned Riolanus testifies along with me, in his Seventh Book. 

Nor let any one imagine that the uses of the pulse and the respiration 
are the same, because, under the influences of the same causes, such as 
running, anger, the warm bath, or any other heating thing, as Galen 
says, they become more frequent and forcible together. For not only is 
experience in opposition to this idea, though Galen endeavours to explain 
it away, when we see that with excessive repletion the pulse beats more 
forcibly, whilst the respiration is diminished in amount; but in young 
persons the pulse is quick, whilst respiration is slow. So it is also in 
alarm, and amidst care, and under anxiety of mind; sometimes, too, in 
fevers, the pulse is rapid, but the respiration is slower than usual. 

These and other objections of the same kind may be urged against 
the opinions mentioned. Nor are the views that are entertained of the 
ofHces and pulse of the heart, perhaps, less bound up with great and 
most inextricable difficulties. The heart, it is vulgarly said, is the foun- 
tain and workshop of the vital spirits, the centre from which life is 
dispensed to the several parts of the body. Yet it is denied that the right 
ventricle makes spirits, which is rather held to supply nourishment to 
the lungs. For these reasons it is maintained that fishes are without any 
right ventricle (and indeed every animal wants a right ventricle which 
is unfurnished with lungs), and that the right ventricle is present solely 
for the sake of the lungs. 

r. Why, I ask, when we see that the structure of both ventricles is 
almost identical, there being the same apparatus of fibres, and braces, 
and valves, and vessels, and auricles, and both in the same way in our 
dissections are found to be filled up with blood similarly black in colour, 
and coagulated — why, I say, should their uses be imagined to be different, 
when the action, motion, and pulse of both are the same? If the three 
tricuspid valves placed at the entrance into the right ventricle prove 
obstacles to the reflux of the blood into the vena cava, and if the three 
semilunar valves which are situated at the commencement of the pul- 



JO INTRODUCTION 

monary artery be there, that they may prevent the return of the blood 
into the ventricle; why, when we find similar structures in connexion 
with the left ventricle, should we deny that they are there for the same 
end, of preventing here the egress, there the regurgitation, of the blood? 

2. And, when we have these structures, in points of size, form, and 
situation, almost in every respect the same in the left as in the right 
ventricle, why should it be said that things are arranged in the former 
for the egress and regress of spirits, and in the latter or right ventricle, 
for the blood ? The same arrangement cannot be held fitted to favour or 
impede the motion of the blood and of spirits indifferently. 

3. And when we observe that the passages and vessels are severally in 
relation to one another in point of size, viz., the pulmonary artery to 
the pulmonary veins; why should the one be destined to a private pur- 
pose, that of furnishing the lungs, the other to a public function? 

4. And as Realdus Columbus says, is it probable that such a quantity 
of blood should be required for the nutrition of the lungs; the vessel 
that leads to them, the vena arteriosa or pulmonary artery being of 
greater capacity than both the iliac veins? 

5. And I ask, as the lungs are so close at hand, and in continual 
motion, and the vessel that supplies them is of such dimensions, what 
is the use or meaning of this pulse of the right ventricle? and why was 
nature reduced to the necessity of adding another ventricle for the sole 
purpose of nourishing the lungs? 

When it is said that the left ventricle draws materials for the formation 
of spirits, air and blood, from the lungs and right sinuses of the heart, 
and in like manner sends spirituous blood into the aorta, drawing 
fuliginous vapours from there, and sending them by the pulmonary 
vein into the lungs, whence spirits are at the same time obtained for 
transmission into the aorta, I ask how, and by what means is the separa- 
tion effected? And how comes it that spirits and fuliginous vapours 
can pass hither and thither without admixture or confusion? If the 
mitral cuspidate valves do not prevent the egress of fuliginous vapours 
to the lungs, how should they oppose the escape of air? And how should 
the semilunars hinder the regress of spirits from the aorta upon each 
supervening diastole of the heart? Above all, how can they say that the 
spirituous blood is sent from the pulmonary veins by the left ventricle 
into the lungs without any obstacle to its passage from the mitral valves, 
when they have previously asserted that the air entered by the same 
vessel from the lungs into the left ventricle, and have brought forward 
these same mitral valves as obstacles to its retrogression? Good God! 



INTRODUCTION 7I 

how should the mitral valves prevent the regurgitation of air and not 
of blood? 

Moreover, when they appoint the pulmonary artery, a vessel of great 
size, with the coverings of an artery, to none but a kind of private and 
single purpose, that, namely, of nourishing the lungs, why should the 
pulmonary vein, which is scarcely so large, which has the coats of a 
vein, and is soft and lax, be presumed to be made for many — three or 
four different — uses? For they will have it that air passes through this 
vessel from the lungs into the left ventricle; that fuliginous vapours 
escape by it from the heart into the lungs; and that a portion of the 
spirituous blood is distributed to the lungs for their refreshment. 

If they will have it that fumes and air — fumes flowing from, air pro- 
ceeding towards the heart — are transmitted by the same conduit, I reply, 
that nature is not wont to construct but one vessel, to contrive but one 
way for such contrary motions and purposes, nor is anything of the 
kind seen elsewhere. 

If fumes or fuliginous vapours and air permeate this vessel, as they 
do the pulmonary bronchia, wherefore do we find neither air nor 
fuliginous vapours when we divide the pulmonary vein? Why do we 
always find this vessel full of sluggish blood, never of air, whilst in the 
lungs we find abundance of air remaining? 

If any one will perform Galen's experiment of dividing the trachea of 
a living dog, forcibly distending the lungs with a pair of bellows, and 
then tying the trachea securely, he will find, when he has laid open the 
thorax, abundance of air in the lungs, even to their extreme investing 
tunic, but none in either the pulmonary veins or the left ventricle of the 
heart. But did the heart either attract air from the lungs, or did the 
lungs transmit any air to the heart, in the living dog, much more ought 
this to be the case in the experiment just referred to. Who, indeed, 
doubts that, did he inflate the lungs of a subject in the dissecting-room, 
he would instantly see the air making its way by this route, were there 
actually any such passage for it? But this office of the pulmonary veins, 
namely, the transference of air from the lungs to the heart, is held of 
such importance, that Hieronymus Fabricius of Aquapendente, contends 
that the lungs were made for the sake of this vessel, and that it con- 
stitutes the principal element in their structure. 

But I should like to be informed why, if the pulmonary vein were 
destined for the conveyance of air, it has the structure of a blood-vessel 
here. Nature had rather need of annular tubes, such as those of the 
bronchi in order that they might always remain open, and not be liable 



72 INTRODUCTION 

to collapse; and that they might continue entirely free from blood, lest 
the liquid should interfere with the passage of the air, as it so obviously 
does when the lungs labour from being either greatly oppressed or 
loaded in a less degree with phlegm, as they are when the breathing is 
performed with a sibilous or rattling noise. 

Still less is that opinion to be tolerated which, as a two-fold material, 
one aerial, one sanguineous, is required for the composition of vital 
spirits, supposes the blood to ooze through the septum of the heart from 
the right to the left ventricle by certain hidden porosities, and the air to 
be attracted from the lungs through the great vessel, the pulmonary vein; 
and which, consequently, will have it, that there are numerous porosities 
in the septum of the heart adapted for the transmission of the blood. 
But by Hercules! no such pores can be demonstrated, nor in fact do any 
such exist. For the septum of the heart is of a denser and more compact 
structure than any portion of the body, except the bones and sinews. 
But even supposing that there were foramina or pores in this situation, 
how could one of the ventricles extract anything from the other — the 
left, e.g., obtain blood from the right, when we see that both ventricles 
contract and dilate simultaneously? Why should we not rather believe 
that the right took spirits from the left, than that the left obtained blood 
from the right ventricle through these foramina? But it is certainly 
mysterious and incongruous that blood should be supposed to be most 
commodiously drawn through a set of obscure or invisible ducts, and air 
through perfectly open passages, at one and the same moment. And 
why, I ask, is recourse had to secret and invisible porosities, to uncertain 
and obscure channels, to explain the passage of the blood into the left 
ventricle, when there is so open a way through the pulmonary veins? I 
own it has always appeared extraordinary to me that they should have 
chosen to make, or rather to imagine, a way through the thick, hard, 
dense, and most compact septum of the heart, rather than take that by 
the open pulmonary vein, or even through the lax, soft and spongy sub- 
stance of the lungs at large. Besides, if the blood could permeate the 
substance of the septum, or could be imbibed from the ventricles, what 
use were there for the coronary artery and vein, branches of which pro- 
ceed to the septum itself, to supply it with nourishment? And what is 
especially worthy of notice is this: if in the foetus, where everything is 
more lax and soft, nature saw herself reduced to the necessity of bringing 
the blood from the right to the left side of the heart by the foramen 
ovale, from the vena cava through the pulmonary vein, how should it 
be likely that in the adult she should pass it so commodiously, and with- 



INTRODUCTION 73 

out an effort through the septum of the ventricles which has now become 
denser by age? 

Andreas Laurentius/ resting on the authority of Galen^ and the ex- 
perience of HoUerius, asserts and proves that the serum and pus in 
empyema, absorbed from the cavities of the chest into the pulmonary 
vein may be expelled and got rid of with the urine and fsces through 
the left ventricle of the heart and arteries. He quotes the case of a cer- 
tain person affected with melancholia, and who suffered from repeated 
fainting fits, who was relieved from the paroxysms on passing a quantity 
of turbid, fetid and acrid urine. But he died at last, worn out by disease; 
and when the body came to be opened after death, no fluid like that he 
had micturated was discovered either in the bladder or the kidneys; 
but in the left ventricle of the heart and cavity of the thorax plenty of 
it was met with. And then Laurentius boasts that he had predicted the 
cause of the symptoms. For my own part, however, I cannot but won- 
der, since he had divined and predicted that heterogeneous matter could 
be discharged by the course he indicates, why he could not or would not 
perceive, and inform us that, in the natural state of things, the blood 
might be commodiously transferred from the lungs to the left ventricle 
of the heart by the very same route. 

Since, therefore, from the foregoing considerations and many others 
to the same effect, it is plain that what has heretofore been said con- 
cerning the motion and function of the heart and arteries must appear 
obscure, inconsistent, or even impossible to him who carefully considers 
the entire subject, it would be proper to look more narrowly into the 
matter to contemplate the motion of the heart and arteries, not only in 
man, but in all animals that have hearts; and also, by frequent appeals 
to vivisection, and much ocular inspection, to investigate and discern 
the truth. 

' Lib. ix, cap. xi, quest. 12. ^ De Locis Affectis. lib. vi, cap. 7. 



ON THE MOTION 

OF THE HEART AND BLOOD 

IN ANIMALS 

CHAPTER I 
The Author's Motives for Writing 

WHEN I first gave my mind to vivisections, as a means of 
discovering the motions and uses of the heart, and sought 
to discover these from actual inspection, and not from 
the writings of others, I found the task so truly arduous, so full of 
difficulties, that I was almost tempted to think, with Fracastorius, 
that the motion of the heart was only to be comprehended by God. 
For I could neither rightly perceive at first when the systole and 
when the diastole took place, nor when and where dilatation and 
contraction occurred, by reason of the rapidity of the motion, which 
in many animals is accomplished in the twinkling of an eye, com- 
ing and going like a flash of lightning; so that the systole pre- 
sented itself to me now from this point, now from that; the diastole 
the same; and then everything was reversed, the motions occurring, 
as it seemed, variously and confusedly together. My mind was 
therefore greatly unsettled nor did I know what I should myself 
conclude, nor what believe from others. I was not surprised that 
Andreas Laurentius should have written that the motion of the 
heart was as perplexing as the flux and reflux of Euripus had ap- 
peared to Aristotle. 

At length, by using greater and daily diligence and investigation, 
making frequent inspection of many and various animals, and 
collating numerous observations, I thought that I had attained to 
the truth, that I should extricate myself and escape from this laby- 
rinth, and that I had discovered what I so much desired, both the 
motion and the use of the heart and arteries. From that time I 

75 



y6 WILLIAM HARVEY 

have not hesitated to expose my views upon these subjects, not only 
in private to my friends, but also in public, in my anatomical lec- 
tures, after the manner of the Academy of old. 

These views as usual, pleased some more, others less; some chid 
and calumniated me, and laid it to me as a crime that I had dared to 
depart from the precepts and opinions of all anatomists; others 
desired further explanations of the novelties, which they said were 
both worthy of consideration, and might perchance be found of 
signal use. At length, yielding to the requests of my friends, that 
all might be made participators in my labors, and partly moved by 
the envy of others, who, receiving my views with uncandid minds 
and understanding them indifferently, have essayed to traduce me 
publicly, I have moved to commit these things to the press, in 
order that all may be enabled to form an opinion both of me and my 
labours. This step I take all the more willingly, seeing that Hieron- 
ymus Fabricius of Aquapendente, although he has accurately and 
learnedly delineated almost every one of the several parts of ani- 
mals in a special work, has left the heart alone untouched. Finally, 
if any use or benefit to this department of the republic of letters 
should accrue from my labours, it will, perhaps, be allowed that I 
have not lived idly, and as the old man in the comedy says: 

For never yet hath any one attained 

To such perfection, but that time, and place. 

And use, have brought addition to his knowledge; 

Or made correction, or admonished him, 

That he was ignorant of much which he 

Had thought he knew; or led him to reject 

What he had once esteemed of highest price. 

So will it, perchance, be found with reference to the heart at this 
time; or others, at least, starting hence, with the way pointed out to 
them, advancing under the guidance of a happier genius, may make 
occasion to proceed more fortunately, and to inquire more accurately. 



CIRCULATION OF THE BLOOD 77 

CHAPTER II 

On the Motions of the Heart, as Seen in the Dissection 
OF Living Animals 

In the first place, then, when the chest of a Hving animal is laid 
open and the capsule that immediately surrounds the heart is slit up- 
or removed, the organ is seen now to move, now to be at rest; 
there is a time when it moves, and a time when it is motionless. 

These things are more obvious in the colder animals, such as 
toads, frogs, serpents, small fishes, crabs, shrimps, snails, and shell- 
fish. They also become more distinct in warm-blooded animals, such 
as the dog and hog, if they be attentively noted when the heart 
begins to flag, to move more slowly, and, as it were, to die: the 
movements then become slower and rarer, the pauses longer, by 
which it is made much more easy to perceive and unravel what the 
motions really are, and how they are performed. In the pause, as in 
death, the heart is soft, flaccid, exhausted, lying, as it were, at rest. 

In the motion, and interval in which this is accomplished, three 
principal circumstances are to be noted: 

1. That the heart is erected, and rises upwards to a point, so that 
at this time it strikes against the breast and the pulse is felt exter- 
nally. 

2. That it is everywhere contracted, but more especially towards 
the sides so that it looks narrower, relatively longer, more drawn 
together. The heart of an eel taken out of the body of the animal 
and placed upon the table or the hand, shows these particulars; but 
the same things are manifest in the hearts of all small fishes and of 
those colder animals where the organ is more conical or elongated. 

3. The heart being grasped in the hand, is felt to become harder 
during its action. Now this hardness proceeds from tension, pre- 
cisely as when the forearm is grasped, its tendons are perceived to 
become tense and resilient when the fingers are moved. 

4. It may further be observed in fishes, and the colder blooded 
animals, such as frogs, serpents, etc., that the heart, when it moves, 
becomes of a paler color, when quiescent of a deeper blood-red color. 

From these particulars it appears evident to me that the motion 



yS WILLIAM HARVEY 

-of the heart consists in a certain universal tension — both contrac- 
tion in the Une of its fibres, and constriction in every sense. It be- 
comes erect, hard, and of diminished size during its action; the 
motion is plainly of the same nature as that of the muscles when 
they contract in the line of their sinews and fibres; for the muscles, 
when in action, acquire vigor and tenseness, and from soft become 
hard, prominent, and thickened: and in the same manner the 
lieart. 

We are therefore authorized to conclude that the heart, at the 
moment of its action, is at once constricted on all sides, rendered 
thicker in its parietes and smaller in its ventricles, and so made apt 
to project or expel its charge of blood. This, indeed, is made suffi- 
■ciently manifest by the preceding fourth observation in which we 
have seen that the heart, by squeezing out the blood that it con- 
tains, becomes paler, and then when it sinks into repose and the ven- 
tricle is filled anew with blood, that the deeper crimson colour 
returns. But no one need remain in doubt of the fact, for if the 
ventricle be pierced the blood will be seen to be forcibly projected 
outwards upon each motion or pulsation when the heart is tense. 

These things, therefore, happen together or at the same instant: 
the tension of the heart, the pulse of its apex, which is felt externally 
Ijy its striking against the chest, the thickening of its parietes, and 
the forcible expulsion of the blood it contains by the constriction of 
its ventricles. 

Hence the very opposite of the opinions commonly received ap- 
pears to be true; inasmuch as it is generally believed that when the 
heart strikes the breast and the pulse is felt without, the heart is 
dilated in its ventricles and is filled with blood; but the contrary 
of this is the fact, and the heart, when it contracts (and the impulse 
of the apex is conveyed through the chest wall), is emptied. 
Whence the motion which is generally regarded as the diastole of 
the heart, is in truth its systole. And in like manner the intrinsic 
motion of the heart is not the diastole but the systole; neither is 
it in the diastole that the heart grows firm and tense, but in the 
systole, for then only, when tense, is it moved and made vigorous. 

Neither is it by any means to be allowed that the heart only 
imoves in the lines of its straight fibres, although the great Vesalius 



CIRCULATION OF THE BLOOD 79 

giving this notion countenance, quotes a bundle of osiers bound in 
a pyramidal heap in illustration; meaning, that as the apex is ap- 
proached to the base, so are the sides made to bulge out in the 
fashion of arches, the cavities to dilate, the ventricles to acquire the 
form of a cupping-glass and so to suck in the blood. But the true 
effect of every one of its fibres is to constringe the heart at the same 
time they render it tense; and this rather with the effect of thicken- 
ing and amplifying the walls and substance of the organ than en- 
larging its ventricles. And, again, as the fibres run from the apex 
to the base, and draw the apex towards the base, they do not tend 
to make the walls of the heart bulge out in circles, but rather the 
contrary; inasmuch as every fibre that is circularly disposed, tends 
to become straight when it contracts; and is distended laterally and 
thickened, as in the case of muscular fibres in general, when they 
contract, that is, when they are shortened longitudinally, as we 
see them in the bellies of the muscles of the body at large. To all 
this let it be added, that not only are 'the ventricles contracted in 
virtue of the direction and condensation of their walls, but farther, 
that those fibres, or bands, styled nerves by Aristotle, which are so 
conspicuous in the ventricles of the larger animals, and contain all 
the straight fibres (the parietes of the heart containing only circular 
ones), when they contract simultaneously by an admirable adjust- 
ment all the internal surfaces are drawn together as if with cords, 
and so is the charge of blood expelled with force. 

Neither is it true, as vulgarly believed, that the heart by any dila- 
tation or motion of its own, has the power of drawing the blood 
into the ventricles; for when it acts and becomes tense, the blood is 
expelled; when it relaxes and sinks together it receives the blood in 
the manner and wise which will by-and-by be explained. 

CHAPTER III 

Of the Motions of the Arteries, as Seen in the 
Dissection of Living Animals 

In connexion with the motions of the heart these things are fur- 
ther to be observed having reference to the motions and pulses of 
the arteries. 



8o WILLIAM HARVEY 

1. At the moment the heart contracts, and when the breast is 
struck, when in short the organ is in its state of systole, the arteries 
are dilated, yield a pulse, and are in the state of diastole. In like 
manner, when the right ventricle contracts and propels its charge of 
blood, the pulmonary artery is distended at the same time with the 
other arteries of the body. 

2. When the left ventricle ceases to act, to contract, to pulsate, 
the pulse in the arteries also ceases; further, when this ventricle con- 
tracts languidly, the pulse in the arteries is scarcely perceptible. In 
like manner, the pulse in the right ventricle failing, the pulse in 
the pulmonary artery ceases also. 

3. Further, when an artery is divided or punctured, the blood is 
seen to be forcibly propelled from the wound the moment the left 
ventricle contracts; and, again, when the pulmonary artery is 
wounded, the blood will be seen spouting forth with violence at the 
instant when the right ventricle contracts. 

So also in fishes, if the vessel which leads from the heart to the 
gills be divided, at the moment when the heart becomes tense and 
contracted, at the same moment does the blood flow with force from 
the divided vessel. 

In the same way, when we see the blood in arteriotomy projected 
now to a greater, now to a less distance, and that the greater jet 
corresponds to the diastole of the artery and to the time when the 
heart contracts and strikes the ribs, and is in its state of systole, we 
understand that the blood is expelled by the same movement. 

From these facts it is manifest, in opposition to commonly re- 
ceived opinions, that the diastole of the arteries corresponds with the 
time of the heart's systole; and that the arteries are filled and dis- 
tended by the blood forced into them by the contraction of the ven- 
tricles; the arteries, therefore, are distended, because they are filled 
like sacs or bladders, and are not filled because they expand like 
bellows. It is in virtue of one and the same cause, therefore, that all 
the arteries of the body pulsate, viz., the contraction of the left 
ventricle; in the same way as the pulmonary artery pulsates by the 
contraction of the right ventricle. 

Finally, that the pulses of the arteries are due to the impulses of 
the blood from the left ventricle, may be illustrated by blowing into 



CIRCULATION OF THE BLOOD 8 1 

a glove, when the whole of the fingers will be found to become dis- 
tended at one and the same time, and in their tension to bear some 
resemblance to the pulse. For in the ratio of the tension is the pulse 
of the heart, fuller, stronger, and more frequent as that acts more 
vigorously, still preserving the rhythm and volume, and order of 
the heart's contractions. Nor is it to be expected that because of the 
motion of the blood, the time at which the contraction of the heart 
takes place, and that at which the pulse in an artery (especially a 
distant one) is felt, shall be otherwise than simultaneous: it is here 
the same as in blowing up a glove or bladder; for in a plenum (as in 
a drum, a long piece of timber, etc.) the stroke and the motion occur 
at both extremities at the same time. Aristotle,' too, has said, "the 
blood of all animals palpitates within their veins (meaning the 
arteries), and by the pulse is sent everywhere simultaneously." And 
further,^ "thus do all the veins pulsate together and by successive 
strokes, because they all depend upon the heart; and, as it is always 
in motion, so are they likewise always moving together, but by 
successive movements." It is well to observe with Galen, in this place, 
that the old philosophers called the arteries veins. 

I happened upon one occasion to have a particular case under my 
care, which plainly satisfied me of the truth: A certain person was 
afiFected with a large pulsating tumour on the right side of the neck, 
called an aneurism, just at that part where the artery descends into 
the axilla, produced by an erosion of the artery itself, and daily in- 
creasing in size; this tumour was visibly distended as it received the 
charge of blood brought to it by the artery, with each stroke of the 
heart; the connexion of parts was obvious when the body of the 
patient came to be opened after his death. The pulse in the corre- 
sponding arm was small, in consequence of the greater portion of 
the blood being diverted into the tumour and so intercepted. 

Whence it appears that whenever the motion of the blood through 
the arteries is impeded, whether it be by compression or infarction, 
or interception, there do the remote divisions of the arteries beat less 
forcibly, seeing that the pulse of the arteries is nothing more than the 
impulse or shock of the blood in these vessels. 

' De Anim., iii, cap. 9. ' De Respir., cap. 20. 



82 WILLIAM HARVEY 

CHAPTER IV 

Of the Motion of the Heart and Its Auricles, as Seen in the 
Bodies of Living Animals 

Besides the motions already spoken of, we have still to consider 
those that appertain to the auricles. 

Caspar Bauhin and John Riolan,' most learned men and skilful 
anatomists, inform us that from their observations, that if we care- 
fully watch the movements of the heart in the vivisection of an 
animal, we shall perceive four motions distinct in time and in place, 
two of which are proper to the auricles, two to the ventricles. With 
all deference to such authority I say that there are four motions 
distinct in point of place, but not of time; for the two auricles move 
together, and so also do the two ventricles, in such wise that though 
the places be four, the times are only two. And this occurs in the 
following manner: 

There are, as it were, two motions going on together: one of the 
auricles, another of the ventricles; these by no means taking place 
simultaneously, but the motion of the auricles preceding, that of 
the heart following; the motion appearing to begin from the auri- 
cles and to extend to the ventricles. When all things are becoming 
languid, and the heart is dying, as also in fishes and the colder 
blooded animals there is a short pause between these two motions, 
so that the heart aroused, as it were, appears to respond to the mo- 
tion, now more quickly, now more tardily; and at length, when 
near to death, it ceases to respond by its proper motion, but seems, as 
it were, to nod the head, and is so slightly moved that it appears 
rather to give signs of motion to the pulsating auricles than actually 
to move. The heart, therefore, ceases to pulsate sooner than the 
auricles, so that the auricles have been said to outlive it, the left 
ventricle ceasing to pulsate first of all; then its auricle, next the right 
ventricle; and, finally, all the other parts being at rest and dead, as 
Galen long since observed, the right auricle still continues to beat; 
life, therefore, appears to linger longest in the right auricle. Whilst 
the heart is gradually dying, it is sometimes seen to reply, after two 

' Bauhin, lib. ii, cap. 21. Riolan, lib. viii, cap. i. 



CIRCULATION OF THE BLOOD 83 

or three contractions of the auricles, roused as it were to action, 
and making a single pulsation, slowly, unwillingly, and with an 
effort. 

But this especially is to be noted, that after the heart has ceased 
to beat, the auricles however still contracting, a finger placed upon 
die ventricles perceives the several pulsations of the auricles, pre- 
cisely in the same way and for the same reason, as we have said, 
that 'the pulses of the ventricles are felt in the arteries, to wit, the 
distension produced by the jet of blood. And if at this time, the 
auricles alone pulsating, the point of the heart be cut off with a pair 
of scissors, you will perceive the blood flowing out upon each con- 
traction of the auricles. Whence it is manifest that the blood enters 
the ventricles, not by any attraction or dilatation of the heart, but 
by being thrown into them by the pulses of the auricles. 

And here I would observe, that whenever I speak of pulsations as 
occurring in the auricles or ventricles, I mean contractions : first the 
auricles contract, and then and subsequendy the heart itself con- 
tracts. When the auricles contract they are seen to become whiter, 
especially where they contain but little blood; but they are filled 
as magazines or reservoirs of the blood, which is tending spon- 
taneously and, by its motion in the veins, under pressure towards 
the centre; the whiteness indicated is most conspicuous towards 
the extremities or edges of the auricles at 'the time of their con- 
tractions. 

In fishes and frogs, and other animals which have hearts with 
but a single ventricle, and for an auricle have a kind of bladder 
much distended with blood, at the base of the organ, you may very 
plainly perceive this bladder contracting first, and the contracuon 
of the heart or ventricle following afterwards. 

But I think it right to describe what I have observed of an op- 
posite character: the heart of an eel, of several fishes, and even of 
some (of the higher) animals taken oot of the body, pulsates with- 
out auricles; nay, if it be cut in pieces the several parts may still be 
seen contracting and relaxing; so that in these creatures the body of 
the heart may be seen pulsating and palpitating, after the cessadon 
of all motion in the auricle. But is not this perchance peculiar to 
animals more tenacious of life, whose radical moisture is more 



84 WILLIAM HARVEY 

glutinous, or fat and sluggish, and less readily soluble? The same 
faculty indeed appears in the flesh of eels, which even when skinned 
and embowelled, and cut into pieces, are still seen to move. 

Experimenting with a pigeon upon one occasion, after the heart 
had wholly ceased to pulsate, and the auricles too had become 
motionless, I kept my finger wetted with saliva and warm for a short 
time upon the heart, and observed that under the influence of this 
fomentation it recovered new strength and life, so that both ventri- 
cles and auricles pulsated, contracting and relaxing alternately, 
recalled as it were from death to life. 

Besides this, however, I have occasionally observed, after the heart 
and even its right auricle had ceased pulsating, — when it was in 
articulo mortis in short, — that an obscure motion, an undulation or 
palpitation, remained in the blood itself, which was contained in the 
right auricle, this being apparent so long as it was imbued with heat 
and spirit. And, indeed, a circumstance of the same kind is ex- 
tremely manifest in the course of the generation of animals, as may 
be seen in the course of the first seven days of the incubation of the 
chick: A drop of blood makes its appearance which palpitates, as 
Aristotle had already observed; from this, when the growth is 
further advanced and the chick is fashioned, the auricles of the 
heart are formed, which pulsating henceforth give constant signs of 
life. When at length, and after the lapse of a few days, the outline 
of the body begins to be distinguished, then is the ventricular part 
of the heart also produced, but it continues for a time white and 
apparently bloodless, like the rest of the animal; neither does it 
pulsate or give signs of motion. I have seen a similar condition of 
the heart in the human foetus about the beginning of the third 
month, the heart then being whitish and bloodless, although its 
auricles contained a considerable quantity of purple blood. In the 
same way in the egg, when the chick was formed and had increased 
in size, the heart too increased and acquired ventricles, which then 
began to receive and to transmit blood. 

And this leads me to remark that he who inquires very particularly 
into this matter will not conclude that the heart, as a whole, is the 
primum vivens, ultimum moriens, — ^the first part to live, the last 
to die, — but rather its auricles, or the part which corresponds to the 



CIRCULATION OF THE BLOOD 85 

auricles in serpents, fishes, etc.. which both lives before the heart 
and dies after it. 

Nay, has not the blood itself or spirit an obscure palpitation in- 
herent in it, which it has even appeared to me to retain after death ? 
and it seems very questionable whether or not we are to say that 
life begins with the palpitation or beating of the heart. The seminal 
fluid of all animals — the prolific spirit, as Aristode observed, leaves 
their body with a bound and like a living thing; and nature in death, 
as Aristotle^ further remarks, retracing her steps, reverts to where she 
had set out, and returns at the end of her course to the goal whence 
she had started. As animal generation proceeds from that which is 
not animal, entity from non-entity, so, by a retrograde course, entity, 
by corruption, is resolved into non-entity, whence that in animals, 
which was last created, fails first and that which was first, fails last. 

I have also observed that almost all animals have truly a heart, 
not the larger creatures only, and those that have red blood, but the 
smaller, and pale-blooded ones also, such as slugs, snails, scallops, 
shrimps, crabs, crayfish, and many others; nay, even in wasps, 
hornets, and flies, I have, with the aid of a magnifying glass, and at 
the upper part of what is called the tail, both seen the heart pul- 
sating myself, and shown it to many others. 

But in the pale^blooded tribes the heart pulsates sluggishly and 
deliberately, contracting slowly as in animals that are moribund, a 
fact that may readily be seen in the snail, whose heart will be found 
at the bottom of that orifice in the right side of the body which is 
seen to be opened and shut in the course of respiration, and whence 
saliva is discharged, the incision being made in the upper aspect of 
the body, near the part which corresponds to the liver. 

This, however, is to be observed: that in winter and the colder 
season, exsanguine animals, such as the snail, show no pulsation; 
they seem rather to live after the manner of vegetables, or of those 
other productions which are therefore designated plant-animals. 

It is also to be noted that all animals which have a heart have 

also auricles, or something analogous to auricles; and, further, that 

whenever the heart has a double ventricle, there are always two 

auricles present, but not otherwise. If you turn to the production of 

' De Motu Animal., cap. 8. 



86 WILLIAM HARVEY 

the chick in ovo, however, you will find at first no more a vesicle 
or auricle, or pulsating drop of blood; it is only by and by, when 
the development has made some progress, that the heart is fashioned; 
even so in certain animals not destined to attain to the highest per- 
fection in their organization, such as bees, wasps, snails, shrimps, 
crayfish, etc., we only find a certain pulsating vesicle, like a sort of 
red or white palpitating point, as the beginning or principle of 
their life. 

We have a small shrimp in these countries, which is taken in the 
Thames and in the sea, the whole of whose body is transparent; this 
creature, placed in a little water, has frequently afforded myself and 
particular friends an opportunity of observing the motions of the 
heart with the greatest distinctness, the external parts of the body 
presenting no obstacle to our view, but the heart being perceived as 
though it had been seen through a window. 

I have also observed the first rudiments of the chick in the course 
of the fourth or fifth day of the incubation, in the guise of a little 
cloud, the shell having been removed and the egg immersed in clear 
tepid water. In the midst of the cloudlet in question there was a 
bloody point so small that it disappeared during the contraction and 
escaped the sight, but in the relaxation it reappeared again, red and 
like the point of a pin; so that betwixt the visible and invisible, 
betwixt being and not being, as it were, it gave by its pulses a kind 
of representation of the commencement of life. 

CHAPTER V 
Of the Motion, Action and Office of the Heart 

From these and other observations of a similar nature, I am per- 
suaded it will be found that the motion of the heart is as follows: 

First of all, the auricle contracts, and in the course of its contrac- 
tion forces the blood (which it contains in ample quantity as the 
head of the veins, the store-house and cistern of the blood) into 
the ventricle, which, being filled, the heart raises itself straightway, 
makes all its fibres tense, contracts the ventricles, and performs a 
beat, by which beat it immediately sends the blood supplied to it 
by the auricle into the arteries. The right ventricle sends its charge 



CIRCULATION OF THE BLOOD 87 

into the lungs by the vessel which is called vena arteriosa, but which 
in structure and function, and all other respects, is an artery. The 
left ventricle sends its charge into the aorta, and through this by the 
arteries to the body at large. 

These two motions, one of the ventricles, the other of the auricles, 
take place consecutively, but in such a manner that there is a kind 
of harmony or rhythm preserved between them, the two concurring 
in such wise that but one motion is apparent, especially in the 
warmer blooded animals, in which the movements in question are 
rapid. Nor is this for any other reason than it is in a piece of ma- 
chinery, in which, though one wheel gives motion to another, yet all 
the wheels seem to move simultaneously; or in that mechanical con- 
trivance which is adapted to firearms, where, the trigger being 
touched, down comes the flint, strikes against the steel, elicits a 
spark, which faUing among the powder, ignites it, when the flame 
extends, enters the barrel, causes the explosion, propyls the ball, and 
the mark is attained — all of which incidents, by reason of the celerity 
with which they happen, seem to take place in the twinkling of an 
eye. So also in deglutition: by the elevation of the root of the 
tongue, and the compression of the mouth, the food or drink is 
pushed into the fauces, when the larynx is closed by its muscles and 
by the epiglottis. The pharynx is then raised and opened by its mus- 
cles in the same way as a sac that is to be filled is lifted up and its 
mouth dilated. Upon the mouthful being received, it is forced down- 
wards by the transverse muscles, and then carried farther by the 
longitudinal ones. Yet all these motions, though executed by differ- 
ent and distinct organs, are performed harmoniously, and in such 
order that they seem to constitute but a single motion and act, which 
we call deglutition. 

Even so does it come to pass with the motions and action of the 
heart, which constitute a kind of deglutition, a transfusion of the 
blood from the veins to the arteries. And if anyone, bearing these 
things in mind, will carefully watch the motions of the heart in the 
body of a living animal, he will perceive not only all the particulars 
I have mentioned, viz., the heart becoming erect, and making one 
continuous motion with its auricles; but farther, a certain obscure 
undulation and lateral incUnation in the direction of the axis of the 



88 WILLIAM HARVEY 

right ventricle, as i£ twisting itself slightly in performing its work. 
And indeed everyone may see, when a horse drinks, that the water 
is drawn in and transmitted to the stomach at each movement of 
the throat, which movement produces a sound and yields a pulse 
both to the ear and the touch; in the same way it is with each 
motion of the heart, when there is the delivery of a quantity of 
blood from the veins to the arteries a pulse takes place, and can 
be heard within the chest. 

The motion of the heart, then, is entirely of this description, and 
the one action of the heart is the transmission of the blood and its 
distribution, by means of the arteries, to the very extremities of the 
body; so that the pulse which we feel in the arteries is nothing more 
than the impulse of the blood derived from the heart. 

Whether or not the heart, besides propelling the blood, giving it 
motion locally, and distributing it to the body, adds anything else 
to it — ^heat, spirit, perfection, — must be inquired into by-and-by, 
and decided upon other grounds. So much may suffice at this time, 
when it is shown that by the action of the heart the blood is trans- 
fused throug'h the ventricles from the veins to the arteries, and dis- 
tributed by them to all parts of the body. 

The above, indeed, is admitted by all, both from the structure 
of the heart and the arrangement and action of its valves. But still 
they are like persons purblind or groping about in the dark, for 
they give utterance to various, contradictory, and incoherent senti- 
ments, delivering many things upon conjecture, as we have already 
shown. 

The grand cause of doubt and error in this subject appears to me 
to have been the intimate connexion between the heart and the 
lungs. When men saw both the pulmonary artery and the pul- 
monary veins losing themselves in the lungs, of course it became a 
puzzle to them to know how or by what means the right ventricle 
should distribute the blood to the body, or the left draw it from 
the venje cava. This fact is borne witness to by Galen, whose words, 
when writing against Erasistratus in regard to the origin and use of 
the veins and the coction of the blood, are the following': "You 
will reply," he says, "that the effect is so; that the blood is prepared 
*De Placitis Hippocratis et Platonis, vi. 



CIRCULATION OF THE BLOOD 89 

in the liver, and is thence transferred to the heart to receive its 
proper form and last perfection; a statement which does not appear 
devoid of reason; for no great and perfect work is ever accomplished 
at a single effort, or receives its final polish from one instrument. 
But if this be actually so, then show us another vessel which draws 
the absolutely perfect blood from the heart, and distributes it as the 
arteries do the spirits over the whole body." Here then is a reason- 
able opinion not allowed, because, forsooth, besides not seeing the 
true means of transit, he could not discover the vessel which should 
transmit the blood from the heart to the body at large! 

But had anyone been there in behalf of Erasistratus, and of that 
opinion which we now espouse, and which Galen himself acknowl- 
edges in other respects consonant with reason, to have pointed to 
the aorta as the vessel which distributes the blood from the heart to 
the rest of the body, I wonder what would have been the answer of 
chat most ingenious and learned man .'' Had he said that the artery 
transmits spirits and not blood, he would indeed sufficiently have 
answered Erasistratus, who imagined that the arteries contained 
nothing but spirits; but then he would have contradicted himself, 
and given a foul denial to that for which he had keenly contended 
in his writings against this very Erasistratus, to wit, that blood in 
substance is contained in the arteries, and not spirits; a fact which 
he demonstrated not only by many powerful arguments, but by 
experiments. 

But if the divine Galen will here allow, as in other places he does, 
"that all the arteries of the body arise from the great artery, and that 
this takes its origin from the heart; that all these vessels naturally 
contain and carry blood; that the three semilunar valves situated at 
the orifice of the aorta prevent the return of the blood into the heart, 
and that nature never connected them with this, the most noble 
viscus of the body, unless for some important end"; if, I say, this 
father of physicians concedes all these things, — and I quote his own 
words, — I do not see how he can deny that the great artery is the 
very vessel to carry the blood, when it has attained its highest term 
of perfection, from the heart for distribution to all parts of the body. 
Gr would he perchance still hesitate, like all who have come after 
him, even to the present hour, because he did not perceive the route 



90 WILLIAM HARVEY 

by which the blood was transferred from the veins to the arteries, in 
consequence, as I have already said, of the intimate connexion be- 
tween the heart and the lungs? And that this difficulty puzzled 
anatomists not a little, when in their dissections they found the 
pulmonary artery and left ventricle full of thick, black, and clotted 
blood, plainly appears, when they felt themselves compelled to 
affirm that the blood made its way from the right to the left ventricle 
by transuding through the septum of the heart. But this fancy I 
have already refuted. A new pathway for the blood must therefore 
be prepared and thrown open, and being once exposed, no further 
difficulty will, I believe, be experienced by anyone in admitting what 
I have already proposed in regard to the pulse of the heart and 
arteries, viz., the passage of the blood from the veins to the arteries, 
and its distribution to the whole of the body by means of these 
vessels. 

CHAPTER VI 

Of the Course by which the Blood is Carried from the Vena 
Cava into the Arteries, or from the Right into the Left 
Ventricle of the Heart 

Since the intimate connexion of the heart with the lungs, which is 
apparent in the human subject, has been the probable cause of the 
errors that have been committed on this point, they plainly do amiss 
who, pretending to speak of the parts of animals generally, as anat- 
omists for the most pant do, confine their researches to the human 
body alone, and that when it is dead. They obviously do not act 
otherwise than he who, having studied the forms of a single com- 
monwealth, should set about the composition of a general system 
of polity; or who, having taken cognizance of the nature of a 
single field, should imagine that he had mastered the science of 
agriculture; or who, upon the ground of one particular proposition, 
should proceed to draw general conclusions. 

Had anatomists only been as conversant with the dissection of 
the lower animals as they are with that of the human body, the 
matters that have hitherto kept them in a perplexity of doubt would, 
in my opinion, have met them freed from every kind of difficulty. 



CIRCULATION OF THE BLOOD 91 

And first, in fishes, in which the heart consists of but a single ven- 
tricle, being devoid of lungs, the thing is sufficiently manifest. Here 
the sac, which is situated at the base of the heart, and is the part 
analogous to the auricle in man, plainly forces the blood into the 
heart, and the heart, in its turn, conspicuously transmits it by a pipe 
or artery, or vessel analogous to an artery; these are facts which are 
confirmed by simple ocular inspection, as well as by a division of 
the vessel, when the blood is seen to be projected by each pulsation 
of the heart. 

The same thing is also not difficult of demonstration in those 
animals that have, as it were, no more than a single ventricle to 
the heart, such as toads, frogs, serpents, and lizards, which have 
lungs in a certain sense, as they have a voice. I have many observa- 
tions by me on the admirable structure of the lungs of these animals, 
and matters appertaining, which, however, I cannot introduce in 
this place. Their anatomy plainly shows us that the blood is trans- 
ferred in them from the veins to the arteries in the same manner as 
in higher animals, viz., by the action of the heart; the way, in fact, 
is patent, open, manifest; there is no difficulty, no room for doubt 
about it; for in them the matter stands precisely as it would in man 
were the septum of his heart perforated or removed, or one ven- 
tricle made out of two; and this being the case, I imagine that no one 
will doubt as to the way by which the blood may pass from the 
veins into the arteries. 

But as there are actually more animals which have no lungs than 
there are furnished with them, and in like manner a greater, num- 
ber which have only one ventricle than there are with two, it is open 
to us to conclude, judging from the mass or multitude of living 
creatures, that for the major part, and generally, there is an open way 
by which the blood is transmitted from the veins through the 
sinuses or cavities of the heart into the arteries. 

I have, however, cogitating with myself, seen further, that the 
same thing obtained most obviously in the embryos of those animals 
that have lungs; for in the foetus the four vessels belonging to the 
heart, viz., the vena cava, the pulmonary artery, the pulmonary 
vein, and the great artery or aorta, are all connected otherwise than 
in the adult, a fact sufficiently known to every anatomist. The first 



92 WILLIAM HARVEY 

contact and union o£ the vena cava with the pulmonary veins, which 
occurs before the cava opens properly into the right ventricle of the 
heart, or gives off the coronary vein, a little above its escape from 
the liver, is by a lateral anastomosis; this is an ample foramen, of 
an oval form, communicating between the cava and the pulmonary 
vein, so that the blood is free to flow in the greatest abundance by 
that foramen from the vena cava into the pulmonary vein, and left 
auricle, and from thence into the left ventricle. Farther, in this fora- 
men ovale, from that part which regards the pulmonary vein, there 
is a thin tough membrane, larger than the opening, extended like an 
operculum or cover; this membrane in the adult blocking up the 
foramen, and adhering on all sides, finally closes it up, and almost 
obliterates every trace of it. In the foetus, however, this membrane 
is so contrived that falling loosely upon itself, it permits a ready 
access to the lungs and heart, yielding a passage to the blood which is 
streaming from the cava, and hindering the tide at the same time 
from flowing back into that vein. All things, in short, permit us 
to believe that in the embryo the blood must constantly pass by this 
foramen from the vena cava into the pulmonary vein, and from 
thence into the left auricle of the heart; and having once entered 
there, it can never regurgitate. 

Another union is that by the pulmonary artery, and is effected 
when that vessel divides into two branches after its escape from the 
right ventricle of the heart. It is as if to the two trunks already men- 
tioned a third were superadded, a kind of arterial canal, carried 
obliquely from the pulmonary artery, to perforate and terminate in 
the great artery or aorta. So that in the dissection of the embryo, as 
it were, two aortas, or two roots of the great artery, appear springing 
from die heart. This canal shrinks gradually after birth, and after 
a time becomes withered, and finally almost removed, like the 
umbilical vessels. 

The arterial canal contains no membrane or valve to direct or 
impede the flow of blood in this or in that direction : for at the root 
of the pulmonary artery, of which the arterial canal is the contin- 
uation in the foetus, there are three semilunar valves, which open 
from within outwards, and oppose no obstacle to the blood flowing 



CIRCULATION OF THE BLOOD 93 

in this direction or from the right ventricle into the pulmonary 
artery and aorta; but they prevent all regurgitation from the aorta 
or pulmonic vessels back upon the right ventricle; closing with per- 
fect accuracy, they oppose an effectual obstacle to everything of the 
kind in the embryo. So that there is also reason to believe that when 
the heart contracts, the blood is regularly propelled by the canal or 
passage indicated from the right ventricle into the aorta. 

What is commonly said in regard to these two great communica- 
tions, to wit, that they exist for the nutrition of the lungs, is both 
improbable and inconsistent; seeing that in the adiJt they are closed 
up, abolished, and consolidated, although the lungs, by reason of 
their heat and motion, must then be presumed to require a larger 
supply of nourishment. The same may be said in regard to the asser- 
tion that the heart in the embryo does not pulsate, that it neither acts 
nor moves, so that nature was forced to make these communications 
for the nutrition of the lungs. This is plainly false; for simple in- 
spection of the incubated egg, and of embryos just taken out of the 
uterus, shows that the heart moves in them precisely as in adults, 
and that nature feels no such necessity. I have myself repeatedly 
seen these motions, and Aristotle is likewise witness of their reality. 
"The pulse," he observes, "inheres in the very constitution of the 
heart, and appears from the beginning as is learned both from the 
dissection of living animals and the formation of the chick in the 
egg." ' But we further observe that the passages in question are 
not only pervious up to the period of birth in man, as well as in other 
animals, as anatomists in general have described them, but for sev- 
eral months subsequently, in some indeed for several years, not to 
say for the whole course of life; as, for example, in the goose, snipe, 
and various birds and many of the smaller animals. And this circum- 
stance it was, perhaps, that imposed upon Botallus, who thought he 
had discovered a new passage for the blood from the vena cava into 
the left ventricle of the heart; and I own that when I met with the 
same arrangement in one of the larger members of the mouse family, 
in the adult state, I was myself at first led to something of a like 
conclusion. 

* Lib. de Spiritu, cap. v. 



94 WILLIAM HARVEY 

From this it will be understood that in the human embryo, and in 
the embryos of animals in which the communications are not 
closed, the same thing happens, namely, that the heart by its motion 
propels the blood by obvious and open passages from the vena cava 
into the aorta through the cavities of both the ventricles, the right 
one receiving the blood from the auricle, and propelling it by the 
pulmonary artery and its continuation, named the ductus arteriosus, 
into the aorta; the left, in like manner, charged by the contraction of 
its auricle, which has received its supply through the foramen ovale 
from the vena cava, contracting, and projecting the blood through 
the root of the aorta into the trunk of that vessel. 

In embryos, consequendy, whilst the lungs are yet in a state of 
inaction, performing no function, subject to no motion any more 
than if they had not been present, nature uses the two ventricles of 
the heart as if they formed but one, for the transmission of the blood. 
The condition of the embryos of 'those animals which have lungs, 
whilst these organs are yet in abeyance and not employed, is the 
same as that of those animals which have no lungs. 

So it clearly appears in the case of the foetus that the heart by its 
action transfers the blood from the vena cava into the aorta, and 
that by a route as obvious and open, as if in the adult the two ven- 
tricles were made to communicate by the removal of their septum. 
We therefore find that in the greater number of animals — ^in all, 
indeed, at a certain period of their existence — the channels for the 
transmission of the blood through the heart are conspicuous. But we 
have to inquire why in some creatures — ^those, namely, that have 
warm blood, and that have attained to the adult age, man among 
the number — we should not conclude that the same thing is accom- 
plished through the substance of the lungs, which in the embryo, and 
at a time when the function of these organs is in abeyance, nature 
effects by the direct passages described, and which, indeed, she 
seems compelled to adopt through want of a passage by the lungs; 
or why it should be better (for nature always does that which is 
best) that she should close up the various open routes which she 
had formerly made use of in the embryo and foetus, and still uses in 
all other animals. Not only does she thereby open up no new ap- 



CIRCULATION OF THE BLOOD 95 

parent channels for the passages of the blood, but she even shuts up 
those which formerly existed. 

And now the discussion is brought to this point, that they who 
inquire into the ways by which the blood reaches the left ventricle 
of the heart and pulmonary veins from the vena cava, vdll pursue 
the wisest course if they seek by dissection to discover the causes 
why in the larger and more perfect animals of mature age nature has 
rather chosen to make the blood percolate the parenchyma of the 
lungs, than, as in other instances, chosen a direct and obvious course 
— for I assume that no other path or mode of transit can be enter- 
tained. It must be because the larger and more perfect animals are 
warmer, and when adult their heat greater — ignited, as I might say, 
and requiring to be damped or mitigated, that the blood is sent 
through the lungs, in order that it may be tempered by the air that 
is inspired, and prevented from boiling up, and so becoming extin- 
guished, or something else of the sort. But to determine these mat- 
ters, and explain them satisfactorily, were to enter on a speculation 
in regard to the office of the lungs and the ends for which they 
exist. Upon such a subject, as well as upon what pertains to respira- 
tion, to the necessity and use of the air, etc., as also to the variety and 
diversity of organs that exist in the bodies of animals in connexion 
with these matters, although I have made a vast number of observa- 
tions, I shall not speak till I can more conveniently set them forth in 
a treatise apart, lest I should be held as wandering too wide of my 
present purpose, which is the use and motion of the heart, and be 
charged with speaking of things beside the question, and rather com- 
pUcating and quitting than illustrating it. And now returning to my 
immediate subject, I go on with what yet remains for demonstra- 
tion, viz., that in the more perfect and warmer adult animals, and 
man, the blood passes from the right ventricle of the heart by the 
pulmonary artery, into the lungs, and thence by the pulmonary 
veins into the left auricle, and from there into the left ventricle of 
the heart. And, first, I shall show that this may be so, and then I 
shall prove that it is so in fact. 



96 WILLIAM HARVEY 

CHAPTER VII 

The Blood Passes through the Substance of the Lungs from the 
Right Ventricle of the Heart into the Pulmonary Veins 
AND Left Ventricle 

That this is possible, and that there is nothing to prevent it from 
being so, appears when we reflect on the way in which water per- 
meating the earth produces springs and rivulets, or when we specu- 
late on the means by which the sweat passes through the skin, or the 
urine through the substance of the kidneys. It is well known that 
persons who use the Spa waters or those of La Madonna, in the ter- 
ritories of Padua, or others of an acidulous or vitriolated nature, or 
who simply swallow drinks by the gallon, pass all off again within 
an hour or two by the bladder. Such a quantity of liquid must take 
some short time in the concoction: it must pass through the liver 
(it is allowed by all that the juices of the food we consume pass 
twice through this organ in the course of the day); it must flow 
through the veins, through the tissues of the kidneys, and through 
the ureters into the bladder. 

To those, therefore, whom I hear denying that the blood, aye, the 
whole mass of the blood, may pass through the substance of the 
lungs, even as the nutritive juices percolate the liver, asserting such 
a proposition to be impossible, and by no means to be entertained as 
credible, I reply, with the poet, that they are of that race of men 
who, w^hen they will, assent full readily, and when they will not, 
by no manner of means; who, when their assent is wanted, fear, and 
when it is not, fear not to give it. 

The substance of the liver is extremely dense, so is that of the 
kidney; the lungs, however, are of a much looser texture, and if 
compared with the kidneys are absolutely spongy. In the liver there 
is no forcing, no impelling power; in the lungs the blood is forced 
on by the pulse of the right ventricle, the necessary effect of whose 
impulse is the distension of the vessels and the pores of the lungs. 
And then the lungs, in respiration, are perpetually rising and fall- 
ing: motions, the effect of which must needs be to open and shut the 
pores and vessels, precisely as in the case of a sponge, and of parts 



CIRCULATION OF THE BLOOD 97 

having a spongy structure, when they are alternately compressed and 
again are suffered to expand. The liver, on the contrary, remains 
at rest, and is never seen to be dilated or constricted. Lastly, if no 
one denies the possibility in man, oxen, and the larger animals gen- 
erally, of the whole of the ingested juices passing through the liver, 
in order to reach the vena cava, for this reason, that if nourishment 
is to go on, these juices must needs get into the veins, and there is no 
other way but the one indicated, why should not the same arguments 
be held of avail for the passage of the blood in adults through the 
lungs? Why not maintain, with Columbus, that skilful and learned 
anatomist, that it must be so from the capacity and structure of the 
pulmonary vessels, and from the fact of the pulmonary veins and 
ventricle corresponding with them, being always found to contain 
blood, which must needs have come from the veins, and by no 
other passage save through the lungs? Columbus, and we also, 
from what precedes, from dissections, and other arguments, conceive 
the thing to be clear. But as there are some who admit nothing 
unless upon authority, let them learn that the truth I am contend- 
ing for can be confirmed from Galen's own words, namely, that not 
only may the blood be transmitted from the pulmonary artery into 
the pulmonary veins, then into the left ventricle of the heart, and 
from thence into the arteries of the body, but that this is effected by 
the ceaseless pulsation of the heart and the motion of the lungs in 
breathing. 

There are, as everyone knows, three sigmoid or semilunar valves 
situated at the orifice of the pulmonary artery, which effectually pre- 
vent the blood sent into the vessel from returning into the cavity of 
the heart. Now Galen, explaining the use of these valves, and the 
necessity for them, employs the following language:' "There is 
everywhere a mutual anastomosis and inosculation of the arteries 
with the veins, and they severally transmit both blood and spirit, by 
certain invisible and undoubtedly very narrow passages. Now if the 
mouth of the pulmonary artery had stood in like manner continually 
open, and nature had found no contrivance for closing it when 
requisite, and opening it again, it would have been impossible that 
the blood could ever have passed by the invisible and delicate 
'De Usu partium, lib. vi, cap. 10. 



98 WILLIAM HARVEY 

mouths, during the contractions of the thorax, into the arteries; 
for all things are not alike readily attracted or repelled; but that 
which is light is more readily drawn in, the instrument being dilated, 
and forced out again when it is contracted, than that which is 
heavy; and in like manner is anything drawn more rapidly along 
an ample conduit, and again driven forth, than it is through a nar- 
row tube. But when the thorax is contracted the pulmonary veins, 
which are in the lungs, being driven inwardly, and powerfully 
compressed on every side, immediately force out some of the spirit 
they contain, and at the same time assume a certain portion of blood 
by those subtle mouths, a thing that could never come to pass were 
the blood at liberty to flow back into the heart through the great 
orifice of the pulmonary artery. But its return through this great 
opening being prevented, when it is compressed on every side, a 
certain portion of it distils into the pulmonary veins by the minute 
orifices mentioned." And shortly afterwards, in the next chapter, 
he says: "The more the thorax contracts, the more it strives to force 
out the blood, the more exactly do these membranes (viz., the 
semilunar valves) close up the mouth of the vessel, and suffer noth- 
ing to regurgitate." The same fact he has also alluded to in a pre- 
ceding part of the tenth chapter: "Were there no valves, a three- 
fold inconvenience would result, so that the blood would then per- 
form this lengthened course in vain; it would flow inwards during 
the disastoles of the lungs and fill all their arteries; but in the systoles, 
in the manner of the tide, it would ever and anon, like the Euripus, 
flow backwards and forwards by the same way, with a reciprocating 
motion, which would nowise suit the blood. This, however, may 
seem a matter of little moment: but if it meantime appear that the 
function of respiration suffer, then I think it would be looked upon 
as no trifle, etc." Shortly afterwards he says : "And then a third in- 
convenience, by no means to be thought lightly of, would follow, 
were the blood moved backwards during the expirations, had not 
our Maker instituted those supplementary membranes." In the 
eleventh chapter he concludes: "That they (the valves) have all a 
common use, and that it is to prevent regurgitation or backward 
motion; each, however, having a proper function, the one set draw- 
ing matters from the heart, and preventing their return, the other 



CIRCULATION OF THE BLOOD 99 

drawing matters into the heart, and preventing their escape from it. 
For nature never intended to distress the heart with needless la- 
bour, neither to bring aught into the organ which it had been better 
to have kept away, nor to take from it again aught which it was 
requisite should be brought. Since, then, there are four orifices in 
all, two in either ventricle, one of these induces, the other educes." 
And again he says: "Farther, since there is one vessel, which con- 
sists of a simple covering implanted in the heart, and another which 
is double, extending from it (Galen is here speaking of the right 
side of the heart, but I extend his observations to the left side also), 
a kind of reservoir had to be provided, to which both belonging, the 
blood should be drawn in by one, and sent out by the other." 

Galen adduces this argument for the transit of the blood by the 
right ventricle from the vena cava into the lungs; but we can use it 
with still greater propriety, merely changing the terms, for the 
passage of the blood from the veins through the heart into the 
arteries. From Galen, however, that great man, that father of phy- 
sicians, it clearly appears that the blood passes through the lungs 
from the pulmonary artery into the minute branches of the pul- 
monary veins, urged to this both by the pulses of the heart and by 
the motions of the lungs and thorax; that the heart, moreover, is 
incessantly receiving and expelling the blood by and from its ven- 
tricles, as from a magazine or cistern, and for this end it is furnished 
with four sets of valves, two serving for the induction and two for 
the eduaion of the blood, lest, like the Euripus, it should be incom- 
modiously sent hither and thither, or flow back into the cavity 
which it should have quitted, or quit the part where its presence 
was required, and so the heart might be oppressed with labour in 
vain, and the office of the lungs be interfered with.^ Finally, our posi- 
tion that the blood is continually permeating from the right to the 
left ventricle, from the vena cava into the aorta, through the poros- 
ities of the lungs, plainly appears from this, that since the blood is 
incessantly sent from the right ventricle into the lungs by the pul- 
monary artery, and in like manner is incessantly drawn from the 
lungs into the left ventricle, as appears from what precedes and the 

' See the Commentary of the learned Hofmann upon the Sixth Book of Galen, 
"De Usu partium," a work which I first saw after I had written what precedes. 



100 WILLIAM HARVEY 

position of the valves, it cannot do otherwise than pass through 
continuously. And then, as the blood is incessantly flowing into the 
right ventricle of the heart, and is continually passed out from the 
left, as appears in like manner, and as is obvious, both to sense and 
reason, it is impossible that the blood can do otherwise than pass 
continually from the vena cava into the aorta. 

Dissection consequently shows distinctly what takes place in the 
majority of animals, and indeed in all, up to the period of their 
maturity; and that the same thing occurs in adults is equally cer- 
tain, both from Galen's words, and what has already been said, only 
that in the former the transit is effected by open and obvious pas- 
sages, in the latter by the hidden porosities of the lungs and the min- 
ute inosculations of vessels. It therefore appears that, although one 
ventricle of the heart, the left to wit, would suffice for the distribu- 
tion of the blood over the body, and its eduction from the vena cava, 
as indeed is done in those creatures that have no lungs, nature, 
nevertheless, when she ordained that the same blood should also 
percolate the lungs, saw herself obliged to add the right ventricle, the 
pulse of which should force the blood from the vena cava through 
the lungs into the cavity of the left ventricle. In this way, it may be 
said, that the right ventricle is made for the sake of the lungs, and 
for the transmission of the blood through them, not for their nutri- 
tion; for it were unreasonable to suppose that the lungs should re- 
quire so much more copious a supply of nutriment, and that of so 
much purer and more spirituous a nature as coming immediately 
from the ventricle of the heart, that either the brain, with its pecu- 
liarly pure substance, or the eyes, with their lustrous and truly ad- 
mirable structure, or the flesh of the heart itself, which is more 
suitably nourished by the coronary artery. 

CHAPTER VIII 

Of the Quantity of Blood Passing Through the Heart from 

THE Veins to the Arteries; and of the Circular Motion of 

THE Blood 

Thus far I have spoken of the passage of the blood from the veins 

into the arteries, and of the manner in which it is transmitted and 

distributed by the action of the heart; points to which some, moved 



CIRCULATION OF THE BLOOD lOI 

either by the authority of Galen or Ck)lumbus, or the reasonings o£ 
others, will give in their adhesion. But what remains to be said 
upon the quantity and source of the blood which thus passes is of a 
character so novel and unheard-of that I not only fear injury to my- 
self from the envy of a few, but I tremble lest I have mankind at 
large for my enemies, so much doth wont and custom become a 
second nature. Doctrine once sown strikes deep its root, and respect 
for antiquity influences all men. Still the die is cast, and my trust 
is in my love of truth and the candour of cultivated minds. And 
sooth to say, when I surveyed my mass of evidence, whether derived 
from vivisections, and my various reflections on them, or from the 
study of the ventricles of the heart and the vessels that enter into 
and issue from them, the symmetry and size of these conduits, — for 
nature doing nothing in vain, would never have given them so large 
a relative size without a purpose, — or from observing the arrange- 
ment and intimate structure of the valves in particular, and of the 
other parts of the heart in general, with many things besides, I fre- 
quently and seriously bethought me, and long revolved in my mind, 
what might be the quantity of blood which was transmitted, in 
how short a time its passage might be effected, and the like. But 
not finding it possible that this could be supplied by the juices of 
the ingested aliment without the veins on the one hand becoming 
drained, and the arteries on the other getting ruptured through the 
excessive charge of blood, unless the blood should somehow find its 
way from the arteries into the veins, and so return to the right side 
of the heart, I began to think whether there might not be a motion, 
AS IT WERE, IN A CIRCLE. Now, this I afterwards found to be true; 
and I finally saw that the blood, forced by the action of the left 
ventricle into the arteries, was distributed to the body at large, and 
its several parts, in the same manner as it is sent through the lungs, 
impelled by the right ventricle into the pulmonary artery, and that 
it then passed through the veins and along the vena cava, and so 
round to the left ventricle in the manner already indicated. This 
motion we may be allowed to call circular, in the same way as 
Aristotle says that the air and the rain emulate the circular motion 
of the superior bodies; for the moist earth, warmed by the sun, 
evaporates; the vapours drawn upwards are condensed, and de- 



102 WILLIAM HARVEY 

scending in the form of rain, moisten the earth again. By this 
arrangement are generations of Hving things produced; and in Uke 
manner are tempests and meteors engendered by the circular motion, 
and by the approach and recession of the sun. 

And similarly does it come to pass in the body, through the mo- 
tion of the blood, that the various parts are nourished, cherished, 
quickened by the warmer, more perfect, vaporous, spirituous, and, 
as I may say, alimentive blood; which, on the other hand, owing to 
its contact with these parts, becomes cooled, coagulated, and so to 
speak effete. It then returns to its sovereign, the heart, as if to its 
source, or to the inmost home of the body, there to recover its state 
of excellence or perfection. Here it renews its fluidity, natural heat, 
and becomes powerful, fervid, a kind of treasury of life, and im- 
pregnated with spirits, it might be said with balsam. Thence it is 
again dispersed. All this depends on the motion and action of the 
heart. 

The heart, consequently, is the beginning of life; the sun of the 
microcosm, even as the sun in his turn might well be designated the 
heart of the world; for it is the heart by whose virtue and pulse the 
blood is moved, perfected, and made nutrient, and is preserved from 
corruption and coagulation; it is the household divinity which, dis- 
charging its function, nourishes, cherishes, quickens the whole 
body, and is indeed the foundation of life, the source of all action. 
But of these things we shall speak more opportunely when we come 
to speculate upon the final cause of this motion of the heart. 

As the blood-vessels, therefore, are the canals and agents that 
transport the blood, they are of two kinds, the cava and the aorta; 
and this not by reason of there being two sides of the body, as 
Aristotle has it, but because of the difference of office, not, as is 
commonly said, in consequence of any diversity of structure, for in 
many animals, as I have said, the vein does not differ from the 
artery in the thickness of its walls, but solely in virtue of their 
distinct functions and uses. A vein and an artery, both styled veins 
by the ancients, and that not without reason, as Galen has remarked, 
for the artery is the vessel which carries the blood from the heart 
to the body at large, the vein of the present day bringing it back 
from the general system to the heart; the former is the conduit from, 



CIRCULATION OF THE BLOOD IO3 

the latter the channel to, the heart; the latter contains the cruder, 
effete blood, rendered unfit for nutrition; the former transmits the 
digested, perfect, peculiarly nutritive fluid. 

CHAPTER IX 

That there is a Circulation of the Blood is Confirmed from 
THE First Proposition 

But lest anyone should say that we give them vs'ords only, and 
make mere specious assertions without any foundation, and desire 
to innovate without sufficient cause, three points present themselves 
for confirmation, which, being stated, I conceive that the truth I 
contend for will follow necessarily, and appear as a thing obvious 
to all. First, the blood is incessantly transmitted by the action of 
the heart from the vena cava to the arteries in such quantity that it 
cannot be supplied from the ingesta, and in such a manner that the 
whole must very quickly pass through the organ; second, the blood 
under the influence of the arterial pulse enters and is impelled in a 
continuous, equable, and incessant stream through every part and 
member of the body, in much larger quantity than were sufficient 
for nutrition, or than the whole mass of fluids could supply; third, 
the veins in like manner return this blood incessantly to the heart 
from parts and members of the body. These points proved, I con- 
ceive it will be manifest that the blood circulates, revolves, propelled 
and then returning, from the heart to the extremities, from the ex- 
tremities to the heart, and thus that it performs a kind of circular 
motion. 

Let us assume, either arbitrarily or from experiment, the quantity 
of blood which the left ventricle of the heart will contain when 
distended, to be, say, two ounces, three ounces, or one ounce and a 
half — in the dead body I have found it to hold upwards of two 
ounces. Let us assume further how much less the heart will hold 
in the contracted than in the dilated state; and how much blood it 
will project into the aorta upon each contraction; and all the world 
allows that with the systole something is always projected, a neces- 
sary consequence demonstrated in the third chapter, and obvious 
from the structure of the valves; and let us suppose as approaching 



104 WILLIAM HARVEY 

the truth that the fourth, or fifth, or sixth, or even but the eighth 
part of its charge is thrown into the artery at each contraction; this 
would give either half an ounce, or three drachms, or one drachm 
of blood as propelled by the heart at each pulse into the aorta; 
which quantity, by reason of the valves at the root of the vessel, can 
by no means return into the ventricle. Now, in the course of half 
an hour, the heart will have made more than one thousand beats, 
in some as many as two, three, and even four thousand. Multiplying 
the number of drachms propelled by the number of pulses, we 
shall have either one thousand half ounces, or one thousand times 
three drachms, or a like proportional quantity of blood, according 
to the amount which we assume as propelled with each stroke of 
the heart, sent from this organ into the artery — a larger quantity in 
every case than is contained in the whole body! In the same way, 
in the sheep or dog, say but a single scruple of blood passes with 
each stroke of the heart, in one half-hour we should have one 
thousand scruples, or about three pounds and a half, of blood injected 
into the aorta; but the body of neither animal contains above four 
pounds of blood, a fact which I have myself ascertained in the case 
of the sheep. 

Upon this supposition, therefore, assumed merely as a ground 
for reasoning, we see the whole mass of blood passing through the 
heart, from the veins to the arteries, and in like manner through 
the lungs. 

But let it be said that this does not take place in half an hour,, 
but in an hour, or even in a day; any way, it is still manifest that 
more blood passes through the heart in consequence of its action, 
than can either be supplied by the whole of the ingesta, or than can 
be contained in the veins at the same moment. 

Nor can it be allowed that the heart in contracting sometimes 
propels and sometimes does not propel, or at most propels but very 
little, a mere nothing, or an imaginary something: all this, indeed, 
has already been refuted, and is, besides, contrary both to sense and 
reason. For if it be a necessary effect of the dilatation of the heart 
that its ventricles become filled with blood, it is equally so that, 
contracting, these cavities should expel their contents; and this not 
in any trifling measure. For neither are the conduits small, nor the 



CIRCULATION OF THE BLOOD IO5 

contractions few in number, but frequent, and always in some cer- 
tain proportion, whether it be a third or a sixth, or an eiglith, to 
the total capacity of the ventricles, so that a like proportion of blood 
must be expelled, and a like proportion received with each stroke 
of the heart, the capacity of the ventricle contracted always bearing 
a certain relation to the capacity of the ventricle when dilated. And 
since, in dilating, the ventricles cannot be supposed to get filled with 
nothing, or with an imaginary something, so in contracting they 
never expel nothing or aught imaginary, but always a certain some- 
thing, viz., blood, in proportion to the amount of the contraction. 
Whence it is to be concluded that if at one stroke the heart of man, 
the ox, or the sheep, ejects but a single drachm of blood and there 
are one thousand strokes in half an hour, in this interval there will 
have been ten pounds five ounces expelled; if with each stroke two 
drachms are expelled, the quantity would, of course, amount to 
twenty pounds and ten ounces; if half an ounce, the quantity would 
come to forty-one pounds and eight ounces; and were there one 
ounce, it would be as much as eighty-three pounds and four ounces; 
the whole of which, in the course of one-half hour, would have 
been transfused from the veins to the arteries. The actual quantity 
of blood expelled at each stroke of the heart, and the circumstances 
under which it is either greater or less than ordinary, I leave for 
particular determination afterwards, from numerous observations 
which I have made on the subject. 

Meantime this much I know, and would here proclaim to all, 
that the blood is transfused at one time in larger, at another in 
smaller, quantity; and that the circuit of the blood is accomplished 
now more rapidly, now more slowly, according to the temperament, 
age, etc., of the individual, to external and internal circumstances, 
to naturals and non-naturals — sleep, rest, food, exercise, affections 
of the mind, and the like. But, supposing even the smallest quantity 
of blood to be passed through the heart arid the lungs with each 
pulsation, a vastly greater amount would still be thrown into the 
arteries and whole body than could by any possibility be supplied 
by the food consumed. It could be furnished in no other way than 
by making a circuit and returning. 

This truth, indeed, presents itself obviously before us when we 



I06 WILLIAM HARVEY 

consider what happens in the dissection of living animals; the great 
artery need not be divided, but a very small branch only (as Galen 
even proves in regard to man), to have the whole of the blood in 
the body, as well that of the veins as of the arteries, drained away 
in the course of no long time — some half-hour or less. Butchers are 
well aware of the fact and can bear witness to it; for, cutting the 
throat of an ox and so dividing the vessels of the neck, in less than 
a quarter of an hour they have all the vessels bloodless — the whole 
mass of blood has escaped. The same thing also occasionally occurs 
with great rapidity in performing amputations and removing tumors 
in the human subject. 

Nor would this argument lose of its force, did any one say that 
in kilhng animals in the shambles, and performing amputations, 
the blood escaped in equal, if not perchance in larger quantity by 
the veins than by the arteries. The contrary of this statement, in- 
deed, is certainly the truth; the veins, in fact, collapsing, and being 
without any propelling power, and further, because of the impedi- 
ment of the valves, as I shall show immediately, pour out but very 
little blood; whilst the arteries spout it forth with force abundantly, 
impetuously, and as if it were propelled by a syringe. And then the 
experiment is easily tried of leaving the vein untouched and only 
dividing the artery in the neck o£ a sheep or dog, when it viall be 
seen with what force, in what abundance, and how quickly, the 
whole blood in the body, of the veins as well as of the arteries, is 
emptied. But the arteries receive blood from the veins in no other 
way than by transmission through the heart, as we have already 
seen; so that if the aorta be tied at the base of the heart, and the 
carotid or any other artery be opened, no one will now be surprised 
to find it empty, and the veins only replete with blood. 

And now the cause is manifest, why in our dissections we usually 
find so large a quantity of blood in the veins, so little in the arteries; 
why there is much in the right ventricle, little in the left, which 
probably led the ancients to believe that the arteries (as their name 
implies) contained nothing but spirits during the life of an animal. 
The true cause of the difference is perhaps this, that as there is no 
passage to the arteries, save through the lungs and heart, when an 
animal has ceased to breathe and the lungs to move, the blood in 



CIRCULATION OF THE BLOOD IO7 

the pulmonary artery is prevented from passing into the pulmonary 
veins, and from thence into the left ventricle of the heart; just as 
we have already seen the same transit prevented in the embryo, by 
the vi^ant of movement in the lungs and the alternate opening and 
shutting of their hidden and invisible porosities and apertures. But 
the heart not ceasing to act at the same precise moment as the lungs, 
but surviving them and continuing to pulsate for a time, the left 
ventricle and arteries go on distributing their blood to the body at 
large and sending it into the veins; receiving none from the lungs, 
however, they are soon exhausted, and left, as it were, empty. But 
even this fact confirms our views, in no trifling manner, seeing that 
it can be ascribed to no other than the cause we have just assumed. 

Moreover, it appears from this that the more frequently or forcibly 
the arteries pulsate, the more speedily will the body be exhausted 
of its blood during hemorrhage. Hence, also, it happens, that in 
fainting fits and in states of alarm, when the heart beats more lan- 
guidly and less forcibly, hemorrhages are diminished and arrested. 

Still further, it is from this, that after death, when the heart has 
ceased to beat, it is impossible, by dividing either the jugular or 
femoral veins and arteries, by any effort, to force out more than 
one-half of the whole mass of the blood. Neither could the butcher 
ever bleed the carcass effectually did he neglect to cut the throat of 
the ox which he has knocked on the head and stunned, before the 
heart had ceased beating. 

Finally, we are now in a condition to suspect wherefore it is that 
no one has yet said anything to the purpose upon the anastomosis 
of the veins and arteries, either as to where or how it is effected, or 
for what purpose. I now enter upon the investigation of the subject. 

CHAPTER X 

The First Position : of the Quantity of Blood Passing from the 
Veins to the Arteries. And that there is a Circuit of the 
Blood, Freed from Objections, and Farther Confirmed by 
Experiment 

So far our first position is confirmed, whether the thing be re- 
ferred to calculation or to experiment and dissection, viz., that the 



I08 WILLIAM HARVEY 

blood is incessantly poured into the arteries in larger quantities than 
it can be supplied by the food; so that the whole passing over in a 
short space o£ time, it is matter of necessity that the blood perform 
a circuit, that it return to whence it set out. 

But if anyone shall here object that a large quantity may pass 
through and yet no necessity be found for a circulation, that all may 
come from the meat and drink consumed, and quote as an illustra- 
tion the abundant supply of milk in the mammae — for a cow will give 
three, four, and even seven gallons and more in a day, and a woman 
two or three pints whilst nursing a child or twins, which must 
manifestly be derived from the food consumed; it may be answered 
that the heart by computation does as much and more in the course 
of an hour or two. 

And if not yet convinced, he shall still insist that when an artery 
is divided, a preternatural route is, as it were, opened, and that so 
the blood escapes in torrents, but that the same thing does not hap- 
pen in the healthy and uninjured body when no outlet is made; and 
that in arteries filled, or in their natural state, so large a quantity of 
blood cannot pass in so short a space of time as to make any return 
necessary — to all this it may be answered that, from the calculation 
already made, and the reasons assigned, it appears that by so much 
as the heart in its dilated state contains, in addition to its contents 
in the state of constriction, so much in a general way must it emit 
upon each pulsation, and in such quantity must the blood pass, the 
body being entire and naturally constituted. 

But in serpents, and several fishes, by tying the veins some way 
below the heart you will perceive a space between the ligature and 
the heart speedily to become empty; so that, unless you would deny 
the evidence of your senses, you must needs admit the return of the 
blood to the heart. The same thing will also plainly appear when 
we come to discuss our second position. 

Let us here conclude with a single example, confirming all that 
has been said, and from which everyone may obtain conviction 
through the testimony of his own eyes. 

If a live snake be laid open, the heart will be seen pulsating quietly, 
distincdy, for more than an hour, moving like a worm, contracting 
in its longitudinal dimensions, (for it is of an oblong shape), and 



CIRCULATION OF THE BLOOD IO9 

propelling its contents. It becomes of a paler colour in the systole, 
of a deeper tint in the diastole; and almost all things else are seen 
by which I have already said that the truth I contend for is estab- 
lished, only that here everything takes place more slowly, and is 
more distinct. This point in particular may be observed more clearly 
than the noonday sun: the vena cava enters the heart at its lower 
part, the artery quits it at the superior part; the vein being now 
seized either with forceps or between the finger and the thumb, and 
the course of the blood for some space below the heart interrupted, 
you will perceive the part that intervenes between the fingers and 
the heart almost immediately to become empty, the blood being 
exhausted by the action of the heart; at the same time the heart will 
become of a much paler colour, even in its state of dilatation, than it 
was before; it is also smaller than at first, from wanting blood: and 
then it begins to beat more slowly, so that it seems at length as if it 
were about to die. But the impediment to the flow of blood being 
removed, instantly the colour and the size of the heart are restored. 

If, on the contrary, the artery instead of the vein be compressed 
or tied, you will observe the part between the obstacle and the heart, 
and the heart itself, to become inordinately distended, to assume a 
deep purple or even livid colour, and at length to be so much op- 
pressed with blood that you will believe it about to be choked; but 
the obstacle removed, all things immediately return to their natural 
state and colour, size, and impulse. 

Here then we have evidence of two kinds of death: extinction 
from deficiency, and suffocation from excess. Examples of both 
have now been set before you, and you have had opportunity of 
viewing the truth contended for with your own eyes in the heart. 

CHAPTER XI 

The Second Position is Demonstrated 

That this may the more clearly appear to everyone, I have here 
to cite certain experiments, from which it seems obvious that the 
blood enters a limb by the arteries, and returns from it by the veins; 
that the arteries are the vessels carrying the blood from the heart, 
and the veins the returning channels of the blood to the heart; that 



no WILLIAM HARVEY 

in the limbs and extreme parts o£ the body the blood passes either 
immediately by anastomosis from the arteries into the veins, or 
mediately by the porosities of the flesh, or in both ways, as has 
already been said in speaking of the passage of the blood through 
the lungs whence it appears manifest that in the circuit the blood 
moves from that place to this place, and from that point to this one; 
from the centre to the extremities, to wit; and from the extreme 
parts back to the centre. Finally, upon grounds of calculation, with 
the same elements as before, it will be obvious that the quantity can 
neither be accounted for by the ingesta, nor yet be held necessary to 
nutrition. 

The same thing will also appear in regard to ligatures, and 
wherefore they are said to draw; though this is neither from the 
heat, nor the pain, nor the vacuum they occasion, nor indeed from 
any other cause yet thought of; it will also explain the uses and 
advantages to be derived from ligatures in medicine, the principle 
upon which they either suppress or occasion hemorrhage; how they 
induce sloughing and more extensive mortification in extremities; 
and how they act in the castration of animals and the removal of 
warts and fleshy tumours. But it has come to pass, from no one 
having duly weighed and understood the cause and rationale of 
these various effects, that though almost all, upon the faith of the 
old writers, recommend ligatures in the treatment of disease, yet 
very few comprehend their proper employment, or derive any real 
assistance from them in effecting cures. 

Ligatures are either very tight or of medium tightness. A ligature 
I designate as tight or perfect when it so constricts an extremity 
that no vessel can be felt pulsating beyond it. Such a ligature we 
use in amputations to control the flow of blood; and such also are 
employed in the castration of animals and the ablation of tumours. 
In the latter instances, all afflux of nutriment and heat being pre- 
vented by the ligature, we see the testes and large fleshy tumours 
dwindle, die, and finally fall off. 

Ligatures of medium tightness I regard as those which compress 
a limb firmly all round, but short of pain, and in such a way as still 
suffers a certain degree of pulsation to be felt in the artery beyond 
them. Such a hgature is in use in blood-letting, an operation in 



CIRCULATION OF THE BLOOD III 

which the fillet applied above the elbow is not drawn so tight but 
that the arteries at the wrist may still be felt beating under the finger. 

Now let anyone make an experiment upon the arm of a man, 
either using such a fillet as is employed in blood-letting, or grasping 
the limb lightly with his hand, the best subject for it being one who 
is lean, and who has large veins, and the best time after exercise, 
when the body is warm, the pulse is full, and the blood carried in 
larger quantity to the extremities, for all then is more conspicuous; 
under such circumstances let a ligature be thrown about the ex- 
tremity, and drawn as tightly as can be borne, it will first be per- 
ceived that beyond the ligature, neither in the wrist nor anywhere 
else, do the arteries pulsate, at the same time that immediately above 
the ligature the artery begins to rise higher at each diastole, to throb 
more violently, and to swell in its vicinity with a kind of tide, as if 
it strove to break through and overcome the obstacle to its current; 
the artery here, in short, appears as if it were preternaturally full. 
The hand under such circumstances retains its natural colour and 
appearance; in the course of time it begins to fall somewhat in 
temperature, indeed, but nothing is drawn into it. 

After the bandage has been kept on for some short time in this 
way, let it be slackened a little, brought to that state or term of 
medium tightness which is used in bleeding, and it will be seen 
that the whole hand and arm will instantly become deeply coloured 
and distended, and the veins show themselves tumid and knotted; 
after ten or twelve pulses of the artery, the hand will be perceived 
excessively distended, injected, gorged with blood, drawn, as it is 
said, by this medium ligature, without pain, or heat, or any horror 
of a vacuum, or any other cause yet indicated. 

If the finger be applied over the artery as it is pulsating by the 
edge of the fillet, at the moment of slackening it, the blood will be 
felt to glide through, as it were, underneath the finger; and he, too, 
upon whose arm the experiment is made, when the ligature is 
slackened, is distinctly conscious of a sensation of warmth, and of 
something, viz., a stream of blood suddenly making its way along 
the course of the vessels and diffusing itself through the hand, 
which at the same time begins to feel hot, and becomes distended. 

As we had noted, in connexion with the tight ligature, that the 



112 WILLIAM HARVEY 

artery above the bandage was distended and pulsated, not below it, 
so, in the case of the moderately tight bandage, on the contrary, do 
we find that the veins below, never above, the fillet, swell, and be- 
come dilated, whilst the arteries shrink; and such is the degree of 
distension of the veins here, that it is only very strong pressure that 
will force the blood beyond the fillet, and cause any of the veins in 
the upper part of the arm to rise. 

From these facts it is easy for every careful observer to learn that 
the blood enters an extremity by the arteries; for when they are 
effectually compressed nothing is drawn to the member; the hand 
preserves its colour; nothing flows into it, neither is it distended; 
but when the pressure is diminished, as it is with the bleeding fillet, 
it is manifest that the blood is instantly thrown in with force, for 
then the hand begins to swell; which is as much as to say, that when 
the arteries pulsate the blood is flowing through them, as it is when 
the moderately tight ligature is applied; but where they do not pul- 
sate, as, when a tight ligature is used, they cease from transmitting 
anything, they are only distended above the part where the ligature 
is applied. The veins again being compressed, nothing can flow 
through them; the certain indication of which is, that below the 
ligature they are much more tumid than above it, and than they 
usually appear when there is no bandage upon the arm. 

It therefore plainly appears that the ligature prevents the return 
of the blood through the veins to the parts above it, and maintains 
those beneath it in a state of permanent distension. But the arteries, 
in spite of its pressure, and under the force and impulse of the 
heart, send on the blood from the internal parts of the body to the 
parts beyond the ligature. And herein consists the difference be- 
tween the tight and the medium ligature, that the former not only 
prevents the passage of the blood in the veins, but in the arteries 
also; the latter, however, whilst it does not prevent the force of the 
pulse from extending beyond it, and so propelling the blood to the 
extremities of the body, compresses the veins, and greatly or alto- 
gether impedes the return of the blood through them. 

Seeing, therefore, that the moderately tight ligature renders the 
veins turgid and distended, and the whole hand full of blood, I ask, 
whence is this? Does the blood accumulate below the ligature 



CIRCULATION OF THE BLOOD II3 

coming through the veins, or through the arteries, or passing by 
certain hidden porosities? Through the veins it cannot come; still 
less can it come through invisible channels; it must needs, then, 
arrive by the arteries, in conformity with all that has been already 
said. That it cannot flow in by the veins appears plainly enough 
from the fact that the blood cannot be forced towards the heart 
unless the ligature be removed; when this is done suddenly all the 
veins collapse, and disgorge themselves of their contents into the 
superior parts, the hand at the same time resumes its natural pale 
colour, the tumefaction and the stagnating blood having disap- 
peared. 

Moreover, he whose arm or wrist has thus been bound for some 
little time with the medium bandage, so that it has not only got 
swollen and livid but cold, when the fillet is undone is aware of 
something cold making its way upwards along with the returning 
blood, and reaching the elbow or the axilla. And I have myself 
been inclined to think that this cold blood rising upwards to the 
heart was the cause of the fainting that often occurs after blood- 
letting: fainting frequently supervenes even in robust subjects, and 
mostly at the moment of undoing the fillet, as the vulgar say, from 
the turning of the blood. 

Farther, when we see the veins below the ligature instantly swell 
up and become gorged, when from extreme tightness it is somewhat 
relaxed, the arteries meantime continuing unaffected, this is an ob- 
vious indication that the blood passes from the arteries into the 
veins, and not from the veins into the arteries, and that there is 
either an anastomosis of the two orders of vessels, or porosities in 
the flesh and solid parts generally that are permeable to the blood. 
It is farther an indication that the veins have frequent communica- 
tions with one another, because they all become turgid together, 
whilst under the medium ligature applied above the elbow; and if 
any single small vein be pricked with a lancet, they all speedily 
shrink, and disburthening themselves into this they subside almost 
simultaneously. 

These considerations will enable anyone to understand the nature 
of the attraction that is exerted by ligatures, and perchance of 
fluxes generally; how, for example, when the veins are compressed 



114 WILLIAM HARVEY 

by a bandage of medium tightness applied above the elbow, the 
blood cannot escape, whilst it still continues to be driven in, by the 
forcing power of the heart, by which the parts are of necessity filled, 
gorged with blood. And how should it be otherwise? Heat and 
pain and a vacuum draw, indeed; but in such wise only that parts 
are filled, not preternaturally distended or gorged, and not so sud- 
denly and violently overwhelmed with the charge of blood forced 
in upon them, that the flesh is lacerated and the vessels ruptured. 
Nothing of the kind as an effect of heat, or pain, or the vacuum 
force, is either credible or demonstrable. 

Besides, the ligature is competent to occasion the afHux in question 
without either pain, or heat, or a vacuum. Were pain in any way 
the cause, how should it happen that, with the arm bound above 
the elbow, the hand and fingers should swell below the bandage, 
and their veins become distended? The pressure of the bandage 
certainly prevents the blood from getting there by the veins. And 
then, wherefore is there neither swelling nor repletion of the veins, 
nor any sign or symptom of attraction or afflux, above the ligature? 
But this is the obvious cause of the preternatural attraction and 
swelling below the bandage, and in the hand and fingers, that the 
blood is entering abundantly, and with force, but cannot pass out 
again. 

Now is not this the cause of all tumefaction, as indeed Avicenna 
has it, and of all oppressive redundancy in parts, that the access to 
them is open, but the egress from them is closed? Whence it comes 
that they are gorged and tumefied. And may not the same thing 
happen in local inflammations, where, so long as the swelling is on 
the increase, and has not reached its extreme term, a full pulse is 
felt in the part, especially when the disease is of the more acute 
kind, and the swelling usually takes place most rapidly. But these 
are matters for after discussion. Or does this, which occurred in 
my own case, happen from the same cause? Thrown from a car- 
riage upon one occasion, I struck my forehead a blow upon the 
place where a twig of the artery advances from the temple, and 
immediately, within the time in which twenty beats could have 
been made I felt a tumour the size of an egg developed, without 
either heat or any great pain: the near vicinity of the artery had 



CIRCULATION OF THE BLOOD II 5 

caused the blood to be effused into the bruised part with unusual 
force and velocity. 

And now, too, we understand why in phlebotomy we apply our 
ligature above the part that is punctured, not below it; did the 
flow come from above, not from below, the constriction in this case 
would not only be of no service, but would prove a positive hin- 
drance; it would have to be applied below the orifice, in order to 
have the flow more free, did the blood descend by the veins from 
superior to inferior parts; but as it is elsewhere forced through the 
extreme arteries into the extreme veins, and the return in these last 
is opposed by the ligature, so do they fill and swell, and being thus 
filled and distended, they are made capable of projecting their 
charge with force, and to a distance, when any one of them is sud- 
denly punctured; but the ligature being slackened, and the returning 
channels thus left open, the blood forthwith no longer escapes, save 
by drops; and, as all the world knows, if in performing phlebotomy 
the bandage be either slackened too much or the limb be bound 
too tightly, the blood escapes without force, because in the one case 
the returning channels are not adequately obstructed; in the other 
the channels of influx, the arteries, are impeded. 

CHAPTER XII 

That there is a Circulation of the Blood is Shown from the 
Second Position Demonstrated 

If these things be so, another point which I have already referred 
to, viz., the continual passage of the blood through the heart will 
also be confirmed. We have seen, that the blood passes from the 
arteries into the veins, not from the veins into the arteries; we have 
seen, farther, that almost the whole of the blood may be withdrawn 
from a puncture made in one of the cutaneous veins of the arm if 
a bandage properly applied be used; we have seen, still farther, that 
the blood flows so freely and rapidly that not only is the whole 
quantity which was contained in the arm beyond the ligature, and 
before the puncture was made, discharged, but the whole which is 
contained in the body, both that of the arteries and that of the veins. 

Whence we must admit, first, that the blood is sent along with 



Il6 WILLIAM HARVEY 

an impulse, and that it is urged with force below the ligature; for it 
escapes with force, which force it receives from the pulse and power 
of the heart; for the force and motion of the blood are derived from 
the heart alone. Second, that the afflux proceeds from the heart, 
and through the heart by a course from the great veins; for it gets 
into the parts below the ligature through the arteries, not through 
the veins; and the arteries nowhere receive blood from the veins, 
nowhere receive blood save and except from the left ventricle of 
the heart. Nor could so large a quantity of blood be drawn from 
one vein (a ligature having been duly applied), nor with such im- 
petuosity, such readiness, such celerity, unless through the medium 
of the impelling power of the heart. 

But if all things be as they are now represented, we shall feel 
ourselves at liberty to calculate the quantity of the blood, and to 
reason on its circular motion. Should anyone, for instance, per- 
forming phlebotomy, suffer the blood to flow in the manner it 
usually does, with force and freely, for some half hour or so, no 
question but that the greatest part of the blood being abstracted, 
faintings and syncopes would ensue, and that not only would the 
arteries but the great veins also be nearly emptied of their contents. 
It is only consonant with reason to conclude that in the course of 
the half hour hinted at, so much as has escaped has also passed from 
the great veins through the heart into the aorta. And further, if 
we calculate how many ounces flow through one arm, or how many 
pass in twenty or thirty pulsations under the medium ligature, we 
shall have some grounds for estimating how much passes through 
the other arm in the same space of time: how much through both 
lower extremities, how much through the neck on either side, and 
through all the other arteries and veins of the body, all of which 
have been supplied with fresh blood, and as this blood must have 
passed through the lungs and ventricles of the heart, and must have 
come from the great veins, — we shall perceive that a circulation is 
absolutely necessary, seeing that the quantities hinted at cannot be 
supplied immediately from the ingesta, and are vastly more than 
can be requisite for the mere nutrition of the parts. 

It is still further to be observed, that in practising phlebotomy 
the truths contended for are sometimes confirmed in another way; 



CIRCULATION OF THE BLOOD II 7 

for having tied up the arm properly, and made the puncture duly, 
still, if from alarm or any other causes, a state of faintness super- 
venes, in which the heart always pulsates more languidly, the blood 
does not flow freely, but distils by drops only. The reason is, that 
with a somewhat greater than usual resistance offered to the transit 
of the blood by the bandage, coupled with the weaker action of the 
heart, and its diminished impelling power, the stream cannot make 
its way under the ligature; and farther, owing to the weak and 
languishing state of the heart, the blood is not transferred in such 
quantity as wont from the veins to the arteries through the sinuses 
of that organ. So also, and for the same reasons, are the menstrual 
fluxes of women, and indeed hemorrhages of every kind, controlled. 
And now, a contrary state of things occurring, the patient getting 
rid of his fear and recovering his courage, the pulse strength is in- 
creased, the arteries begin again to beat with greater force, and to 
drive the blood even into the part that is bound; so that the blood 
now springs from the puncture in the vein, and flows in a continuous 
stream. 

CHAPTER XIII 

The Third Position is Confirmed: and the Circulation of the 
Blood is Demonstrated from It 

Thus far we have spoken of the quantity of blood passing through 
the heart and the lungs in the centre of the body, and in like man- 
ner from the arteries into the veins in the peripheral parts and the 
body at large. We have yet to explain, however, in what manner 
the blood finds its way back to the heart from the extremities by the 
veins, and how and in what way these are the only vessels that con- 
vey the blood from the external to the central parts; which done, I 
conceive that the three fundamental propositions laid down for the 
circulation of the blood will be so plain, so well established, so ob- 
viously true, that they may claim general credence. Now the re- 
maining position will be made sufHciently clear from the valves 
which are found in the cavities of the veins themselves, from the 
uses of these, and from experiments cognizable by the senses. 

The celebrated Hieronymus Fabricius of Aquapendente, a most 



Il8 WILLIAM HARVEY 

skilful anatomist, and venerable old man, or, as the learned Riolan 
will have it, Jacobus Silvius, first gave representations of the valves 
in the veins, which consist of raised or loose portions of the inner 
membranes of these vessels, of extreme deUcacy, and a sigmoid or 
semilunar shape. They are situated at different distances from one 
another, and diversely in different individuals; they are connate at 
the sides of the veins; they are directed upwards towards the trunks 
of the veins; the two — for there are for the most part two together 
— regard each other, mutually touch, and are so ready to come into 
contact by their edges, that if anything attempts to pass from the 
trunks into the branches of the veins, or from the greater vessels 
into the less, they completely prevent it; they are farther so arranged, 
that the horns of those that succeed are opposite the middle of the 
convexity of those that precede, and so on alternately. 

The discoverer of these valves did not rightly understand their 
use, nor have succeeding anatomists added anything to our knowl- 
edge: for their ofBce is by no means explained when we are told 
that it is to hindei the blood, by its weight, from all flowing into 
inferior parts; for the edges of the valves in the jugular veins hang 
downwards, and are so contrived that they prevent the blood from 
rising upwards; the valves, in a word, do not invariably look up- 
wards, but always toward the trunks of the veins, invariably towards 
the seat of the heart. I, and indeed others, have sometimes found 
valves in the emulgent veins, and in those of the mesentery, the 
edges of which were directed towards the vena cava and vena 
portse. Let it be added that there are no valves in the arteries, and 
that dogs, oxen, etc., have invariably valves at the divisions of their 
crural veins, in the veins that meet towards the top of the os sacrum, 
and in those branches which come from the haunches, in which no 
such effect of gravity from the erect position was to be apprehended. 
Neither are there valves in the jugular veins for the purpose of 
guarding against apoplexy, as some have said; because in sleep the 
head is more apt to be influenced by the contents of the carotid 
arteries. Neither are the valves present, in order that the blood may 
be retained in the divarications or smaller trunks and minuter 
branches, and not be suffered to flow entirely into the more open 
and capacious channels; for they occur where there are no divari- 



CIRCULATION OF THE BLOOD Up 

cations; although it must be owned that they are most frequent at 
the points where branches join. Neither do they exist for the pur- 
pose of rendering the current of blood more slow from the centre 
of the body; for it seems likely that the blood would be disposed to 
flow with sufficient slowness of its own accord, as it would have to 
pass from larger into continually smaller vessels, being separated 
from the mass and fountain head, and attaining from warmer into 
colder places. 

But the valves are solely made and instituted lest the blood should 
pass from the greater into the lesser veins, and either rupture them 
or cause them to become varicose; lest, instead of advancing from 
the extreme to the central parts of the body, the blood should rather 
proceed along the veins from the centre to the extremities; but the 
delicate valves, while they readily open in the right direction, en- 
tirely prevent all such contrary motion, being so situated and ar- 
ranged, that if anything escapes, or is less perfectly obstructed by 
the cornua of the one above, the fluid passing, as it were, by the 
chinks between the cornua, it is immediately received on the con- 
vexity of the one beneath, which is placed transversely with reference 
to the former, and so is effectually hindered from getting any far- 
ther. 

And this I have frequently experienced in my dissections of the 
veins: if I attempted to pass a probe from the trunk of the veins 
into one of the smaller branches, whatever care I took I found it 
impossible to introduce it far any way, by reason of the valves; 
whilst, on the contrary, it was most easy to push it along in the 
opposite direction, from without inwards, or from the branches 
towards the trunks and roots. In many places two valves are so 
placed and fitted, that when raised they come exactly together in 
the middle of the vein, and are there united by the contact of their 
margins; and so accurate is the adaptation, that neither by the eye 
nor by any other means of examination, can the slightest chink 
along the line of contact be perceived. But if the probe be now in- 
troduced from the extreme towards the more central parts, the 
valves, like the floodgates of a river, give way, and are most readily 
pushed aside. The effect of this arrangement plainly is to prevent 
all motion of the blood from the heart and vena cava, whether it 



120 WILLIAM HARVEY 

be upwards towards the head, or downwards towards the feet, or 
to either side towards the arms, not a drop can pass; all motion of 
the blood, beginning in the larger and tending towards the smaller 
veins, is opposed and resisted by them; whilst the motion that pro- 
ceeds from the lesser to end in the larger branches is favoured, or, 
at all events, a free and open passage is left for it. 

But that this truth may be made the more apparent, let an arm 
be tied up above the elbow as if for phlebotomy (A, A, fig. i). At 
intervals in the course of the veins, especially in labouring people 
and those whose veins are large, certain knots or elevations (B, C, 
D, E, F) will be perceived, and this not only at the places where a 
branch is received (E, F), but also where none enters (C, D) : these 
knots or risings are all formed by valves, which thus show them- 
selves externally. And now if you press the blood from the space 
above one of the valves, from H to O, (fig. 2,) and keep the point 
of a finger upon the vein inferiorly, you will see no influx of blood 
from above; the portion of the vein between the point of the finger 
and the valve O will be obliterated; yet will the vessel continue 
sufficiently distended above the valve (O, G). The blood being 
thus pressed out and the vein emptied, if you now apply a finger 
of the other hand upwn the distended part of the vein above the 
valve O, (fig. 3,) and press downwards, you will find that you can- 
not force the blood through or beyond the valve; but the greater 
effort you use, you will only see the portion of vein that is between 
the finger and the valve become more distended, that portion of 
the vein which is below the valve remaining all the while empty 
(H,0,fig.3). 

It would therefore appear that the function of the valves in the 
veins is the same as that of the three sigmoid valves which we find 
at the commencement of the aorta and pulmonary artery, viz., to 
prevent all reflux of the blood that is passing over them. 

[Note. — Woodcuts of the veins of the arm to which these letters 
and figures refer appear here in the original. — C. N. B. C] 

Farther, the arm being bound as before, and the veins looking 
full and distended, if you press at one part in the course of a vein 
with the point of a finger (L, fig. 4), and then with another finger 
streak the blood upwards beyond the next valve (N), you will per- 



CIRCULATION OF THE BLOOD 121 

ceive that this portion of the vein continues empty (L. N), and 
that the blood cannot retrograde, precisely as we have already seen 
the case to be in fig. 2; but the finger first applied (H, fig. 2, L, fig. 
4), being removed, immediately the vein is filled from below, and 
the arm becomes as it appears at D C, fig. i. That the blood in the 
veins therefore proceeds from inferior or more remote parts, and 
towards the heart, moving in these vessels in this and not in the 
contrary direction, appears most obviously. And although in some 
places the valves, by not acting with such perfect accuracy, or where 
there is but a single valve, do not seem totally to prevent the passage 
of the blood from the centre, still the greater number of them 
plainly do so; and then, where things appear contrived more negli- 
gently, this is compensated either by the more frequent occurrence 
or more perfect action of the succeeding valves, or in some other 
way: the veins in short, as they are the free and open conduits of 
the blood returning to the heart, so are they effectually prevented 
from serving as its channels of distribution from the heart. 

But this other circumstance has to be noted: The arm being 
bound, and the veins made turgid, and the valves prominent, as 
before, apply the thumb or finger over a vein in the situation of 
one of the valves in such a way as to compress it, and prevent any 
blood from passing upwards from the hand; then, with a finger of 
the other hand, streak the blood in the vein upwards till it has 
passed the next valve above (N, fig. 4), the vessel now remains 
empty; but the finger at L being removed for an instant, the vein 
is immediately filled from below; apply the finger again, and hav- 
ing in the same manner streaked the blood upwards, again remove 
the finger below, and again the vessel becomes distended as before; 
and this repeat, say a thousand times, in a short space of time. And 
now compute the quantity of blood which you have thus pressed 
up beyond the valve, and then multiplying the assumed quantity 
by one thousand, you will find that so much blood has passed 
through a certain portion of the vessel; and I do now believe that 
you will find yourself convinced of the circulation of the blood, 
and of its rapid motion. But if in this experiment you say that a 
violence is done to nature, I do not doubt but that, if you proceed 
in the same way, only taking as great a length of vein as possible. 



122 WILLIAM HARVEY 

and merely remark with what rapidity the blood flows upwards, 
and fills the vessel from below, you will come to the same conclusion. 

CHAPTER XIV 

Conclusion of the Demonstration of the Circulation 

And now I may be allowed to give in brief my view of the cir- 
culation of the blood, and to propose it for general adoption. 

Since all things, both argument and ocular demonstration, show 
that the blood passes through the lungs, and heart by the force of 
the ventricles, and is sent for distribution to all parts of the body, 
where it makes its way into the veins and porosities of the flesh, 
and then flows by the veins from the circumference on every side 
to the centre, from the lesser to the greater veins, and is by them 
finally discharged into the vena cava and right auricle of the heart, 
and this in such a quantity or in such a flux and reflux thither by 
the arteries, hither by the veins, as cannot possibly be supplied by 
the ingesta, and is much greater than can be required for mere 
purposes of nutrition; it is absolutely necessary to conclude that 
the blood in the animal body is impelled in a circle, and is in a state 
of ceaseless motion; that this is the act or function which the heart 
performs by means of its pulse; and that it is the sole and only end 
of the motion and contraction of the heart. 

CHAPTER XV 

The Circulation of the Blood is Further Confirmed by Probable 

Reasons 

It will not be foreign to the subject if I here show further, from 
certain familiar reasonings, that the circulation is matter both of 
convenience and necessity. In the first place, since death is a cor- 
ruption which takes place through deficiency of heat,' and since all 
living things are warm, all dying things cold, there must be a 
particular seat and fountain, a kind of home and hearth, where the 
cherisher of nature, the original of the native fire, is stored and 
preserved; from which heat and life are dispensed to all parts as 
' Aristoteles De Respiratione, lib. ii et iii: De Part. Animal, ct alibi. 



CIRCULATION OF THE BLOOD 1 23 

from a fountain head; from which sustenance may be derived; and 
upon which concoction and nutrition, and all vegetative energy 
may depend. Now, that the heart is this place, that the heart is the 
principle of life, and that all passes in the manner just mentioned, 
I trust no one will deny. 

The blood, therefore, required to have motion, and indeed such 
a motion that it should return again to the heart; for sent to the 
external parts of the body far from its fountain, as Aristotle says, 
and without motion, it would become congealed. For we see motion 
generating and keeping up heat and spirits under all circumstances, 
and rest allowing them to escape and be dissipated. The blood, 
therefore, becoming thick or congealed by the cold of the extreme 
and outward parts, and robbed of its spirits, just as it is in the dead, 
it was imperative that from its fount and origin, it should again 
receive heat and spirits, and all else requisite to its preservation — 
that, by returning, it should be renovated and restored. 

We frequently see how the extremities are chilled by the external 
cold, how the nose and cheeks and hands look blue, and how the 
blood, stagnating in them as in the pendent or lower parts of a 
corpse, becomes of a dusky hue; the limbs at the same time getting 
torpid, so that they can scarcely be moved, and seem almost to have 
lost their vitality. Now they can by no means be so effectually, and 
especially so speedily restored to heat and colour and life, as by a 
new efflux and contact of heat from its source. But how can parts 
attract in which the heat and life are almost extinct ? Or how should 
they whose passages are filled with condensed and frigid blood, 
admit fresh aliment — renovated blood— unless they had first got rid 
of their old contents? Unless the heart were truly that fountain 
where life and heat are restored to the refrigerated fluid, and whence 
new blood, warm, imbued with spirits, being sent out by the arteries, 
that which has become cooled and effete is forced on, and all the 
particles recover their heat which was failing, and their vital stimulus 
wellnigh exhausted. 

Hence it is that if the heart be unaffected, life and health may be 
restored to almost all the other parts of the body; but if the heart 
be chilled, or smitten with any serious disease, it seems matter of 
necessity that the whole animal fabric should suffer and fall into 



124 WILLIAM HARVEY 

decay. When the source is corrupted, there is nothing, as Aristotle 
says,^ which can be of service either to it or aught that depends on 
it. And hence, by the way, it may perchance be why grief, and 
love, and envy, and anxiety, and all affections of the mind of a 
similar kind are accompanied with emaciation and decay, or with 
disordered fluids and crudity, which engender all manner of diseases 
and consume the body of man. For every affection of the mind 
that is attended with either pain or pleasure, hope or fear, is the 
cause of an agitation whose influence extends to the heart, and there 
induces change from the natural constitution, in the temperature, 
the pulse and the rest, which impairing all nutrition in its source 
and abating the powers at large, it is no wonder that various forms 
of incurable disease in the extremities and in the trunk are the con- 
sequence, inasmuch as in such circumstances the whole body labours 
under the effects of vitiated nutrition and a want of native heat. 

Moreover, when we see that all animals live through food digested 
in their interior, it is imperative that the digestion and distribution 
be perfect, and, as a consequence, that there be a place and receptacle 
where the aliment is perfected and whence it is distributed to the 
several members. Now this place is the heart, for it is the only 
organ in the body which contains blood for the general use; all the 
others receive it merely for their peculiar or private advantage, just 
as the heart also has a supply for its own especial behoof in its 
coronary veins and arteries. But it is of the store which the heart 
contains in its auricles and ventricles that I here speak. Then the 
heart is the only organ which is so situated and constituted that it 
can distribute the blood in due proportion to the several parts of 
the body, the quantity sent to each being according to the dimen- 
sions of the artery which supplies it, the heart serving as a magazine 
or fountain ready to meet its demands. 

Further, a certain impulse or force, as well as an impeller or 
forcer, such as the heart, was required to effect this distribution and 
motion of the blood; both because the blood is disposed from slight 
causes, such as cold, alarm, horror, and the like, to collect in its 
source, to concentrate like parts to a whole, or the drops of water 
spilt upon a table to the mass of liquid; and because it is forced 

^ De Part. Animal., iii. 



CIRCULATION OF THE BLOOD 1 25 

from the capillary veins into the smaller ramifications, and from 
these into the larger trunks by the motion of the extremities and 
the compressioa of the muscles generally. The blood is thus more 
disposed to move from the circumference to the centre than in the 
opposite direction, even were there no valves to oppose its motion; 
wherefore, that it may leave its source and enter more confined 
and colder channels, and flow against the direction to which it 
spontaneously inclines, the blood requires both force and impelling 
power. Now such is the heart and the heart alone, and that in the 
way and manner already explained. 

CHAPTER XVI 

The Circulation of the Blood is Further Proved from Certain 

Consequences 

There are still certain problems, which, taken as consequences 
of this truth assumed as proven, are not without their use in exciting 
belief, as it were, a posteriore; and which, although they may seem 
to be involved in much doubt and obscurity, nevertheless readily 
admit of having reasons and causes assigned for them. Of such a 
nature are those that present themselves in connexion with con- 
tagions, poisoned wounds, the bites of serpents and rabid animals, 
lues venerea and the like. We sometimes see the whole system con- 
taminated, though the part first infected remains sound; the lues 
venerea has occasionally made its attack with pains in the shoulders 
and head, and other symptoms, the genital organs being all the 
while unaffected; and then we know that the wound made by a 
rabid dog having healed, fever and a train of disastrous symptoms 
may nevertheless supervene. Whence it appears that the contagion 
impressed upon or deposited in a particular part, is by-and-by carried 
by the returning current of blood to the heart, and by that organ is 
sent to contaminate the whole body. 

In tertian fever, the morbific cause seeking the heart in the first 
instance, and hanging about the heart and lungs, renders the patient 
short-winded, disposed to sighing, and indisposed to exertion, because 
the vital principle is oppressed and the blood forced into the lungs 
and rendered thick. It does not pass through them, (as I have 



126 WILLIAM HARVEY 

myself seen in opening the bodies of those who had died in the 
beginning of the attack,) when the pulse is always frequent, small, 
and occasionally irregular; but the heat increasing, the matter becom- 
ing attenuated, the passages forced, and the transit made, the whole 
body begins to rise in temperature, and the pulse becomes fuller 
and stronger. The febrile paroxysm is fully formed, whilst the 
preternatural heat kindled in the heart is thence diffused by the 
arteries through the whole body along with the morbific matter, 
which is in this way overcome and dissolved by nature. 

When we perceive, further, that medicines applied externally 
exert their influence on the body just as if they had been taken inter- 
nally, the truth we are contending for is confirmed. Colocynth and 
aloes in this way move the belly, cantharides excites the urine, gar- 
lic applied to the soles of the feet assists expectoration, cordials 
strengthen, and an infinite number of examples of the same kind 
might be cited. Perhaps it will not, therefore, be found unreason- 
able, if we say that the veins, by means of their orifices, absorb some 
of the things that are applied externally and carry this inwards with 
the blood, not otherwise, it may be, than those of the mesentery 
imbibe the chyle from the intestines and carry it mixed with the 
blood to the liver. For the blood entering the mesentery by the 
coeliac artery, and the superior and inferior mesenteries, proceeds 
to the intestines, from which, along with the chyle that has been 
attracted into the veins, it returns by their numerous ramifications 
into the vena portae of the liver, and from this into the vena cava, 
and this in such wise that the blood in these veins has the same 
colour and consistency as in other veins, in opposition to what many 
believe to be the fact. Nor indeed can we imagine two contrary 
motions in any capillary system — the chyle upwards, the blood 
downwards. This could scarcely take place, and must be held as 
altogether improbable. But is not the thing rather arranged as it is 
by the consummate providence of nature? For were the chyle 
mingled with the blood, the crude with the digested, in equal pro- 
portions, the result would not be concoction, transmutation, and 
sanguification, but rather, and because they are severally active and 
passive, a mixture or combination, or medium compound of the 
two, precisely as happens when wine is mixed with water and 



CIRCULATION OF THE BLOOD 12/ 

syrup. But when a very minute quantity of chyle is mingled with a 
very large quantity of circulating blood, a quantity of chyle that 
bears no kind of proportion to the mass of blood, the effect is the 
same, as Aristotle says, as when a drop of water is added to a cask 
of wine, or the contrary; the mass does not then present itself as a 
mixture, but is still sensibly either wine or water. 

So in the mesenteric veins of an animal we do not find either 
chyme or chyle and blood, blended together or distinct, but only 
blood, the same in colour, consistency, and other sensible properties, 
as it appears in the veins generally. Still as there is a certain though 
small and inappreciable portion of chyle or incompletely digested 
matter mingled with the blood, nature has interposed the liver, in 
whose meandering channels it suffers delay and undergoes addi- 
tional change, lest arriving prematurely and crude at the heart, it 
should oppress the vital principle. Hence in the embryo, there is 
almost no use for the liver, but the umbilical vein passes directly 
through, a foramen or an anastomosis existing from the vena porta:. 
The blood returns from the intestines of the foetus, not through the 
liver, but into the umbilical vein mentioned, and flows at once into 
the heart, mingled with the natural blood which is returning from 
the placenta; whence also it is that in the development of the fcetus 
the liver is one of the organs that is last formed. I have observed 
all the members perfectly marked out in the human foetus, even the 
genital organs, whilst there was yet scarcely any trace of the liver. 
And indeed at the period when all the parts, like the heart itself in 
the beginning, are still white, and except in the veins there is no 
appearance of redness, you shall see nothing in the seat of the liver 
but a shapeless collection, as it were, of extravasated blood, which 
you might take for the effects of a contusion or ruptured vein. 

But in the incubated egg there are, as it were, two umbilical 
vessels, one from the albumen passing entire through the liver, and 
going straight to the heart; another from the yelk, ending in the 
vena portx; for it appears that the chick, in the first instance, is 
entirely formed and nourished by the white; but by the yelk after it 
has come to perfection and is excluded from the shell; for this part 
may still be found in the abdomen of the chick many days after its 
exclusion, and is a substitute for the milk to other animals. 



128 WILLIAM HARVEY 

But these matters will be better spoken of in my observations 
on the formation of the fcEtus, where many propositions, the follow- 
ing among the number, will be discussed: Wherefore is this part 
formed or perfected first, that last, and of the several members, what 
part is the cause of another? And there are many points having 
special reference to the heart, such as wherefore does it first acquire 
consistency, and appear to possess life, motion, sense, before any 
other part of the body is perfected, as Aristotle says in his third book, 
"De partibus Animalium"? And so also of the blood, wherefore 
does it precede all the rest? And in what way does it possess the 
vital and animal principle, and show a tendency to motion, and to 
be impelled hither and thither, the end for which the heart appears 
to be made? In the same way, in considering the pulse, why should 
one kind of pidse indicate death, another recovery? And so of all 
the other kinds of pulse, what may be the cause and indication of 
each? Likewise we must consider the reason of crises and natural 
critical discharges; of nutrition, and especially the distribution of the 
nutriment; and of defluxions of every description. Finally, reflecting 
on every part of medicine, physiology, pathology, semeiotics and 
therapeutics, when I see how many questions can be answered, how 
many doubts resolved, how much obscurity illustrated by the truth 
we have declared, the light we have made to shine, I see a field of 
such vast extent in which I might proceed so far, and expatiate so 
widely, that this my tractate would not only swell out into a volume, 
which was beyond my purpose, but my whole life, perchance, would 
not suffice for its completion. 

In this place, therefore, and that indeed in a single chapter, I shall 
only endeavour to refer the various particulars that present them- 
selves in the dissection of the heart and arteries to their several uses 
and causes; for so I shall meet with many things which receive light 
from the truth I have been contending for, and which, in their 
turn, render it more obvious. And indeed I would have it con- 
firmed and illustrated by anatomical arguments above all others. 

There is but a single point which indeed would be more correctly 
placed among our observations on the use of the spleen, but which 
it will not be altogether impertinent to notice in this place inci- 
dentally. From the splenic branch which passes into the pancreas. 



CIRCULATION OF THE BLOOD 1 29 

and from the upper part, arise the posterior coronary, gastric, and 
gastroepiploic veins, all o£ which are distributed upon the stomach 
in numerous branches and twigs, just as the mesenteric vessels are 
upon the intestines. In a similar way, from the inferior part of the 
same splenic branch, and along the back of the colon and rectum 
proceed the hemorrhoidal veins. The blood returning by these veins, 
and bringing the cruder juices along with it, on the one hand from 
the stomach, where they are thin, watery, and not yet perfectly 
chylified; on the other thick and more earthy, as derived from the 
faeces, but all poured into this splenic branch, are duly tempered by 
the admixture of contraries; and nature mingling together these two 
kinds of juices, difficult of coction by reason of most opposite defects, 
and then diluting them with a large quantity of warm blood, (for 
we see that the quantity returned from the spleen must be very 
large when we contemplate the size of its arteries,) they are brought 
to the porta of the liver in a state of higher preparation. The defects 
of either extreme are supplied and compensated by this arrange- 
ment of the veins. 

CHAPTER XVII 

The Motion and Circulation of the Blood are Confirmed from 
THE Particulars Apparent in the Structure of the Heart, 
and from Those Things which Dissection Unfolds 

I do not find the heart as a distinct and separate part in all animals; 
some, indeed, such as the zoophytes, have no heart; this is because 
these animals are coldest, of one great bulk, of soft texture, or of a 
certain uniform sameness or simplicity of structure; among the 
number I may instance grubs and earth-worms, and those that are 
engendered of putrefaction and do not preserve their species. These 
have no heart, as not requiring any impeller of nourishment into 
the extreme parts; for they have bodies which. are connate and homo- 
geneous and without limbs; so that by the contraction and relaxation 
of the whole body they assume and expel, move and remove, the 
aliment. Oysters, mussels, sponges, and the whole genus of zoophytes 
or plant-animals have no heart, for the whole body is used as a 
heart, or the whole animal is a heart. In a great number of ani- 



130 WILLIAM HARVEY 

mals, — almost the whole tribe of insects — we cannot see distinctly 
by reason of the smallness of the body; still in bees, flies, hornets, and 
the like we can perceive something pulsating with the help of a 
magnifying-glass; in pediculi, also, the same thing may be seen, and 
as the body is transparent, the passage of the food through the 
intestines, like a black spot or stain, may be perceived by the aid 
of the same magnifying-glass. 

But in some of the pale-blooded and colder animals, as in snails, 
whelks, shrimps, and shell-iish, there is a part which pulsates, — a 
kind of vesicle or auricle without a heart, — slowly, indeed, and not 
to be perceived except in the warmer season of the year. In these 
creatures this part is so contrived that it shall pulsate, as there is 
here a necessity for some impulse to distribute the nutritive fluid, 
by reason of the variety of organic parts, or of the density of the 
substance; but the pulsations occur unfrequently, and sometimes in 
consequence of the cold not at all, an arrangement the best adapted 
to them as being of a doubtful nature, so that sometimes they appear 
to live, sometimes to die; sometimes they show the vitality of an 
animal, sometimes of a vegetable. This seems also to be the case 
with the insects which conceal themselves in winter, and lie, as it 
were, defunct, or merely manifesting a kind of vegetative existence. 
But whether the same thing happens in the case of certain animals 
that have red blood, such as frogs, tortoises, serpents, swallows, may 
be very properly doubted. 

In all the larger and warmer animals which have red blood, there 
was need of an impeller of the nutritive fluid, and that, perchance, 
possessing a considerable amount of power. In fishes, serpents, 
lizards, tortoises, frogs, and others of the same kind there is a heart 
present, furnished with both an auricle and a ventricle, whence it is 
perfectly true, as Aristotle has observed,' that no sanguineous animal 
is without a heart, by the impelling power of which the nutritive 
fluid is forced, both with greater vigour and rapidity, to a greater 
distance; and not merely agitated by an auricle, as it is in lower 
forms. And then in regard to animals that are yet larger, warmer, 
and more perfect, as they abound in blood, which is always hotter 
and more spirituous, and which possess bodies of greater size and 
' De Part. Animal., lib. iii. 



CIRCULATION OF THE BLOOD I3I 

consistency, these require a larger, stronger, and more fleshy heart, 
in order that the nutritive fluid may be propelled with yet greater 
force and celerity. And further, inasmuch as the more perfect ani- 
mals require a still more perfect nutrition, and a larger supply of 
native heat, in order that the aliment may be thoroughly concocted 
and acquire the last degree of perfection, they required both lungs 
and a second ventricle, which should force the nutritive fluid through 
them. 

Every animal that has lungs has, therefore, two ventricles to its 
heart — one right, the other left; and wherever there is a right, there 
also is there a left ventricle; but the contrary of this does not hold 
good: where there is a left there is not always a right ventricle. The 
left ventricle I call that which is distinct in office, not in place from 
the other, that one, namely, which distributes the blood to the body 
at large, not to the lungs only. Hence the left ventricle seems to 
form the principal part of the heart; situated in the middle, more 
strongly marked, and constructed with greater care, the heart seems 
formed for the sake of the left ventricle, and the right but to 
minister to it. The right neither reaches to the apex of the heart 
nor is it nearly of such strength, being three times thinner in its 
walls, and in some sort jointed on to the left (as Aristotle says), 
though, indeed, it is of greater capacity, inasmuch as it has not 
only to supply material to the left ventricle, but likewise to furnish 
aliment to the lungs. 

It is to be observed, however, that all this is otherwise in the 
embryo, where there is not such a difference between the two ven- 
tricles. There, as in a double nut, they are nearly equal in all respects, 
the apex of the right reaching to the apex of the left, so that the 
heart presents itself as a sort of double-pointed cone. And this is so, 
because in the foetus, as already said, whilst the blood is not passing 
through the lungs from the right to the left cavities of the heart, 
it flows by the foramen ovale and ductus arteriosus directly from 
the vena cava into the aorta, whence it is distributed to the whole 
body. Both ventricles have, therefore, the same office to perform, 
whence their equality of constitution. It is only when the lungs come 
to be used and it is requisite that the passages indicated should be 
blocked up that the difference in point of strength and other things 



132 WILLIAM HARVEY 

between the two ventricles begins to be apparent. In the altered 
circumstances the right has only to drive the blood through the 
lungs, whilst the left has to propel it through the whole body. 

There are, moreover, within the heart numerous braces, in the 
form of fleshy columns and fibrous bands, which Aristotle, in his 
third book on "Respiration," and the "Parts of Animals," entitles 
nerves. These are variously extended, and are either distinct or 
contained in grooves in the walls and partition, where they occasion 
numerous pits or depressions. They constitute a kind of small 
muscles, which are superadded and supplementary to the heart, 
assisting it to execute a more powerful and perfect contraction, and 
so proving subservient to the complete expulsion of the blood. They 
are, in some sort, like the elaborate and artful arrangement of ropes 
in a ship, bracing the heart on every side as it contracts, and so 
enabling it more effectually and forcibly to expel the charge of 
blood from its ventricles. This much is plain, at all events, that in 
some animals they are less strongly marked than in others; and, 
in all that have them, they are more numerous and stronger in the 
left than in the right ventricle; and while some have them present 
in the left, yet they are absent in the right ventricle. In man they 
are more numerous in the left than in the right ventricle, more 
abundant in the ventricles than in the auricles; and occasionally 
there appear to be none present in the auricles. They are numerous 
in the large, more muscular and hardier bodies of countrymen, but 
fewer in more slender frames and in females. 

In those animals in which the ventricles of the heart are smooth 
within and entirely without fibres of muscular bands, or anything 
like hollow pits, as in almost all the smaller birds, the partridge and 
the common fowl, serpents, frogs, tortoises, and most fishes, there 
are no chordse tendineae, nor bundles of fibres, neither are there any 
tricuspid valves in the ventricles. 

Some animals have the right ventricle smooth internally, but the 
left provided with fibrous bands, such as the goose, swan, and 
larger birds; and the reason is the same here as elsewhere. As the 
lungs are spongy and loose and soft, no great amount of force is 
required to force the blood through them; therefore the right ven- 
tricle is either without the bundles in question, or they are fewer 



CIRCULATION OF THE BLOOD I33 

and weaker, and not so fleshy or like muscles. Those of the left 
ventricle, however, are both stronger and more numerous, more 
fleshy and muscular, because the left ventricle requires to be stronger, 
inasmuch as the blood which it propels has to be driven through the 
whole body. And this, too, is the reason why the left ventricle 
occupies the middle of the heart, and has parietes three times thicker 
and stronger than those of the right. Hence all animals — and among 
men it is similar — that are endowed with particularly strong 
frames, and with large and fleshy limbs at a great distance from the 
heart, have this central organ of greater thickness, strength, and 
muscularity. This is manifest and necessary. Those, on the con- 
trary, that are of softer and more slender make have the heart more 
flaccid, softer, and internally either less or not at all iibrous. Con- 
sider, farther, the use of the several valves, which are all so arranged 
that the blood, once received into the ventricles of the heart, shall 
never regurgitate; once forced into the pulmonary artery and aorta, 
shall not flow back upon the ventricles. When the valves are raised 
and brought together, they form a three-cornered line, such as is left 
by the bite of a leech; and the more they are forced, the more firmly 
do they oppose the passage of the blood. The tricuspid valves are 
placed, like gate-keepers, at the entrance into the ventricles from the 
venae cavae and pulmonary veins, lest the blood when most forcibly 
impelled should flow back. It is for this reason that they are not 
found in all animals, nor do they appear to have been constructed 
with equal care in all animals in which they are found. In some 
they are more accurately fitted, in others more remissly or carelessly 
contrived, and always with a view to their being closed under a 
greater or a slighter force of the ventricle. In the left ventricle, 
therefore, in order that the occlusion may be the more perfect against 
the greater impulse, there are only two valves, like a mitre, and 
produced into an elongated cone, so that they come together and 
touch to their middle; a circumstance which perhaps led Aristotle 
into the error of supposing this ventricle to be double, the division 
taking place transversely. For the same reason, and that the blood 
may not regurgitate upon the pulmonary veins, and thus the force 
of the ventricle in propelling the blood through the system at large 
come to be neutralized, it is that these mitral valves excel those of 



134 WILLIAM HARVEY 

the right ventricle in size and strength and exactness of closing. 
Hence it is essential that there can be no heart without a ventricle, 
since this must be the source and store-house of the blood. The 
same law does not hold good in reference to the brain. For 
almost no genus of birds has a ventricle in the brain, as is obvious 
in the goose and swan, the brains of which nearly equal that of a 
rabbit in size; now rabbits have ventricles in the brain, whilst the 
goose has none. In like manner, wherever the heart has a single 
ventricle, there is an auricle appended, flaccid, membranous, hollow, 
filled with blood; and where there are two ventricles, there are like- 
wise two auricles. On the other hand, some animals have an auricle 
without any ventricle; or, at all events, they have a sac analogous 
to an auricle; or the vein itself, dilated at a particular part, performs 
pulsations, as is seen in hornets, bees, and other insects, which 
certain experiments of my own enable me to demonstrate, have not 
only a pulse, but a respiration in that part which is called the tail, 
whence it is that this part is elongated and contracted now more 
rarely, now more frequently, as the creature appears to be blown and 
to require a large quantity of air. But of these things, more in our 
"Treatise on Respiration." 

It is in like manner evident that the auricles pulsate, contract, as 
I have said before, and throw the blood into the ventricles; so that 
wherever there is a ventricle, an auricle is necessary, not merely that 
it may serve, according to the general belief, as a source and maga- 
zine for the blood: for what were the use of its pulsations had it 
only to contain.'' 

The auricles are prime movers of the blood, especially the right 
auricle, which, as already said, is "the first to live, the last to die"; 
whence they are subservient to sending the blood into the ventricles, 
which, contracting continuously, more readily and forcibly expel 
the blood already in motion; just as the ball-player can strike the 
ball more forcibly and further if he takes it on the rebound than if 
he simply threw it. Moreover, and contrary to the general opinion, 
neither the heart nor anything else can dilate or distend itself so as 
to draw anything into its cavity during the diastole, unless, like a 
sponge, it has been first compressed and is returning to its primary 
condition. But in animals all local motion proceeds from, and has 



CIRCULATION OF THE BLOOD I35 

its origin in, the contraction of some part; consequently it is by the 
contraction o£ the auricles that the blood is thrown into the ven- 
tricles, as I have already shown, and from there, by the contraction 
of the ventricles, it is propelled and distributed. Concerning local 
motions, it is true that the immediate moving organ in every motion 
of an animal primarily endowed with a motive spirit (as Aristotle 
has it^) is contractile; in which way the word vwpov is derived from 
vtinii, nuto, contraho; and if I am permitted to proceed in my pur- 
pose of making a particular demonstration of the organs of motion 
in animals from observations in my possession, I trust I shall be able 
to make sufficiently plain how Aristotle was acquainted with the 
muscles, and advisedly referred all motion in animals to the nerves, 
or to the contractile element, and, therefore, called those little bands 
in the heart nerves. 

But that we may proceed with the subject which we have in hand, 
viz., the use of the auricles in filling the ventricles, we should expect 
that the more dense and compact the heart, the thicker its parietes, 
the stronger and more muscular must be the auricle to force and fill 
it, and vice versa. Now this is actually so: in some the auricle pre- 
sents itself as a sanguinolent vesicle, as a thin membrane containing 
blood, as in fishes, in which the sac that stands in lieu of the auricles 
is of such delicacy and ample capacity that it seems to be suspended 
or to float above the heart. In those fishes in which the sac is some- 
what more fleshy, as in the carp, barbel, tench, and others, it bears 
a wonderful and strong resemblance to the lungs. 

In some men of sturdier frame and stouter make the right auricle 
is so strong, and so curiously constructed on its inner surface of 
bands and variously interlacing fibres, that it seems to equal in 
strength the ventricle of the heart in other subjects; and I must say 
that I am astonished to find such diversity in this particular in 
different individuals. It is to be observed, however, that in the 
foetus the auricles are out of all proportion large, which is because 
they are present before the heart makes its appearance or suffices 
for its office even when it has appeared, and they, therefore, have, as 
it were, the duty of the whole heart committed to them, as has 
already been demonstrated. But what I have observed in the forma- 

^ In the book de Spiritu, and elsewhere. 



136 WILLIAM HARVEY 

tion of the foetus, as before remarked (and Aristotle had already 
confirmed all in studying the incubated egg), throws the greatest 
light and likelihood upon the point. Whilst the foetus is yet in the 
form of a soft worm, or, as is commonly said, in the milk, there is 
a mere bloody point or pulsating vesicle, a portion apparently of the 
umbilical vein, dilated at its commencement or base. Afterwards, 
when the outline of the foetus is distinctly indicated and it begins 
to have greater bodily consistence, the vesicle in question becomes 
more fleshy and stronger, changes its position, and passes into the 
auricles, above which the body of the heart begins to sprout, though 
as yet it apparently performs no office. When the foetus is farther 
advanced, when the bones can be distinguished from the fleshy parts 
and movements take place, then it also has a heart which pulsates, 
and, as I have said, throws blood by either ventricle from the vena 
cava into the arteries. 

Thus nature, ever perfect and divine, doing nothing in vain, has 
neither given a heart where it was not required, nor produced it 
before its office had become necessary; but by the same stages in the 
development of every animal, passing through the forms of all, as I 
may say (ovum, worm, foetus), it acquires perfection in each. These 
points will be found elsewhere confirmed by numerous observations 
on the formation of the foetus. 

Finally, it is not without good grounds that Hippocrates in his 
book, "De Corde," entitles it a muscle; its action is the same; so is 
its functions, viz., to contract and move something else — in this 
case the charge of the blood. 

Farther, we can infer the action and use of the heart from the 
arrangement of its fibres and its general structures, as in muscles 
generally. All anatomists admit with Galen that the body of the 
heart is made up of various courses of fibres running straight, 
obliquely, and transversely, with reference to one another; but in a 
heart which has been boiled, the arrangement of the fibres is seen 
to be different. All the fibres in the parietes and septum are circular, 
as in the sphincters; those, again, which are in the columns extend 
lengthwise, and are oblique longitudinally; and so it comes to pass 
that when all the fibres contract simultaneously, the apex of the 
cone is pulled towards its base by the columns, the walls are drawn 



CIRCULATION OF THE BLOOD I37 

circularly together into a globe — the whole heart, in short, is con- 
tracted and the ventricles narrowed. It is, therefore, impossible not 
to perceive that, as the action of the organ is so plainly contraction, 
its function is to propel the blood into the arteries. 

Nor are we the less to agree with Aristotle in regard to the impor- 
tance of the heart, or to question if it receives sense and motion from 
the brain, blood from the liver, or whether it be the origin of the 
veins and of the blood, and such like. They who affirm these propo- 
sitions overlook, or do not rightly understand, the principal argu- 
ment, to the effect that the heart is the first part which exists, and 
that it contains within itself blood, life, sensation, and motion, 
before either the brain or the liver were created or had appeared 
distinctly, or, at all events, before they could perform any function. 
The heart, ready furnished with its proper organs of motion, like a 
kind of internal creature, existed before the body. The first to be 
formed, nature willed that it should afterwards fashion, nourish, 
preserve, complete the entire animal, as its work and dwelling- 
place : and as the prince in a kingdom, in whose hands lie the chief 
and highest authority, rules over all, the heart is the source and 
foundation from which all power is derived, on which all power 
depends in the animal body. 

Many things having reference to the arteries farther illustrate and 
confirm this truth. Why does not the pulmonary vein pulsate, seeing 
that it is numbered among the arteries? Or wherefore is there a 
pulse in the pulmonary artery? Because the pulse of the arteries is 
derived from the impulse of the blood. Why does an artery differ 
so much from a vein in the thickness and strength of its coats? 
Because it sustains the shock of the impelling heart and streaming 
blood. Hence, as perfect nature does nothing in vain, and suffices 
under all circumstances, we find that the nearer the arteries are to 
the heart, the more do they differ from the veins in structure; here 
they are both stronger and more ligamentous, whilst in extreme 
parts of the body, such as the feet and hands, the brain, the mesentery, 
and the testicles, the two orders of vessels are so much alike that it 
is impossible to distinguish between them with the eye. Now this 
is for the following very sufficient reasons: the more remote the 
vessels are from the heart, with so much the less force are they dis- 



138 WILLIAM HARVEY 

tended by the stroke of the heart, which is broken by the great 
distance at which it is given. Add to this that the impulse of the 
heart exerted upon the mass of blood, which must needs fill the 
trunks and branches of the arteries, is diverted, divided, as it were, 
and diminished at every subdivision, so that the ultimate capillary 
divisions of the arteries look like veins, and this not merely in con- 
stitution, but in function. They have either no perceptible pulse, 
or they rarely exhibit one, and never except where the heart beats 
more violently than usual, or at a part where the minute vessel is 
more dilated or open than elsewhere. It, therefore, happens that at 
times we are aware of a pulse in the teeth, in inflammatory tumours, 
and in the fingers; at another time we feel nothing of the sort. By 
this single symptom I have ascertained for certain that young persons 
whose pulses are naturally rapid were labouring under fever; and 
in like manner, on compressing the fingers in youthful and delicate 
subjects during a febrile paroxysm, I have readily perceived the 
pulse there. On the other hand, when the heart pulsates more 
languidly, it is often impossible to feel the pulse not merely in the 
fingers, but the wrist, and even at the temple, as in persons afflicted 
with lipothymis asphyxia, or hysterical symptoms, and in the 
debilitated and moribund. 

Here surgeons are to be advised that, when the blood escapes with 
force in the amputation of limbs, in the removal of tumours, and in 
wounds, it constantly comes from an artery; not always indeed per 
saltum, because the smaller arteries do not pulsate, especially if a 
tourniquet has been applied. 

For the same reason the pulmonary artery not only has the struc- 
ture of an artery, but it does not differ so widely from the veins in 
the thickness of its walls as does the aorta. The aorta sustains a 
more powerful shock from the left than the pulmonary artery does 
from the right ventricle, and the walls of this last vessel are thinner 
and softer than those of the aorta in the same proportion as the 
walls of the right ventricle of the heart are weaker and thinner than 
those of the left ventricle. In like manner the lungs are softer and 
laxer in structure than the flesh and other constituents of the body, 
and in a similar way the walls of the branches of the pulmonary 
aitery differ from those of the vessels derived from the aorta. And 



CIRCULATION OF THE BLOOD 139 

the same proportion in these particulars is universally preserved. 
The more muscular and powerful men are, the firmer their flesh; 
the stronger, thicker, denser, and more fibrous their hearts, the 
thicker, closer, and stronger are the auricles and arteries. Again, in 
those animals the ventricles of whose hearts are smooth on their 
inner surface, without villi or valves, and the walls of which are 
thin, as in fishes, serpents, birds, and very many genera of animals, 
the arteries differ little or nothing in the thickness of their coats 
from the veins. 

Moreover, the reason why the lungs have such ample vessels, both 
arteries and veins (for the capacity of the pulmonary veins exceeds 
that of both crural and jugular vessels), and why they contain so 
large a quantity of blood, as by experience and ocular inspection we 
know they do, admonished of the fact indeed by Aristotle, and not 
led into error by the appearances found in animals which have been 
bled to death, is, because the blood has its fountain, and storehouse, 
and the workshop of its last perfection, in the heart and lungs. Why, 
in the same way, we find in the course of our anatomical dissections 
the pulmonary vein and left ventricle so full of blood, of the same 
black colour and clotted character as that with which the right 
ventricle and pulmonary artery are filled, is because the blood is 
incessantly passing from one side of the heart to the other through 
the lungs. Wherefore, in fine, the pulmonary artery has the struc- 
ture of an artery, and the pulmonary veins have the structure of 
veins. In function and constitution and everything else the first is 
an artery, the others are veins, contrary to what is commonly believed; 
and the reason why the pulmonary artery has so large an orifice is 
because it transports much more blood than is requisite for the 
nutrition of the lungs. 

All these appearances, and many others, to be noted in the course 
of dissection, if rightly weighed, seem clearly to illustrate and 
fully to confirm the truth contended for throughout these pages, and 
at the same time to oppose the vulgar opinion; for it would be very 
difficult to explain in any other way to what purpose all is con- 
structed and arranged as we have seen it to be. 



THE THREE ORIGINAL 

PUBLICATIONS ON VACCINATION 

AGAINST SMALLPOX 



BY 
EDWARD JENNER 



INTRODUCTORY NOTE 

Edward Jenner was born at his father's vicarage at Berkeley, Glou- 
cestershire, England, on May 17, 1749. After leaving school, he was ap 
prenticed to a local surgeon, and in 1770 he went to London and became 
a resident pupil under the great surgeon and anatomist, John Hunter, 
with whom he remained on intimate terms for the rest of Hunter's 
life. In 1773 he took up practise at Berkeley, where, except for numer- 
ous visits to London, he spent the rest of his life. He died of apoplexy 
on January 26, 1823. 

Jenner 's scientific interests were varied, but the importance of his 
work in vaccination has overshadowed his other results. Early in his 
career he had begun to observe the phenomena of cowpox, a disease 
common in the rural parts of the western counties of England, and he 
was familiar with the belief, current among the peasantry, that a person 
who had suffered from the cowpox could not take smallpox. Finally, 
in 1796, he made his first experiment in vaccination, inoculating a boy 
of eight with cowpox, and, after his recovery, with smallpox; with the 
result that the boy did not take the latter disease. 

Jenner's first paper on his discovery was never printed; but in 1798 
appeared the first of the following treatises. Its reception by the medical 
profession was highly discouraging; but progress began when Cline, the 
surgeon of St. Thomas's Hospital, used the treatment with success. Jenner 
continued his investigations, publishing his results from time to time, 
and gradually gaining recognition; though opposition to his theory and 
practise was at first vehement, and has never entirely disappeared. In 
1802, Parliament voted him / 10,000, and in 1806, / 20,000, in recogni- 
tion of the value of his services, and the sacrifices they had entailed. As 
early as 1807, Bavaria made vaccination compulsory; and since that date 
most of the European governments have officially encouraged or com- 
pelled the practise; and smallpox has ceased to be the almost universal 
scourge it was before Jenner's discovery. 



To 

C. H. Parry, M.D. 

At Bath 

My Dear Friend: 

In the present age of scientific investigation it is remarkable that a 
disease of so peculiar a nature as the cow-pox, which has appeared in 
this and some of the neighbouring counties for such a series of years, 
should so long have escaped particular attention. Finding the prevailing 
notions on the subject, both among men of our profession and others, 
extremely vague and indeterminate, and conceiving that facts might 
appear at once both curious and useful, I have instituted as strict an 
inquiry into the causes and effects of this singular malady as local 
circumstances would admit. 

The following pages are the result, which, from motives of the most 
affectionate regard, are dedicated to you, by 

Your sincere friend, 

Edward Jenner. 
Berkeley, Gloucestershire, 
June 2ist, 1798. 



VACCINATION 
AGAINST SMALLPOX 

I 

An Inquiry into the Causes and Effects of the Variola 
Vaccina, or Cow-Pox. 1798 

THE deviation of man from the state in which he was origi- 
nally placed by nature seems to have proved to him a proHfic 
source of diseases. From the love of splendour, from the 
indulgences of luxury, and from his fondness for amusement he has 
familiarised himself with a great number of animals, which may 
not originally have been intended for his associates. 

The wolf, disarmed of ferocity, is now pillowed in the lady's lap.' 
The cat, the litde tiger of our island, whose natural home is the 
forest, is equally domesticated and caressed. The cow, the hog, the 
sheep, and the horse, are all, for a variety of purposes, brought under 
his care and dominion. 

There is a disease to which the horse, from his state of domestica- 
tion, is frequently subject. The farriers have called it the grease. 
It is an inflammation and swelling in the heel, from which issues 
matter possessing properties of a very peculiar kind, which seems 
capable of generating a disease in the human body (after it has 
undergone the modification which I shall presently speak of), which 
bears so strong a resemblance to the smallpox that I think it highly 
probable it may be the source of the disease. 

In this dairy country a great number of cows are kept, and the 
office of milking is performed indiscriminately by men and maid 
servants. One of the former having been appointed to apply dress- 
ings to the heels of a horse affected with the grease, and not paying 
due attention to cleanliness, incautiously bears his part in milking 
the cows, with some particles of the infectious matter adhering to his 

'The late Mr. John Hunter proved, by experiments, that the dog is the wolf in 
a degenerate state. 

145 



146 EDWARD JENNER 

fingers. When this is the case, it commonly happens that a disease 
is communicated to the cows, and from the cows to the dairymaids, 
which spreads through the farm until the most of the cattle and 
domestics feel its unpleasant consequences. This disease has obtained 
the name of the cow-pox. It appears on the nipples of the cows in 
the form of irregular pustules. At their first appearance they are 
commonly of a palish blue, or rather of a colour somewhat approach- 
ing to livid, and are surrounded by an erysipelatous inflammation. 
These pustules, unless a timely remedy be applied, frequently degen- 
erate into phagedenic ulcers, which prove extremely troublesome.^ 
The animals become indisposed, and the secretion of milk is much 
lessened. Inflamed spots now begin to appear on different parts of 
the hands of the domestics employed in milking, and sometimes on 
the wrists, which quickly run on to suppuration, first assuming the 
appearance of the small vesications produced by a burn. Most com- 
monly they appear about the joints of the fingers and at their extrem- 
ities; but whatever parts are affected, if the situation will admit, 
these superficial suppurations put on a circular form, with their edges 
more elevated than their centre, and of a colour distantly approach- 
ing to blue. Absorption takes place, and tumours appear in each 
axilla. The system becomes affected — the pulse is quickened; and 
shiverings, succeeded by heat, with general lassitude and pains about 
the loins and limbs, with vomiting, come on. The head is painful, 
and the patient is now and then even affected with delirium. These 
symptoms, varying in their degrees of violence, generally continue 
from one day to three or four, leaving ulcerated sores about the 
hands, which, from the sensibility of the parts, are very troublesome, 
and commonly heal slowly, frequently becoming phagedenic, like 
those from whence they sprung. The lips, nostrils, eyelids, and other 
parts of the body are sometimes affected with sores; but these evi- 
dently arise from their being heedlessly rubbed or scratched with 
the patient's infected fingers. No eruptions on the skin have followed 
the decline of the feverish symptoms in any instance that has come 
under my inspection, one only excepted, and in this case a very 
few appeared on the arms: they were very minute, of a vivid red 

^ They who attend sick cattle in this country find a speedy remedy for stopping 
the progress o£ this complaint in those applications which act chemically upon the 
morbid matter, such as the solutions of the vitriolum zinci and the vitriolum cupri, etc. 



VACCINATION AGAINST SMALLPOX I47 

colour, and soon died away without advancing to maturation; so 
that I cannot determine whether they had any connection with the 
preceding symptoms. 

Thus the disease makes its progress from the horse' to the nipple 
of the cow, and from the cow to the human subject. 

Morbid matter of various kinds, when absorbed into the system, 
may produce effects in some degree similar; but what renders the 
cow-pox virus so extremely singular is that the person who has been 
thus affected is forever after secure from the infection of the small- 
pox; neither exposure to the variolous effluvia, nor the insertion of 
the matter into the skin, producing this distemper. 

In support of so extraordinary a fact, I shall lay before my reader 
a great number of instances.'' 

Case I. — Joseph Merret, now an under gardener to the Earl of 
Berkeley, lived as a servant with a farmer near this place in the 
year 1770, and occasionally assisted in milking his master's cows. 
Several horses belonging to the farm began to have sore heels, which 
Merret frequently attended. The cows soon became affected with 
the cow-pox, and soon after several sores appeared on his hands. 
Swellings and stiffness in each axilla followed, and he was so much 
indisposed for several days as to be incapable of pursuing his ordi- 
nary employment. Previously to the appearance of the distemper 
among the cows there was no fresh cow brought into the farm, nor 
any servant employed who was affected with the cow-pox. 

'Jenner's conclusion that "grease" and cow-pox were the same disease has since 
been proved erroneous; but this error has not invalidated his main conclusion as to 
the relation of cow-pox and smallpox. — Editor. 

* It is necessary to observe that pustulous sores frequently appear spontaneously on 
the nipples of cows, and instances have occurred, though very rarely, of the hands 
of the servants employed in milking being affected with sores in consequence, and 
even of their feeling an indisposition from absorption. These pustules are of a much 
milder nature than those which arise from that contagion which constitutes the true 
cow-pox. They are always free from the bluish or livid tint so conspicuous in the 
pustules in that disease. No erysipelas attends them, nor do they shew any phagedenic 
disposition as in the other case, but quickly terminate in a scab without creating any 
apparent disorder in the cow. This complaint appears at various seasons of the year, 
but most commonly in the spring, when the cows are first taken from their winter 
food and fed with grass. It is very apt to appear also when they are suckling their 
young. But this disease is not to be considered as similar in any respect to that of 
which I am treating, as it is incapable of producing any specific effects on the human 
Constitudon. However, it is of the greatest consequence to point it out here, lest the 
want of discrimination should occasion an idea of security from the infection of the 
smallpox, which might prove delusive. 



148 EDWARD JENNER 

In April, 1795, a general inoculation taking place here, Merret 
was inoculated with his family; so that a period of twenty-five years 
had elapsed from his having the cow-pox to this time. However, 
though the variolous matter was repeatedly inserted into his arm, 
I found it impracticable to infect him with it; an efflorescence only, 
taking on an erysipelatous look about the centre, appearing on the 
skin near the punctured parts. During the whole time that his 
family had the smallpox, one of whom had it very full, he remained 
in the house with them, but received no injury from exposure to 
the contagion. 

It is necessary to observe that the utmost care was taken to ascer- 
tain, with the most scrupulous precision, that no one whose case is 
here adduced had gone through the smallpox previous to these 
attempts to produce that disease. 

Had these experiments been conducted in a large city, or in a 
populous neighbourhood, some doubts might have been entertained; 
but here, where population is thin, and where such an event as a 
person's having had the smallpox is always faithfully recorded, no 
risk of inaccuracy in this particular can arise. 

Case II. — Sarah Portlock, of this place, was infected with the cow- 
pox when a servant at a farmer's in the neighbourhood, twenty- 
seven years ago.^ 

In the year 1792, conceiving herself, from this circumstance, secure 
from the infection of the smallpox, she nursed one of her own 
children who had accidentally caught the disease, but no indispo- 
sition ensued. During the time she remained in the infected room, 
variolous matter was inserted into both her arms, but without any 
further effect than in the preceding case. 

Case III. — John Phillips, a tradesman of this town, had the cow- 
pox at so early a period as nine years of age. At the age of sixty- 
two I inoculated him, and was very careful in selecting matter in its 
most active state. It was taken from the arm of a boy just before 
the commencement of the eruptive fever, and instantly inserted. It 

*I have purposely selected several cases in which the disease had appeared at a 
very distant period previous to the experiments made with variolous matter, to shew 
that the change produced in the constitution is not affected by time. 



VACCINATION AGAINST SMALLPOX 1 49 

very speedily produced a sting-like feel in the part. An efflorescence 
appeared, which on the fourth day was rather extensive, and some 
degree of pain and stiffness were felt about the shoulder: but on 
the fifth day these symptoms began to disappear, and in a day or 
two after went entirely off, without producing any effect on the 
system. 

Case IV. — Mary Barge, of Woodford, in this parish, was inocu- 
lated with variolous matter in the year 1791. An efflorescence of a 
palish red colour soon appeared about the parts where the matter 
was inserted, and spread itself rather extensively, but died away in 
a few days without producing any variolous symptoms.^ She has 
since been repeatedly employed as a nurse to smallpox patients, 
without experiencing any ill consequences. This woman had the 
cow-pox when she lived in the service of a farmer in this parish 
thirty-one years before. 

Case V. — Mrs. H , a respectable gentlewoman of this town, had 

the cow-pox when very young. She received the infection in rather 
an uncommon manner: it was given by means of her handling 
some of the same utensils' which were in use among the servants of 
the family, who had the disease from milking infected cows. Her 
hands had many of the cow-pox sores upon them, and they were 
communicated to her nose, which became inflamed and very much 
swollen. Soon after this event Mrs. H was exposed to the con- 
tagion of the smallpox, where it was scarcely possible for her to 
have escaped, had she been susceptible of it, as she regularly attended 
a relative who had the disease in so violent a degree that it proved 
fatal to him. 

In the year 1778 the smallpox prevailed very much at Berkeley, and 
Mrs. H , not feeling perfectly satisfied respecting her safety (no 

^ It is remarkable that variolous matter, when the system is disposed to reject it, 
should excite inflammation on the part to which it is applied more speedily than when 
it produces the smallpox. Indeed, it becomes almost a criterion by which we can 
determine whether the infection will be received or not. It seems as if a change, 
which endures through life, had been produced in the action, or disposition to action, 
in the vessels of the skin; and it is remarkable, too, that whether this change has 
been effected by the smallpox or the cow-pox that the disposition to sudden cuticular 
inflammation is the same on the application of variolous matter. 

' When the cow-pox has prevailed in the dairy, it has often been communicated to 
those who have not milked the cows, by the handle o£ the milk pail. 



150 EDWARD JENNER 

indisposition having followed her exposure to the smallpox), I 
inoculated her with active variolous matter. The same appearance 
followed as in the preceding cases — an efflorescence on the arm with- 
out any effect on the constitution. 

Case VI. — It is a fact so well known among our dairy farmers that 
those who have had the smallpox either escape the cow-pox or are 
disposed to have it slightly, that as soon as the complaint shews 
itself among the cattle, assistants are procured, if possible, who are 
thus rendered less susceptible of it, otherwise the business of the 
farm could scarcely go forward. 

In the month of May, 1796, the cow-pox broke out at Mr. Baker's, a 
farmer who lives near this place. The disease was communicated by 
means of a cow which was purchased in an infected state at a neigh- 
bouring fair, and not one of the farmer's cows (consisting of thirty) 
which were at that time milked escaped the contagion. The family 
consisted of a man servant, two dairymaids, and a servant boy, who, 
with the farmer himself, were twice a day employed in milking 
the cattle. The whole of this family, except Sarah Wynne, one of 
the dairymaids, had gone through the smallpox. The consequence 
was that the farmer and the servant boy escaped the infection of the 
cow-pox entirely, and the servant man and one of the maid servants 
had each of them nothing more than a sore on one of their fingers, 
which produced no disorder in the system. But the other dairymaid, 
Sarah Wynne, who never had the smallpox, did not escape in so 
easy a manner. She caught the complaint from the cows, and was 
affected with the symptoms described on page 146 in so violent a 
degree that she was confined to her bed, and rendered incapable for 
several days of pursuing her ordinary vocations in the farm. 

March 28th, 1797, I inoculated this girl and carefully rubbed the 
variolous matter into two slight incisions made upon the left arm. 
A little inflammation appeared in the usual manner around the 
parts where the matter was inserted, but so early as the fifth day 
it vanished entirely without producing any effect on the system. 

Case VII. — Although the preceding history pretty clearly evinces 
that the constitution is far less susceptible of the contagion of the 



VACCINATION AGAINST SMALLPOX I5I 

cow-pox after it has felt that of the smallpox, and although in gen- 
eral, as I have observed, they who have had the smallpox, and are 
employed in milking cows which are infected with the cow-pox, 
either escape the disorder, or have sores on the hands without feel- 
ing any general indisposition, yet the animal economy is subject 
to some variation in this respect, which the following relation will 
point out: 

In the summer of the year 1796 the cow-pox appeared at the farm 
of Mr. Andrews, a considerable dairy adjoining to the town of 
Berkeley. It was communicated, as in the preceding instance, by an 
infected cow purchased at a fair in the neighbourhood. The family 
consisted of the farmer, his wife, two sons, a man and a maid 
servant; all of whom, except the farmer (who was fearful of the 
consequences), bore a part in milking the cows. The whole of them, 
exclusive of the man servant, had regularly gone through the small- 
pox; but in this case no one who milked the cows escaped the con- 
tagion. All of them had sores upon their hands, and some degree 
of general indisposition, preceded by pains and tumours in the axillse : 
but there was no comparison in the severity of the disease as it was 
felt by the servant man, who had escaped the smallpox, and by those 
of the family who had not, for, while he was confined to his bed, 
they were able, without much inconvenience, to follow their ordi- 
nary business. 

February the 13th, 1797, I availed myself of an opportunity of 
inoculating William Rodway, the servant man above alluded to. 
Variolous matter was inserted into both his arms: in the right, by 
means of superficial incisions, and into the left by slight punctures 
into the cutis. Both were perceptibly inflamed on the third day. 
After this the inflammation about the punctures soon died away, but 
a small appearance of erysipelas was manifest about the edges of the 
incisions till the eighth day, when a little uneasiness was felt for 
the space of half an hour in the right axilla. The inflammation then 
hastily disappeared without producing the most distant mark of 
affection of the system. 

Case VIII. — Elizabeth Wynne, aged fifty-seven, lived as a servant 
with a neighbouring farmer thirty-eight years ago. She was then 



152 EDWARD JENNER 

a dairymaid, and the cow-pox broke out among the cows. She 
caught the disease with the rest o£ the family, but, compared with 
them, had it in a very shght degree, one very small sore only break- 
ing out on the little finger of her left hand, and scarcely any per- 
ceptible indisposition following it. 

As the malady had shewn itself in so slight a manner, and as it 
had taken place at so distant a period of her life, I was happy with 
the opportunity of trying the effects of variolous matter upon her 
constitution, and on the 28th of March, 1797, I inoculated her by 
making two superficial incisions on the left arm, on which the mat- 
ter was cautiously rubbed. A little efflorescence soon appeared, and 
a tingling sensation was felt about the parts where the matter was 
inserted until the third day, when both began to subside, and so early 
as the fifth day it was evident that no indisposition would follow. 

Case IX. — Although the cow-pox shields the constitution from 
the smallpox, and the smallpox proves a protection against its own 
future poison, yet it appears that the human body is again and 
again susceptible of the infectious matter of the cow-pox, as the 
following history will demonstrate. 

William Smith, of Pyrton in this parish, contracted this disease 
when he lived with a neighbouring farmer in the year 1780. One 
of the horses belonging to the farm had sore heels, and it fell to his 
lot to attend him. By these means the infection was carried to the 
cows, and from the cows it was communicated to Smith. On one 
of his hands were several ulcerated sores, and he was affected with 
such symptoms as have been before described. 

In the year 1791 the cow-pox broke out at another farm where 
he then lived as a servant, and he became affected with it a second 
time; and in the year 1794 he was so unfortunate as to catch it again. 
The disease was equally as severe the second and third time as it 
was on the first.* 

In the spring of the year 1795 he was twice inoculated, but no 
affection of the system could be produced from the variolous mat- 

' This is not the case in general — a second attack is commonly very slight, and so, 
I am informed, it is among the cows. 



VACCINATION AGAINST SMALLPOX 1 53 

ter; and he has since associated with those who had the smallpox in 
its most contagious state without feeling any effect from it. 

Case X. — Simon Nichols lived as a servant with Mr. Bromedge, a 
gentleman who resides on his own farm in this parish, in the year 
1782. He was employed in applying dressings to the sore heels of 
one of his master's horses, and at the same time assisted in milking 
the cows. The cows became affected in consequence, but the disease 
did not shew itself on their nipples till several weeks after he had 
begun to dress the horse. He quitted Mr. Bromedge's service, and 
went to another farm without any sores upon him; but here his 
hands soon began to be affected in the common way, and he was 
much indisposed with the usual symptoms. Concealing the nature 
of the malady from Mr. Cole, his new master, and being there also 
employed in milking, the cow-pox was communicated to the cows. 

Some years afterward Nichols was employed in a farm where the 
smallpox broke out, when I inoculated him with several other 
patients, with whom he continued during the whole time of their 
confinement. His arm inflamed, but neither the inflammation nor 
his associating with the inoculated family produced the least effect 
upon his constitution. 

Case XI. — William Stinchcomb was a fellow servant with Nichols 
at Mr. Bromedge's farm at the time the cattle had the cow-pox, 
and he was, unfortunately, infected by them. His left hand was 
very severely affected with several corroding ulcers, and a tumour 
of considerable size appeared in the axilla of that side. His right 
hand had only one small tumour upon it, and no tumour discovered 
itself in the corresponding axilla. 

In the year 1792 Stinchcomb was inoculated with variolous matter, 
but no consequences ensued beyond a little inflammation in the 
arm for a few days. A large party were inoculated at the same 
time, some of whom had the disease in a more violent degree than 
is commonly seen from inoculation. He purposely associated with 
them, but could not receive the smallpox. 

During the sickening of some of his companions their symptoms 
so strongly recalled to his mind his own state when sickening 



154 EDWARD JENNER 

with the cow-pox that he very pertinently remarked their striking 
similarity. 

Case XII. — The paupers of the village of Tortworth, in this county, 
were inoculated by Mr. Henry Jenner, Surgeon, of Berkeley, in the 
year 1795. Among them, eight patients presented themselves who 
had at different periods of their lives had the cow-pox. One of them, 
Hester Walkley, I attended with that disease when she lived in the 
service of a farmer in the same village in the year 1782; but neither 
this woman, nor any other of the patients who had gone through 
the cow-pox, received the variolous infection either from the arm or 
from mixing in the society of the other patients who were inocu- 
lated at the same time. This state of security proved a fortunate 
circumstance, as many of the poor women were at the same time in 
a state of pregnancy. 

Case XIII. — One instance has occurred to me of the system being 
affected from the matter issuing from the heels of horses, and of 
its remaining afterwards unsusceptible of the variolous contagion; 
another, where the smallpox appeared obscurely; and a third, in 
which its complete existence was positively ascertained. 

First, Thomas Pearce is the son of a smith and farrier near to this 
place. He never had the cow-pox; but, in consequence of dressing 
horses with sore heels at his father's, when a lad, he had sores on 
his fingers which suppurated, and which occasioned a pretty severe 
indisposition. Six years afterwards I inserted variolous matter into 
his arm repeatedly, without being able to produce any thing more 
than slight inflammation, which appeared very soon after the matter 
was applied, and afterwards I exposed him to the contagion of the 
smallpox with as little effect.' 

Case XIV. — Secondly, Mr. James Cole, a farmer in this parish, had 
a disease from the same source as related in the preceding case, and 

^ It is a remarkable fact, and well known to many, that we are frequently foiled in 
our endeavours to communicate the smallpox by inoculation to blacksmiths, who in 
the country are farriers. They often, as in the above instance, either resist the con- 
tagion entirely, or have the disease anomalously. Shall we not be able to account for 
this on a rational principle? 



VACCINATION AGAINST SMALLPOX 1 55 

some years after was inoculated with variolous matter. He had a 
little pain in the axilla and felt a slight indisposition for three or 
four hours. A few eruptions shewed themselves on the forehead, 
but they very soon disappeared without advancing to maturation. 

Case XV. — Although in the former instances the system seemed 
to be secured, or nearly so, from variolous infection, by the absorp- 
tion of matter from the sores produced by the diseased heels of 
horses, yet the following case decisively proves that this cannot be 
entirely relied upon until a disease has been generated by the morbid 
matter from the horse on the nipple of the cow, and passed through 
that medium to the human subject. 

Mr. Abraham Riddiford, a farmer at Stone in this parish, in con- 
sequence of dressing a mare that had sore heels, was affected with 
very painful sores in both his hands, tumours in each axilla, and 
severe and general indisposition. A surgeon in the neighbourhood 
attended him, who knowing the similarity between the appearance 
of the sores upon his hands and those produced by the cow-pox, and 
being acquainted also with the effects of that disease on the human 
constitution, assured him that he never need to fear the infection of 
the smallpox; but this assertion proved fallacious, for, on being 
exposed to the infection upwards of twenty years afterwards, he 
caught the disease, which took its regular course in a very mild way. 
There certainly was a difference perceptible, although it is not easy 
to describe it, in the general appearance of the pustules from that 
which we commonly see. Other practitioners who visited the patient 
at my request agreed with me in this point, though there was no 
room left for suspicion as to the reality of the disease, as I inoculated 
some of his family from the pustules, who had the smallpox, with 
its usual appearances, in consequence. 

Case XVI. — Sarah Nelmes, a dairymaid at a farmer's near this 
place, was infected with the cow-pox frorri her master's cows in 
May, 1796. She received the infection on a part of her hand which 
had been previously in a slight degree injured by a scratch from a 
thorn. A large pustulous sore and the usual symptoms accompany- 
ing the disease were produced in consequence. The pustule was so 



156 EDWARD JENNER 

expressive of the true character of the cow-pox, as it commonly 
appears upon the hand, that I have given a representation of it in 
the annexed plate. [In original.] The two small pustules on the 
wrists arose also from the application of the virus to some minute 
abrasions of the cuticle, but the livid tint, if they ever had any, was 
not conspicuous at the time I saw the patient. The pustule on the 
forefinger shews the disease in an earlier stage. It did not actually 
appear on the hand of this young woman, but was taken from that 
of another, and is annexed for the purpose of representing the malady 
after it has newly appeared. 

Case XVII. — The more accurately to observe the progress of the 
infection I selected a healthy boy, about eight years old, for the pur- 
pose of inoculation for the cow-pox. The matter was taken from a 
sore on the hand of a dairymaid,'" who was infected by her master's 
cows, and it was inserted, on the 14th of May, 1796, into the arm of 
the boy by means of two superficial incisions, barely penetrating the 
cutis, each about half an inch long. 

On the seventh day he complained of uneasiness in the axilla, and 
on the ninth he became a little chilly, lost his appetite, and had a 
slight headache. During the whole of this day he was perceptibly 
indisposed, and spent the night with some degree of restlessness, 
but on the day following he was perfectly well. 

The appearance of the incisions in their progress to a state of 
maturation were much the same as when produced in a similar man- 
ner by variolous matter. The only difference which I perceived was 
in the state of the limpid Huid arising from the action of the virus, 
which assumed rather a darker hue, and in that of the efflorescence 
spreading round the incisions, which had more of an erysipelatous 
look than we commonly perceive when variolous matter has been 
made use of in the same manner; but the whole died away (leaving 
on the inoculated parts scabs and subsequent eschars) without giving 
me or my patient the least trouble. 

In order to ascertain whether the boy, after feeling so slight an 
affection of the system from the cow-pox virus, was secure from 

'" From the sore on the hand o£ Sarah Nelmes. See the preceding case. 



VACCINATION AGAINST SMALLPOX 157 

the contagion of the smallpox, he was inoculated the ist of July 
following with variolous matter, immediately taken from a pustule. 
Several slight punctures and incisions were made on both his arms, 
and the matter was carefully inserted, but no disease followed. The 
same appearances were observable on the arms as we commonly see 
when a patient has had variolous matter applied, after having either 
the cow-pox or smallpox. Several months afterwards he was again 
inoculated with variolous matter, but no sensible effect was pro- 
duced on the constitution. 

Here my researches were interrupted till the spring of the year 
1798, when, from the wetness of the early part of the season, many 
of the farmers' horses in this neighbourhood were affected with sore 
heels, in consequence of which the cow-pox broke out among several 
of our dairies, which afforded me an opportunity of making further 
observations upon this curious disease. 

A mare, the property of a person who keeps a dairy in a neighbour- 
ing parish, began to have sore heels the latter end of the month of 
February, 1798, which were occasionally washed by the servant men 
of the farm, Thomas Virgoe, William Wherret, and William Haynes, 
who in consequence became affected with sores in their hands, fol- 
lowed by inflamed lymphatic glands in the arms and axillae, shiver- 
ings succeeded by heat, lassitude, and general pains in the limbs. A 
single paroxysm terminated the disease; for within twenty-four 
hours they were free from general indisposition, nothing remaining 
but the sores on their hands. Haynes and Virgoe, who had gone 
through the smallpox from inoculation, described their feelings as 
very similar to those which affected them on sickening with that 
malady. Wherret never had had the smallpox. Haynes was daily 
employed as one of the milkers at the farm, and the disease began to 
shew itself among the cows about ten days after he first assisted 
in washing the mare's heels. Their nipples became sore in the usual 
way, with bluish pustules; but as remedies were early applied, they 
did not ulcerate to any extent. 

Case XVIII. — John Baker, a child of five years old, was inoculated 
March 16, 1798, with matter taken from a pustule on the hand of 



158 EDWARD JENNER 

Thomas Virgoe, one o£ the servants who had been infected from 
the mare's heels. He became ill on the sixth day with symptoms 
similar to those excited by cow-pox matter. On the eighth day he 
was free from indisposition. 

There was some variation in the appearance of the pustule on the 
arm. Although it somewhat resembled a smallpox pustule, yet its 
similitude was not so corispicuous as when excited by matter from 
the nipple of the cow, or when the matter has passed from thence 
through the medium of the human subject. 

This experiment was made to ascertain the progress and subse- 
quent effects of the disease when thus propagated. We have seen 
that the virus from the horse, when it proves infectious to the human 
subject, is not to be relied upon as rendering the system secure from 
variolous infection, but that the matter produced by it upon the 
nipple of the cow is perfectly so. Whether its passing from the horse 
through the human constitution, as in the present instance, will 
produce a similar effect, remains to be decided. This would now 
have been effected, but the boy was rendered unfit for inoculation 
from having felt the effects of a contagious fever in a workhouse 
soon after this experiment was made. 

Case XIX. — ^William Summers, a child of five years and a half 
old, was inoculated the same day with Baker, with matter taken 
from the nipples of one of the infected cows, at the farm alluded 
to. He became indisposed on the sixth day, vomited once, and felt 
the usual slight symptoms till the eighth day, when he appeared 
perfectly well. The progress of the pustule, formed by the infection 
of the virus, was similar to that noticed in Case XVII, with this 
exception, its being free from the livid tint observed in that 
instance. 

Case XX. — From William Summers the disease was transferred 
to William Pead, a boy of eight years old, who was inoculated March 
28th. On the sixth day he complained of pain in the axilla, and 
on the seventh was affected with the common symptoms of a patient 
sickening with the smallpox from inoculation, which did not termi- 
nate till the third day after the seizure. So perfect was the similarity 



VACCINATION AGAINST SMALLPOX I59 

to the variolous fever that I was induced to examine the skin, con- 
ceiving there might have been some eruptions, but none appeared. 
The efflorescent blush around the part punctured in the boy's arm 
was so truly characteristic of that which appears on variolous inocu- 
lation that I have given a representation of it. [In original.] The 
drawing was made when the pustule was beginning to die away and 
the areola retiring from the centre. 

Case XXI. — April 5th: Several children and adults were inocu- 
lated from the arm of William Pead. The greater part of them 
sickened on the sixth day, and were well on the seventh, but in three 
of the number a secondary indisposition arose in consequence of an 
extensive erysipelatous inflammation which appeared on the inocu- 
lated arms. It seemed to arise from the state of the pustule, which 
spread out, accompanied with some degree of pain, to about half 
the diameter of a sixpence. One of these patients was an infant of 
half a year old. By the application of mercurial ointment to the 
inflamed parts (a treatment recommended under similar circum- 
stances in the inoculated smallpox) the complaint subsided without 
giving much trouble. 

Hannah Excell, an healthy girl of seven years old, and one of the 
patients above mentioned, received the infection from the insertion 
of the virus under the cuticle of the arm in three distinct points. 
The pustules which arose in consequence so much resembled, on 
the twelfth day, those appearing from the infection of variolous 
matter, that an experienced inoculator would scarcely have dis- 
covered a shade of difference at that period. Experience now tells 
me that almost the only variation which follows consists in the 
pustulous fluids remaining limpid nearly to the time of its total dis- 
appearance; and not, as in the direct smallpox, becoming purulent. 

Case XXII. — ^From the arm of this girl matter was taken and 
inserted April 12th into the arms of John Marklove, one year and 
a half old, Robert F. Jenner, eleven months old, Mary Pead, five years 
old, and Mary James, six years old. 

Among these, Robert P. Jenner did not receive the infection. 
The arms of the other three inflamed properly and began to affect 



l6o EDWARD JENNER 

the system in the usual manner; but being under some apprehen- 
sions from the preceding cases that a troublesome erysipelas might 
arise, I determined on making an experiment with the view of cut- 
ting off its source. Accordingly, after the patients had felt an indis- 
position of about twelve hours, I applied in two of these cases out 
of the three, on the vesicle formed by the virus, a little mild caustic, 
composed of equal parts of quick-lime and soap, and suffered it to 
remain on the part six hours." It seemed to give the children but 
little uneasiness, and effectually answered my intention in prevent- 
ing the appearance of erysipelas. Indeed, it seemed to do more, for 
in half an hour after its application the indisposition of the children 
ceased." These precautions were perhaps unnecessary, as the arm 
of the third child, Mary Pead, which was suffered to take its com- 
mon course, scabbed quickly, without any erysipelas. 

Case XXIII. — ^From this child's arm matter was taken and trans- 
ferred to that of J. Barge, a boy of seven years old. He sickened on 
the eighth day, went through the disease with the usual slight 
symptoms, and without any inflammation on the arm beyond the 
common efflorescence surrounding the pustule, an appearance so 
often seen in inoculated smallpox. 

After the many fruitless attempts to give the smallpox to those 
who had had the cow-pox, it did not appear necessary, nor was it 
convenient to me, to inoculate the whole of those who had been the 
subjects of these late trials; yet I thought it right to see the effects 
of variolous matter on some of them, particularly William Summers, 
the first of these patients who had been infected with matter taken 
from the cow. He was, therefore, inoculated with variolous matter 
from a fresh pustule; but, as in the preceding cases, the system did 
not feel the effects of it in the smallest degree. I had an opportunity 
also of having this boy and William Pead inoculated by my nephew, 
Mr. Henry Jenner, whose report to me is as follows : "I have inocu- 
lated Pead and Barge, two of the boys whom you lately infected 
with the cow-pox. On the second day the incisions were inflamed 

" Perhaps a few touches with the lapis septicus would have proved equally effica- 
cious. 

'^What effect would a similar treatment produce in inoculation for the smallpox? 



VACCINATION AGAINST SMALLPOX l6l 

and there was a pale inflammatory stain around them. On the third 
day these appearances were still increasing and their arms itched 
considerably. On the fourth day the inflammation was evidently 
subsiding, and on the sixth day it was scarcely perceptible. No 
symptom of indisposition followed. 

"To convince myself that the variolous matter made use of was in 
a perfect state I at the same time inoculated a patient with some of 
it who never had gone through the cow-pox, and it produced the 
smallpox in the usual regular manner." 

These experiments afforded me much satisfaction; they proved 
that the matter, in passing from one human subject to another, 
through five gradations, lost none of its original properties, J. Barge 
being the fifth who received the infection successively from William 
Summers, the boy to whom it was communicated from the cow. 

I shall now conclude this inquiry with some general observations 
on the subject, and on some others which are interwoven with it. 

Although I presume it may be unnecessary to produce further 
testimony in support of my assertion "that the cow-pox protects the 
human constitution from the infection of the smallpox," yet it affords 
me considerable satisfaction to say that Lord Somerville, the Presi- 
dent of the Board of Agriculture, to whom this paper was shewn 
by Sir Joseph Banks, has found upon inquiry that the statements 
were confirmed by the concurring testimony of Mr. Dolland, a sur- 
geon, who resides in a dairy country remote from this, in which 
these observations were made. With respect to the opinion adduced 
"that the source of the infection is a peculiar morbid matter arising 
in the horse," although I have not been able to prove it from actual 
experiments conducted immediately under my own eye, yet the 
evidence I have adduced appears sufficient to establish it. 

They who are not in the habit of conducting experiments may 
not be aware of the coincidence of circumstances necessary for their 
being managed so as to prove perfectly decisive; nor how often men 
engaged in professional pursuits are liable to interruptions which 
disappoint them almost at the instant of their being accomplished: 
however, I feel no room for hesitation respecting the common origin 
of the disease, being well convinced that it never appears among the 
cows (except it can be traced to a cow introduced among the gen- 



1 62 EDWARD JENNER 

eral herd which has been previously infected, or to an infected serv- 
ant) unless they have been milked by some one vi^ho, at the same 
time, has the care of a horse affected with diseased heels. 

The spring of the year 1797, which I intended particularly to have 
devoted to the completion of this investigation, proved, from its 
dryness, remarkably adverse to my wishes; for it frequently happens, 
while the farmers' horses are exposed to the cold rains which fall 
at that season, that their heels become diseased, and no cow-pox then 
appeared in the neighbourhood. 

The active quality of the virus from the horses' heels is greatly 
increased after it has acted on the nipples of the cow, as it rarely 
happens that the horse affects his dresser with sores, and as rarely 
that a milkmaid escapes the infection when she milks infected cows. 
It is most active at the commencement of the disease, even before 
it has acquired a pus-like appearance; indeed, I am not confident 
whether this property in the matter does not entirely cease as soon 
as it is secreted in the form of pus. I am induced to think it does 
cease," and that it is the thin, darkish-looking fluid only, oozing 
from the newly-formed cracks in the heels, similar to what some- 
times appears from erysipelatous blisters, which gives the disease. 
Nor am I certain that the nipples of the cows are at all times in a 
state to receive the infection. The appearance of the disease in the 
spring and the early part of the summer, when they are disposed 
to be affected with spontaneous eruptions so much more frequently 
than at other seasons, induces me to think that the virus from the 
horse must be received upon them when they are in this state, in 
order to produce effects: experiments, however, must determine 
these points. But it is clear that when the cow-pox virus is once 
generated, that the cows cannot resist the contagion, in whatever 
state their nipples may chance to be, if they are milked with an 
infected hand. 

Whether the matter, either from the cow or the horse, will affect 
the sound skin of the human body, I cannot positively determine; 
probably it will not, unless on those parts where the cuticle is ex- 

'' It is very easy to procure pus from old sores on the heels of horses. This I have 
often inserted into scratches made with a lancet, on the sound nipples of cows, and 
have seen no other effects from it than simple inflammation. 



VACCINATION AGAINST SMALLPOX 1 63 

tremely thin, as on the Hps, for example. I have known an instance 
of a poor girl who produced an ulceration on her hp by frequently 
holding her finger to her mouth to cool the raging of a cow-pox 
sore by blowing upon it. The hands of the farmers' servants here, 
from the nature of their employments, are constantly exposed to 
those injuries which occasion abrasions of the cuticle, to punctures 
from thorns, and such like accidents; so that they are always in a 
state to feel the consequence of exposure to infectious matter. 

It is singular to observe that the cow-pox virus, although it renders 
the constitution unsusceptible of the variolous, should nevertheless, 
leave it unchanged with respect to its own action. I have already 
produced an instance" to point out this, and shall now corroborate 
it with another. 

Elizabeth Wynne, who had the cow-pox in the year 1759, was 
inoculated with variolous matter, without effect, in the year 1797, 
and again caught the cow-pox in the year 1798. When I saw her, 
which was on the eighth day after she received the infection, I 
found her affected with general lassitude, shiverings, alternating 
with heat, coldness of the extremities, and a quick and irregular 
pulse. These symptoms were preceded by a pain in the axilla. On 
her hand was one large pustulous sore, which resembled that deline- 
ated in Plate No. i. (Plate appears in original.) 

It is curious also to observe that the virus, which with respect 
to its effects is undetermined and uncertain previously to its pass- 
ing from the horse through the medium of the cow, should then not 
only become more active, but should invariably and completely 
possess those specific properties which induce in the human consti- 
tution symptoms similar to those of the variolous fever, and effect in 
it that peculiar change which for ever renders it unsusceptible of the 
variolous contagion. 

May it not then be reasonably conjectured that the source of the 
smallpox is morbid matter of a peculiar kind, generated by a disease 
in the horse, and that accidental circumstances may have again and 
again arisen, still working new changes upon it until it has acquired 
the contagious and malignant form under which we now commonly 
see it making its devastations amongst us? And, from a considera- 

" See Case IX. 



164 EDWARD JENNER 

tion o£ the change which the infectious matter undergoes from pro- 
ducing a disease on the cow, may we not conceive that many con- 
tagious diseases, now prevalent among us, may owe their present 
appearance not to a simple, but to a compound, origin ? For example, 
is it difficult to imagine that the measles, the scarlet fever, and the 
ulcerous sore throat with a spotted skin have all sprung from the 
same source, assuming some variety in their forms according to the 
nature of their new combinations? The same question will apply 
respecting the origin of many other contagious diseases which bear a 
strong analogy to each other. 

There are certainly more forms than one, without considering the 
common variation between the confluent and distinct, in which the 
smallpox appears in what is called the natural way. About seven 
years ago a species of smallpox spread through many of the towns 
and villages of this part of Gloucestershire: it was of so mild a 
nature that a fatal instance was scarcely ever heard of, and conse- 
quently so little dreaded by the lower orders of the community that 
they scrupled not to hold the same intercourse with each other as 
if no infectious disease had been present among them. I never saw 
nor heard of an instance of its being confluent. The most accurate 
manner, perhaps, in which I can convey an idea of it is by saying 
that had fifty individuals been taken promiscuously and infected by 
exposure to this contagion, they would have had as mild and light 
a disease as if they had been inoculated with variolous matter in 
the usual way. The harmless manner in which it shewed itself 
could not arise from any peculiarity either in the season or the 
weather, for I watched its progress upwards of a year without per- 
ceiving any variation in its general appearance. I consider it then as 
a variety of the smallpox.'^ 

In some of the preceding cases I have noticed the attention that 
was paid to the state of the variolous matter previous to the experi- 
ment of inserting it into the arms of those who had gone through 
the cow-pox. This I conceived to be of great importance in con- 
ducting these experiments, and, were it always properly attended to 

'* My friend, Dr. Hicks, of Bristol, who, during the prevalence of this distemper, 
was resident at Gloucester, and physician to the hospital there (where it was seen 
soon after its first appearance in this country), had opportunities of making numerous 
observations upon it, which it is his intention to communicate to the public. 



VACCINATION AGAINST SMALLPOX 1 65 

by those who inoculate for the smallpox, it might prevent much 
subsequent mischief and confusion. With the view of enforcing 
so necessary a precaution I shall take the liberty of digressing so 
far as to point out some unpleasant facts relative to mismanage- 
ment in this particular, which have fallen under my own observa- 
tion. 

A medical gentleman (now no more), who for many years inocu- 
lated in this neighbourhood, frequently preserved the variolous 
matter intended for his use on a piece of lint or cotton, which, in 
its fluid state, was put into a vial, corked, and conveyed into a warm 
pocket; a situation certainly favourable for speedily producing putre- 
faction in it. In this state (not unfrequently after it had been taken 
several days from the pustules) it was inserted into the arms of his 
patients, and brought on inflammation of the incised parts, swellings 
of the axillary glands, fever, and sometimes eruptions. But what was 
this disease? Certainly not the smallpox; for the matter having 
from putrefaction lost or suffered a derangement in its specific prop- 
erties, was no longer capable of producing that malady, those who 
had been inoculated in this manner being as much subject to the 
contagion of the smallpox as if they had never been under the influ- 
ence of this artificial disease; and many, unfortunately, fell victims 
to it, who thought themselves in perfect security. The same unfortu- 
nate circumstance of giving a disease, supposed to be the smallpox, 
with inefficacious variolous matter, having occurred under the direc- 
tion of some other practitioners within my knowledge, and prob- 
ably from the same incautious method of securing the variolous 
matter, I avail myself of this opportunity of mentioning what I con- 
ceive to be of great importance; and, as a further cautionary hint, I 
shall again digress so far as to add another observation on the 
subject of inoculation. 

Whether it be yet ascertained by experiment that the quantity of 
variolous matter inserted into the skin makes any difference with 
respect to the subsequent mildness or violence of the disease, I 
know not; but I have the strongest reason for supposing that if 
either the punctures or incisions be made so deep as to go through 
it and wound the adipose membrane, that the risk of bringing on 
a violent disease is greatly increased. I have known an inoculator 



l66 EDWARD JENNER 

whose practice was to cut deep enough (to use his own expression) 
to see a bit o£ fat," and there to lodge the matter. The great num- 
ber of bad cases, independent of inflammations and abscesses on 
the arms, and the fatahty which attended this practice, was almost 
inconceivable; and I cannot account for it on any other principle than 
that of the matter being placed in this situation instead of the skin. 

It was the practice of another, whom I well remember, to pinch 
up a small portion of the skin on the arms of his patients and 
to pass through it a needle, with a thread attached to it previously 
dipped in variolous matter. The thread was lodged in the perforated 
part, and consequently left in contact with the cellular membrane. 
This practice was attended with the same ill success as the former. 
Although it is very improbable that any one would now inoculate in 
this rude way by design, yet these observations may tend to place 
a double guard over the lancet, when infants, whose skins are com- 
paratively so very thin, fall under the care of the inoculator. 

A very respectable friend of mine, Dr. Hardwicke, of Sodbury 
in this county, inoculated great numbers of patients previous to the 
introduction of the more modern method by Sutton, and with such 
success that a fatal instance occurred as rarely as since that method 
has been adopted. It was the doctor's practice to make as slight an 
incision as possible upon the skin, and there to lodge a thread 
saturated with the variolous matter. When his patients became 
indisposed, agreeably to the custom then prevailing, they were 
directed to go to bed and were kept moderately warm. Is it not 
probable then that the success of the modern practice may depend 
more upon the method of invariably depositing the virus in or upon 
the skin, than on the subsequent treatment of the disease? 

I do not mean to insinuate 'that exposure to cool air, and suffer- 
ing the patient to drink cold water when hot and thirsty, may not 
moderate the eruptive symptoms and lessen the number of pustules; 
yet, to repeat my former observation, I cannot account for the unin- 
terrupted success, or nearly so, of one practitioner, and the wretched 
state of the patients under the care of another, where, in both 
instances, the general treatment did not differ essentially, wdthout 
conceiving it to arise from the different modes of inserting the mat- 
ter for the purpose of producing the disease. As it is not the identi- 



VACCINATION AGAINST SMALLPOX 1 67 

cal matter inserted which is absorbed into the constitution, but 
that which is, by some peculiar process in the animal economy, gen- 
erated by it, is it not probable that different parts of the human 
body may prepare or modify the virus differently? Although the 
skin, for example, adipose membrane, or mucous membranes are all 
capable of producing the variolous virus by the stimulus given by 
the particles originally deposited upon them, yet I am induced to 
conceive that each of these parts is capable of producing some vari- 
ation in the qualities of the matter previous to its affecting the 
constitution. What else can constitute the difference between the 
smallpox when communicated casually or in what has been termed 
the natural way, or when brought on artificially through the medium 
of the skin? 

After all, are the variolous particles, possessing their true specific 
and contagious principles, ever taken up and conveyed by the lym- 
phatics unchanged into the blood vessels ? I imagine not. Were this 
the case, should we not find the blood sufficiently loaded with them 
in some stages of the smallpox to communicate the disease by insert- 
ing it under the cuticle, or by spreading it on the surface of an 
ulcer? Yet experiments have determined the impracticability of its 
being given in this way; although it has been proved that variolous 
matter, when much diluted with water and applied to the skin in 
the usual manner, will produce the disease. But it would be digress- 
ing beyond a proper boundary to go minutely into this subject 
here. 

At what period the cow-pox was first noticed here is not upon 
record. Our oldest farmers were not unacquainted with it in their 
earliest days, when it appeared among their farms without any 
deviation from the phenomena which it now exhibits. Its connec- 
tion with the smallpox seems to have been unknown to them. 
Probably the general introduction of inoculation first occasioned 
the discovery. 

Its rise in this country may not have been of very remote date, 
as the practice of milking cows might formerly have been in the 
hands of women only; which I believe is the case now in some other 
dairy countries, and, consequently, that the cows might not in 
former times have been exposed to the contagious matter brought 



1 68 EDWARD JENNER 

by the men servants from the heels of horses.'^ Indeed, a knowledge 
of the source of the infection is new in the minds of most of the 
farmers in this neighbourhood, but it has at length produced good 
consequences; and it seems probable, from the precautions they are 
now disposed to adopt, that the appearance of the cow-pox here may 
either be entirely extinguished or become extremely rare. 

Should it be asked whether this investigation is a matter of mere 
curiosity, or whether it tends to any beneficial purpose, I should 
answer that, notwithstanding the happy effects of inoculation, with 
all the improvements which the practice has received since its first 
introduction into this country, it not very unfrequently produces 
deformity of the skin, and sometimes, under the best management, 
proves fatal. 

These circumstances must naturally create in every instance some 
degree of painful solicitude for its consequences. But as I have 
never known fatal effects arise from the cow-pox, even when im- 
pressed in the most unfavourable manner, producing extensive 
inflammations and suppurations on the hands; and as it clearly 
appears that this disease leaves the constitution in a state of perfect 
security from the infection of the smallpox, may we not infer that 
a mode of inoculation may be introduced preferable to that at pres- 
ent adopted, especially among those families which, from previous 
circumstances, we may judge to be predisposed to have the disease 
unfavourably? It is an excess in the number of pustules which we 
chiefly dread in the smallpox; but in the cow-pox no pustules appear, 
nor does it seem possible for the contagious matter to produce the 
disease from effluvia, or by any other means than contact, and that 
probably not simply between the virus and the cuticle; so that a 
single individual in a family might at any time receive it without 
the risk of infecting the rest or of spreading a distemper that fills a 
country with terror. 

Several instances have come under my observation which justify 
the assertion that the disease cannot be propagated by effluvia. The 

" I have been informed from respectable authority that in Ireland, although dairies 
abound in many parts of the island, the disease is entirely unknown. The reason seems 
obvious. The business of the dairy is conducted by women only. Were the meanest 
vassal among the men employed there as a milker at a dairy, he would feel his situa- 
tion unpleasant beyond all endurance. 



VACCINATION AGAINST SMALLPOX 1 69 

first boy whom I inoculated with the matter of cow-pox slept in a 
bed, while the experiment was going forward, with two children 
who never had gone through either that disease or the smallpox, 
without infecting either of them. 

A young woman who had the cow-pox to a great extent, several 
sores which maturated having appeared on the hands and wrists, 
slept in the same bed with a fellow-dairymaid who never had been 
infected with either the cow-pox or the smallpox, but no indisposi- 
tion followed. 

Another instance has occurred of a young woman on whose hands 
were several large suppurations from the cow-pox, who was at the 
same time a daily nurse to an infant, but the complaint was not 
communicated to the child. 

In some other points of view the inoculation of this disease appears 
preferable to the variolous inoculation. 

In constitutions predisposed to scrophula, how frequently we see 
the inoculated smallpox rouse into activity that distressful malady! 
This circumstance does not seem to depend on the manner in which 
the distemper has shewn itself, for it has as frequently happened 
among those who have had it mildly as when it has appeared in the 
contrary way. 

There are many who, from some peculiarity in the habit, resist 
the common effects of variolous matter inserted into the skin, and 
who are in consequence haunted through life with the distressing 
idea of being insecure from subsequent infection. A ready mode of 
dissipating anxiety originating from such a cause must now appear 
obvious. And, as we have seen that the constitution may at any 
time be made to feel the febrile attack of cow-pox, might it not, 
in many chronic diseases, be introduced into the system, with the 
probability of affording relief, upon well-known physiological 
principles ? 

Although I say the system may at any time be made to feel the 
febrile attack of cow-pox, yet I have a single instance before me 
where the virus acted locally only, but it is not in the least probable 
that the same person would resist the action both of the cow-pox 
virus and the variolous. 

Elizabeth Sarfenet lived as a dairymaid at Newpark farm, in this 



170 EDWARD JENNER 

parish. All the cows and the servants employed in milking had the 
cow-pox; but this woman, though she had several sores upon her 
fingers, felt no tumours in the axillae, nor any general indisposition. 
On being afterwards casually exposed to variolous infection, she 
had the smallpox in a mild way. Hannah Pick, another of the dairy- 
maids who was a fellow-servant with Elizabeth Sarfenet when the 
distemper broke out at the farm, was, at the same time, infected; 
but this young woman had not only sores upon her hands, but felt 
herself also much indisposed for a day or two. After this, I made 
several attempts to give her the smallpox by inoculation, but they 
all proved fruitless. From the former case then we see that the 
animal economy is subject to the same laws in one disease as the 
other. 

The following case, which has very lately occurred, renders it 
highly probable that not only the heels of the horse, but other parts 
of the body of that animal, are capable of generating the virus which 
produces the cow-pox. 

An extensive inflammation of the erysipelatous kind appeared 
without any apparent cause upon the upper part of the thigh of 
a sucking colt, the property of Mr. Millet, a farmer at Rockhamp- 
ton, a village near Berkeley. The inflammation continued several 
weeks, and at length terminated in the formation of three or four 
small abscesses. The inflamed parts were fomented, and dressings 
were applied by some of the same persons who were employed in 
milking the cows. The number of cows milked was twenty-four, 
and the whole of them had the cow-pox. The milkers, consisting 
of the farmer's wife, a man and a maid servant, were infected by 
the cows. The man-servant had previously gone through the small- 
pox, and felt but little of the cow-pox. The servant maid had some 
years before been infected with the cow-pox, and she also felt it 
now in a slight degree; but the farmer's wife, who never had gone 
through either of the diseases, felt its effects very severely. 

That the disease produced upon the cows by the colt and from 
thence conveyed to those who milked them was the true and not 
the spurious cow-pox," there can be scarcely any room for suspi- 
cion; yet it would have been more completely satisfactory had the 

"See Note 4, p. 147. 



VACCINATION AGAINST SMALLPOX I7I 

effects o£ variolous matter been ascertained on the farmer's wife, but 
there was a peculiarity in her situation which prevented my making 
the experiment. 

Thus far have I proceeded in an inquiry founded, as it must 
appear, on the basis of experiment; in which, however, conjecture 
has been occasionally admitted in order to present to persons well 
situated for such discussions, objects for a more minute investigation. 
In the mean time I shall myself continue to prosecute this inquiry, 
encouraged by the hope of its becoming essentially beneficial to 
mankind. 

II 

Further Observations on the VARioLiE Vaccina, or 
Cow-pox. 1799 

Although it has not been in my power to extend the inquiry 
into the causes and effects of the variolas vaccinae much beyond its 
original limits, yet, perceiving that it is beginning to excite a gen- 
eral spirit of investigation, I think it of importance, without delay, 
to communicate such facts as have since occurred, and to point out 
the fallacious sources from whence a disease imitative of the true 
varioljE vaccinae might arise, with the view of preventing those who 
may inoculate from producing a spurious disease; and, further, to 
enforce the precaution suggested in the former treatise on the sub- 
ject, of subduing the inoculated pustule as soon as it has sufficiently 
produced its influence on the constitution. From a want of due 
discrimination of the real existence of the disease, either in the brute 
or in the human subject, and also of that stage of it in which it is 
capable of producing the change in the animal economy which 
renders it unsusceptible of the contagion of the smallpox, unpleasant 
consequences might ensue, the source of which, perhaps, might not 
be suspected by one inexperienced in conducting such experiments. 

My late publication contains a relation of most of the facts which 
had come under my own inspection at the time it was written, inter- 
spersed with some conjectural observations. Since then Dr. G. 
Pearson has established an inquiry into the validity of my principal 
assertion, the result of which cannot but be highly flattering to my 



172 EDWARD JENNER 

feelings. It contains not a single case which I think can be called 
an exception to the fact I was so firmly impressed with — that the 
cow-pox protects the human body from the smallpox. I have myself 
received some further confirmations, which shall be subjoined. I 
have lately also been favoured with a letter from a gentleman of great 
respectability (Dr. Ingenhousz), informing me that, on making an 
inquiry into the subject in the county of Wilts, he discovered that 
a farmer near Calne had been infected with the smallpox after 
having had the cow-pox, and that the disease in each instance was 
so strongly characterized as to render the facts incontrovertible. The 
cow-pox, it seems, from the doctor's information, was communicated 
to the farmer from his cows at the time that they gave out an 
offensive stench from their udders. 

Some other instances have likewise been represented to me of 
the appearance of the disease, apparently marked with its character- 
istic symptoms, and yet that the patients have afterwards had the 
smallpox. On these cases I shall, for the present, suspend any par- 
ticular remarks, but hope that the general observations I have to 
offer in the sequel will prove of sufficient weight to render the idea 
of their ever having had existence, but as cases of spurious cow-pox, 
extremely doubtful. 

Ere I proceed let me be permitted to observe that truth, in this 
and every other physiological inquiry that has occupied my atten- 
tion, has ever been the object of my pursuit, and should it appear in 
the present instance that I have been led into error, fond as I may 
appear of the offspring of my labours, I had rather see it perish 
at once than exist and do a public injury. 

I shall proceed to enumerate the sources, or what appear to me as 
such, of a spurious cow-pox. 

Firstly : That arising from pustules on the nipples or udder of the 
cow; which pustules contain no specific virus. 

Secondly : From matter (although originally possessing the specific 
virus) which has suffered a decomposition, either from putrefac- 
tion or from any other cause less obvious to the senses. 

Thirdly: From matter taken from an ulcer in an advanced stage, 
which ulcer arose from a true cow-pock. 



VACCINATION AGAINST SMALLPOX 1 73 

Fourthly: From matter produced on the human skin from con- 
tact with some pecuHar morbid matter generated by a horse. 

On these subjects I shall offer some comments: First, to what 
length pustulous diseases of the udder and nipples of the cow may 
extend it is not in my power to determine; but certain it is that 
these parts of the animal are subject to some variety of maladies 
of this nature; and as many of these eruptions (probably all of 
them) are capable of giving a disease to the human body, would it 
not be discreet for those engaged in this investigation to suspend 
controversy and cavil until they can ascertain with precision what is 
and what is not the genuine cow-pox? 

For example: A farmer who is not conversant with any of these 
maladies, but who may have heard of the cow-pox in general terms, 
may acquaint a neighbouring surgeon that the distemper appears 
at his farm. The surgeon, eager to make an experiment, takes away 
matter, inoculates, produces a sore, uneasiness in the axilla, and per- 
haps some affection of the system. This is one way in which a 
fallacious idea of security both in the mind of the inoculator and the 
patient may arise; for a disease may thus have been propagated from 
a simple eruption only. 

One of the first objects then of this pursuit, as I have observed, 
should be, to learn how to distinguish with accuracy between that 
peculiar pustule which is the true cow-pock, and that which is spuri- 
ous. Until experience has determined this, we view our object 
through a mist. Let us, for instance, suppose that the smallpox and 
the chicken-pox were at the same time to spread among the inhabi- 
tants of a country which had never been visited by either of these 
distempers, and where they were quite unknown before: what con- 
fusion would arise! The resemblance between the symptoms of the 
eruptive fever and between the pustules in either case would be so 
striking that a patient who had gone through the chicken-pox to 
any extent would feel equally easy with regard to his future security 
from the smallpox as the person who had actually passed through 
that disease. Time and future observation would draw the line of 
distinction. 

So I presume it will be with the cow-pox until it is more gen- 



174 EDWARD JENNER 

erally understood. All cavilling, therefore, on the mere report of 
those who tell us they have had this distemper, and are afterwards 
found susceptible of the smallpox, should be suspended. To illus- 
trate this I beg leave to give the following history : 

Sarah Merlin, of the parish of Eastington in this county, when 
about thirteen or fourteen years of age lived as a servant with farmer 
Clarke, who kept a dairy consisting of about eighteen cows at Stone- 
house, a neighbouring village. The nipples and udders of three of 
the cows were extensively affected with large white blisters. These 
cows the girl milked daily, and at the time she assisted, with two 
others, in milking the rest of the herd. It soon appeared that the 
disease was communicated to the girl. The rest of the cows escaped 
the infection, although they were milked several days after the three 
above specified, had these eruptions on the nipples and udders, and 
even after the girl's hand became sore. The two others who were 
engaged in milking, although they milked the cows indiscriminately, 
received no injury. On the fingers of each of the girl's hands there 
appeared several large white blisters — she supposes about three or 
four on each finger. The hands and arms inflamed and swelled, but 
no constitutional indisposition followed. The sores were anointed 
with some domestic ointment and got well without ulcerating. 

As this malady was called the cow-pox, and recorded as such in 
the mind of the patient, she became regardless of the smallpox; but, 
on being exposed to it some years afterwards she was infected, and 
had a full burthen. 

Now, had any one conversant with the habits of the disease heard 
this history, they would have had no hesitation in pronouncing it 
a case of spurious cow-pox; considering its deviation in the numerous 
blisters which appeared on the girl's hands; their termination without 
ulceration; its not proving more generally contagious at the farm, 
either among the cattle or those employed in milking; and consider- 
ing also that the patient felt no general indisposition, although there 
tvas so great a number of vesicles. 

This is perhaps the most deceptions form in which an eruptive 
disease can be communicated from the cow, and it certainly requires 
some attention in discriminating it. The most perfect criterion by 
which the judgment may be guided is perhaps that adopted by those 



VACCINATION AGAINST SMALLPOX 1 75 

who attend infected cattle. These white blisters on the nipples, they 
say, never eat into the fieshy parts like those which are commonly of 
a bluish cast, and which constitute the true cow-pox, but that they 
affect the skin only, quickly end in scabs, and are not nearly so 
infectious. 

That which appeared to me as one cause of spurious eruptions, 
I have already remarked in the former treatise, namely, the transi- 
tion that the cow makes in the spring from a poor to a nutritious 
diet, and from the udder's becoming at this time more vascular 
than usual for the supply of milk. But there is another source of 
inflammation and pustules which I believe is not uncommon in all 
the dairy counties in the west of England. A cow intended to be 
exposed for sale, having naturally a small udder, is previously for a 
day or two neither milked artificially nor is her calf suffered to have 
access to her. Thus the milk is preternaturally accumulated, and the 
udder and nipples become greatly distended. The consequences 
frequently are inflammation and eruptions which maturate. 

Whether a disease generated in this way has the power of affecting 
the constitution in any peculiar manner I cannot presume positively 
to determine. It has been conjectured to have been a cause of the 
true cow-pox, though my inquiries have not led me to adopt this 
supposition in any one instance; on the contrary, I have known the 
milkers affected by it, but always found that an affection thus 
induced left the system as susceptible of the smallpox as before. 

What is advanced in my second position I consider also of very 
great importance, and I could wish it to be strongly impressed on the 
minds of all who may be disposed to conclude hastily on my observa- 
tions, whether engaged in their investigation by experiments or not. 
To place this in its clearest point of view (as the similarity between 
the action of the smallpox and the cow-pox matter is so obvious) it 
will be necessary to consider what we sometimes observe to take place 
in inoculation for the smallpox when imperfect variolous matter is 
made use of. The concise history on this subject that was brought 
forward respecting what I had observed in this neighbourhood' I 
perceive, by a reference since made to the Memoirs of the Medical 

' Inquiry into the Causes and Effects of the Variolae Vaccinae, p. 56 o£ the original 
article. 



176 EDWARD JENNER 

Society of London, may be considered as no more than a corrobora- 
tion of the facts very clearly detailed by Mr. Kite.^ To this copious 
evidence I have to add still more in the following communications 
from Mr. Earle, surgeon, of Frampton-upon-Severn, in this county, 
which I deem the more valuable, as he has with much candour per- 
mitted me to make them public: 

"Sir: 

"I have read with satisfaction your late publication on the Variolae 
Vaccinae, and being, among many other curious circumstances, par- 
ticularly struck with that relating to the inefficacy of smallpox matter 
in a particular state, I think it proper to lay before you the following 
facts which came within my own knowledge, and which certainly 
tend to strengthen the opinions advanced in pages 56 and 57 of your 
treatise, 

"In March, 1784, a general inoculation took place at Arlingham 
in this county. I inoculated several patients with active variolous 
matter, all of whom had the disease in a favourable way; but the 
matter being all used, and not being able to procure any more in 
the state I wished, I was under the necessity of taking it from a 
pustule which, experience has since proved, was advanced too far 
to answer the purpose I intended. Of five persons inoculated with 
this last matter, four took the smallpox afterwards in the natural 
way, one of whom died, three recovered, and the other, being 
cautioned by me to avoid as much as possible the chance of catch- 
ing it, escaped from the disease through life. He died of another 
disorder about two years ago. 

"Although one of these cases ended unfortunate, yet I cannot sup- 
pose that any medical man will think me careless or inattentive in 
their management; for I conceive the appearances were such as 
might have induced any one to suppose that the persons were per- 
fectly safe from future infection. Inflammation in every case took 
place in the arm, and fever came on with a considerable degree of 
pain in the axilla. In some of their arms the inflammation and 
suppuration were more violent than is commonly observed when 
perfect matter is made use of; in one there was an ulcer which cast 

^ See an account o£ some anomalous appearances subsequent to the inoculation of 
the smallpox, by Charles Kite, Surgeon, of Gravesend, in the Memoirs of the Medical 
Society of London, vol. iv, p. 114. 



VACCINATION AGAINST SMALLPOX 1 77 

off several large sloughs. About the ninth day eruptions appeared, 
which died away earlier than common without maturation. From 
these circumstances I should suppose that no medical practitioner 
would scarcely have entertained a doubt but that these patients 
had been infected with a true smallpox; yet I must confess that some 
small degree of doubt presented itself to me at the speedy disappear- 
ance of the eruptions; and in order, as far as I could, to ascertain 
their safety, I sent one of them to a much older practitioner than 
myself. This gentleman, on hearing the circumstances of the case, 
pronounced the patient perfectly secure from future infection. 

"The following facts are also a striking proof of the truth of your 
observations on this subject: 

"In the year 1789 I inoculated three children of Mr. Coaley, of 
Hurst farm in this county. The arms inflamed properly, fever and 
pain in the axillae came on precisely the same as in the former cases, 
and in ten days eruptions appeared, which disappeared in the course 
of two days. I must observe that the matter here made use of was 
procured for me by a friend; but no doubt it was in an improper 
state; for, from the similarity of these cases to those which happened 
at Arlingham five years before, I was somewhat alarmed for their 
safety, and desired to inoculate them again: which being permitted, 
I was particularly careful to procure matter in its most perfect state. 
All the children took the smallpox from this second inoculation, and 
all had a very full burthen. These facts I conceive strikingly cor- 
roborate your opinion relative to the different states of matter; for 
in both instances that I have mentioned it was capable of producing 
something strongly resembling the true smallpox, although it after- 
wards proved not to be so. 

"As I think the communication of these cases is a duty I owe 
to the public, you are at liberty to make what use you please of this 
letter. I remain, &c., 

"John Earle. 

"Frampton-upon Severn, Gloucestershire, November 10, 1798. 

"P. S. I think it necessary to observe that I can pronounce, with 
the greatest certainty, that the matter with which the Arlingham 
patients were inoculated was taken from a true smallpox pustule. I 
took it myself from a subject that had a very full burthen." 



178 EDWARD JENNER 

Certain then it is that variolous matter may undergo such a 
change from the putrefactive process, as well as from some of the 
more obscure and latent processes of nature, as will render it in- 
capable of giving the smallpox in such a manner as to secure the 
human constitution from future infection, although we see at the 
same time it is capable of exciting a disease which bears so strong a 
resemblance to it as to produce inflammation and matter in the 
incised skin (frequently, indeed, more violent than when it pro- 
duces its effects perfectly), swelling of the axillary glands, general 
indisposition, and eruptions. So strongly persuaded was the gentle- 
man, whose practice I have mentioned in page 51 of the late treatise, 
that he could produce a mild smallpox by his mode of managing the 
matter, that he spoke of it as a useful discovery until convinced of 
his error by the fatal consequence which ensued. 

After this ought we to be in the smallest degree surprised to find, 
among a great number of individuals who, by living in dairies, have 
been casually exposed to the cow-pox virus when in a state analogous 
to that of the smallpox above described, some who may have had 
the disease so imperfectly as not to render them secure from variolous 
attacks ? For the matter, when burst from the pustules on the nipples 
of the cow, by being exposed, from its lodgment there, to the heat 
of an inflamed surface, and from being at the same time in a situ- 
ation to be occasionally moistened with milk, is often likely to be in 
a state conducive to putrefaction; and thus, under some modification 
of decomposition, it must, of course, sometimes find access to the 
hand of the milker in such a way as to infect him. What confusion 
should we have were there no other mode of inoculating the small- 
pox than such as would happen from handling the diseased skin 
of a person labouring under that distemper in some of its advanced 
and loathsome stages! It must be observed that every case of cow- 
pox in the human species, whether communicated by design or 
otherwise, is to be considered as a case of inoculation. And here I 
may be allowed to make an observation on the case of the farmer 
communicated to me by Dr. Ingenhousz. That he was exposed to 
the matter when it had undergone the putrefactive change is highly 
probable from the doctor's observing that the sick cows at the farm 
gave out an o'Qensive stench from their udders. However, I must 



VACCINATION AGAINST SMALLPOX 1 79 

remark that it is unusual for cattle to suffer to such an extent, when 
disordered with the cow-pox, as to make a bystander sensible of any 
ill smell. I have often stood among a herd which had the distemper 
without being conscious of its presence from any particular effluvia. 
Indeed, in this neighbourhood it commonly receives an early check 
from escharotic applications of the cow leech. It has been conceived 
to be contagious without contact; but this idea cannot be well 
founded because the cattle in one meadow do not infect those in 
another (although there may be no other partition than a hedge) 
unless they be handled or milked by those who bring the infectious 
matter with them; and of course, the smallest particle imaginable, 
when applied to a part susceptible of its influence, may produce 
the effect. Among the human species it appears to be very clear 
that the disease is produced by contact only. All my attempts, 
at least, to communicate it by effluvia have hitherto proved ineffec- 
tual. 

As well as the perfect change from that state in which variolous 
matter is capable of producing full and decisive effects on the con- 
stitution, to that wherein its specific properties are entirely lost, it 
may reasonably be supposed that it is capable of undergoing a variety 
of intermediate changes. The following singular occurrences in ten 
cases of inoculation, obligingly communicated to me by Mr. Trye, 
Senior Surgeon to the Infirmary at Gloucester, seem to indicate that 
the variolous matter, previously to its being taken from the patient 
for the intended purpose, was beginning to part with some of its 
original properties, or, in other words, that it had suffered a partial 
decomposition. Mr. Trye says: "I inoculated ten children with mat- 
ter taken at one time and from the same subject. I observed no pecu- 
liarity in any of them previously to their inoculation, nor did any- 
thing remarkable appear in their arms till after the decline of the 
disease. Two infants of three months old had erysipelas about the 
incisions, in one of them extending from the shoulders to the 
fingers' ends. Another infant had abscesses in the cellular substance 
in the neighbourhood of the incisions, and five or six of the rest had 
axillary abscesses. The matter was taken from the distinct small- 
pox late in its progress, and when some pustules had been dried. 
It was received upon glass and slowly dried by the fire. All the 



l80 EDWARD JENNER 

children had pustules which maturated, so that I suppose them all 
secure from future infection; at least, as secure as any others whom 
I have ever inoculated. My practice never afforded a sore arm 
before." 

In regard to my former observation on the improper and danger- 
ous mode of preserving variolous matter, I shall here remark that it 
seems not to have been clearly understood. Finding that it has been 
confounded with the more eligible modes of preservation, I will 
explain myself further. When the matter is taken from a fit pustule 
and properly prepared for preservation, it may certainly be kept 
without losing its specific properties a great length of time; for 
instance, when it is previously dried in the open air on some com- 
pact body, as a quill or a piece of glass, and afterwards secured in a 
small vial.' But when kept several days in a state of moisture, and 
during that time exposed to a warm temperature, I do not think 
it can be relied upon as capable of giving a perfect disease, although, 
as I have before observed, the progress of the symptoms arising from 
the action of the imperfect matter bear so strong a resemblance to 
the smallpox when excited completely. 

Thirdly. That the first formed virus, or what constitutes the true 
cow-pox pustule, invariably possesses the power I have ascribed to 
it, namely, that of affecting the constitution with a specific disease, is 
a truth that no subsequent occurrence has yet led me to doubt. But 
as I am now endeavouring to guard the public as much as possible 
against erroneous conclusions, I shall observe that when this pustule 
has degenerated into an ulcer (to which state it is often disposed to 
pass unless timely checked), I suspect that matter possessing very 
different properties may sooner or later be produced; and although 
it may have passed that stage wherein the specific properties of the 
matter secreted are no longer present in it, yet when applied to a 
sore (as in the casual way) it might dispose that sore to ulcerate, 
and from its irritation the system would probably become affected; 
and thus, by assuming some of its strongest characters, it would 
imitate the genuine cow-pox. 

From the preceding observations on the matter of smallpox when 

'Thus prepared, the cow-pox virus was found perfectly active, and possessing all 
its specific properties, at the end of three months. 



VACCINATION AGAINST SMALLPOX l8l 

decomposed' it must, I conceive, be admitted that cow-pox matter 
in the state now described may produce a disease, the effects of which 
may be felt both locally and generally, yet that the disease thus 
induced may not be effectual in obviating the future effects of vari- 
olous contagion. In the case of Mary Miller, related by Mr. Kite 
in the volume above alluded to, it appears that the inflammation 
and suppuration of the inoculated arm were more than usually 
severe, although the system underwent no specific change from the 
action of the virus; which appears from the patient's sickening 
seven weeks afterwards with the natural smallpox, which went 
through its course. Some of the cases communicated by Mr. Earle 
tend further to confirm this fact, as the matter there manifestly 
produced ulceration on the inoculated part to a considerable ex- 
tent. 

Fourthly. Whether the cow-pox is a spontaneous disease in the 
cow, or is to be attributed to matter conveyed to the animal, as I 
have conceived, from the horse, is a question which, though I shall 
not attempt now fully to discuss, yet I shall digress so far as to 
adduce some further observations, and to give my reasons more at 
large for taking up an opinion that to some had appeared fanciful. 
The aggregate of these observations, though not amounting to posi- 
tive proof, forms presumptive evidence of so forcible a kind that I 
imagine it might, on any other person, have made the same impres- 
sion it did on me, without fixing the imputation of credulity. 

Firstly : I conceived this was the source, from observing that where 
the cow-pox had appeared among the dairies here (unless it could 
be traced to the introduction of an infected cow or servant) it had 
been preceded at the farm by a horse diseased in the manner already 
described, which horse had been attended by some of the milkers. 

Secondly : From its being a popular opinion throughout this great 
dairy country, and from its being insisted on by those who here 
attend sick cattle. 

Thirdly : From the total absence of the disease in Ireland and Scot- 
land, where the men-servants are not employed in the dairies.* 

Fourthly: From having observed that morbid matter generated 
by the horse frequently communicates, in a casual way, a disease to 

*This information was communicated to me from the first authorities. 



1 82 EDWARD JENNER 

the human subject so Hke the cow-pox that, in many cases, it would 
be diiBcult to make the distinction between one and the other.^ 

Fifthly: From being induced to suppose, from experiments, that 
some of those who had been thus affected from the horse resisted 
the smallpox. 

Sixthly : From the progress and general appearance of the pustule 
on the arm of the boy whom I inoculated with matter taken from 
the hand of a man infected by a horse; and from the similarity to 
the cow-pox of general constitutional symptoms which followed.^ 

I fear it would be trespassing too far to adduce the general testi- 
mony of our farmers in support of this opinion; yet I beg leave to 
introduce an extract of a letter on this subject from the Rev. Mr. 
Moore, of Chalford Hill, in this county : 

"In the month of November, 1797, my horse had diseased heels, 
which was certainly what is termed the grease; and at a short sub- 
sequent period my cow was also affected with what a neighbouring 
farmer (who was conversant with the complaints of cattle) pro- 
nounced to be the cow-pox, which he at the same time observed my 
servant would be infected with: and this proved to be the case; for 
he had eruptions on his hands, face, and many parts of the body, 
the pustules appearing large, and not much like the smallpox, for 
which he had been inoculated a year and a half before, and had then 
a very heavy burthen. The pustules on the face might arise from 
contact with his hands, as he had a habit of rubbing his forehead, 
where the sores were the largest and the thickest. 

"The boy associated with the farmer's sons during the continu- 
ance of the disease, neither of whom had had the smallpox, but they 
felt no ill effects whatever. He was not much indisposed, as the 
disease did not prevent him from following his occupations as usual. 
No other person attended the horse or milked the cow but the lad 
above mentioned. I am firmly of opinion that the disease in the 

^ The sound skin does not appear to be susceptible of this virus when inserted into 
it, but, when previously diseased from little accidents, its effects are often conspicuous. 

^ This case (on which I laid no inconsiderable stress in my late treatise, as presump- 
tive evidence of the fact adduced) seems to have been either mistaken or overlooked 
by those who have commented upon it. (See Case XVIII, p. 157.) The boy, unfor- 
tunately, died of a fever at a parish workhouse before I had an opportunity of 
observing what effects would have been produced by the matter of smallpox. 



VACCINATION AGAINST SMALLPOX 1 83 

heels of the horse, which was a virulent grease, was the origin of 
the servant's and the cow's malady." 

But to return to the more immediate object of this proposition. 

From the similarity of symptoms, both constitutional and local, 
between the cow-pox and the disease received from morbid matter 
generated by a horse, the common people in this neighbourhood, 
when infected with this disease, through a strange perversion of 
terms, frequently call it the cow-pox. Let us suppose, then, such a 
malady to appear among some of the servants at a farm, and at the 
same time that the cow-pox were to break out among the cattle; and 
let us suppose, too, that some of the servants were infected in this 
way, and that others received the infection from the cows. It would 
be recorded at the farm, and among the servants themselves wherever 
they might afterwards be dispersed, that they had all had the cow- 
pox. But it is clear that an individual thus infected from the horse 
would neither be for a certainty secure himself, nor would he impart 
security to others were they inoculated by virus thus generated. He 
still would be in danger of taking the smallpox. Yet were this to 
happen before the nature of the cowpox be more maturely considered 
by the public my evidence on the subject might be depreciated un- 
justly. For an exempUfication of what is here advanced relative to 
the nature of the infection when received directly from the horse see 
Inquiry into the Causes and Effects of the Variolas Vaccinae, pp. 27, 28, 
29, 30, and p. 35; and by way of further example, I beg leave to sub- 
join the following intelligence received from Mr. Fewster, Surgeon, 
of Thornbury, in this county, a gentleman perfectly well acquainted 
with the appearances of the cow-pox on the human subject: 

"William Morris, aged thirty-two, servant to Mr. Cox of Almonds- 
bury, in this county, applied to me the 2d of April, 1798. He told 
me that, four days before, he found a stiffness and swelling in both 
his hands, which were so painful it was with difficulty he con- 
tinued his work; that he had been seized with pain in his head, 
small of the back, and limbs, and with frequent chilly fits suc- 
ceeded by fever. On examination I found him still affected with 
these symptoms, and that there was a great prostration of strength. 
Many parts of his hands on the inside were chapped, and on the 
middle joint of the thumb of the right hand there was a small 



184 EDWARD JENNER 

phagedenic ulcer, about the size of a large pea, discharging an 
ichorous fluid. On the middle finger of the same hand there was 
another ulcer of a similar kind. These sores were of a circular form, 
and he described their first appearance as being somewhat like 
blisters arising from a burn. He complained of excessive pain, 
which extended up his arm into the axilla. These symptoms and 
appearances of the sores were so exactly like the cow-pox that I 
pronounced he had taken the distemper from milking cows. He 
assured me he had not milked a cow for more than half a year, 
and that his master's cows had nothing the matter with them. I 
then asked him if his master had a greasy horse, which he answered 
in the affirmative, and further said that he had constantly dressed 
him twice a day for the last three weeks or more, and remarked that 
the smell of his hands was much like that of the horse's heels. On 
the 5th of April I again saw him, and found him still complaining 
of pain in both hands, nor were his febrile symptoms at all relieved. 
The ulcers had now spread to the size of a seven-shilling gold coin, 
and another ulcer, which I had not noticed before, appeared on the 
first joint of the forefinger of the left hand, equally painful with that 
on the right. I ordered him to bathe his hands in warm bran and 
water, applied escharotics to the ulcers, and wrapped his hands 
up in a soft cataplasm. The next day he was much relieved, and in 
something more than a fortnight got well. He lost his nails from 
the thumb and fingers that were ulcerated." 

The sudden disappearance of the symptoms in this case after the 
application of the escharotics to the sores is worthy of observation; 
it seems to show that they were kept up by the irritation of the 
ulcers. 

The general symptoms which I have already described of the cow- 
pox, when communicated in a casual way to any great extent, will, 
I am convinced, from the many cases I have seen, be found accurate; 
but from the very slight indisposition which ensues in cases of inocu- 
lation, where the pustule, after affecting the constitution, quickly 
runs into a scab spontaneously, or is artificially suppressed by some 
proper application, I am induced to believe that the violence of the 
symptoms may be ascribed to the inflanunation and irritation of the 



VACCINATION AGAINST SMALLPOX 1 85 

ulcers (when ulceration takes place to any extent, as in the casual 
cow-pox), and that the constitutional symptoms which appear dur- 
ing the presence of the sore, while it assumes the character of a 
pustule only, are felt but in a very trifling degree. This mild 
affection of the system happens when the disease makes but a 
slight local impression on those who have been accidentally in- 
fected by cows; and, as far as I have seen, it has uniformly happened 
among those who have been inoculated, when a pustule only and no 
great degree of inflammation or any ulceration has taken place 
from the inoculation. The following cases will strengthen this 
opinion. 

The cow-pox appeared at a farm in the village of Stonehouse, 
in this county, about Michaelmas last, and continued gradually to 
pass from one cow to another till the end of November. On the 
twenty-sixth of that month some ichorous matter was taken from 
a cow and dried upon a quill. On the 2d of December some of it 
was inserted into a scratch, made so superficial that no blood ap- 
peared, on the arms of Susan Phipps, a child seven years old. The 
common inflammatory appearances took place in consequence, and 
advanced till the fifth day, when they had so much subsided that I 
did not conceive anything further would ensue. 

6th: Appearances stationary. 

7th : The inflammation began to advance. 

8th: A vesication, perceptible on the edges, forming, as in the 
inoculated smallpox, an appearance not unlike a grain of wheat, 
with the cleft, or indentation in the centre. 

9th: Pain in the axilla. 

loth: A little headache; pulse, no; tongue not discoloured; coun- 
tenance in health. 

nth, I2th: No perceptible illness; pulse about 100. 

13th: The pustule was now surrounded by an efflorescence, inter- 
spersed with very minute confluent pustules to the extent of about 
an inch. Some of these pustules advanced in size and maturated. 
So exact was the resemblance of the arm at this stage to the general 
appearance of the inoculated smallpox that Mr. D., a neighbouring 
surgeon, who took some matter from it, and who had never seen 



l86 EDWARD JENNER 

the cow-pox before, declared he could not perceive any difference.' 
The child's arm now shewed a disposition to scab, and remained 
nearly stationary for two or three days, when it began to run into an 
ulcerous state, and then commenced a febrile indisposition accom- 
panied with an increase of axillary tumour. The ulcer continued 
spreading near a week, during which time the child continued ill, 
when it increased to a size nearly as large as a shilling. It began 
now to discharge pus; granulations sprang up, and it healed. This 
child had before been of a remarkably sickly constitution, but is 
now in very high health. 

Mary Hearn, twelve years of age, was inoculated with matter 
taken from the arm of Susan Phipps. 

6th day: A pustule beginning to appear, slight pain in the axilla. 

7th: A distinct vesicle formed. 

8th: The vesicle increasing; edges very red; no deviation in its 
appearance at this time from the inoculated smallpox. 

9th: No indisposition; pustule advancing. 

loth: The patient felt this evening a slight febrile attack. 

nth: Free from indisposition. 

i2th, 13th: The same. 

14th: An efflorescence of a faint red colour extending several inches 
round the arm. The pustule, beginning to shew a disposition to 
spread, was dressed with an ointment composed of hydrarg. nit. rub. 
and ung. cerce. The efflorescence itself was covered with a plaster 
of ung. hydr. fort. In six hours it was examined, when it was found 
that the efflorescence had totally disappeared. 

The application of the ointment with the hydr. nit. rub. was 
made use of for three days, when, the state of the pustule remaining 
stationary, it was exchanged for the ung. hydr. nit. This appeared 
to have a more active effect than the former, and in two or three 
days the virus seemed to be subdued, when a simple dressing was 

'That the cow-pox was a supposed guardian of the constitution from the action 
of the smallpox has been a prevalent idea for a long time past; but the similarity in 
the constitutional effects between one disease and the other could never have been 
so accurately observed had not the inoculation of the cow-pox placed it in a new 
and stronger point of view. This practice, too, has shewn us, what before lay con- 
cealed, the rise and progress of the pustule formed by the insertion of the virus, which 
places in a most conspicuous light its striking resemblance to the pustule formed 
from the inoculated smallpox. 



VACCINATION AGAINST SMALLPOX 1 87 

made use of; but the sore again shewing a disposition to inflame, 
the ung. hydr. nit. was again appUed, and soon answered the in- 
tended purpose effectually. The girl, after the tenth day, when, as 
has been observed, she became a little ill, shewed not the least 
symptom of indisposition. She was afterwards exposed to the action 
of variolous matter, and completely resisted it. Susan Phipps also 
went through a similar trial. Conceiving these cases to be impor- 
tant, I have given them in detail: first, to urge the precaution of 
using such means as may stop the progress of the pustule; and, 
secondly, to point out (what appears to be the fact) that the most 
material indisposition, or at least that which is felt most sensibly, 
does not arise primarily from the first action of the virus on the 
constitution, but that it often comes on, if the pustule is left to 
chance, as a secondary disease. This leads me to conjecture, what 
experiment must finally determine, that they who have had the 
smallpox are not afterwards susceptible of the primary action of the 
cow-pox virus; for seeing that the simple virus itself, when it has 
not passed beyond the boundary of a vesicle, excites in the system 
so little commotion, is it not probable the trifling illness thus in- 
duced may be lost in that which so quickly, and oftentimes so 
severely, follows in the casual cow-pox from the presence of cor- 
roding ulcers? This consideration induces me to suppose that I 
may have been mistaken in my former observation on this sub- 
ject. 

In this respect, as well as many others, a parallel may be drawn 
between this disease and the smallpox. In the latter, the patient 
first feels the effect of what is called the absorption of the virus. 
The symptoms then often nearly retire, when a fresh attack com- 
mences, different from the first, and the illness keeps pace with 
the progress of the pustules through their different stages of matura- 
tion, ulceration, etc. 

Although the application I have mentioned in the case of Mary 
Hearn proved sufficient to check the progress of ulceration and pre- 
vent any secondary symptoms, yet, after the pustule has duly exerted 
its influence, I should prefer the destroying it quickly and effectually 
to any other mode. The term caustic to a tender ear (and I con- 
ceive none feel more interested in this inquiry than the anxious 



1 88 EDWARD JENNER 

guardians of a nursery) may sound harsh and unpleasing, but 
every solicitude that may arise on this account will no longer exist 
when it is understood that the pustule, in a state fit to be acted 
upon, is then quite superficial, and that it does not occupy the space 
of a silver penny.* 

As a proof of the efficacy of this practice, even before the virus 
has fully exerted itself on the system, I shall lay before my reader 
the following history : 

By a reference to the treatise on the Variolae Vaccinae it will be 
seen that, in the month of April, 1798, four children were inoculated 
with the matter of cow-pox, and that in two of these cases the virus 
on the arm was destroyed soon after it had produced a perceptible 
sickening. Mary James, aged seven years, one of the children alluded 
to, was inoculated in the month of December following with fresh 
variolous matter, and at the same time was exposed to the effluvia 
of a patient affected with the smallpox. The appearance and progress 
of the infected arm was, in every respect, similar to that which we 
generally observe when variolous matter has been inserted into the 
skin of a person who has not previously undergone either the cow- 
pox or the smallpox. On the eighth day, conceiving there was infec- 
tion in it, she was removed from her residence among those who 
had not had the smallpox. I was now anxiously waiting the result, 
conceiving, from the state of the girl's arm, she would fall sick 
about this time. On visiting her on the evening of the following day 
(the ninth) all I could learn from the woman who attended her was 
that she felt somewhat hotter than usual during the night, but was 
not restless; and that in the morning there was the faint appearance 
of a rash about her wrists. This went off in a few hours, and was 
not at all perceptible to me on my visit in the evening. Not a single 
eruption appeared, the skin having been repeatedly and carefully 
examined. The inoculated arm continued to make the usual prog- 
ress to the end, through all the stages of inflammation, maturation, 
and scabbing. 

On the eighth day matter was taken from the arm of this girl 
(Mary James) and inserted into the arms of her mother and brother 

*I mention escharotics for stopping the progress of the pustule because I am ac- 
quainted with their efficacy; probably more simple means might answer the purpose 
quite as well, such as might be found among the mineral and vegetable astringents. 



VACCINATION AGAINST SMALLPOX 1 89 

(neither of whom had had either the smallpox or the cow-pox), 
the former about fifty years of age, the latter six. 

On the eighth day after the insertion the boy felt indisposed, and 
continued unwell two days, when a measles-like rash appeared on 
his hands and wrists, and was thinly scattered over his arms. The day 
following his body was marbled over with an appearance somewhat 
similar, but he did not complain, nor did he appear indisposed. A 
few pustules now appeared, the greater part of which went away 
without maturating. 

On the ninth day the mother began to complain. She was a little 
chilly and had a headache for two days, but no pustule appeared on 
the skin, nor had she any appearance of a rash. 

The family was attended by an elderly woman as a nurse, who in 
her infancy had been exposed to the contagion of the smallpox, 
but had resisted it. This woman was now infected, but had the 
disease in the slightest manner, a very few eruptions appearing, two 
or three of which only maturated. 

From a solitary instance like that adduced of Mary James, whose 
constitution appears to have resisted the action of the variolous 
virus, after the influence of the cow-pox virus had been so soon 
arrested in its progress, no positive conclusion can be fairly drawn; 
nor from the history of the three other patients who were subse- 
quently infected, but, nevertheless, the facts collectively may be 
deemed interesting. 

That one mild variety of the smallpox has appeared I have al- 
ready plainly shewn;' and by the means now mentioned we prob- 
ably have it in our power to produce at will another. 

At the time when the pustule was destroyed in the arm of Mary 
James I was informed she had been indisposed about twelve hours; 
but I am now assured by those who were with her that the space of 
time was much less. Be that as it may, in cases of cow-pox inocula- 
tion I would not recommend any application to subdue the action 
of the pustule until convincing proofs had appeared of the patient's 
having felt its effects at least twelve hours. No harm, indeed, 
could ensue were a longer period to elapse before the application was 

' See Inquiry into the Causes and Effects of the Variolae Vaccina, p. 54 (of original 
article). 



190 EDWARD JENNER 

made use of. In short, it should be suffered to have as full an effect 
as it could, consistently with the state of the arm. 

As the cases of inoculation multiply, I am more and more con- 
vinced of the extreme mildness of the symptoms arising merely from 
the primary action of the virus on the constitution, and that those 
symptoms which, as in the accidental cow-pox, affect the patient 
with severity, are entirely secondary, excited by the irritating proc- 
esses of inflammation and ulceration; and it appears to me that this 
singular virus possesses an irritating quality of a peculiar kind, but 
as a single cow-pox pustule is all that is necessary to render the 
variolous virus ineffectual, and as we possess the means of allaying 
the irritation, should any arise, it becomes of little or no conse- 
quence. 

It appears then, as far as an inference can be drawn from the 
present progress of cow-pox inoculation, that it is an accidental 
circumstance only which can render this a violent disease, and a 
circumstance of that nature which, fortunately, it is in the power of 
almost every one to avoid. I allude to the communication of the 
disease from cows. In this case, should the hands of the milker be 
affected with little accidental sores to any extent, every sore would 
become the nidus of infection and feel the influence of the virus; 
and the degree of violence in the constitutional symptoms would be 
in proportion to the number and to the state of these local affections. 
Hence it follows that a person, either by accident or design, might be 
so filled with these wounds from contact with the virus that the 
constitution might sink under the pressure. 

Seeing that we possess the means of rendering the action of the 
sores mild, which, when left to chance, are capable of producing 
violent effects; and seeing, too, that these sores bear a resemblance 
to the smallpox, especially the confluent, should it not encourage 
the hope that some topical application might be used with advantage 
to counteract the fatal tendency of that disease, when it appears in 
this terrific form? At what stage or stages of the disease this may 
be done with the most promising expectation of success I will not 
pretend now to determine. I only throw out this idea as the basis 
of further reasoning and experiment. 

I have often been foiled in my endeavours to communicate the 



VACCINATION AGAINST SMALLPOX I9I 

cow-pox by inoculation. An inflammation will sometimes succeed 
the scratch or puncture, and in a few days disappear without pro- 
ducing any further effect. Sometimes it will even produce an ichorous 
fluid, and yet the system will not be afEected.^" The same thing, we 
know, happens with the smallpox virus. 

Four or five servants were inoculated at a farm contiguous to 
this place, last summer, with matter just taken from an infected 
cow. A little inflammation appeared on all their arms, but died 
away without producing a pustule; yet all these servants caught the 
disease within a month afterwards from milking the infected cows, 
and some of them had it severely. At present no other mode than 
that commonly practiced for inoculating the smallpox has been used 
for giving the cow-pox; but it is probable this might be varied with 
advantage. We should imitate the casual communication more 
clearly were we first, by making the smallest superficial incision or 
puncture on the skin, to produce a little scab, and then, removing it, 
to touch the abraded part with the virus. A small portion of a 
thread imbrued in the virus (as in the old method of inoculating 
the smallpox) and laid upon the slightly incised skin might prob- 
ably prove a successful way of giving the disease; or the cutis might 
be exposed in a minute point by an atom of blistering plaster, and 
the virus brought in contact with it. In the cases just alluded to, 
where I did not succeed in giving the disease constitutionally, the 
experiment was made with matter taken in a purulent state from a 
pustule on the nipple of a cow. 

Is pure pus, though contained in a smallpox pustule, ever capable 
of producing the smallpox perfectly? I suspect it is not. Let us 
consider that it is always preceded by the limpid fluid, which, in 
constitutions susceptible of variolous contagion, is always infectious; 
and though, on opening a pustule, its contents may appear perfectly 
purulent, yet a given quantity of the limpid fluid may, at the same 
time, be blended with it, though it would be impercepdble to the 
only test of our senses, the eye. The presence, then, of this fluid, 
or its mechanical diffusion through pus, may at all times render 
active what is apparently mere pus, while its total absence (as in 

'"At this period of the inquiry I had not discovered the importance of inoculating 
with virus newly formed in the pustule. The reader will find this explained as he 
proceeds. 



192 EDWARD JENNER 

Stale pustules) may be attended with the imperfect effects we have 
seen. 

It would be digressing too widely to go far into the doctrine of 
secretion, but as it will not be quite extraneous, I shall just observe 
that I consider both the pus and the limpid fluid of the pustule as 
secretions, but that the organs established by nature to perform the 
office of secreting these fluids may differ essentially in their mechani- 
cal structure. What but a difference in the organization of glandular 
bodies constitutes the difference in the qualities of the fluids secreted ? 
From some peculiar derangement in the structure or, in other words, 
some deviation in the natural action of a gland destined to create 
a mild, innoxious fluid, a poison of the most deadly nature may be 
created. For example: That gland, which in its sound state secretes 
pure saliva, may, from being thrown into diseased action, produce a 
poison of the most destructive quality. Nature appears to have no 
more difficulty in forming minute glands among the vascular parts 
of the body than she has in forming blood vessels, and millions of 
these can be called into existence, when inflammation is excited, in a 
few hours." 

In the present early stage of the inquiry (for early it certainly 
must be deemed), before we know for an absolute certainty how 
soon the virus of the cow-pox may suffer a change in its specific 
properties, after it has quitted the limpid state it possesses when 
forming a pustule, it would be prudent for those who have been 
inoculated with it to submit to variolous inoculation. No injury 
or inconvenience can accrue from this; and were the same method 
practiced among those who, from inoculation, have felt the smallpox 
in an unsatisfactory manner at any period of their lives, it might 
appear that I had not been too officious in offering a cautionary hint 
in recommending a second inoculation with matter in its most 
perfect state. 

And here let me suppose, for argument's sake (not from convic- 
tion), that one person in an hundred after having had the cow-pox 
should be found susceptible of the smallpox, would this invalidate 
the utility of the practice? For, waiving all other considerations, 
who will deny that the inoculated smallpox, although abstractedly 

" Mr. Home, in his excellent dissertation on pus and mucus, justifies this assertion. 



VACCINATION AGAINST SMALLPOX 1 93 

it may be considered as harmless, does not involve in itself some- 
thing that in numberless instances proves baneful to the human 
frame. 

That in delicate constitutions it sometimes excites scrofula is a fact 
that must generally be subscribed to, as it is so obvious to common 
observation. This consideration is important. 

As the effects of the smallpox inoculation on those who have had 
the cow-pox will be watched with the most scrupulous eye by those 
who prosecute this inquiry, it may be proper to bring to their recol- 
lection some facts relative to the smallpox, which I must consider 
here as of consequence, but which hitherto seem not to have made a 
due impression. 

It should be remembered that the constitution cannot, by previous 
infection, be rendered totally unsusceptible of the variolous poison; 
neither the casual nor the inoculated smallpox, whether it produces 
the disease in a mild or in a violent way, can perfectly extinguish 
the susceptibility. The skin, we know, is ever ready to exhibit, 
though often in a very limited degree, the effects of the poison when 
inserted there; and how frequently do we see, among nurses, when 
much exposed to the contagion, eruptions, and these sometimes pre- 
ceded by sensible illness! Yet should any thing like an eruption 
appear, or the smallest degree of indisposition, upon the insertion 
of the variolous matter on those who have gone through the cow- 
pox, my assertions respecting the peculiarities of the disease might 
be unjustly discredited. 

I know a gentleman who, many years ago, was inoculated for the 
smallpox, but having no pustules, or scarcely any constitutional 
affection that was perceptible, he was dissatisfied, and has since been 
repeatedly inoculated. A vesicle has always been produced in the 
arm in consequence, with axillary swelling and a slight indisposition; 
this is by no means a rare occurrence. It is probable that fluid thus 
excited upon the skin would always produce .the smallpox. 

On the arm of a person who had gone through the cow-pox many 
years before I once produced a vesication by the insertion of variolous 
matter, and, with a little of the fluid, inoculated a young woman 
who had a mild, but very efficacious, smallpox in consequence, al- 
though no constitutional effect was produced on the patient from 



194 EDV/ARD JENNER 

whom the matter was taken. The following communication from 
Mr. Fewster affords a still clearer elucidation of this fact. Mr. 

Fewster says: "On the 3d of April, 1797, I inoculated Master H , 

aged fourteen months, for the smallpox. At the usual time he sick- 
ened, had a plentiful eruption, particularly on his face, and got 
well. His nursemaid, aged twenty-four, had many years before 
gone through the smallpox, in the natural way, which was evident 
from her being much pitted with it. She had used the child to sleep 
on her left arm, with her left cheek in contact with his face, and 
during his inoculation he had mostly slept in that manner. About a 
week after the child got well she (the nurse) desired me to look at 
her face, which she said was very painful. There was a plentiful 
eruption on the left cheek, but not on any other part of the body, 
which went on to maturation. 

"On enquiry I found that three days before the appearance of the 
eruption she was taken with sUght chilly fits, pain in her head and 
limbs, and some fever. On the appearance of the eruption these 
pains went off, and now, the second day of the eruption, she com- 
plains of a little sore throat. Whether the above symptoms are the 
effects of the smallpox or a recent cold I do not know. On the fifth 
day of the eruption I charged a lancet from two of the pustules, and 
on the next day I inoculated two children, one two years, the other 
four months old, with the matter. At the same time I inoculated the 
mother and eldest sister with variolous matter taken from Master 
H . On the fifth day of their inoculation all their arms were in- 
flamed alike; and on the eighth day the eldest of those inoculated 
from the nurse sickened, and the youngest on the eleventh. They had 
both a plentiful eruption, from which I inoculated several others, 
who had the disease very favourably. The mother and the other 
child sickened about the same time, and likewise had a plentiful 
eruption. 

"Soon after, a man in the village sickened with the smallpox 
and had a confluent kind. To be convinced that the children had 
had the disease effectually I took them to his house and inoculated 
them in both arms with matter taken from him, but without effect." 

These are not brought forward as uncommon occurrences, but as 



VACCINATION AGAINST SMALLPOX 1 95 

exemplifications of the human system's susceptibiUty of the vario- 
lous contagion, although it has been previously sensible of its ac- 
tion. 

Happy is it for mankind that the appearance of the smallpox a 
second time on the same person, beyond a trivial extent, is so ex- 
tremely rare that it is looked upon as a phsenomenon! Indeed, since 
the publication of Dr. Heberden's paper on the Varicella, or chicken- 
pox, the idea of such an occurrence, in deference to authority so truly 
respectable, has been generally relinquished. This I conceive has 
been without just reason; for after we have seen, among many 
others, so strong a case as that recorded by Mr. Edward Withers, 
Surgeon, of Newbury, Berks, in the fourth volume of the Memoirs 
of the Medical Society of London (from which I take the following 
extracts), no one, I think, will again doubt the fact: 

"Mr. Richard Langford, a farmer of West Shefiord, in this 
county (Berks), about fifty years of age, when about a month old 
had the smallpox at a time when three others of the family had 
the same disease, one of whom, a servant man, died of it. Mr. 
Langford's countenance was strongly indicative of the malignity of 
the distemper, his face being so remarkably pitted and seamed as to 
attract the notice of all who saw him, so that no one could entertain 
a doubt of his having had that disease in a most inveterate manner." 

Mr. Withers proceeds to state that Mr. Langford was seized a 
second time, had a bad confluent smallpox, and died on the twenty- 
first day from the seizure; and that four of the family, as also a 
sister of the patient's, to whom the disease was conveyed by her son's 
visiting his uncle, falling down with the smallpox, fully satisfied the 
country with regard to the nature of the disease, which nothing 
short of this would have done. The sister died. 

"This case was thought so extraordinary a one as to induce the 
rector of the parish to record the particulars in the parish regis- 
ter. 

It is singular that in most cases of this kind the disease in the first 
instance has been confluent; so that the extent of the ulceration on 
the skin (as in the cow-pox) is not the process in nature which 
affords security to the constitution. 



196 EDWARD JENNER 

As the subject of the smallpox is so interwoven with that which 
is the more immediate object of my present concern, it must plead 
my excuse for so often introducing it. At present it must be con- 
sidered as a distemper not well understood. The inquiry I have 
instituted into the nature of the cow-pox will probably promote its 
more perfect investigation. 

The inquiry of Dr. Pearson into the history of the cow-pox having 
produced so great a number of attestations in favour of my assertion 
that it proves a protection to the human body from the smallpox, I 
have not been assiduous in seeking for more; but as some of my 
friends have been so good as to communicate the following, I shall 
conclude these observations with their insertion. 

Extract of a letter from Mr. Drake, Surgeon, at Stroud, in this 
county, and late Surgeon to the North Gloucester Regiment of 
MiUtia: 

"In the spring of the year 1796 I inoculated men, women, and chil- 
dren to the amount of about seventy. Many of the men did not re- 
ceive the infection, although inoculated at least three times and kept 
in the same room with those who actually underwent the disease 
during the whole time occupied by them in passing through it. Be- 
ing anxious they should, in future, be secure against it, I was very 
particular in my inquiries to find out whether they ever had previ- 
ously had it, or at any time been in the neighbourhood of people 
labouring under it. But, after all, the only satisfactory information 
I could obtain was that they had had the cow-pox. As I was then 
ignorant of such a disease affecting the human subject, I flattered 
myself what they imagined to be the cow-pox was in reality the 
smallpox in a very slight degree. I mentioned the circumstance in 
the presence of the officers, at the time expressing my doubts if it 
were not smallpox, and was not a little surprised when I was told 
by the Colonel that he had frequently heard you mention the cow- 
pox as a disease endemial to Gloucestershire, and that if a person 
were ever affected by it, you supposed him afterwards secure from 
the smallpox. This excited my curiosity, and when I visited Glouces- 
tershire I was very inquisitive concerning the subject, and from the 
information I have since received, both from your publication and 
from conversation with medical men of the greatest accuracy in their 



VACCINATION AGAINST SMALLPOX 1 97 

observations, I am fully convinced that what the men supposed to 
be cow-pox was actually so, and I can safely affirm that they effec- 
tually resisted the smallpox." 

Mr. Fry, Surgeon, at Dursley in this county, favours me with the 
following communication : 

"During the spring of the year 1797 I inoculated fourteen hundred 
and seventy-five patients, of all ages, from a fortnight old to seventy 
years; amongst whom there were many who had previously gone 
through the cow-pox. The exact number I cannot state; but if I 
say there were nearly thirty, I am certainly within the number. 
There was not a single instance of the variolous matter producing 
any constitutional effect on these people, nor any greater degree of 
local inflammation than it would have done in the arm of a person 
who had before gone through the smallpox, notwithstanding it 
was invariably inserted four, five, and sometimes six different times, 
10 satisfy the minds of the patients. In the common course of inocu- 
lation previous to the general one scarcely a year passed without my 
meeting with one or two instances of persons who had gone through 
the cow-pox, resisting the action of the variolous contagion. I may 
fairly say that the number of people I have seen inoculated with 
the smallpox who, at former periods, had gone through the cow- 
pox, are not less than forty; and in no one instance have I known a 
patient rsceive the smallpox, notwithstanding they invariably con- 
tinued to associate with other inoculated patients during the progress 
of the disease, and many of them purposely exposed themselves to 
the contagion of the natural smallpox; whence I am fully convinced 
that a person who had fairly had the cow-pox is no longer capable 
of being acted upon by the variolous matter. 

"I also inoculated a very considerable number of those who had 
had a disease which ran through the neighbourhood a few years 
ago, and was called by the common people the swine-pox, not one 
of whom received the smallpox.'^ 

"There were about half a dozen instances of people who never 
had either the cow- or swine-pox, yet did not receive the smallpox, 
the system not being in the least deranged, or the arms inflamed, 

'^This was that mild variety of the smallpox which I have noticed in the late 
Treatise on the Cow-Pox (p. 233). 



198 EDWARD JENNER 

although they were repeatedly inoculated, and associated with others 
who were labouring under the disease; one of them was the son 
of a farrier." 

Mr. Tierny, Assistant Surgeon of the South Gloucester Regiment 
of Militia, has obliged me with the following information: 

"That in the summer of the year of 1798 he inoculated a great 
number of the men belonging to the regiment, and that among 
them he found eleven who, from having lived in dairies, had gone 
through the cow-pox. That all of them resisted the smallpox except 
one, but that on making the most rigid and scrupulous enquiry at 
the farm in Gloucestershire, where the man said he lived when he 
had the disease, and among those with whom, at the same time, he 
declared he had associated, and particularly of a person in the 
parish, whom he said had dressed his fingers, it most clearly ap- 
peared that he aimed at an imposition, and that he never had been 
affected with the cow-pox." " 

Mr. Tierny remarks that the arms of many who were inoculated 
after having had the cow-pox inflamed very quickly, and that in 
several a little ichorous fluid was formed. 

Mr. Cline, who in July last was so obliging at my request as to 
try the efficacy of the cow-pox virus, was kind enough to give me a 
letter on the result of it, from which the following is an extract: 

"My Dear Sir: 

"The cow-pox experiment has succeeded admirably. The child 
sickened on the seventh day, and the fever, which was moderate, 
subsided on the eleventh. The inflammation arising from the in- 
sertion of the virus extended to about four inches in diameter, and 
then gradually subsided, without having been attended with pain 
or other inconvenience. There were no eruptions. 

"I have since inoculated him with smallpox matter in three places, 
which were slightly inflamed on the third day, and then subsided. 

"Dr. Lister, who was formerly physician to the Smallpox Hospital, 
attended the child with me, and he is convinced that it is not 
possible to give him the smallpox. I think the substituting the 

" The public cannot be too much upon their guard respecting persons of this 
description. 



VACCINATION AGAINST SMALLPOX I99 

cow-pox poison for the smallpox promises to be one of the greatest 

improvements that has ever been made in medicine; and the more 

I think on the subject, the more I am impressed with its importance. 

"With great esteem 

"I am, etc., 

"Lincoln's Inn Fields. "H^^Y CliNE. 

August 2, 1798." 

From communications, with which I have been favoured from 
Dr. Pearson, who has occasionally reported to me the result of his 
private practice with the vaccine virus in London, and from Dr. 
Woodville, who also has favoured me with an account of his more 
extensive inoculation with the same virus at the Smallpox Hospital, 
it appears that many of their patients have been affected with erup- 
tions, and that these eruptions have maturated in a manner very 
similar to the variolous. The matter they made use of was taken in 
the first instance from a cow belonging to one of the great milk 
farms in London. Having never seen maturated pustules produced 
either in my own practice among those who were casually infected 
by cows, or those to whom the disease had been communicated by 
inoculation, I was desirous of seeing the effect of the matter generated 
in London, on subjects living in the country. A thread imbrued in 
some of this matter was sent to me, and with it two children were 
inoculated, whose cases I shall transcribe from my notes. 

Stephen Jenner, three years and a half old. 

3d day : The arm shewed a proper and decisive inflammation. 

6th: A vesicle arising. 

7th: The pustule of a cherry colour. 

8th: Increasing in elevation. A few spots now appear on each arm 
near the insertion of the inferior tendons of the biceps muscles. They 
are very small and of a vivid red colour. The pulse natural; tongue 
of its natural hue; no loss of appetite or any symptom of indisposition. 

9th: The inoculated pustule on the arm this evening began to 
inflame, and gave the child uneasiness; he cried and pointed to the 
seat of it, and was immediately afterwards affected with febrile 
symptoms. At the expiration of two hours after the seizure a plaster 
of ung. hydrarg. fort, was applied, and its effect was very quickly 



200 EDWARD JENNER 

perceptible, for in ten minutes he resumed his usual looks and play- 
fulness. On examining the arm about three hours after the applica- 
tion of the plaster its effects in subduing the inflammation were 
very manifest. 

loth: The spots on the arms have disappeared, but there are three 
visible in the face. 

nth: Two spots on the face are gone; the other barely perceptible. 

13th: The pustule delineated in the second plate in the Treatise on 
the Variolae Vaccina is a correct representation of that on the child's 
arm as it appears at this time. 

14th: Two fresh spots appear on the face. The pustule on the arm 
nearly converted into a scab. As long as any fluid remained in it it 
was limpid. 

James Hill, four years old, was inoculated on the same day, and 
with part of the same matter which infected Stephen Jenner. It 
did not appear to have taken effect till the fifth day. 

7th: A perceptible vesicle. This evening the patient became a little 
chilly; no pain or tumour discoverable in the axilla. 

8th: Perfectly well. 

9th: The same. 

loth: The vesicle more elevated than I have been accustomed to 
see it, and assuming more perfectly the variolous character than is 
common with the cow-pox at this stage. 

nth: Surrounded by an inflammatory redness, about the size of a 
shilling, studded over with minute vesicles. The pustule contained 
a limpid fluid till the fourteenth day, after which it was incrusted 
over in the usual manner; but this incrustation or scab being acci- 
dentally rubbed off, it was slow in healing. 

These children were afterwards fully exposed to the smallpox 
contagion without effect. 

Having been requested by my friend, Mr. Henry Hicks, of 
Eastington, in this county, to inoculate two of his children, and at 
the same time some of his servants and the people employed in his 
manufactory, matter was taken from the arm of this boy for the 
purpose. The numbers inoculated were eighteen. They all took 
the infection, and either on the fifth or sixth day a vesicle was per- 
ceptible on the punctured part. Some of them began to feel a little 



VACCINATION AGAINST SMALLPOX 201 

unwell on the eighth day, but the greater number on the ninth. 
Their illness, as in the former cases described, was of short duration, 
and not sufficient to interrupt, but at very short intervals, the chil- 
dren from their amusements, or the servants and manufacturers 
from following their ordinary business. 

Three of the children whose employment in the manufactory 
was in some degree laborious had an inflammation on their arms 
beyond the common boundary about the eleventh or twelfth day, 
when the feverish symptoms, which before were nearly gone off, 
again returned, accompanied with increase of axillary tumour. In 
these cases (clearly perceiving that the symptoms were governed 
by the state of the arms) I applied on the inoculated pustules, and 
renewed the application three or four times within an hour, a pledget 
of lint, previously soaked in aqua lythargyri acetati^* and covered 
the hot efflorescence surrounding them with cloths dipped in cold 
water. 

The next day I found this simple mode of treatment had suc- 
ceeded perfectly. The inflammation was nearly gone off, and with 
it the symptoms which it had produced. 

Some of these patients have since been inoculated with variolous 
matter, without any effect beyond a little inflammation on the part 
where it was inserted. 

Why the arms of those inoculated with the vaccine matter in 
the country should be more disposed to inflame than those inoculated 
in London it may be difficult to determine. From comparing my 
own cases with some transmitted to me by Dr. Pearson and Dr. 
Woodville, this appears to be the fact; and what strikes me as still 
more extraordinary with respect to those inoculated in London is 
the appearance of maturating eruptions. In the two instances only 
which I have mentioned (the one from the inoculated, the other 
from the casual, cow-pox) a few red spots appeared, which quickly 
went off without maturating. The case of the Rev. Mr. Moore's 
servant may, indeed, seem like a deviation from the common ap- 
pearances in the country, but the nature of these eruptions was not 
ascertained beyond their not possessing the property of communicat- 
ing the disease by their effluvia. Perhaps the difference we perceive 

'^ Goulard's extract of Saturn. 



202 EDWARD JENNER 

may be owing to some variety in the mode of action o£ the virus 
upon the skin of those who breathe the air of London and those 
who hve in the country. That the erysipelas assumes a different 
form in London from what we see it put on in this country is a fact 
very generally acknowledged. In calling the inflammation that is 
excited by the cow-pox virus erysipelatous, perhaps I may not be 
critically exact, but it certainly approaches near to it. Now, as 
the diseased action going forward in the part infected with the 
virus may undergo different modifications according to the pe- 
culiarities of the constitution on which it is to produce its effect, may 
it not account for the variation which has been observed? 

To this it may probably be objected that some of the patients in- 
oculated, and who had pustules in consequence, were newly come 
from the country; but I conceive that the changes wrought in the 
human body through the medium of the lungs may be extremely 
rapid. Yet, after all, further experiments made in London with 
vaccine virus generated in the country must finally throw a light 
on what now certainly appears obscure and mysterious. 

The principal variation perceptible to me in the action of the 
vaccine virus generated in London from that produced in the 
country was its proving more certainly infectious and giving a less 
disposition in the arm to inflame. There appears also a greater 
elevation of the pustule above the surrounding skin. In my former 
cases the pustule produced by the insertion of the virus was more 
hke one of those which are so thickly spread over the body in a bad 
kind of confluent smallpox. This was more like a pustule of the 
distinct smallpox, except that I saw no instance of pus being formed 
in it, the matter remaining limpid till the period of scabbing. 

Wishing to see the effects of the disease on an infant newly born, 
my nephew, Mr. Henry Jenner, at my request, inserted the vaccine 
virus into the arm of a child about twenty hours old. His report to 
me is that the child went through the disease without apparent ill- 
ness, yet that it was found effectually to resist the action of variolous 
matter with which it was subsequently inoculated. 

I have had an opportunity of trying the effects of the cow-pox 
matter on a boy, who, the day preceding its insertion, sickened with 
the measles. The eruption of the measles, attended with cough, a 



VACCINATION AGAINST SMALLPOX 203 

little pain in the chest, and the usual symptoms accompanying the 
disease, appeared on the third day and spread all over him. The 
disease went through its course without any deviation from its usual 
habits; and, notwithstanding this, the cow-pox virus excited its 
common appearances, both on the arm and on the constitution, 
without any febrile interruption; on the sixth day there was a 
vesicle. 

8th: Pain in the axilla, chilly, and affected with headache. 

9th: Nearly well. 

I2th: The pustule spread to the size of a large split-pea, but with- 
out any surrounding efflorescence. It soon afterwards scabbed, and 
the boy recovered his general health rapidly. But it should be ob- 
served that before it scabbed the efflorescence which had suffered a 
temporary suspension advanced in the usual manner. 

Here we see a deviation from the ordinary habits of the smallpox, 
as it has been observed that the presence of the measles suspends the 
action of the variolous matter. 

The very general investigation that is now taking place, chiefly 
through inoculation (and I again repeat my earnest hope that it 
may be conducted with that calmness and moderation which should 
ever accompany a philosophical research), must soon place the 
vaccine disease in its just point of view. The result of all my trials 
with the virus on the human subject has been uniform. In every 
instance the patient who has felt its influence, has completely lost 
the susceptibility for the variolous contagion; and as these instances 
are now become numerous, I conceive that, joined to the observations 
in the former part of this paper, they sufficiently preclude me from 
the necessity of entering into controversies with those who have 
circulated reports adverse to my assertions, on no other evidence 
than what has been casually collected. 

Ill 

A Continuation of Facts and Observations Helative 
TO THE Variola Vaccina, or Cow-pox. 1800 

Since my former publications on the vaccine inoculation I have 
had the satisfaction of seeing it extend very widely. Not only in this 



204 EDWARD JENNER 

country is the subject pursued with ardour, but from my correspond- 
ence with many respectable medical gentlemen on the Continent 
(among whom are Dr. De Carro, of Vienna, and Dr. Ballhorn, of 
Hanover) I find it is as warmly adopted abroad, where it has 
afforded the greatest satisfaction. I have the pleasure, too, of seeing 
that the feeble efforts of a few individuals to depreciate the new 
practice are sinking fast into contempt beneath the immense mass 
of evidence which has arisen up in support of it. 

Upwards of six thousand persons have now been inoculated with 
the virus of cow-pox, and the far greater part of them have since 
been inoculated with that of smallpox, and exposed to its infection 
in every rational way that could be devised, without effect. 

It was very improbable that the investigation of a disease so 
analogous to the smallpox should go forward without engaging the 
attention of the physician of the Smallpox Hospital in London. 

Accordingly, Dr. Woodville, who fills that department with so 
much respectability, took an early opportunity of instituting an 
inquiry into the nature of the cow-pox. This inquiry was begun in 
the early part of the present year, and in May, Dr. Woodville pub- 
lished the result, which differs essentially from mine in a point of 
much importance. It appears that three-fifths of the patients inocu- 
lated were affected with eruptions, for the most part so perfectly 
resembling the smallpox as not to be distinguished from them. On 
this subject it is necessary that I should make some comments. 

When I consider that out of the great number of cases of casual 
inoculation immediately from cows which from time to time pre- 
sented themselves to my observation, and the many similar instances 
which have been communicated to me by medical gentlemen in this 
neighbourhood; when I consider, too, that the matter with which 
my inoculations were conducted in the years 1797, 1798, and 1799, 
was taken from some different cows, and that in no instance any 
thing like a variolous pustule appeared, I cannot feel disposed to 
imagine that eruptions, similar to those described by Dr. Woodville, 
have ever been produced by the pure uncontaminated cow-pox virus; 
on the contrary, I do suppose that those which the doctor speaks of 
originated in the action of variolous matter which crept into the 
constitution with the vaccine. And this I presume happened from the 



VACCINATION AGAINST SMALLPOX 205 

inoculation of a great number of the patients with variolous matter 
(some on the third, others on the fifth, day) after the vaccine had 
been applied; and it should be observed that the matter thus propa- 
gated became the source of future inoculations in the hands of many 
medical gentlemen who appeared to have been previously un- 
acquainted with the nature of the cow-pox. 

Another circumstance strongly, in my opinion, supporting this 
supposition is the following: The cow-pox has been known among 
our dairies time immemorial. If pustules, then, like the variolous, 
were to follow the communication of it from the cow to the milker, 
would not such a fact have been known and recorded at our farms .'' 
Yet neither our farmers nor the medical people of the neighbour- 
hood have noticed such an occurrence. 

A few scattered pimples I have sometimes, though very rarely, 
seen, the greater part of which have generally disappeared quickly, 
but some have remained long enough to suppurate at their apex. 
That local cuticular inflammation, whether springing up spon- 
taneously or arising from the application of acrid substances, such 
for instance, as cantharides, pix Burgundica, antimonium tartariza- 
tum, etc., will often produce cutaneous affections, not only near the 
seat of the inflammation, but on some parts of the skin far beyond 
its boundary, is a well-known fact. It is, doubtless, on this principle 
that the inoculated cow-pox pustule and its concomitant efflorescence 
may, in very irritable constitutions, produce this affection. The erup- 
tion I allude to has commonly appeared some time in the third 
week after inoculation. But this appearance is too trivial to excite 
the least regard. 

The change which took place in the general appearance during 
the progress of the vaccine inoculation at the Smallpox Hospital 
should likewise be considered. 

Although at first it took on so much of the variolous character 
as to produce pustules in three cases out of five, yet in Dr. Wood- 
ville's last report, published in June, he says: "Since the publication 
of my reports of inoculations for the cow-pox, upwards of three 
hundred cases have been under my care; and out of this number 
only thirty-nine had pustules that suppurated; viz., out of the first 
hundred, nineteen had pustules; out of the second, thirteen; and out 



206 EDWARD JENNER 

of the last hundred and ten, only seven had pustules. Thus it appears 
that the disease has become considerably milder; which I am in- 
clined to attribute to a greater caution used in the choice of the 
matter, with which the infection was communicated; for, lately, 
that which has been employed for this purpose has been taken only 
from those patients in whom the cow-pox proved very mild and well 
characterized." ' 

The inference I am induced to draw from these premises is very 
different. The decline, and, finally, the total extinction nearly, of 
these pustules, in my opinion, are more fairly attributable to the cow- 
pox virus, assimilating the variolous,^ the former probably being the 
original, the latter the same disease under a peculiar, and at present 
an inexplicable, modification. 

One experiment tending to elucidate the point under discussion I 
had myself an opportunity of instituting. On the supposition of its 
being possible that the cow which ranges over the fertile meadows 
in the vale of Gloucester might generate a virus differing in some 
respects in its quaHties from that produced by the animal artificially 
pampered for the production of milk for the metropolis, I procured, 
during my residence there in the spring, some cow-pox virus from a 
cow at one of the London milk-farms.' It was immediately conveyed 
into Gloucestershire to Dr. Marshall, who was then extensively en- 
gaged in the inoculation of the cow-pox, the general result of which, 
and of the inoculation in particular with this matter, I shall lay before 
my reader in the following communication from the doctor: 

"Dear Sir: 

"My neighbour, Mr. Hicks, having mentioned your wish to be 
informed of the progress of the inoculation here for the cow-pox, 

' In a few weeks after the cow-pox inoculation was introduced at the Smallpox 
Hospital I was favoured with some virus from this stock. In the first instance it 
produced a few pustules, which did not maturate; but in the subsequent cases none 
appeared. — E. J. 

^ In my first publication on this subject I expressed an opinion that the smallpox 
and the cow-pox were the same diseases under different modifications. In this opinion 
Dr. Woodville has concurred. The axiom of the immortal Hunter, that two diseased 
actions cannot take place at the same time in one and the same part, will not be 
injured by the admission of this theory. 

'It was taken by Mr. Tanner, then a student at the Veterinary College, from a 
cow at Mr. Clark's farm at Kentish Town. 



VACCINATION AGAINST SMALLPOX 207 

and he also having taken the trouble to transmit to you my minutes 
of the cases which have fallen under my care, I hope you will par- 
don the further trouble I now give you in stating the observations 
I have made upon the subject. When first informed of it, having two 
children who had not had the smallpox, I determined to inoculate 
them for the cow-pox whenever I should be so fortunate as to procure 
matter proper for the purpose. I was, therefore, particularly happy 
when I was informed that I could procure matter from some of 
those whom you had inoculated. In the first instance I had no inten- 
tion of extending the disease further than my own family, but the 
very extensive influence which the conviction of its efficacy in resist- 
ing the smallpox has had upon the minds of the people in general 
has rendered that intention nugatory, as you will perceive, by the 
condnuation of my cases enclosed in this letter,^ by which it will 
appear that since the 22d of March I have inoculated an hundred and 
seven persons; which, considering the retired situation I resided in, 
is a very great number. There are also other considerations which, 
besides that of its influence in resisting the smallpox, appear to have 
had their weight; the peculiar mildness of the disease, the known 
safety of it, and its not having in any instance prevented the patient 
from following his ordinary business. In all the cases under my 
care there have only occurred two or three which required any 
application, owing to erysipelatous inflammadon on the arm, and 
they immediately yielded to it. In the remainder the constitutional 
illness has been slight but sufficiently marked, and considerably less 
than I ever observed in the same number inoculated with the small- 
pox. In only one or two of the cases have any other eruptions 
appeared than those around the spot where the matter was inserted, 
and those near the infected part. Neither does there appear in the 
cow-pox to be the least exciting cause to any other disease, which in 
the smallpox has been frequently observed, the constitution remain- 
ing in as full health and vigour after the termination of the disease 
as before the infection. Another important consideration appears 
to be the impossibility of the disease being communicated except by 
the actual contact of the matter of the pustule, and consequently 

■* Doctor Marshall has detailed these cases with great accuracy, but their publica- 
tion would now be deemed superfluous. — E. J. 



208 EDWARD JENNER 

the perfect safety of the remaining part of the family, supposing only 
one or two should wish to be inoculated at the same time. 

"Upon the whole, it appears evident to me that the cow-pox is 
a pleasanter, shorter, and infinitely more safe disease than the inocu- 
lated smallpox when conducted in the most careful and approved 
manner; neither is the local affection of the inoculated part, or the 
constitutional illness, near so violent. I speak with confidence on the 
subject, having had an opportunity of observing its effects upon a 
variety of constitutions, from three months old to sixty years; and to 
which I have paid particular attention. In the cases alluded to here 
you will observe that the removal from the original source of the 
matter had made no alteration or change in the nature or appear- 
ance of the disease, and that it may be continued, ad infinitum (I 
imagine), from one person to another (if care be observed in taking 
the matter at a proper period) without any necessity of recurring 
to the original matter of the cow. 

"I should be happy if any endeavours of mine could tend further 
to elucidate the subject, and shall be much gratified in sending you 
any further observations I may be enabled to make. 

"I have the pleasure to subscribe myself, 
"Dear sir, etc., 

"Joseph H. Marshall. 
"Eastington, Gloucestershire, April 26, 1799." 

The gentleman who favoured me with the above account has 
continued to prosecute his inquiries with unremitting industry, and 
has communicated the result in another letter, which at his request 
I lay before the public without abbreviation. 

Dr. Marshall's second letter: 

"Dear Sir: 

"Since the date of my former letter I have continued to inoculate 
with the cow-pox virus. Including the cases before enumerated, 
the number now amounts to four hundred and twenty-three. It 
would be tedious and useless to detail the progress of the disease 
in each individual — it is sufficient to observe that I noticed no devi- 
ation in any respect from the cases I formerly adduced. The general 



VACCINATION AGAINST SMALLPOX 209 

appearances of the arm exactly corresponded with the account given 
in your first publication. When they were disposed to become 
troublesome by erysipelatous inflammation, an application of equal 
parts of vinegar and water always answered the desired intention. 
I must not omit to inform you that when the disease had duly acted 
upon the constitution I have frequently used the vitriolic acid. A 
portion of a drop applied with the head of a probe or any convenient 
utensil upon the pustule, suffered to remain about forty seconds, 
and afterwards washed off with sponge and water, never failed to 
stop its progress and expedite the formation of a scab. 

"I have already subjected two hundred and eleven of my patients 
to the action of variolous matter, hut every one resisted it. 

"The result of my experiments (which were made with every 
requisite caution) has fully convinced me that the true cow-pox is a 
safe and infaUible preventive from the smallpox; that in no case 
which has fallen under my observation has it been in any consid- 
erable degree troublesome, much less have I seen any thing like 
danger; for in no instance were the patients prevented from follow- 
ing their ordinary employments. 

"In Dr. Woodville's publication on the cow-pox I notice an 
extraordinary fact. He says that the generality of his patients had 
pustules. It certainly appears extremely extraordinary that in all my 
cases there never was but one pustule, which appeared on a patient's 
elbow on the inoculated arm, and maturated. It appeared exacdy 
like that on the incised part. 

"The whole of my observations, founded as it appears on an 
extensive experience, leads me to these obvious conclusions; that 
those cases which have been or may be adduced against the pre- 
ventive powers of the cow-pox could not have been those of the 
true kind, since it must appear to be absolutely impossible that I 
should have succeeded in such a number of cases without a single 
exception if such a preventive power did not exist. I cannot enter- 
tain a doubt that the inoculated cow-pox must quickly supersede 
that of the smallpox. If the many important advantages which must 
result from the new practice are duly considered, we may reasonably 
infer that public benefit, the sure test of the real merit of discoveries, 
will render it generally extensive. 



210 EDWARD JENNER 

"To you, Sir, as the discoverer of this highly beneficial practice, 
mankind are under the highest obligations. As a private individual 
I participate in the general feeling; more particularly as you have 
afforded me an opportunity of noticing the effects of a singular 
disease, and of viewing the progress of the most curious experiment 
that ever was recorded in the history of physiology. 

"I remain, dear sir, etc., 

"Joseph H. Marshall." 

"P.S. I should have observed that, of the patients I inoculated 
and enumerated in my letter, one hundred and twenty-seven were 
infected with the matter you sent me from the London cow. I dis- 
covered no dissimilarity of symptoms in these cases from those 
which I inoculated from matter procured in this country. No 
pustules have occurred, except in one or two cases, where a single 
one appeared on the inoculated arm. No difference was apparent 
in the local inflammation. There was no suspension of ordinary 
employment among the labouring people, nor was any medicine 
required. 

"I have frequently inoculated one or two in a family, and the 
remaining part of it some weeks afterwards. The uninfected have 
slept with the infected during the whole course of the disease with- 
out being affected; so that I am fully convinced that the disease 
cannot be taken but by actual contact with the matter. 

"A curious fact has lately fallen under my observation, on which 
I leave you to comment. 

"I visited a patient with the confluent smallpox and charged a 
lancet with some of the matter. Two days afterwards I was desired 
to inoculate a woman and four children with the cow-pox, and I 
inadvertently took the vaccine matter on the same lancet which was 
before charged with that of smallpox. In three days I discovered 
the mistake, and fully expected that my five patients would be in- 
fected with smallpox; but I was agreeably surprised to find the 
disease to be genuine cow-pox, which proceeded without deviating 
in any particular from my former cases. I afterwards inoculated these 
patients with variolous matter, but all of them resisted its action. 

"I omitted mentioning another great advantage that now occurs 
to me in the inoculated cow-pox; I mean the safety with which 



VACCINATION AGAINST SMALLPOX 211 

pregnant women may have the disease communicated to them. I 
have inoculated a great number of females in that situation, and 
never observed their cases to differ in any respect from those of my 
other patients. Indeed, the disease is so mild that it seems as if it 
might at all times be communicated with the most perfect safety." 

I shall here take the opportunity of thanking Dr. Marshall and 
those other gentlemen who have obligingly presented me with the 
result of their inoculations; but, as they all agree in the same point 
as that given in the above communication, namely, the security of 
the patient from the effects of the smallpox after the cow-pox, their 
perusal, I presume, would afford us no satisfaction that has not 
been amply given already. Particular occurrences I shall, of course, 
detail. Some of my correspondents have mentioned the appearance 
of smallpox-like eruptions at the commencement of their inocula- 
tions; but in these cases the matter was derived from the original 
stock at the Smallpox Hospital. 

I have myself inoculated a very considerable number from the 
matter produced by Dr. Marshall's patients, originating in the Lon- 
don cow, without observing pustules of any kind, and have dis- 
persed it among others who have used it with a similar effect. 
From this source Mr. H. Jenner informs me he has inoculated above 
an hundred patients without observing eruptions. Whether the 
nature of the virus will undergo any change from being farther 
removed from its original source in passing successively from one 
person to another time alone can determine. That which I am now 
employing has been in use near eight months, and not the least 
change is perceptible in its mode of action either locally or constitu- 
tionally. There is, therefore, every reason to expect that its effects will 
remain unaltered and that we shall not be under the necessity of 
seeking fresh suppHes from the cow. 

The following observations were obligingly sent me by Mr. 
Tierny, Assistant Surgeon to the South Gloucester Regiment of 
Militia, to whom I am indebted for a former report on this sub- 
ject: 

"I inoculated with the cow-pox matter from the eleventh to the 
latter part of April, twenty-five persons, including women and chil- 
dren. Some on the eleventh were inoculated with the matter Mr. 



212 EDWARD JENNER 

Shrapnell (surgeon to the regiment) had from you, the others with 
matter taken from these. The progress of the puncture was accu- 
rately observed, and its appearance seemed to differ from the small- 
pox in having less inflammation around its basis on the first days — 
that is, from the third to the seventh; but after this the inflamma- 
tion increased, extending on the tenth or eleventh day to a circle of 
an inch and a half from its centre, and threatening very sore arms; 
but this I am happy to say was not the case; for, by applying mer- 
curial ointment to the inflamed part, which was repeated daily until 
the inflammation went off, the arm got well without any further 
application or trouble. The constitutional symptoms which appeared 
on the eighth or ninth day after inoculation scarcely deserved the 
name of disease, as they were so slight as to be scarcely perceptible, 
except that I could connect a slight headache and languor, with a 
stiffness and rather painful sensation in the axilla. This latter symp- 
tom was the most striking — it remained from twelve to forty-eight 
hours. In no case did 1 observe the smallest pustule, or even dis- 
colouration of the skin, like an incipient pustule, except about the 
part where the virus has been applied. 

"After all these symptoms had subsided and the arms were well, 
I inoculated four of this number with variolous matter, taken from 
a patient in another regiment. In each of these it was inserted sev- 
eral times under the cuticle, producing slight inflammation on the 
second or third day, and always disappearing before the fifth or sixth, 
except in one who had the cow-pox in Gloucestershire before he 
joined us, and who also received it at this time by inoculation. In 
this man the puncture inflamed and his arm was much sorer than 
from the insertion of the cow-pox virus; but there was no pain in 
the axilla, nor could any constitutional affection be observed. 

"I have only to add that I am now fully satisfied of the efficacy 
of the cow-pox in preventing the appearance of the smallpox, and 
that it is a most happy and salutary substitute for it. 

I remain, etc., 

"M. J. TiERNY." 

Although the susceptibility of the virus of the cow-pox is, for 
the most part, lost in those who have had the smallpox, yet in some 



VACCINATION AGAINST SMALLPOX 213 

constitutions it is only partially destroyed, and in others it does not 
appear to be in the least diminished. 

By far the greater number on whom trials were made resisted 
it entirely; yet I found some on whose arm the pustule from inocu- 
lation was formed completely, but without producing the common 
efflorescent blush around it, or any constitutional illness, while others 
have had the disease in the most perfect manner. A case of the 
latter kind having been presented to me by Mr. Fewster, Surgeon, 
of Thornbury, I shall insert it: 

"Three children were inoculated with the vaccine matter you 
obligingly sent me. On calling to look at their arms three days 
after I was told that John Hodges, one of the three, had been inocu- 
lated with the smallpox when a year old, and that he had a full 
burthen, of which his face produced plentiful marks, a circumstance 
I was not before made acquainted with. On the sixth day the arm 
of the boy appeared as if inoculated with variolous matter, but the 
pustule was rather more elevated. On the ninth day he complained 
of violent pain in his head and back, accompanied with vomiting 
and much fever. The next day he was very well and went to work 
as usual. The punctured part began to spread, and there was the 
areola around the inoculated part to a considerable extent. 

"As this is contrary to an assertion made in the Medical and 
Physical Journal, No. 8, I thought it right to give you this informa- 
tion, and remain, "Dear sir, etc., 

"J. Fewster." 

It appears, then, that the animal economy with regard to the action 
of this virus is under the same laws as it is with respect to the 
variolous virus, after previously feeling its influence, as far as com- 
parisons can be made between the two diseases. 

Some striking instances of the power of the cow-pox in suspending 
the progress of the smallpox after the patients had been several days 
casually exposed to the infection have been laid before me by Mr. 
Lyford, Surgeon, of Winchester, and my nephew, the Rev. G. C. 
Jenner. Mr. Lyford, after giving an account of his extensive and 
successful practice in the vaccine inoculation in Hampshire, writes 
as follows: 



214 EDWARD JENNER 

"The following case occurred to me a short time since, and may 
probably be worth your notice. I was sent for to a patient with 
the smallpox, and on inquiry found that five days previous to my 
seeing him the eruption began to appear. During the whole of this 
time two children who had not had the smallpox, were constantly 
in the room with their father, and frequently on the bed with him. 
The mother consulted me on the propriety of inoculating them, but 
objected to my taking the matter from their father, as he was sub- 
ject to erysipelas. I advised her by all means to have them inoculated 
at that time, as I could not procure any variolous matter elsewhere. 
However, they were inoculated with vaccine matter, but I cannot 
say I flattered myself with its proving successful, as they had previ- 
ously been so long and still continued to be exposed to the variolous 
infection. Notwithstanding this I was agreeably surprised to find the 
vaccine disease advance and go through its regular course; and, if I 
may be allowed the expression, to the total extinction of the 
smallpox." 
Mr. Jenner's cases were not less satisfactory. He writes as follows: 
"A son of Thomas Stinchcomb, of Woodford, near Berkeley, was 
infected with the natural smallpox at Bristol, and came home to his 
father's cottage. Four days after the eruptions had appeared upon 
the boy, the family (none of which had ever had the smallpox), 
consisting of the father, mother, and five children, was inoculated 
with vaccine virus. On the arm of the mother it failed to produce 
the least effect, and she, of course, had the smallpox,'' but the rest 
of the family had the cow-pox in the usual way, and were not affected 
with the smallpox, although they were in the same room, and the 
children slept in the same bed with their brother who was confined 
to it with the natural smallpox; and subsequently with their mother. 
"I attended this family with my brother, Mr. H. Jenner." 
The following cases are of too singular a nature to remain 
unnoticed. 

Miss R , a young lady about five years old, was seized on the 

evening of the eighth day after inoculation with vaccine virus, 
with such symptoms as commonly denote the accession of violent 

'Under similar circumstances I think it would be advisable to insert the matter 
into each arm, which would be more likely to insure the success of the operation. 
— E. J. 



VACCINATION AGAINST SMALLPOX 215 

fever. Her throat was also a little sore, and there were some uneasy 
sensations about the muscles of the neck. The day following a rash 
was perceptible on her face and neck, so much resembling the efflor- 
escence of the scarlatina anginosa that I was induced to ask whether 

Miss R had been exposed to the contagion of that disease. An 

answer in the affirmative, and the rapid spreading of the redness 
over the skin, at once relieved me from much anxiety respecting 
the nature of the malady, which went through its course in the ordi- 
nary way, but not without symptoms which were alarming both to 
myself and Mr. Lyford, who attended with me. There was no appar- 
ent deviation in the ordinary progress of the pustule to a state of 
maturity from what we see in general; yet there was a total suspen- 
sion of the areola or florid discolouration around it, until the scar- 
latina had retired from the constitution. As soon as the patient 
was freed from this disease this appearance advanced in the usual 
way.^ 

The case of Miss H R is not less interesting than that of 

her sister, above related. She was exposed to the contagion of the 
scarlatina at the same time, and sickened almost at the same hour. 
The symptoms continued severe about twelve hours, when the 
scarlatina-rash shewed itself faintly upon her face, and partly upon 
her neck. After remaining two or three hours it suddenly disap- 
peared, and she became perfectly free from every complaint. My 
surprise at this sudden transition from extreme sickness to health in 
great measure ceased when I observed that the inoculated pustule 
had occasioned, in this case, the common efflorescent appearance 
around it, and that as it approached the centre it was nearly in an 
erysipelatous state. But the most remarkable part of this history 
is that, on the fourth day afterwards, so soon as the efflorescence 
began to die away upon the arm and the pustule to dry up, the 
scarlatina again appeared, her throat became sore, the rash spread 
all over her. She went fairly through the disease with its common 
symptoms. 

That these were actually cases of scarlatina was rendered certain 
by two servants in the family falling ill at the same time with the 

^ I witnessed a similar fact in a case of measles. The pustule from the cow-pox virus 
advanced to maturity, while the measles existed in the constitution, but no efflorescence 
appeared around it until the measles had ceased to exert its influence. 



2l6 EDWARD JENNER 

distemper, who had been exposed to the infection with the young 
ladies. 

Some there are who suppose the security from the smallpox ob- 
tained through the cow-pox will be of a temporary nature only. 
This supposition is refuted not only by analogy with respect to the 
habits of diseases of a similar nature, but by incontrovertible facts, 
which appear in great numbers against it. To those already adduced 
in the former part of my first treatise' many more might be adduced 
were it deemed necessary; but among the cases I refer to, one will 
be found of a person who had the cow-pox fifty-three years before the 
effect of the smallpox was tried upon him. As he completely resisted 
it, the intervening period I conceive must necessarily satisfy any 
reasonable mind. Should further evidence be thought necessary, I 
shall observe that, among the cases presented to me by Mr. Fry, Mr. 
Darke, Mr. Tierny, Mr. H. Jenner, and others, there were many 
whom they inoculated ineffectually with variolous matter, who had 
gone through the cow-pox many years before this trial was made. 

It has been imagined that the cow-pox is capable of being com- 
municated from one person to another by effluvia without the inter- 
vention of inoculation. My experiments, made with the design of 
ascertaining this important point, all tend to establish my original 
position, that it is not infectious except by contact. I have never 
hesitated to suffer those on whose arms there were pustules exhaling 
the effluvia from associating or even sleeping with others who never 
had experienced either the cow-pox or the smallpox. And, further, 
I have repeatedly, among children, caused the uninfected to breathe 
over the inoculated vaccine pustules during their whole progress, 
yet these experiments were tried without the least effect. However, 
to submit a matter so important to a still further scrutiny, I desired 
Mr. H. Jenner to make any further experiments which might strike 
him as most likely to establish or refute what had been advanced on 
this subject. He has since informed me that he inoculated children at 
the breast, whose mothers had not gone through either the small- 
pox or the cow-pox; that he had inoculated mothers whose sucking 
infants have never undergone either of these diseases; that the 
effluvia from the inoculated pustules, in either case, had been inhaled 

'See pages 206, 207, 208, 209, 210, etc. 



VACCINATION AGAINST SMALLPOX 21 7 

from day to day during the whole progress of their maturation, and 
that there was not the least perceptible effect from these exposures. 
One woman he inoculated about a week previous to her accouche- 
ment, that her infant might be the more fully and conveniently 
exposed to the pustule; but, as in the former instances, no infection 
was given, although the child frequently slept on the arm of its 
mother with its nostrils and mouth exposed to the pustule in the 
fullest state of maturity. In a word, is it not impossible for the cow- 
pox, whose only manifestation appears to consist in the pustules 
created by contact, to produce itself by effluvia ? 

In the course of a late inoculation I observed an appearance which 
it may be proper here to relate. The punctured part on a boy's arm 
(who was inoculated with fresh limpid virus) on the sixth day, 
instead of shewing a beginning vesicle, which is usual in the cow- 
pox at that period, was encrusted over with a rugged, amber-coloured 
scab. The scab continued to spread and increase in thickness for 
some days, when, at its edges, a vesicated ring appeared, and the 
disease went through its ordinary course, the boy having had sore- 
ness in the axilla and some slight indisposition. With the fluid matter 
taken from his arm five persons were inoculated. In one it took 
no effect. In another it produced a perfect pustule without any 
deviation from the common appearance; but in the other three the 
progress of the inflammation was exactly similar to the instance 
which afforded the virus for their inoculation; there was a creeping 
scab of a loose texture, and subsequently the formation of limpid 
fluid at its edges. As these people were all employed in laborious 
exercises, it is possible that these anomalous appearances might owe 
their origin to the friction of the clothes on the newly inflamed part 
of the arm. I have not yet had an opportunity of exposing them to 
the smallpox. 

In the early part of this inquiry I felt far more anxious respecting 
the inflammation of the inoculated arm than at present; yet that this 
affection will go on to a greater extent than could be wished is a 
circumstance sometimes to be expected. As this can be checked, or 
even entirely subdued, by very simple means, I see no reason why 
the patient should feel an uneasy hour because an application may 
not be absolutely necessary. About the tenth or eleventh day, if the 



21 8 EDWARD JENNER 

pustule has proceeded regularly, the appearance of the arm will 
almost to a certainty indicate whether this is to be expected or not. 
Should it happen, nothing more need be done than to apply a single 
drop of the aqua lythargyri acetat^ upon the pustule, and, having 
suffered it to remain two or three minutes, to cover the efflorescence 
surrounding the pustule with a piece of Unen dipped in the aqua 
lythargyri compost The former may be repeated twice or thrice 
during the day, the latter as often as it may feel agreeable to the 
patient. 

When the scab is prematurely rubbed off (a circumstance not 
unfrequent among children and working people), the application of 
a little aqua lythargyri acet. to the part immediately coagulates the 
surface, which supplies its place, and prevents a sore. 

In my former treatises on this subject I have remarked that the 
human constitution frequently retains its susceptibility to the small- 
pox contagion (both from effluvia and contact) after previously feel- 
ing its influence. In further corroboration of this declaration many 
facts have been communicated to me by various correspondents. 
I shall select one of them, 

"Dear Sir: 

"Society at large must, I think, feel much indebted to you for 
your Inquiries and Observations on the Nature and Effects of the 
Variolse Vaccins, etc., etc. As I conceive what I am now about to 
communicate to be of some importance, I imagine it cannot be 
uninteresting to you, especially as it will serve to corroborate your 
assertion of the susceptibility of the human system of the variolous 
contagion, although it has previously been made sensible of its action. 
In November, 1793, I was desired to inoculate a person with the 
smallpox. I took the variolous matter from a child under the disease 
in the natural way, who had a large burthen of distinct pustules. 
The mother of the child being desirous of seeing my method of 
communicating the disease by inoculation, after having opened a 
pustule, I introduced the point of my lancet in the usual way on the 
back part of my own hand, and thought no more of it until I felt 

* Extract of Saturn. 

' Goulard water. For further information on this subject see the first Treatise on 
the Var. Vac, Dr. Marshall's letters, etc. 



VACCINATION AGAINST SMALLPOX 2I9 

a sensation in the part which reminded me of the transaction. This 
happened upon the third day; on the fourth there were all the 
appearances common to inoculation, at which I was not at all sur- 
prised, nor did I feel myself uneasy upon perceiving the inflammation 
continue to increase to the sixth and seventh day, accompanied with, 
a very small quantity of fluid, repeated experiments having taught 
me it might happen so with persons who had undergone the disease, 
and yet would escape any constitutional affection; but I was not so 
fortunate; for on the eighth day I was seized with all the symptoms 
of the eruptive fever, but in a much more violent degree than when 
I was before inoculated, which was about eighteen years previous 
to this, when I had a considerable number of pustules. I must con- 
fess I was now greatly alarmed, although I had been much engaged 
in the smallpox, having at different times inoculated not less than 
two thousand persons. I was convinced my present indisposition 
proceeded from the insertion of the variolous matter, and, therefore, 
anxiously looked for an eruption. On the tenth day I felt a very 
unpleasant sensation of stillness and heat on each side of my face 
near my ear, and the fever began to decline. The affection in my 
face soon terminated in three or four pustules attended with inflam- 
mation, but which did not maturate, and I was presently well. 

"I remain, dear sir, etc., 

"Thomas Miles." 

This inquiry is not now so much in its infancy as to restrain me 
from speaking more positively than formerly on the important point 
of scrophula as connected with the smallpox. 

Every practitioner in medicine who has extensively inoculated 
with the smallpox, or has attended many of those who have had 
the distemper in the natural way, must acknowledge that he has fre- 
quendy seen scrophulous affections, in some form or another, some- 
times rather quickly shewing themselves after the recovery of the 
patients. Conceiving this fact to be admitted, as I presume it must 
be by all who have carefully attended to the subject, may I not ask 
whether it does not appear probable that the general introduction 
of the smallpox into Europe has not been among the most conductive 
means in exciting that formidable foe to health.'' Having attentively 



220 EDWARD JENNER 

watched the effects of the cow-pox in this respect, I am happy in 
being able to declare that the disease does not appear to have the 
least tendency to produce this destructive malady. 

The scepticism that appeared, even among the most enlightened 
o£ medical men when my sentiments on the important subject of 
the cow-pox were first promulgated, was highly laudable. To have 
admitted the truth of a doctrine, at once so novel and so unlike any 
thing that ever had appeared in the annals of medicine, without the 
test of the most rigid scrutiny, would have bordered upon temerity; 
but now, when that scrutiny has taken place, not only among our- 
selves, but in the first professional circles in Europe, and when it has 
been uniformly found in such abundant instances that the human 
frame, when once it has felt the influence of the genuine cow-pox 
in the way that has been described, is never afterwards at any period 
of its existence assailable by the smallpox, may I not with perfect 
confidence congratulate my country and society at large on their 
beholding, in the mild form of the cow-pox, an antidote that is 
capable of extirpating from the earth a disease which is every hour 
devouring its victims; a disease that has ever been considered as the 
severest scourge of the human race! 



THE CONTAGIOUSNESS OF 
PUERPERAL FEVER 

BY 
OLIVER WENDELL HOLMES 



INTRODUCTORY NOTE 

Oliver Wendell Holmes was born in Cambridge, Massachusetts, 
August 29, 1809, and educated at Phillips Academy, Andover, and 
Harvard College. After graduation, he entered the Law School, but 
soon gave up law for medicine. He studied first in Boston, and later 
spent two years in medical schools in Europe, mainly in Paris. On his 
return he began to practise in Boston, but in two years he was appointed 
professor of anatomy at Dartmouth College, a position which he held 
from 1838 to 1840, when he again took up his Boston practice. It was 
soon after this, in 1843, that he published his essay on the "Contagious- 
ness of Puerperal Fever," his only contribution of high distinction to 
medical science. From 1847 to 1882 he was Parkman professor of 
anatomy and physiology in the Harvard Medical School. He died in 
Boston, October 7, 1894. 

In spite of the importance of the paper here printed, Holmes's reputa- 
tion as a scientist was overshadowed by that won by him as a wit and 
a man of letters. When he was only twenty-one his "Old Ironsides" 
brought him into notice; and through his poetry and fiction, and the 
sparkling talk of the "Breakfast Table" series, he took a high place 
among the most distinguished group of writers that America has yet 
produced. 



THE CONTAGIOUSNESS OF 
PUERPERAL FEVER 

IN collecting, enforcing and adding to the evidence accumulated 
upon this most serious subject, I would not be understood to 
imply that there exists a doubt in the mind of any well-informed 
member of the medical profession as to the fact that puerperal fever 
is sometimes communicated from one person to another, both 
directly and indirectly. In the present state of our knowledge upon 
this point I should consider such doubts merely as a proof that the 
sceptic had either not examined the evidence, or, having examined 
it, refused to accept its plain and unavoidable consequences. I 
should be sorry to think, with Dr. Rigby, that it was a case of 
"oblique vision"; I should be unwilling to force home the argumen- 
tum ad hominem of Dr. Blundell, but I would not consent to make 
a question of a momentous fact which is no longer to be considered 
as a subject for trivial discussions, but to be acted upon with silent 
promptitude. It signifies nothing that wise and experienced prac- 
titioners have sometimes doubted the reality of the danger in ques- 
tion; no man has the right to doubt it any longer. No negative 
facts, no opposing opinions, be they what they may, or whose they 
may, can form any answer to the series of cases now within the 
reach of all who choose to explore the records of medical science. 

If there are some who conceive that any important end would be 
answered by recording such opinions, or by collecting the history of 
all the cases they could find in which no evidence of the influence 
of contagion existed, I believe they are in error. Suppose a few 
writers of authority can be found to profess a disbelief in contagion, 
— and they are very few compared with those who think differ- 
ently, — is it quite clear that they formed their opinions on a view 

tiote. — This essay appeared first in 1843, '" T*^? 'New England Quarterly Journal 
of Medicine, and was reprinted in the "Medical Essays" in 1855. 

223 



224 °- W- HOLMES 

of all the facts, or is it not apparent that they relied mostly on their 
own solitary experience? Still further, of those whose names are 
quoted, is it not true that scarcely a single one could, by any possi- 
bility, have known the half or the tenth of the facts bearing on the 
subject which have reached such a frightful amount within the last 
few years? Again, as to the utility of negative facts, as we may 
briefly call them, — instances, namely, in which exposure has not been 
followed by disease, — although, like other truths, they may be worth 
knowing, I do not see that they are like to shed any important light 
upon the subject before us. Every such instance requires a good 
deal of circumstantial explanation before it can be accepted. It is 
not enough that a practitioner should have had a single case of 
puerperal fever not followed by others. It must be known whether 
he attended others while this case was in progress, whether he went 
directly from one chamber to others, whether he took any, and what, 
precautions. It is important to know that several women were 
exposed to infection derived from the patient, so that allowance may 
be made for want of predisposition. Now if of negative facts so 
sifted there could be accumulated a hundred for every one plain 
instance of communication here recorded, I trust it need not be said 
that we are bound to guard and watch over the hundredth tenant 
of our fold, though the ninety and nine may be sure of escaping 
the wolf at its entrance. If any one is disposed, then, to take a 
hundred instances of lives, endangered or sacrificed out of those I 
have mentioned, and make it reasonably clear that within a similar 
time and compass ten thousand escaped the same exposure, I shall 
thank him for his industry, but I must be permitted to hold to my 
own practical conclusions, and beg him to adopt or at least to 
examine them also. Children that walk in calico before open fires 
are not always burned to death; the instances to the contrary may 
be worth recording; but by no means if they are to be used as 
arguments against woollen frocks and high fenders. 

I am not sure that this paper will escape another remark which it 
might be wished were founded in justice. It may be said that the 
facts are too generally known and acknowledged to require any 
formal argument or exposition, that there is nothing new in the 
positions advanced, and no need of laying additional statements 



PUERPERAL FEVER 225 

before the profession. But on turning to two works, one almost 
universally, and the other extensively, appealed to as authority in 
this country, I see ample reason to overlook this objection. In the 
last edition of Dewees's Treatise on the "Diseases of Females" it is 
expressly said, "In this country, under no circumstance that puer- 
peral fever has appeared hitherto, does it afford the slightest ground 
for the belief that it is contagious." In the "Philadelphia Practice of 
Midwifery" not one word can be found in the chapter devoted to 
this disease which would lead the reader to suspect that the idea of 
contagion had ever been entertained. It seems proper, therefore, to 
remind those who are in the habit of referring to the works for' 
guidance that there may possibly be some sources of danger they 
have slighted or omitted, quite as important as a trifling irregularity 
of diet, or a confined state of the bowels, and that whatever confi- 
dence a physician may have in his own mode of treatment, his 
services are of questionable value whenever he carries the bane as 
well as the antidote about his person. 

The practical point to be illustrated is the following: The disease 
\nown as Puerperal Fever is so jar contagious as to be frequently 
carried from patient to patient by physicians and nurses. 

Let me begin by throwing out certain incidental questions, which, 
without being absolutely essential, would render the subject more 
complicated, and by making such concessions and assumptions as 
may be fairly supposed to be without the pale of discussion. 

I. It is granted that all the forms of what is called puerperal fever 
may not be, and probably are not, equally contagious or infectious. 
I do not enter into the distinctions which have been drawn by 
authors, because the facts do not appear to me sufBcient to establish 
any absolute line of demarcation between such forms as may be 
propagated by contagion and those which are never so propagated. 
This general result I shall only support by the authority of Dr. 
Ramsbotham, who gives, as the result of his experience, that the 
same symptoms belong to what he calls the infectious and the 
sporadic forms of the disease, and the opinion of Armstrong in his 
original Essay. If others can show any such distinction, I leave 
it to them to do it. But there are cases enough that show the preva- 
lence of the disease among the patients of a single practitioner when 



226 O. W. HOLMES 

it was in no degree epidemic, in the proper sense of the term. I 
may refer to those of Mr. Roberton and of Dr, Peirson, hereafter 
to be cited, as examples. 

2. I shall not enter into any dispute about the particular mode of 
infection, whether it be by the atmosphere the physician carries 
about him into the sick-chamber, or by the direct application of the 
virus to the absorbing surfaces with which his hand comes in con- 
tact. Many facts and opinions are in favour of each of these modes 
of transmission. But it is obvious that, in the majority of cases, it 
must be impossible to decide by which of these channels the disease 
is conveyed, from the nature of the intercourse between the physician 
and the patient. 

3. It is not pretended that the contagion of puerperal fever must 
always be followed by the disease. It is true of all contagious diseases 
that they frequently spare those who appear to be fully submitted to 
their influence. Even the vaccine virus, fresh from the subject, fails 
every day to produce its legitimate effect, though every precaution is 
taken to insure its action. This is still more remarkably the case 
with scarlet fever and some other diseases. 

4. It is granted that the disease may be produced and variously 
modified by many causes besides contagion, and more especially by 
epidemic and endemic influences. But this is not peculiar to the 
disease in question. There is no doubt that smallpox is propagated 
to a great extent by contagion, yet it goes through the same records 
of periodical increase and diminution which have been remarked 
in puerperal fever. If the question is asked how we are to reconcile 
the great variations in the mortality of puerperal fever in different 
seasons and places with the supposition of contagion, I will answer 
it by another question from Mr. Farr's letter to the Registrar- 
General. He makes the statement that "five die weekly of smallpox 
in the metropolis when the disease is not epidemic," and adds, "The 
problem for solution is, — Why do the five deaths become 10, 15, 20, 
31, 58, 88, weekly, and then progressively fall through the same 
measured steps?" 

5. I take it for granted that if it can be shown that great numbers 
of lives have been and are sacrificed to ignorance or blindness on this 
point, no other error of which physicians or nurses may be occasion- 



PUERPERAL FEVER 227 

ally suspected will be alleged in palliation of this; but that whenever 
and wherever they can be shown to carry disease and death instead 
of health and safety, the common instincts of humanity will silence 
every attempt to explain away their responsibility. 

The treatise of Dr. Gordon, of Aberdeen, was published in the 
year 1795, being among the earlier special works upon the disease. 
A part of his testimony has been occasionally copied into other 
works, but his expressions are so clear, his experience is given with 
such manly distinctness and disinterested honesty, that it may be 
quoted as a model which might have been often followed with 
advantage. 

"This disease seized such women only as were visited or delivered 
by a practitioner, or taken care of by a nurse, who had previously 
attended patients affected with the disease." 

"I had evident proofs of its infectious nature, and that the infection 
was as readily communicated as that of the smaUpox or measles, 
and operated more speedily than any other infection with which I 
am acquainted." 

"I had evident proofs that every person who had been with a 
patient in the puerperal fever became charged with an atmosphere 
of infection, which was communicated to every pregnant woman 
who happened to come within its sphere. This is not an assertion, 
but a fact, admitting of demonstration, as may be seen by a perusal 
of the foregoing table" — referring to a table of seventy-seven cases, 
in many of which the channel of propagation was evident. 

He adds: "It is a disagreeable declaration for me to mention, that 
I myself was the means of carrying the infection to a great number 
of women." He then enumerates a number of instances in which 
the disease was conveyed by midwives and others to the neighboring 
villages, and declares that "these facts fully prove that the cause of 
the puerperal fever, of which I treat, was a specific contagion, or 
infection, altogether unconnected with a noxious constitution of the 
atmosphere." 

But his most terrible evidence is given in these words: "I arrived 

AT THAT CERTAINTY IN THE MATTER THAT I COULD VENTURE TO FORETELL 
WHAT WOMEN WOULD BE AFFECTED WITH THE DISEASE, UPON HEARING BY 



228 O. W. HOLMES 

WHAT MIDWIFE THEY WERE TO BE DELIVERED, OR BY WHAT NURSE THEY 
WERE TO BE ATTENDED, DURING THEIR LYING-IN: AND ALMOST IN EVERY 
INSTANCE MY PREDICTION WAS VERIFIED." 

Even previously to Gordon, Mr. White, of Manchester, had said: 
"I am acquainted with two gentlemen in another town, where the 
whole business of midwifery is divided betwixt them, and it is very 
remarkable that one of them loses several patients every year of the 
puerperal fever, and the other never so much as meets with the 
disorder" — a difference which he seems to attribute to their various 
modes of treatment.' 

Dr. Armstrong has given a number of instances in his Essay on 
Puerperal Fever of the prevalence of the disease among the patients 
of a single practitioner. At Sunderland, "in all, forty-three cases 
occurred from the ist of January to the ist of October, when the 
disease ceased; and of this number, forty were witnessed by Mr. 
Gregson and his assistant, Mr. Gregory, the remainder having been 
separately seen by three accoucheurs." There is appended to the 
London edition of this Essay a letter from Mr. Gregson, in which 
that gentleman says, in reference to the great number of cases occur- 
ring in his practice, "The cause of this I cannot pretend fully to 
explain, but I should be wanting in common liberality if I were to 
make any hesitation in asserting that the disease which appeared in 
my practice was highly contagious, and communicable from one 
puerperal woman to another." "It is customary among the lower and 
middle ranks of people to make frequent personal visits to puerperal 
women resident in the same neighborhood, and I have ample evi- 
dence for affirming that the infection of the disease was often carried 
about in that manner; and, however painful to my feelings, I must 
in candour declare that it is very probable the contagion was con- 
veyed, in some instances, by myself, though I took every possible 
care to prevent such a thing from happening the moment that I 
ascertained that the distemper was infectious." Dr. Armstrong goes 
on to mention six other instances within his knowledge, in which 
the disease had at different times and places been limited, in the 
same singular manner, to the practice of individuals, while it existed 
scarcely, if at all, among the patients of others around them. Two 
' On the Management of Lying-in Women, p. 120. 



PUERPERAL FEVER 229 

of the gentlemen became so convinced of their conveying the con- 
tagion that they withdrew for a time from practice. 

I find a brief notice, in an American journal, of another series of 
cases, first mentioned by Mr. Davies, in the "Medical Repository." 
This gentleman stated his conviction that the disease is contagious. 

"In the autumn of 1822 he met with twelve cases, while his medical 
friends in the neighbourhood did not meet with any, 'or at least very 
few.' He could attribute this circumstance to no other cause than 
his having been present at the examination after death, of two 
cases, some time previous, and of his having imparted the disease 
to his patients, notwithstanding every precaution." ^ 

Dr. Gooch says: "It is not uncommon for the greater number of 
cases to occur in the practice of one man, whilst the other practition- 
ers of the neighborhood, who are not more skilful or more busy, 
meet with few or none. A practitioner opened the body of a woman 
who had died of puerperal fever, and continued to wear the same 
clothes. A lady whom he delivered a few days afterwards was 
attacked with and died of a similar disease; two more of his lying-in 
patients, in rapid succession, met with the same fate; struck by the 
thought that he might have carried contagion in his clothes, he 
instantly changed them, and met with no more cases of the kind.' 
A woman in the country who was employed as washerwoman and 
nurse washed the linen of one who had died of puerperal fever; the 
next lying-in patient she nursed died of the same disease; a third 
nursed by her met the same fate, till the neighbourhood, getting 
afraid of her, ceased to employ her." ■* 

In the winter of the year 1824, "several instances occurred of its 
prevalence among the patients of particular practitioners, whilst 
others who were equally busy met with few or none. One instance 
of this kind was very remarkable. A general practitioner, in large 
midwifery practice, lost so many patients from puerperal fever that 
he determined to deliver no more for some time, but that his partner 
should attend in his place. This plan was pursued for one month, 
during which not a case of the disease occurred in their practice. 

^Philad. Med. Journal for 1825, p. 408. 

'A similar anecdote is related by Sir Benjamin Brodie, of the late Dr. John Clark, 
Lancet, May 2, 1840. 

* An Account of Some of the Most Important Diseases Peculiar to Women, p. 4. 



230 O. W. HOLMES 

The elder practitioner, being then sufficiently recovered, returned to 
his practice, but the first patient he attended was attacked by the 
disease and died. A physician who met him in consultation soon 
afterwards, about a case of a different kind, and who knew nothing 
of his misfortune, asked him whether puerperal fever was at all 
prevalent in his neighbourhood, on which he burst into tears, and 
related the above circumstances. 

"Among the cases which I saw this season in consultation, four 
occurred in one month in the practice of one medical man, and all 
of them terminated fatally." ' 

Dr. Ramsbotham asserted, in a lecture at the London Hospital, 
that he had known the disease spread through a particular district, 
or be confined to the practice of a particular person, almost every 
patient being attacked with it, while others had not a single case. 
It seemed capable, he thought, of conveyance, not only by com- 
mon modes, but through the dress of the attendants upon the pa- 
tient." 

In a letter to be found in the "London Medical Gazette" for 
January, 1840, Mr. Roberton, of Manchester, makes the statement 
which I here give in a somewhat condensed form. 

A midwife delivered a woman on the 4th of December, 1830, who 
died soon after with the symptoms of puerperal fever. In one 
month from this date the same midwife delivered thirty women, 
residing in different parts of an extensive suburb, of which number 
sixteen caught the disease and all died. These were the only cases 
which had occurred for a considerable time in Manchester. The 
other midwives connected with the same charitable institution as 
the woman already mentioned are twenty-five in number, and 
deliver, on an average, ninety women a week, or about three hun- 
dred and eighty a month. None of these women had a case of 
puerperal fever. "Yet all this time this woman was crossing the 
other midwives in every direction, scores of the patients of the charity 
being delivered by them in the very same quarters where her cases 
of fever were happening." 

Mr. Roberton remarks that little more than half the women she 
delivered during this month took the fever; that on some days all 
^Gooch, op. cit., p. 71. ^ Load. Med. Gaz., May 2, 1835. 



PUERPERAL FEVER 23 I 

escaped, on others only one or more out of three or four; a circum- 
stance similar to what is seen in other infectious maladies. 

Dr. Blundell says: "Those who have never made the experiment 
can have but a faint conception how difficult it is to obtain the exact 
truth respecting any occurrence in which feelings and interests are 
concerned. Omitting particulars, then, I content myself with remark- 
ing, generally, that from more than one district I have received 
accounts of the prevalence of puerperal fever in the practice of some 
individuals, while its occurrence in that of others, in the same 
neighborhood, was not observed. Some, as I have been told, have 
lost ten, twelve, or a greater number of patients, in scarcely broken 
succession; like their evil genius, the puerperal fever has seemed to 
stalk behind them wherever they went. Some have deemed it pru- 
dent to retire for a time from practice. In fine, that this fever may 
occur spontaneously, I admit; that its infectious nature may be 
plausibly disputed, I do not deny; but I add, considerately, that in 
my own family I had rather that those I esteemed the most should 
be delivered, unaided, in a stable, by the mangerside, than that they 
should receive the best help, in the fairest apartment, but exposed to 
the vapors of this pitiless disease. Gossiping friends, wet-nurses, 
monthly nurses, the practitioner himself, these are the channels by 
which, as I suspect, the infection is principally conveyed." ' 

At a meeting of the Royal Medical and Chirurgical Society Dr. 
King mentioned that some years since a practitioner at Woolwich 
lost sixteen patients from puerperal fever in the same year. He was 
compelled to give up practice for one or two years, his business being 
divided among the neighboring practitioners. No case of puerperal 
fever occurred afterwards, neither had any of the neighboring sur- 
geons any cases of this disease. 

At the same meeting Mr. Hutchinson mentioned the occurrence of 
three consecutive cases of puerperal fever, followed subsequently by 
two others, all in the practice of one accoucheur.* 

Dr. Lee makes the following statement: "In the last two weeks of 
September, 1827, five fatal cases of uterine inflammation came under 
our observation. All the individuals so attacked had been attended 
in labor by the same midwife, and no example of a febrile or 

"'Led. on Midwifery, p. 395. ^Lancet, May 2, 1840. 



232 O. W. HOLMES 

inflammatory disease of a serious nature occurred during that period 
among the other patients of the Westminster General Dispensary, 
who had been attended by the other midwives belonging to that 
institution." * 

The recurrence of long series of cases like those I have cited, 
reported by those most interested to disbelieve in contagion, scattered 
along through an interval of half a century, might have been thought 
sufficient to satisfy the minds of all inquirers that here was some- 
thing more than a singular coincidence. But if, on a more extended 
observation, it should be found that the same ominous groups of 
cases clustering about individual practitioners were observed in a 
remote country, at different times, and in widely separated regions, 
it would seem incredible that any should be found too prejudiced 
or indolent to accept the solemn truth knelled into their ears by the 
funeral bells from both sides of the ocean — the plain conclusion that 
the physician and the disease entered, hand in hand, into the cham- 
ber of the unsuspecting patient. 

That such series of cases have been observed in this country, and 
in this neighborhood, I proceed to show. 

In Dr. Francis's "Notes to Denman's Midwifery" a passage is 
cited from Dr. Hosack in which he refers to certain puerperal cases 
which proved fatal to several lying-in women, and in some of which 
the disease was supposed to be conveyed by the accoucheurs them- 
selves.'" 

A writer in the "New York Medical and Physical Journal" for 
October, 1829, in speaking of the occurrence of puerperal fever con- 
fined to one man's practice, remarks : "We have known cases of this 
kind occur, though rarely, in New York." 

I mention these little hints about the occurrence of such cases 
partly because they are the first I have met with in American medical 
literature, but more especially because they serve to remind us that 
behind the fearful array of published facts there lies a dark list of 
similar events, unwritten in the records of science, but long remem- 
bered by many a desolated fireside. 

Certainly nothing can be more open and explicit than the account 

' Land. Cyc. of Pract. Med., art., "Fever, Puerperal." 
*" Denman's Midwifery, p. 675, third Am. ed. 



PUERPERAL FEVER 233 

given by Dr. Peirson, of Salem, of the cases seen by him. In the 
first nineteen days of January, 1829, he had five consecutive cases 
of puerperal fever, every patient he attended being attacked, and the 
three first cases proving fatal. In March of the same year he had 
two moderate cases, in June, another case, and in July, another, 
which proved fatal. "Up to this period," he remarks, "I am not 
informed that a single case had occurred in the practice of any other 
physician. Since that period I have had no fatal case in my practice, 
although I have had several dangerous cases. I have attended in all 
twenty cases of this disease, of which four have been fatal. I am 
not aware that there has been any other case in the town of distinct 
puerperal peritonitis, although I am willing to admit my informa- 
tion may be very defective on this point. I have been told of some 
'mixed cases,' and 'morbid affections after delivery.' " " 

In the "Quarterly Summary of the Transactions of the College of 
Physicians of Philadelphia" " may be found some most extraordinary 
developments respecting a series of cases occurring in the practice of 
a member of that body. 

Dr. Condie called the attention of the Society to the prevalence, at 
the present time, of puerperal fever of a peculiarly insidious and 
malignant character. "In the practice of one gentleman extensively 
engaged as an obstetrician nearly every female he has attended in 
confinement, during several weeks past, within the above limits" 
(the southern sections and neighboring districts), "had been attacked 
by the fever." 

"An important query presents itself, the doctor observed, in refer- 
ence to the particular form of fever now prevalent. Is it, namely, 
capable of being propagated by contagion, and is a physician who 
has been in attendance upon a case of the disease warranted in con- 
tinuing, without interruption, his practice as an obstetrician ? Dr. C, 
although not a believer in the contagious character of many of those 
affections generally supposed to be propagated in this manner, has, 
nevertheless, become convinced by the facts that have fallen under 
his notice that the puerperal fever now prevailing is capable of 
being communicated by contagion. How, otherwise, can be explained 

^^ Remar/(s on Puerperal Fever, pp. 12 and 13. 
'^ For May, June, and July, 1842. 



234 O- W. HOLMES 

the very curious circumstance of the disease in one district being 
exclusively confined to the practice of a single physician, a Fellow 
of this College, extensively engaged in obstetrical practice, while no 
instance of the disease has occurred in the patients under the care 
of any other accoucheur practising within the same district; scarcely 
a female that has been delivered for weeks past has escaped an 
attack?" 

Dr. Rutter, the practitioner referred to, "observed that, after the 
occurrence of a number of cases of the disease in his practice, he 
had left the city and remained absent for a week, but, on returning, 
no article of clothing he then wore having been used by him before, 
one of the very first cases of parturition he attended was followed 
by an attack of the fever and terminated fatally; he cannot readily, 
therefore, believe in the transmission of the disease from female to 
female in the person or clothes of the physician." 

The meeting at which these remarks were made was held on 
the 3d of May, 1842. In a letter dated December 20, 1842, addressed 
to Dr. Meigs, and to be found in the "Medical Examiner," " he 
speaks of "those horrible cases of puerperal fever, some of which 
you did me the favor to see with me during the past summer," and 
talks of his experience in the disease, "now numbering nearly seventy 
cases, all of which have occurred within less than a twelve-month 
past." 

And Dr. Meigs asserts, on the same page, "Indeed, I believe that 
his practice in that department o£ the profession was greater than 
that of any other gentleman, which was probably the cause of his 
seeing a greater number of the cases." This from a professor of 
midwifery, who some time ago assured a gentleman whom he met 
in consultation that the night on which they met was the eighteenth 
in succession that he himself had been summoned from his repose," 
seems hardly satisfactory. 

I must call the attention of the inquirer most particularly to the 
Quarterly Report above referred to, and the letters of Dr. Meigs and 
Dr. Rutter, to be found in the "Medical Examiner." Whatever 
impression they may produce upon his mind, I trust they will at 

^ For January 21, 1843. 

" Medical Examiner for December lo, 184J. 



PUERPERAL FEVER 235 

least convince him that there is some reason for looking into this 
apparently uninviting subject. 

At a meeting of the College of Physicians just mentioned Dr. 
Warrington stated that a few days after assisting at an autopsy of 
puerperal peritonitis, in which he laded out the contents of the 
abdominal cavity with his hands, he was called upon to deliver three 
women in rapid succession. All of these women were attacked with 
different forms of what is commonly called puerperal fever. Soon 
after these he saw two other patients, both on the same day, with 
the same disease. Of these five patients, two died. 

At the same meeting Dr. West mentioned a fact related to him 
by Dr. Samuel Jackson, of Northumberland. Seven females, deliv- 
ered by Dr. Jackson in rapid succession, while practising in Nor- 
thumberland County, were all attacked with puerperal fever, and 
five of them died. "Women," he said, "who had expected me to 
attend upon them, now becoming alarmed, removed out of my 
reach, and others sent for a physician residing several miles distant. 
These women, as well as those attended by midwives, all did well; 
nor did we hear of any deaths in child-bed within a radius of fifty 
miles, excepting two, and these I afterwards ascertained to have 
been caused by other diseases." He underwent, as he thought, a 
thorough purification, and still his next patient was attacked with 
the disease and died. He was led to suspect that the contagion might 
have been carried in the gloves which he had worn in attendance 
upon the previous cases. Two months or more after this he had two 
other cases. He could find nothing to account for these unless it 
were the instruments for giving enemata, which had been used in 
two of the former cases and were employed by these patients. When 
the first case occurred, he was attending and dressing a limb exten- 
sively mortified from erysipelas, and went immediately to the 
accouchement with his clothes and gloves most thoroughly imbued 
with its effluvia. And here I may mendon that this very Dr. Samuel 
Jackson, of Northumberland, is one of Dr. Dewees's authorities 
against contagion. 

The three following statements are now for the first time given to 
the public. All of the cases referred to occurred within this State, 
and two of the three series in Boston and its immediate vicinity. 



236 O. W. HOLMES 

I. The first is a series of cases which took place during the last 
spring in a town at some distance from this neighborhood. A 
physician of that town, Dr. C, had the following consecutive cases: 

No. r, delivered March 20, died March 24. 

2, " April 9, " April 14. 

3, 10, 14. 

it tt U tt il 

4, II, 18. 

5, ^^ ^^ 27, May 3. 

6, " " 28, had some symptoms, recovered. 

7, " May 8, had some symptoms, also recovered. 

These were the only cases attended by this physician during the 
period referred to. "They were all attended by him until their 
termination, with the exception of the patient No. 6, who fell into 
the hands of another physician on the 2d of May. (Dr. C. left town 
for a few days at this time.) Dr. C. attended cases immediately 
before and after the above-named periods, none of which, however, 
presented any peculiar symptoms of the disease." 

About the ist of July he attended another patient in a neighbor- 
ing village, who died two or three days after delivery. 

The first patient, it is stated, was delivered on the 20th of March. 
"On the 19th Dr. C. made the autopsy of a man who had died 
suddenly, sick only forty-eight hours; had oedema of the thigh and 
gangrene extending from a little above the ankle into the cavity 
of the abdomen." Dr. C. wounded himself very slightly in the 
right hand during the autopsy. The hand was quite painful the 
night following, during his attendance on the patient No. i. He 
did not see this patient after the 20th, being confined to the house, 
and very sick from the wound just mentioned, from this time until 
the 3d of April. 

Several cases of erysipelas occurred in the house where the autopsy 
mentioned above took place, soon after the examination. There 
were also many cases of erysipelas in town at the time of the fatal 
puerperal cases which have been mentioned. 

The nurse who laid out the body of the patient No. 3 was taken 
on the evening of the same day with sore throat and erysipelas, and 
died in ten days from the first attack. 



PUERPERAL FEVER 237 

The nurse who laid out the body of the patient No. 4 was taken 
on the day following with symptoms like those of this patient, and 
died in a week, without any external marks of erysipelas. 

"No other cases of similar character with those of Dr. C. occurred 
in the practice of any of the physicians in the town or vicinity at the 
time. Deaths following confinement have occurred in the practice 
of other physicians during the past year, but they were not cases of 
puerperal fever. No post-mortem examinations were held in any 
of these puerperal cases." 

Some additional statements in this letter are deserving of inser- 
tion: 

"A physician attended a woman in the immediate neighborhood 
of the cases numbered 2, 3, and 4. This patient was confined the 
morning of March ist, and died on the night of March 7th. It is 
doubtful whether this should be considered a case of puerperal fever. 
She had suffered from canker, indigestion, and diarrhoea for a year 
previous to her delivery. Her complaints were much aggravated 
for two or three months previous to delivery; she had become greatly 
emaciated, and weakened to such an extent that it had not been 
expected that she would long survive her confinement, if indeed she 
reached that period. Her labor was easy enough; she flowed a good 
deal, seemed exceedingly prostrated, had ringing in her ears, and 
other symptoms of exhaustion; the pulse was quick and small. On 
the second and third day there was some tenderness and tumefaction 
of the abdomen, which increased somewhat on the fourth and fifth. 
He had cases in midwifery before and after this, which presented 
nothing peculiar." 

It is also mentioned in the same letter that another physician had 
a case during the last summer and another last fall, both of which 
recovered. 

Another gentleman reports a case last December, a second case 
five weeks, and another three weeks, since. All these recovered. A 
case also occurred very recently in the practice of a physician in the 
village where the eighth patient of Dr. C. resides, which proved 
fatal. "This patient had some patches of erysipelas on the legs and 
arms. The same physician has delivered three cases since, which 
have all done well. There have been no other cases in this town or 



238 O. W. HOLMES 

its vicinity recently. There have been some fevi' cases of erysipelas." 
It deserves notice that the partner of Dr. C, who attended the 
autopsy of the man above mentioned and took an active part in it, 
who also suffered very slightly from a prick under the thumb-nail 
received during the examination, had twelve cases of midwifery 
between March 26th and April 12th, all of which did well, and 
presented no peculiar symptoms. It should also be stated that during 
these seventeen days he was in attendance on all the cases of ery- 
sipelas in the house where the autopsy had been performed. I owe 
these facts to the prompt kindness of a gentleman whose intelligence 
and character are sufficient guaranty for their accuracy. 

The two following letters were addressed to my friend Dr. Storer 
by the gentleman in whose practice the cases of puerperal fever 
occurred. His name renders it unnecessary to refer more particularly 
to these gentlemen, who on their part have manifested the most 
perfect freedom and courtesy in affording these accounts of their 
painful experience. 

"January 28, 1843. 

II. . . . "The time to which you allude was in 1830. The first 
case was in February, during a very cold time. She was confined 
the 4th, and died the 12th. Between the loth and 28th of this 
month I attended six women in labor, all of whom did well except 
the last, as also two who were confined March ist and 5th. Mrs. E., 
confined February 28th, sickened, and died March 8th. The next 
day, 9th, I inspected the body, and the night after attended a lady, 
Mrs. B., who sickened, and died i6th. The loth, I attended another, 
Mrs. G., who sickened, but recovered. March i6th I went from 
Mrs. G.'s room to attend a Mrs. H., who sickened, and died 21st. 
The 17th, I inspected Mrs. B. On 19th, I went directly from Mrs. 
H.'s room to attend another lady, Mrs. G., who also sickened, and 
died 22d. While Mrs. B. was sick, on 15th, I went directly from her 
room a few rods, and attended another woman, who was not sick. 
Up to 20th of this month I wore the same clothes. I now refused 
to attend any labor, and did not till April 21st, when, having thor- 
oughly cleansed myself, I resumed my practice, and had no more 
puerperal fever. 



PUERPERAL FEVER 239 

"The cases were not confined to a narrow space. The two nearest 
were half a mile from each other, and half that distance from my 
residence. The others were from two to three miles apart, and 
nearly that distance from my residence. There were no other cases 
in their immediate vicinity which came to my knowledge. The 
general health of all the women was pretty good, and all the labors 
as good as common, except the first. This woman, in consequence 
of my not arriving in season, and the child being half-born some 
time before I arrived, was very much exposed to the cold at the 
time of confinement, and afterwards, being confined in a very open, 
cold room. Of the six cases, you perceive only one recovered. 

"In the winter of 1817 two of my patients had puerperal fever, 
one very badly, the other not so badly. Both recovered. One other 
had swelled leg or phlegmasia dolens, and one or two others did 
not recover as well as usual. 

"In the summer of 1835 another disastrous period occurred in my 
practice. July ist I attended a lady in labor, who was afterwards 
quite ill and feverish; but at the time I did not consider her case a 
decided puerperal fever. On 8th I attended one who did well. On 
I2th, one who was seriously sick. This was also an equivocal case, 
apparently arising from constipation and irritation of the rectum. 
These women were ten miles apart and five from my residence. 
On 15th and 20th, two who did well. On 25th I attended another. 
This was a severe labor, and followed by unequivocal puerperal 
fever, or peritonitis. She recovered. August 2d and 3d, in about 
twenty-four hours, I attended four persons. Two of them did very 
well; one was attacked with some of the common symptoms, which, 
however, subsided in a day or two, and the other had decided puer- 
peral fever, but recovered. This woman resided five miles from me. 
Up to this time I wore the same coat. All my other clothes had 
frequently been changed. On 6th, I attended two women, one of 
whom was not sick at all; but the other, Mrs. L., was afterwards 
taken ill. On loth, I attended a lady, who did very well. I had 
previously changed all my clothes, and had no garment on which 
had been in a puerperal room. On 12th, I was called to Mrs. S., in 
labor. While she was ill, I left her to visit Mrs. L., one of the ladies 
who was confined on 6th. Mrs. L. had been more unwell than usual, 



240 O. W. HOLMES 

but I Uad not considered Ket case anytUmg moie tV\at\ common uW 
this visit. I had on a surtout at this visit, which, on my return to 
Mrs. S., I left in another room. Mrs. S. was delivered on 13th with 
forceps. These women both died of decided puerperal fever. 

"While I attended these women in their fevers I changed my 
clothes, and washed my hands in a solution of chloride of lime after 
each visit. I attended seven women in labor during this period, all 
of whom recovered without sickness. 

"In my practice I have had several single cases of puerperal fever, 
some of whom have died and some have recovered. Until the year 
1830 I had no suspicion that the disease could be communicated 
from one patient to another by a nurse or midwife; but I now 
think the foregoing facts strongly favor that idea. I was so much 
convinced of this fact that I adopted the plan before related. 

"I believe my own health was as good as usual at each of the 
above periods. I have no recollection to the contrary. 

"I believe I have answered all your questions. I have been more 
particular on some points perhaps than necessary; but I thought 
you could form your own opinion better than to take mine. In 
1830 I wrote to Dr. Channing a more particular statement of my 
cases. If I have not answered your questions sufficiently, perhaps 
Dr. C. may have my letter to him, and you can find your answer 
there." '= 

Boston, February 3, 1843. 

III. "My dear Sir: I received a note from you last evening request- 
ing me to answer certain questions therein proposed, touching the 
cases of puerperal fever which came under my observation the past 
summer. It gives me pleasure to comply with your request, so far 
as it is in my power so to do, but, owing to the hurry in preparing 
for a journey, the notes of the cases I had then taken were lost or 
mislaid. The principal facts, however, are too vivid upon my recol- 
lection to be soon forgotten. I think, therefore, that I shall be able to 
give you all the information you may require. 

"All the cases that occurred in my practice took place between the 
7th of May and the 17th of June, 1842. 

'^ In a letter to myself this gentleman also stated, "I do not recollect that there was 
any erysipelas or any other disease particularly prevalent at the time." 



PUERPERAL FEVER 24 I 

"They were not confined to any particular part of the city. The 
first two cases were patients residing at the South End, the next was 
at the extreme North End, one hving in Sea Street and the other in 
Roxbury. The following is the order in which they occurred : 

"Case i. — Mrs. was confined on the 7th of May, at 5 o'clock, 

p. M., after a natural labor of six hours. At 12 o'clock at night, on 
the 9th (thirty-one hours after confinement), she was taken with 
severe chill, previous to which she was as comfortable as women 
usually are under the circumstances. She died on the loth. 

"Case 2. — Mrs. was confined on the loth of June (four weeks 

after Mrs. C), at 11 a. m., after a natural, but somewhat severe, 
labor of five hours. At 7 o'clock, on the morning of the nth, she 
had a chill. Died on the 12th. 

"Case 3. — Mrs. , confined on the 14th of June, was comfortable 

until the i8th, when symptoms of puerperal fever were manifest. 
She died on the 20th. 

"Case 4. — Mrs. , confined June 17th, at 5 o'clock, a. m., was 

doing well until the morning of the 19th. She died on the evening 
of the 21 St. 

"Case 5. — Mrs. was confined with her fifth child on the 17th 

of June, at 6 o'clock in the evening. This patient had been attacked 
with puerperal fever, at three of her previous confinements, but the 
disease yielded to depletion and other remedies without difficulty. 
This time, I regret to say, I was not so fortunate. She was not 
attacked, as were the other patients, with a chill, but complained of 
extreme pain in the abdomen, and tenderness on pressure, almost 
from the moment of her confinement. In this, as in the other cases, 
the disease resisted all remedies, and she died in great distress on the 
22d of the same month. Owing to the extreme heat of the season 
and my own indisposition, none of the subjects were examined after 
death. Dr. Channing, who was in attendance with me on the three 
last cases, proposed to have a post-mortem examination of the subject 
of case No. 5, but from some cause which I do not now recollect 
it was not obtained. 

"You wish to know whether I wore the same clothes when 
attending the different cases. I cannot positively say, but I should 



242 O. W. HOLMES 

think I did not, as the weather became warmer after the first two 
cases; I therefore think it probable that I made a change of at least 
a part of my dress. I have had no other case of puerperal fever in 
my own practice for three years, save those above related, and I do 
not remember to have lost a patient before with this disease. While 
absent, last July, I visited two patients sick with puerperal fever, with 
a friend of mine in the country. Both of them recovered. 

"The cases that I have recorded were not confined to any particular 
constitution or temperament, but it seized upon the strong and the 
weak, the old and the young — one being over forty years, and the 
youngest under eighteen years of age. ... If the disease is of an 
erysipelatous nature, as many suppose, contagionists may perhaps 
find some ground for their belief in the fact that, for two weeks 
previous to my first case of puerperal fever, I had been attending a 
severe case of erysipelas, and the infection may have been conveyed 
through me to the patient; but, on the other hand, why is not this 
the case with other physicians, or with the same physician at all 
times, for since my return from the country I have had a more 
inveterate case of erysipelas than ever before, and no difficulty what- 
ever has attended any of my midwifery cases?" 

I am assured, on unquestionable authority, that "About three 
years since, a gentleman in extensive midwifery business, in a 
neighboring State, lost in the course of a few weeks eight patients 
in child-bed, seven of them being undoubted cases of puerperal fever. 
No other physician of the town lost a single patient of this disease 
during the same period." And from what I have heard in conver- 
sation with some of our most experienced practitioners, I am inclined 
to think many cases of the kind might be brought to light by 
extensive inquiry. 

This long catalogue of melancholy histories assumes a still darker 
aspect when we remember how kindly nature deals with the par- 
turient female, when she is not immersed in the virulent atmosphere 
of an impure lying-in hospital, or poisoned in her chamber by the 
unsuspected breath of contagion. From all causes together not more 
than four deaths in a thousand births and miscarriages happened in 
England and Wales during the period embraced by the first Report 



PUERPERAL FEVER 243 

of the Registrar-General.'^ In the second Report the mortaHty was 
shown to be about five in one thousand." In the Dublin Lying-in 
Hospital, during the seven years of Dr. CoUins's mastership, there 
was one case of puerperal fever to 178 deliveries, or less than six to the 
thousand, and one death from this disease in 278 cases, or between 
three and four to the thousand.'* Yet during this period the disease 
was endemic in the hospital, and might have gone on to rival the 
horrors of the pestilence of the Maternite, had not the poison been 
destroyed by a thorough purification. 

In private practice, leaving out of view the cases that are to be 
ascribed to the self-acting system of propagation, it would seem 
that the disease must be far from common. Mr. White, of Man- 
chester, says: "Out of the whole number of lying-in patients whom 
I have deUvered (and I may safely call it a great one), I have never 
lost one, nor to the best of my recollection has one been greatly 
endangered, by the puerperal, miliary, low nervous, putrid malig- 
nant, or milk fever." " Dr. Joseph Clarke informed Dr. Collins that 
in the course of forty-five years' most extensive practice he lost but 
four patients from this disease.^" One of the most eminent practi- 
tioners of Glasgow who has been engaged in very extensive practice 
for upwards of a quarter of a century testifies that he never saw more 
than twelve cases of real puerperal fever.^' 

I have myself been told by two gendemen practicing in this city, 
and having for many years a large midwifery business, that they had 
neither of them lost a patient from this disease, and by one of 
them that he had only seen it in consultation with other physicians. 
In five hundred cases of midwifery, of which Dr. Storer has given 
an abstract in the first number of this journal, there was only one 
instance of fatal puerperal peritonitis. 

In the view of these facts it does appear a singular coincidence that 
one man or woman should have ten, twenty, thirty, or seventy cases 
of this rare disease following his or her footsteps with the keenness 
of a beagle, through the streets and lanes of a crowded city, while 
the scores that cross the same paths on the same errands know it only 

'^ First Report, p. 105. ''' Second Report, p. 73. 

'^Collins's Treatise on Midwifery, p. 228, etc. ^^ Op. cit., p. 115. 

20 Op. cit., p. 228. ^^ Lancet, May 4, 1833. 



244 O- W. HOLMES 

by name. It is a series of similar coincidences which has led us to 
consider the dagger, the musket, and certain innocent-looking white 
powders as having some little claim to be regarded as dangerous. 
It is the practical inattention to similar coincidences which has 
given rise to the unpleasant but often necessary documents called 
indictments, which has sharpened a form of the cephalotome some- 
times employed in the case of adults, and adjusted that modification 
of the fillet which delivers the world of those who happen to be too 
much in the way while such striking coincidences are taking place. 

I shall now mention a few instances in which the disease appears 
to have been conveyed by the process of direct inoculation. 

Dr. Campbell, of Edinburgh, states that in October, 1821, he 
assisted at the post-mortem 'examination of a patient who died with 
puerperal fever. He carried the pelvic viscera in his pocket to the 
class-room. The same evening he attended a woman in labor with- 
out previously changing his clothes; this patient died. The next 
morning he delivered a woman with the forceps; she died also, and 
of many others who were seized with the disease within a few weeks, 
three shared the same fate in succession. 

In June, 1823, he assisted some of his pupils at the autopsy of a 
case of puerperal fever. He was unable to wash his hands with 
proper care, for want of the necessary accommodations. On getting 
home he found that two patients required his assistance. He went 
without further ablution or changing his clothes; both these patients 
died with puerperal fever." This same Dr. Campbell is one of Dr. 
Churchill's authorities against contagion. 

Mr. Roberton says that in one instance within his knowledge a 
practitioner passed the catheter for a patient with puerperal fever 
late in the evening; the same night he attended a lady who had the 
symptoms of the disease on the second day. In another instance a 
surgeon was called while in the act of inspecting the body of a 
woman who had died of this fever, to attend a labor; within forty- 
eight hours this patient was seized with the fever.^' 

On the i6th of March, 1831, a medical practitioner examined the 
body of a woman who had died a few days after delivery, from 

^^Lond. Med. Gazette, December 10, 1831. 
^^Ibid. for January, 1832. 



PUERPERAL FEVER 245 

puerperal peritonitis. On the evening of the 17th he deUvered a 
patient, who was seized with puerperal fever on the 19th, and died 
on the 24th. Between this period and the 6th of April the same 
practitioner attended two other patients, both of whom were attacked 
with the same disease and died.^^ 

In the autumn of 1829 a physician was present at the examination 
of a case of puerperal fever, dissected out the organs, and assisted in 
sewing up the body. He had scarcely reached home when he was 
summoned to attend a young lady in labor. In sixteen hours she 
was attacked with the symptoms of puerperal fever, and narrowly 
escaped with her life.^* 

In December, 1830, a midwife, who had attended two fatal cases 
of puerperal fever at the British Lying-in Hospital, examined a 
patient who had just been admitted, to ascertain if labor had com- 
menced. This patient remained two days in the expectation that 
labor would come on, when she returned home and was then sud- 
denly taken in labor and delivered before she could set out for the 
hospital. She went on favorably for two days, and was then taken 
with puerperal fever and died in thirty-six hours.^° 

"A young practitioner, contrary to advice, examined the body of 
a patient who had died from puerperal fever; there was no epidemic 
at the time; the case appeared to be purely sporadic. He delivered 
three other women shortly afterwards; they all died with puerperal 
fever, the symptoms of which broke out very soon after labor. The 
patients of his colleague did well, except one, where he assisted to 
remove some coagula from the uterus; she was attacked in the same 
manner as those whom he had attended, and died also." The writer 
in the "British and Foreign Medical Review," from whom I quote 
this statement, — and who is no other than Dr. Rigby, — adds: "We 
trust that this fact alone will forever silence such doubts, and stamp 
the well-merited epithet of 'criminal,' as above quoted, upon such 
attempts." 

From the cases given by Mr. Ingleby I select the following: Two 
gentlemen, after having been engaged in conducting the post- 
mortem examination of a case of puerperal fever, went in the same 

** London Cyc. of Pract. Med., art., "Fever, Puerperal." ^^ Ibid. 

^Ibid. ^'' Brit, and For. Medical Review for January, 1842, p. 112. 



246 O. W. HOLMES 

dress, each respectively, to a case of midwifery. "The one patient 
was seized with the rigor about thirty hours afterwards. The other 
patient was seized with a rigor the third morning after deUvery. 
One recovered, one died." ^ One of these same gentlemen attended 
another woman in the same clothes two days after the autopsy 
referred to. "The rigor did not take place until the evening of the 
fifth day from the first visit. Result fatal." These cases belonged 
to a series of seven, the first of which was thought to have originated 
in a case of erysipelas. "Several cases of a mild character followed 
the foregoing seven, and their nature being now most unequivocal, 
my friend declined visiting all midwifery cases for a time, and there 
was no recurrence of the disease." These cases occurred in 1833. 
Five of them proved fatal. Mr. Ingleby gives another series of seven 
cases which occurred to a practitioner in 1836, the first of which was 
also attributed to his having opened several erysipelatous abscesses 
a short time previously. 

I need not refer to the case lately read before this Society, in which 
a physician went, soon after performing an autopsy of a case of 
puerperal fever, to a woman in labor, who was seized with the same 
disease and perished. The forfeit of that error has been already 
paid. 

At a meeting of the Medical and Chirurgical Society before 
referred to. Dr. Merriman related an instance occurring in his own 
practice, which excites a reasonable suspicion that two lives were 
sacrificed to a still less dangerous experiment. He was at the exami- 
nation of a case of puerperal fever at two o'clock in the afternoon. 
He too\ care not to touch the body. At nine o'clock the same eve- 
ning he attended a woman in labor; she was so nearly delivered that 
he had scarcely anything to do. The next morning she had severe 
rigors, and in forty-eight hours she was a corpse. Her infant had 
erysipelas and died in two days.^' 

In connection with the facts which have been stated it seems 
proper to allude to the dangerous and often fatal effects which have 
followed from wounds received in the post-mortem examination of 
patients who have died of puerperal fever. The fact that such 

^Edin. Med. and Surg. Journal, April, 1838. 
^^ Lancet, May 2, 1840. 



PUERPERAL FEVER 247 

wounds are attended with peculiar risk has been long noticed. I 
find that Chaussier was in the habit of cautioning his students 
against the danger to which they were exposed in these dissections.^" 
The head pharmacien of the Hotel Dieu, in his analysis of the fluid 
effused in puerperal peritonitis, says that practitioners are convinced 
of its deleterious qualities, and that it is very dangerous to apply it 
to the denuded skin.'^ Sir Benjamin Brodie speaks of it as being 
well known that the inoculation of lymph or pus from the peri- 
toneum of a puerperal patient is often attended with dangerous and 
even fatal symptoms. Three cases in confirmation of this statement, 
two of them fatal, have been reported to this Society within a few 
months. 

Of about fifty cases of injuries of this kind, of various degrees of 
severity, which I have collected from different sources, at least twelve 
were instances of infection from puerperal peritonitis. Some of the 
others are so stated as to render it probable that they may have been 
of the same nature. Five other cases were of peritoneal inflamma- 
tion; three in males. Three were what was called enteritis, in one 
instance complicated with erysipelas; but it is well known that this 
term has been often used to signify inflammation of the peritoneum 
covering the intesdnes. On the other hand, no case of typhus or 
typhoid fever is mentioned as giving rise to dangerous consequences, 
with the exception of the single instance of an undertaker mentioned 
by Mr. Travers, who seems to have been poisoned by a fluid which 
exuded from the body. The other accidents were produced by dis- 
section, or some other mode of contact with bodies of patients who 
had died of various affections. They also differed much in severity, 
the cases of puerperal origin being among the most formidable and 
fatal. Now a moment's reflection will show that the number of 
cases of serious consequences ensuing from the dissection of the 
bodies of those who had perished of puerperal fever is so vastly dis- 
proportioned to the relatively small number of autopsies made in 
this complaint as compared with typhus or pneumonia (from which 
last disease not one case of poisoning happened), and still more from 
all diseases put together, that the conclusion is irresistible that a 

"Stein, L'Art d'Accoucher, 1794; Diet, des Sciences MidicaUs, art., "Puerperal." 
^^ Journal de Pharmacie, January 1836. 



248 O. W. HOLMES 

most fearful morbid poison is often generated in the course of this 
disease. Whether or not it is sui generis, confined to this disease, or 
produced in some others, as, for instance, erysipelas, I need not 
stop to inquire. 

In connection with this may be taken the following statement of 
Dr. Rigby: "That the discharges from a patient under puerperal 
fever are in the highest degree contagious we have abundant evi- 
dence in the history of lying-in hospitals. The puerperal abscesses 
are also contagious, and may be communicated to healthy lying-in 
women by washing with the same sponge; this fact has been repeat- 
edly proved in the Vienna Hospital; but they are equally communi- 
cable to women not pregnant; on more than one occasion the women 
engaged in washing the soiled bed-linen of the General Lying-in 
Hospital have been attacked with abscesses in the fingers or hands, 
attended with rapidly spreading inflammation of the cellular 
tissue." " 

Now add to all this the undisputed fact that within the walls of 
lying-in hospitals there is often generated a miasm, palpable as the 
chlorine used to destroy it, tenacious so as in some cases almost to 
defy extirpation, deadly in some institutions as the plague; which 
has killed women in a private hospital of London so fast that they 
were buried two in one coffin to conceal its horrors; which enabled 
Tonelle to record two hundred and twenty-two autopsies at the 
Maternite of Paris; which has led Dr. Lee to express his deliberate 
conviction that the loss of life occasioned by these institutions com- 
pletely defeats the objects of their founders; and out of this train of 
cumulative evidence, the multiplied groups of cases clustering about 
individuals, the deadly results of autopsies, the inoculation by fluids 
from the living patient, the murderous poison of hospitals — does 
there not result a conclusion that laughs all sophistry to scorn, and 
renders all argument an insult? 

I have had occasion to mention some instances in which there was 
an apparent relation between puerperal fever and erysipelas. The 
length to which this paper has extended does not allow me to enter 
into the consideration of this most important subject. I will only say 
that the evidence appears to me altogether satisfactory that some 
'^ System of Midwifery, p. 292. 



PUERPERAL FEVER 249 

most fatal series of puerperal fever have been produced by an infec- 
tion originating in the matter or effluvia of erysipelas. In evidence 
of some connection between the two diseases, I need not go back to 
the older authors, as Pouteau or Gordon, but will content myself 
with giving the following references, with their dates; from which 
it will be seen that the testimony has been constantly coming before 
the profession for the last few years: 

"London Cyclopaedia of Practical Medicine," article Puerperal 
Fever, 1833. 

Mr. Ceeley's Account of the Puerperal Fever at Aylesbury, "Lan- 
cet," 1835. 

Dr. Ramsbotham's Lecture, "London Medical Gazette," 1835. 

Mr. Yates Ackerly's Letter in the same Journal, 1838. 

Mr. Ingleby on Epidemic Puerperal Fever, "Edinburgh Medical 
and Surgical Journal," 1838. 

Mr. Paley's Letter, "London Medical Gazette," 1839. 

Remarks at the Medical and Chirurgical Society, "Lancet," 1840. 

Dr. Rigby's "System of Midwifery," 1841. 

"Nunneley on Erysipelas," a work which contains a large number 
of references on the subject, 1841. 

"British and Foreign Quarterly Review," 1842. 

Dr. S. Jackson, of Northumberland, as already quoted from the 
Summary of the College of Physicians, 1842. 

And, lastly, a startling series of cases by Mr. Storrs, of Doncaster, 
to be found in the "American Journal of the Medical Sciences" for 
January, 1843. 

The relation of puerperal fever with other continued fevers would 
seem to be remote and rarely obvious. Hey refers to two cases of 
synochus occurring in the Royal Infirmary of Edinburgh, in women 
who had attended upon puerperal patients. Dr. Collins refers to 
several instances in which puerperal fever has appeared to originate 
from a continued proximity to patients suffering with typhus.'' 

Such occurrences as those just mentioned, though most important 
to be remembered and guarded against, hardly attract our notice in 
the midst of the gloomy facts by which they are surrounded. Of 
these facts, at the risk of fatiguing repetitions, I have summoned a 

'' Treatise on Midwifery, p. 228. 



250 O. W. HOLMES 

sufficient number, as I believe, to convince the most incredulous 
that every attempt to disguise the truth which underlies them all is 
useless. 

It is true that some o£ the historians of the disease, especially 
Hulme, Hull, and Leake, in England; Tonelle, Duges, and Baude- 
locque, in France, profess not to have found puerperal fever con- 
tagious. At the most they give us mere negative facts, worthless 
against an extent of evidence which now overlaps the widest range 
of doubt, and doubles upon itself in the redundancy of superfluous 
demonstration. Examined in detail, this and much of the show of 
testimony brought up to stare the daylight of conviction out of 
countenance, proves to be in a great measure unmeaning and inap- 
plicable, as might be easily shown were it necessary. Nor do I feel 
the necessity of enforcing the conclusion which arises spontaneously 
from the facts which have been enumerated by formally citing the 
opinions of those grave authorities who have for the last half-century 
been sounding the unwelcome truth it has cost so many lives to 
establish. 

"It is to the British practitioner," says Dr. Rigby, "that we are 
indebted for strongly insisting upon this important and dangerous 
character of puerperal fever." ^* 

The names of Gordon, John Clarke, Denman, Burns, Young,'^ 
Hamilton,^' Haighton," Good,'' Waller,'^ Blundell, Gooch, Rams- 
botham, Douglas," Lee, Ingleby, Locock,*' Abercrombie,*" Alison,^' 
Travers,''* Rigby, and Watson^'' many of whose writings I have 
already referred to, may have some influence with those who prefer 
the weight of authorities to the simple deductions of their own reason 
from the facts laid before them. A few Continental writers have 

^* British and Foreign Med. Rev. for January, 1842. 

^^ Encyc. Britannica, xiii, 467, art., "Medicine." 

^ Outlines of Midivifery, p. 109. 2' Oral Lectures, etc, 

^^ Study of Medicine, ii, 195. 

'^ Medical and Physical Journal, July, 1830. 

^"Dublin Hospital Reports for 1822. 

*' Library of Practical Medicine, i, 373. 

*^ Researches on Piseases of the Stomach, etc., p. 181. 

^Library of Practical Medicine, i, 96. 

** Further Researches on Constitutional Irritation, p. 128. 

^London Medical Gazette, February, 1842. 



PUERPERAL FEVER 25 I 

adopted similar conclusions/^ It gives me pleasure to remember that, 
while the doctrine has been unceremoniously discredited in one of 
the leading journals/' and made very light of by teachers in two of 
the principal medical schools of this country, Dr. Channing has for 
many years inculcated, and enforced by examples, the danger to be 
apprehended and the precautions to be taken in the disease under 
consideration. 

I have no wish to express any harsh feeling with regard to the 
painful subject which has come before us. If there are any so far 
excited by the story of these dreadful events that they ask for some 
word of indignant remonstrance to show that science does not turn 
the hearts of its followers into ice or stone, let me remind them that 
such words have been uttered by those who speak with an authority 
I could not claim.^* It is as a lesson rather than as a reproach that 
I call up the memory of these irreparable errors and wrongs. No 
tongue can tell the heart-breaking calamity they have caused; they 
have closed the eyes just opened upon a new world of love and 
happiness; they have bowed the strength of manhood into the dust; 
they have cast the helplessness of infancy into the stranger's arms, or 
bequeathed it, with less cruelty, the death of its dying parent. There 
is no tone deep enough for regret, and no voice loud enough for 
warning. The woman about to become a mother or with her new- 
born infant upon her bosom, should be the object of trembling care 
and sympathy wherever she bears her tender burden or stretches her 
aching limbs. The very outcast of the streets has pity upon her sister 
in degradation when the seal of promised maternity is impressed 
upon her. The remorseless vengeance of the law, brought down 
upon its victim by a machinery as sure as destiny, is arrested in its 
fall at a word which reveals her transient claim for mercy. The 
solemn prayer of the liturgy singles out her sorrows from the multi- 
plied trials of life, to plead for her in the hour of peril. God forbid 
that any member of the profession to which she trusts her life, 

^^See British and Foreign Medical Review, vol. iii, p. 525, and vol. iv, p. 517. 
Also Ed. Med. and Surg. Journal for July, 1824, and American Journal of Med. 
Sciences for January, 1841. 

"Phil. Med. Journal, vol. xii, p. 364. 

^ Dr. Blundell and Dr. Rigby in the works already cited. 



252 O. W. HOLMES 

doubly precious at that eventful period, should hazard it negligently, 
unadvisedly, or selfishly! 

There may be some among those whom I address who are dis- 
posed to ask the question. What course are we to follow in relation 
to this matter? The facts are before them, and the answer must be 
left to their own judgment and conscience. If any should care to 
know my own conclusions, they are the following; and in taking 
the liberty to state them very freely and broadly, I would ask the 
inquirer to examine them as freely in the light of the evidence 
which has been laid before him. 

1. A physician holding himself in readiness to attend cases of 
midwifery should never take any active part in the post-mortem 
examination of cases of puerperal fever. 

2. If a physician is present at such autopsies, he should use thor- 
ough ablution, change every article of dress, and allow twenty-four 
hours or more to elapse before attending to any case of midwifery. 
It may be well to extend the same caution to cases of simple peri- 
tonitis. 

3. Similar precautions should be taken after the autopsy or sur- 
gical treatment of cases of erysipelas, if the physician is obliged to 
unite such offices with his obstetrical duties, which is in the highest 
degree inexpedient. 

4. On the occurrence of a single case of puerperal fever in his 
practice, the physician is bound to consider the next female he 
attends in labor, unless some weeks at least have elapsed, as in 
danger of being infected by him, and it is his duty to take every 
precaution to diminish her risk of disease and death. 

5. If within a short period two cases of puerperal fever happen 
close to each other, in the practice of the same physician, the disease 
not existing or prevailing in the neighborhood, he would do wisely 
to relinquish his obstetrical practice for at least one month, and 
endeavor to free himself by every available means from any noxious 
influence he may carry about with him. 

6. The occurrence of three or more closely connected cases, in 
the practice of one individual, no others existing in the neighborhood, 
and no other sufficient cause being alleged for the coincidence, is 
prima facie evidence that he is the vehicle of contagion. 



PUERPERAL FEVER 253 

7. It is the duty of the physician to take every precaution that 
the disease shall not be introduced by nurses or other assistants, by 
making proper inquiries concerning them, and giving timely warn- 
ing of every suspected source of danger. 

8. Whatever indulgence may be granted to those who have here- 
tofore been the ignorant causes of so much misery, the time has 
come when the existence of a private pestilence in the sphere of a 
single physician should be looked upon, not as a misfortune, but a 
crime; and in the knowledge of such occurrences the duties of the 
practitioner to his profession should give way to his paramount 
obligations to society. 

ADDITIONAL REFERENCES AND CASES. 

Fijth Annual Report of the Registrar-General of England, 1843. Appendix. Let- 
ter from William Farr, Esq. — Several new series of cases are given in the letter of 
Mr. Storrs, contained in the appendix to this report. Mr. Storrs suggests precautions 
similar to those I have laid down, and these precautions are strongly enforced by Mr. 
Farr, who is, therefore, obnoxious to the same criticisms as myself. 

Hall and Dexter, in Am. Journal of Med. Sc. for January, 1844. — Cases of 
puerperal fever seeming to originate in erysipelas. 

Ellington, of Birmingham, in Provincial Med. Journal, cited in Am. Journ. Med. 
Sc. for April, 1844. — Six cases in less than a fortnight, seeming to originate in a 
case of erysipelas. 

West's Reports, in Brit, and For. Med. Review for October, 1845, and January, 
1847. — Affection of the arm, resembling malignant pustule, after removing the 
placenta of a patient who died from puerperal fever. Reference to cases at Wurzburg, 
as proving contagion, and to Keiller's cases in the Monthly Journal for February, 
1846, as showing connection of puerperal fever and erysipelas. 

Kneeland. — Contagiousness of Puerperal Fever. Am. Jour. Med. Sc, January, 
1846. Also, Connection between Puerperal Fever and Epidemic Erysipelas. Ibid., 
April, 1846. 

Robert Storrs. — Contagious Effects of Puerperal Fever on the Male Subject; or oa 
Persons not Child-bearing. (From Provincial Med. and Surg. Journal.) Am. Jour. 
Med. Sc, January, 1846. Numerous cases. See also Dr. Reid's case in same journal 
for April, 1846. 

Routh's paper in Proc of Royal Med. Chir. Soc, Am. Jour. Med. Sc, April, 1849, 
also in B. and F. Med. Chir. Review, April, 1850. 

Hill, of Leuchars. — A Series of Cases Illustrating the Contagious Nature of Ery- 
sipelas and Puerperal Fever, and their Intimate Pathological Connection. (From 
Monthly Journal of Med. Sc.) Am. Jour. Med. Sc, July, 1850. 

Sk.oda on the Causes of Puerperal Fever. (Peritonitis in rabbits, from inoculation 
with different morbid secretions.) Am. Jour. Med. Sc, October, 1850. 

Arneth. — Paper read before the National Academy of Medicine. Annales d'Hygiene, 
Tome LXV. i" Partie. (Means of Disinfection proposed by M. "Semmeliveis." Sem- 
melweiss.) Lotions of chloride of lime and use of nail-brush before admission to 
lying-in wards. Alleged sudden and great decrease of mortality from puerperal fever. 
Cause of disease attributed to inoculation with cadaveric matters.) See also Routh's 
paper, mentioned above. 



254 O- W. HOLMES 

Moir. — Remarks at a meeting of the Edinburgh Medico<hirurgical Society. Refers 
to cases of Dr. Kellie, of Leith. Sixteen in succession, all jatal. Also to several in- 
stances of individual pupils having had a succession of cases in various quarters of 
the town, while others, practising as extensively in the same localities, had none. 
Also to several special cases not mentioned elsewhere. Am. Jour. Med. Sc. for Octo- 
ber, 1851. (From New Monthly Journal of Med. Science.) 

5»/npj-on.— Observations at a Meeting of the Edinburgh Obstetrical Society. (An 
"eminent gentleman," according to Dr. Meigs, whose "name is as well known in 
America as in (his) native land," Obstetrics, Phil., 1852, pp. 368, 375.) The student 
is referred to this paper for a valuable resume of many of the facts, and the necessary 
inferences, relating to this subject. Also for another series of cases, Mr. Sidey's, five 
or six in rapid succession. Dr. Simpson attended the dissection of two of Dr. Sidey's 
cases, and freely handled the diseased parts. His next four child-bed patients were 
affected with puerperal fever, and it was the first time he had seen it in practice. 
As Dr. Simpson is a gentleman (Dr. Meigs, as above), and as "a gentleman's hands 
are clean" (Dr. Meigs' sixth letter), it follows that a gentleman with clean hands 
may carry the disease. Am. Jour. Med. Sc, October, 1851. 

Peddie. — ^The five or six cases of Dr. Sidey, followed by the four of Dr. Simpson, 
did not end the series. A practitioner in Leith having examined in Dr. Simpson's 
house, a portion of the uterus obtained from one of the patients, had immediately 
afterwards three fatal cases of puerperal fever. Dr. Peddie referred to two distinct 
series of consecutive cases in his own practice. He had since taken precautions, and 
not met with any such cases. Am. Jour. Med. Sc, October, 1851. 

Copland. — Considers it proved that puerperal fever may be propagated by the hands 
and the clothes, or either, of a third person, the bed-clothes or body-clothes of a 
patient. Mentions a new series of cases, one of which he saw, with the practitioner 
who had attended them. She was the sixth he had had within a few days. All died. 
Dr. Copland insisted that contagion had caused these cases; advised precautionary 
measures, and the practitioner had no other cases for a considerable time. Considers 
it criminal, after the evidence adduced, — which he could have quadrupled, — and the 
weight of authority brought forward, for a practitioner to be the medium of trans- 
mitting contagion and death to his patients. Dr. Copland lays down rules similar to 
those suggested by myself, and is therefore entitled to the same epithet for so doing. 
Medical Dictionary, New York, 1852. Article, Puerperal States and diseases. 

If there is any appetite for facts so craving as to be yet unappeased, — lassata, nec- 
dum satiata,- — more can be obtained. Dr. Hodge remarks that "the frequency and 
importance of this singular circumstance (that the disease is occasionally more prev- 
alent with one practitioner than another) has been exceedingly overrated." More 
than thirty strings of cases, more than two hundred and fifty sufferers from puerperal 
fever, more than one hundred and thirty deaths, appear as the results of a sparing 
estimate of such among the facts I have gleaned as could be numerically valued. These 
facts constitute, we may take it for granted, but a small fraction of those that have 
actually occurred. The number of them might be greater, but " 'tis enough, 'twill 
serve," in Mercutio's modest phrase, so far as frequency is concerned. For a just 
estimate of the importance of the singular circumstance, it might be proper to consult 
the languid survivors, the widowed husbands, and the motherless children, as well as 
"the unfortunate accoucheur." 



ON THE ANTISEPTIC PRINCIPLE OF 
THE PRACTICE OF SURGERY 

BV 
JOSEPH LISTER 



INTRODUCTORY NOTE 

Joseph Lister was born at Upton, Essex, England, in 1827, and re- 
ceived his general education at the University of London. After grad- 
uation he studied medicine in London and Edinburgh, and became 
lecturer in surgery at the University in the latter city. Later he was 
professor of surgery at Glasgow, at Edinburgh, and at King's College 
Hospital, London, and surgeon to Queen Victoria. He was made a 
baronet in 1883; retired from teaching in 1893; and was raised to the 
peerage in 1897, with the title of Baron Lister. He died in 1912. 

Even before the work of Pasteur on fermentation and putrefaction. 
Lister had been convinced of the importance of scrupulous cleanliness 
and the usefulness of deodorants in the operating room; and when, 
through Pasteur's researches, he realized that the formation of pus was 
due to bacteria, he proceeded to develop his antiseptic surgical methods. 
The immediate success of the new treatment led to its general adoption, 
with results of such beneficence as to make it rank as one of the great 
discoveries of the age. 



ON THE ANTISEPTIC PRINCIPLE OF 
THE PRACTICE OF SURGERY 

(1867) 

IN the course of an extended investigation into the nature of 
inflammation, and the healthy and morbid conditions of the 
blood in relation to it, I arrived several years ago at the con- 
clusion that the essential cause of suppuration in wounds is decom- 
position brought about by the influence of the atmosphere upon 
blood or serum retained within them, and, in the case of contused 
wounds, upon portions of tissue destroyed by the violence of the 
injury. 

To prevent the occurrence of suppuration with all its attendant 
risks was an object manifestly desirable, but till lately apparently 
unattainable, since it seemed hopeless to attempt to exclude the 
oxygen which was universally regarded as the agent by which 
putrefaction was effected. But when it had been shown by the 
researches of Pasteur that the septic properties of the atmosphere 
depended not on the oxygen, or any gaseous constituent, but on 
minute organisms suspended in it, which owed their energy to their 
vitality, it occurred to me that decomposition in the injured part 
might be avoided without excluding the air, by applying as a dress- 
ing some material capable of destroying the life of the floating 
particles. Upon this principle I have based a practice of which I 
will now attempt to give a short account. 

The material which I have employed is carbolic or phenic acid, 
a volatile organic compound, which appears to exercise a peculiarly 
destructive influence upon low forms of life, and hence is the most 
powerful antiseptic with which we are at present acquainted. 

The first class of cases to which I applied it was that of compound 
fractures, in which the effects of decomposition in the injured part 
were especially striking and pernicious. The results have been such 
as to establish conclusively the great principle that all local in- 

257 



258 LORD LISTER 

flammatory mischief and general febrile disturbances which follow 
severe injuries are due to the irritating and poisonous influence of 
decomposing blood or sloughs. For these evils are entirely avoided 
by the antiseptic treatment, so that limbs which would otherwise 
be unhesitatingly condemned to amputation may be retained, with 
confidence of the best results. 

In conducting the treatment, the first object must be the destruc- 
tion of any septic germs which may have been introduced into the 
wounds, either at the moment of the accident or during the time 
which has since elapsed. This is done by introducing the acid of 
full strength into all accessible recesses of the wound by means of 
a piece of rag held in dressing forceps and dipped into the liquid.' 
This I did not venture to do in the earlier cases; but experience has 
shown that the compound which carbolic acid forms with the blood, 
and also any portions of tissue killed by its caustic action, including 
even parts of the bone, are disposed of by absorption and organisation, 
provided they are afterwards kept from decomposing. We are 
thus enabled to employ the antiseptic treatment efficiently at a 
period after the occurrence of the injury at which it would other- 
wise probably fail. Thus I have now under my care, in Glasgow 
Infirmary, a boy who was admitted with compound fracture of the 
leg as late as eight and one-half hours after the accident, in whom, 
nevertheless, all local and constitutional disturbance was avoided by 
means of carbolic acid, and the bones were soundly united five weeks 
after his admission. 

The next object to be kept in view is to guard effectually against 
the spreading of decomposition into the wound along the stream 
of blood and serum which oozes out during the first few days after 
the accident, when the acid originally applied has been washed out 
or dissipated by absorption and evaporation. This part of the treat- 
ment has been greatly improved during the past few weeks. The 
method which I have hitherto published (see Lancet for Mar. i6th, 
23rd, 30th, and April 27th of the present year) consisted in the 
application of a piece of lint dipped in the acid, overlapping the 
soimd skin to some extent and covered with a tin cap, which was 

• The addition of a few drops of water to a considerable quantity of the acid, induces 
it to assume permanently the liquid form. 



ON THE ANTISEPTIC PRINCIPLES 259 

daily raised in order to touch the surface of the lint with the anti- 
septic. This method certainly succeeded well with wounds of 
moderate size; and indeed I may say that in all the many cases of 
this kind which have been so treated by myself or my house-surgeons, 
not a single failure has occurred. When, however, the wound is 
very large, the flow of blood and serum is so profuse, especially 
during the first twenty-four hours, that the antiseptic apphcation 
cannot prevent the spread of decomposition into the interior unless 
it overlaps the sound skin for a very considerable distance, and this 
was inadmissible by the method described above, on account of the 
extensive sloughing of the surface of the cutis which it would in- 
volve. This difficulty has, however, been overcome by employing 
a paste composed of common whiting (carbonate of lime), mixed 
with a solution of one part of carbolic acid in four parts of boiled 
linseed oil so as to form a firm putty. This application contains 
the acid in too dilute a form to excoriate the skin, which it may be 
made to cover to any extent that may be thought desirable, while 
its substance serves as a reservoir of the antiseptic material. So long 
as any discharge continues, the paste should be changed daily, and, 
in order to prevent the chance of mischief occurring during the 
process, a piece of rag dipped in the solution of carbolic acid in oil 
is put on next the skin, and maintained there permanently, care 
being taken to avoid raising it along with the putty. This rag is 
always kept in an antiseptic condition from contact with the paste 
above it, and destroys any germs which may fall upon it during 
the short time that should alone be allowed to pass in the changing 
of the dressing. The putty should be in a layer about a quarter of 
an inch thick, and may be advantageously applied rolled out be- 
tween two pieces of thin calico, which maintain it in the form of a 
continuous sheet, which may be wrapped in a moment round the 
whole circumference of a limb if this be thought desirable, while 
the putty is prevented by the calico from sticking to the rag which 
is next the skin.^ When all discharge has ceased, the use of the 

^ In order to prevent evaporation of the acid, which passes readily through any 
organic tissue, such as oiled silk or gutta percha, it is well to cover the paste with a 
sheet of block tin, or tinfoil strengthened with adhesive plaster. The thin sheet lead 
used for lining tea chests will also answer the purpose, and may be obtained from 
any wholesale grocer. 



260 LORD LISTER 

paste is discontinued, but the original rag is left adhering to the 
skin till healing by scabbing is supposed to be complete. I have at 
present in the hospital a man with severe compound fracture of 
both bones of the left leg, caused by direct violence, who, after the 
cessation of the sanious discharge under the use of the paste, with- 
out a drop of pus appearing, has been treated for the last two weeks 
exactly as if the fracture was a simple one. During this time the 
rag, adhering by means of a crust of inspissated blood collected 
beneath it, has continued perfectly dry, and it will be left untouched 
till the usual period for removing the splints in a simple fracture, 
when we may fairly expect to find a sound cicatrix beneath it. 

We cannot, however, always calculate on so perfect a result as 
this. More or less pus may appear after the lapse of the first week, 
and the larger the wound, the more likely this is to happen. And 
here I would desire earnestly to enforce the necessity of persevering 
with the antiseptic application in spite of the appearance of sup- 
puration, so long as other symptoms are favorable. The surgeon is 
extremely apt to suppose that any suppuration is an indication that 
the antiseptic treatment has failed, and that poulticing or water 
dressing should be resorted to. But such a course would in many 
cases sacrifice a limb or a life. I cannot, however, expect my pro- 
fessional brethren to follow my advice blindly in such a matter, and 
therefore I feel it necessary to place before them, as shortly as I 
can, some pathological principles intimately connected, not only 
with the point we are immediately considering, but with the whole 
subject of this paper. 

If a perfectly healthy granulating sore be well washed and covered 
with a plate of clean metal, such as block tin, fitting its surface 
pretty accurately, and overlapping the surrounding skin an inch or 
so in every direction and retained in position by adhesive plaster 
and a bandage, it will be found, on removing it after twenty-four 
or forty-eight hours, that little or nothing that can be called pus is 
present, merely a little transparent fluid, while at the same time 
there is an entire absence of the unpleasant odour invariably per- 
ceived when water dressing is changed. Here the clean metallic 
surface presents no recesses like those of porous lint for the septic 
germs to develope in, the fluid exuding from the surface of the 



ON THE ANTISEPTIC PRINCIPLES 26 1 

granulations has flowed away undecomposed, and the result is the 
absence of suppuration. This simple experiment illustrates the 
important fact that granulations have no inherent tendency to form 
pus, but do so only when subjected to preternatural stimulus. Fur- 
ther, it shows that the mere contact of a foreign body does not of 
itself stimulate granulations to suppurate; whereas the presence of 
decomposing organic matter does. These truths are even more 
strikingly exemplified by the fact that I have elsewhere recorded 
(Lancet, March 23rd, 1867), that a piece of dead bone free from 
decomposition may not only fail to induce the granulations around 
it to suppurate, but may actually be absorbed by them; whereas a 
bit of dead bone soaked with putrid pus infallibly induces suppura- 
tion in its vicinity. 

Another instructive experiment is, to dress a granulating sore 
with some of the putty above described, overlapping the sound skin 
extensively; when we find, in the course of twenty-four hours, that 
pus has been produced by the sore, although the application has 
been perfectly antiseptic; and, indeed, the larger the amount of 
carbolic acid in the paste, the greater is the quantity of pus formed, 
provided we avoid such a proportion as would act as a caustic. The 
carbolic acid, though it prevents decomposition, induces suppuration 
— obviously by acting as a chemical stimulus; and we may safely 
infer that putrescent organic materials (which we know to be 
chemically acrid) operate in the same way. 

In so far, then, carbolic acid and decomposing substances are 
alike; viz., that they induce suppuration by chemical stimulation, as 
distinguished from what may be termed simple inflammatory 
suppuration, such as that in which ordinary abscesses originate — 
where the pus appears to be formed in consequence of an excited 
action of the nerves, independently of any other stimulus. There 
is, however, this enormous difference between the effects of carbolic 
acid and those of decomposition; viz., that carbolic acid stimulates 
only the surface to which it is at first applied, and every drop of 
discharge that forms weakens the stimulant by diluting it; but 
decomposition is a self-propagating and self-aggravating poison, 
and, if it occur at the surface of a severely injured limb, it wdll 
spread into all its recesses so far as any extravasated blood or shreds 



262 LORD LISTER 

of dead tissue may extend, and lying in those recesses, it will be- 
come from hour to hour more acrid, till it requires the energy of a 
caustic sufficient to destroy the vitality of any tissues naturally weak 
from inferior vascular supply, or weakened by the injury they sus- 
tained in the accident. 

Hence it is easy to understand how, when a wound is very large, 
the crust beneath the rag may prove here and there insufficient to 
protect the raw surface from the stimulating influence of the car- 
boHc acid in the putty; and the result will be first the conversion of 
the tissues so acted on into granulations, and subsequently the 
formation of more or less pus. This, however, will be merely super- 
ficial, and will not interfere with the absorption and organisation 
of extravasated blood or dead tissues in the interior. But, on the 
other hand, should decomposition set in before the internal parts 
have become securely consolidated, the most disastrous results may 
ensue. 

I left behind me in Glasgow a boy, thirteen years of age, who, 
between three and four weeks previously, met with a most severe 
injury to the left arm, which he got entangled in a machine at a 
fair. There was a wound six inches long and three inches broad, 
and the skin was very extensively undermined beyond its limits, 
while the soft parts were generally so much lacerated that a pair 
of dressing forceps introduced at the wound and pushed directly 
inwards appeared beneath the skin at the opposite aspect of the 
limb. From this wound several tags of muscle were hanging, and 
among them was one consisting of about three inches of the triceps 
in almost its entire thickness; while the lower fragment of the bone, 
which was broken high up, was protruding four inches and a half, 
stripped of muscle, the skin being tucked in under it. Without the 
assistance of the antiseptic treatment, I should certainly have thought 
of nothing else but amputation at the shoulder -joint; but, as the 
radial pulse could be felt and the fingers had sensation, I did not 
hesitate to try to save the limb and adopted the plan of treatment 
above described, wrapping the arm from the shoulder to below the 
elbow in the antiseptic application, the whole interior of the wound, 
together with the protruding bone, having previously been freely 
treated with strong carbolic acid. About the tenth day, the dis- 



ON THE ANTISEPTIC PRINCIPLES 263 

charge, which up to that time had been only sanious and serous, 
showed a slight admixture o£ slimy pus; and this increased till (a 
few days before I left) it amounted to about three drachms in 
twenty-four hours. But the boy continued as he had been after the 
second day, free from unfavorable symptoms, with pulse, tongue, 
appetite, and sleep natural and strength increasing, while the limb 
remained as it had been from the first, free from swelling, redness, 
or pain. I, therefore, persevered with the antiseptic dressing; and, 
before I left, the discharge was already somewhat less, while the 
bone was becoming firm. I think it likely that, in that boy's case, I 
should have found merely a superficial sore had I taken off all the 
dressings at the end of the three weeks; though, considering the 
extent of the injury, I thought it prudent to let the month expire 
before disturbing the rag next the skin. But I feel sure that, if I 
had resorted to ordinary dressing when the pus first appeared, the 
progress of the case would have been exceedingly different. 

The next class of cases to which I have applied the antiseptic 
treatment is that of abscesses. Here also the results have been ex- 
tremely satisfactory, and in beautiful harmony with the pathological 
principles indicated above. The pyogenic membrane, like the 
granulations of a sore, which it resembles in nature, forms pus, not 
from any inherent disposition to do so, but only because it is sub- 
jected to some preternatural stimulation. In an ordinary abscess, 
whether acute or chronic, before it is opened the stimulus which 
maintains the suppuration is derived from the presence of pus pent 
up within the cavity. When a free opening is made in the ordinary 
way, this stimulus is got rid of, but the atmosphere gaining access 
to the contents, the potent stimulus of decomposition comes into 
operation, and pus is generated in greater abundance than before. 
But when the evacuation is effected on the antiseptic principle, the 
pyogenic membrane, freed from the influence of the former stimulus 
without the substitution of a new one, ceases to suppurate (like the 
granulations of a sore under metallic dressing), furnishing merely 
a trifling amount of clear serum, and, whether the opening be de- 
pendent or not, rapidly contracts and coalesces. At the same time 
any constitutional symptoms previously occasioned by the accumu- 
lation of the matter are got rid of without the slightest risk of the 



264 LORD LISTER 

irritative fever or hectic hitherto so justly dreaded in deaHng with 
large abscesses. 

In order that the treatment may be satisfactory, the abscess must 
be seen before it is opened. Then, except in very rare and peculiar 
cases,' there are no septic organisms in the contents, so that it is 
needless to introduce carbolic acid into the interior. Indeed, such a 
procedure would be objectionable, as it would stimulate the pyogenic 
membrane to unnecessary suppuration. All that is requisite is to 
guard against the introduction of living atmospheric germs from 
without, at the same time that free opportunity is afforded for the 
escape of the discharge from within. 

I have so lately given elsewhere a detailed account o£ the method 
by which this is effected (Lancet, July 27th, 1867), that I shall not 
enter into it at present further than to say that the means employed 
are the same as those described above for the superficial dressing of 
compound fractures; viz., a piece of rag dipped into the solution of 
carbolic acid in oil to serve as an antiseptic curtain, under cover of 
which the abscess is evacuated by free incision, and the antiseptic 
paste to guard against decomposition occurring in the stream of pus 
that flows out beneath it; the dressing being changed daily until 
the sinus is closed. 

The most remarkable results of this practice in a pathological 
point of view have been afforded by cases where the formation of 
pus depended on disease of bone. Here the abscesses, instead of 
forming exceptions to the general class in the obstinacy of the sup- 
puration, have resembled the rest in yielding in a few days only a 
trifling discharge, and frequently the production of pus has ceased 
from the moment of the evacuation of the original contents. Hence 
it appears that caries, when no longer labouring as heretofore under 
the irritation of decomposing matter, ceases to be an opprobrium of 
surgery, and recovers like other inflammatory affections. In the 
publication before alluded to, I have mentioned the case of a middle- 
aged man with a psoas abscess depending in diseased bone, in whom 
the sinus finally closed after months of patient perseverance with 

' As an instance of one of these exceptional cases, I may mention that of an abscess 
in the vicinity of the colon, and afterwards proved by post-mortem examination to have 
once communicated with it. Here the pus was extremely offensive when evacuated, 
and exhibited vibrios under the microscope. 



ON THE ANTISEPTIC PRINCIPLES 265 

the antiseptic treatment. Since that article was written I have had 
another instance of abscess equally gratifying, but the differing in 
the circumstance that the disease and the recovery were more rapid 
in their course. The patient was a blacksmith, who had suffered 
four and a half months before I saw him from symptoms of ulcera- 
tion of cartilage in the left elbow. These had latterly increased in 
severity so as to deprive him entirely of his night's rest and of 
appetite. I found the region of the elbow greatly swollen, and on 
careful examination found a fluctuating point at the outer aspect of 
the articulation. I opened it on the antiseptic principle, the incision 
evidently penetrating to the joint, giving exit to a few drachms of 
pus. The medical gentleman under whose care he was (Dr. Mac- 
gregor, of Glasgow) supervised the daily dressing with the carbolic 
acid paste till the patient went to spend two or three weeks at the 
coast, when his wife was entrusted with it. Just two months after 
I opened the abscess, he called to show me the limb, stating that the 
discharge had been, for at least two weeks, as little as it was then, a 
trifling moisture upon the paste, such as might be accounted for by 
the little sore caused by the incision. On applying a probe guarded 
with an antiseptic rag, I found that the sinus was soundly closed, 
while the limb was free from swelling or tenderness; and, although 
he had not attempted to exercise it much, the joint could already 
be moved through a considerable angle. Here the antiseptic principle 
had effected the restoration of a joint, which, on any other known 
system of treatment, must have been excised. 

Ordinary contused wounds are, of course, amenable to the same 
treatment as compound fractures, which are a complicated variety 
of them. I will content myself with mentioning a single instance of 
this class of cases. In April last, a volunteer was discharging a rifle 
when it burst, and blew back the thumb with its metacarpal bone, 
so that it could be bent back as on a hinge at the trapezial joint, 
which had evidently been opened, while all the soft parts between 
the metacarpal bones of the thumb and forefinger were torn through. 
I need not insist before my present audience on the ugly character 
of such an injury. My house-surgeon, Mr. Hector Cameron, applied 
carbolic acid to the whole raw surface, and completed the dressing 
as if for compound fracture. The hand remained free from pain, 



266 LORD LISTER 

redness or swelling, and with the exception of a shallow groove, all 
the wound consolidated without a drop of matter, so that if it had 
been a clean cut, it would have been regarded as a good example of 
primary union. The small granulating surface soon healed, and at 
present a linear cicatrix alone tells of the injury he has sustained, 
while his thumb has all its movements and his hand a fine grasp. 

If the severest forms of contused and lacerated wounds heal thus 
kindly under the antiseptic treatment, it is obvious that its applica- 
tion to simple incised wounds must be merely a matter of detail. 
I have devoted a good deal of attention to this class, but I have not 
as yet pleased myself altogether with any of the methods I have 
employed. I am, however, prepared to go so far as to say that a 
solution of carbolic acid in twenty parts of water, while a mild and 
cleanly application, may be relied on for destroying any septic 
germs that may fall upon the wound during the performance of an 
operation; and also that, for preventing the subsequent introduction 
of others, the paste above described, applied as for compound frac- 
tures, gives excellent results. Thus I have had a case of strangulated 
inguinal hernia in which it was necessary to take away half a pound 
of thickened omentum, heal without any deep-seated suppuration 
or any tenderness of the sac or any fever; and amputations, includ- 
ing one immediately below the knee, have remained absolutely free 
from constitutional symptoms. 

Further, I have found that when the antiseptic treatment is efB- 
ciently conducted, ligatures may be safely cut short and left to be 
disposed of by absorption or otherwise. Should this particular branch 
of the subject yield all that it promises, should it turn out on further 
trial that when the knot is applied on the antiseptic principle, we 
may calculate as securely as if it were absent on the occurrence of 
healing without any deep-seated suppuration, the deligation of 
main arteries in their continuity will be deprived of the two dangers 
that now attend it, viz., those of secondary hemorrhage and an 
unhealthy state of the wound. Further, it seems not unlikely that 
the present objection to tying an artery in the immediate vicinity 
of a large branch may be done away with; and that even the in- 
nominate, which has lately been the subject of an ingenious experi- 
ment by one of the Dublin surgeons, on account of its well-known 



ON THE ANTISEPTIC PRINCIPLES 267 

fatality under the ligature for secondary hemorrhage, may cease to 
have this unhappy character when the tissues in the vicinity of the 
thread, instead of becoming softened through the influence of an 
irritating decomposing substance, are left at liberty to consolidate 
firmly near an unoffending though foreign body. 

It would carry me far beyond the limited time which, by the 
rules of the Association, is alone at my disposal, were I to enter into 
the various apphcations of the antiseptic principle in the several 
special departments of surgery. 

There is, however, one point more that I cannot but advert to, 
viz., the influence of this mode of treatment upon the general 
healthiness of an hospital. Previously to its introduction the two 
large wards in which most of my cases of accident and of operation 
are treated were among the unhealthiest in the whole surgical divi- 
sion of the Glasgow Royal Infirmary, in consequence apparently 
of those wards being unfavorably placed with reference to the supply 
of fresh air; and I have felt ashamed when recording the results of 
my practice, to have so often to allude to hospital gangrene or 
pyxmia. It was interesting, though melancholy, to observe that 
whenever all or nearly all the beds contained cases with open sores, 
these grievous complications were pretty sure to show themselves; 
so that I came to welcome simple fractures, though in themselves of 
little interest either for myself or the students, because their presence 
diminished the proportion of open sores among the patients. But 
since the antiseptic treatment has been brought into full operation, 
and wounds and abscesses no longer poison the atmosphere with 
putrid exhalations, my wards, though in other respects under pre- 
cisely the same circumstances as before, have completely changed 
their character; so that during the last nine months not a single 
instance of pyaemia, hospital gangrene, or erysipelas has occurred 
in them. 

As there appears to be no doubt regarding the cause of this change, 
the importance of the fact can hardly be exaggerated. 



THE PHYSIOLOGICAL THEORY 
OF FERMENTATION 

BY 
LOUIS PASTEUR 

TRANSLATED BY 
F. FAULKNER AND D. C. ROBB 

AND REVISED 

THE GERM THEORY AND 

ITS APPLICATION TO MEDICINE 

AND SURGERY 

BY 

MM. PASTEUR, JOURBERT, AND CHAMBERLAND 

TRANSLATED BY 
H. C. ERNST, M. D. 

PROFESSOR OF BACTERIOLOGY IN THE HARVARD MEDICAL SCHOOL 

ON THE EXTENSION OF THE 

GERM THEORY TO THE ETIOLOGY 

OF CERTAIN COMMON DISEASES 

BY 
LOUIS PASTEUR 

TRANSLATED BY 
H. C. ERNST, M. D. . 



INTRODUCTORY NOTE 

L.OUIS PASTEtiR was born at Dole, Jura, France, December 27, 1822, 
and died near Saint-Cloud, September 28, 1895. His interest in science, 
and especially in chemistry, developed early, and by the time he was 
twenty-six he was professor of the physical sciences at Dijon. The most 
important academic positions held by him later were those as professor 
of chemistry at Strasburg, 1849; <isan of the Faculty of Sciences at Lille, 
1854; science director of the Ecole Normale Superieure, Paris, 1857; 
professor of geology, physics, and chemistry at the Ecole des Beaux Arts; 
professor of chemistry at the Sorbonne, 1867. After 1875 he carried on 
his researches at the Pasteur Institute. He was a member of the Institute, 
and received many honors from learned societies at home and abroad. 

In respect of the number and importance, practical as well as scientific, 
of his discoveries, Pasteur has hardly a rival in the history of science. He 
may be regarded as the founder of modern stereo-chemistry; and his 
discovery that living organisms are the cause of fermentation is the 
basis of the whole modern germ-theory of disease and of the antiseptic 
method of treatment. His investigations of the diseases of beer and 
wine; of pebrine, a disease affecting silk-worms; of anthrax, and of 
fowl cholera, were of immense commercial importance and led to con- 
clusions which have revolutionized physiology, pathology, and thera- 
peutics. By his studies in the culture of bacteria of attenuated virulence 
he extended widely the practise of inoculation with a milder form of 
various diseases, with a view to producing immunity. 

The following papers present some of the most important of his con- 
tributions, and exemplify his extraordinary powers of lucid exposition 
and argument. 



TO 

THE MEMORY OF MY FATHER 

FORMERLY A SOLDIER UNDER THE FIRST EMPIRE 
CHEVALIER OF THE LEGION OF HONOR 

The longer I live, the better I understand the kindness of thy heart 
and the high quality of thy mind. 

The efforts which I have devoted to these Studies, as well as those 
which preceded them, are the fruit of thy counsel and example. 

Desiring to honor these filial remembrances, I dedicate this work to 
thy memory. 

L. Pasteur. 



AUTHOR'S PREFACE 

Our misfortunes inspired me with the idea of these researches. I 
undertook them immediately after the war of 1870, and have since con- 
tinued them without interruption, with the determination of perfecting 
them, and thereby benefiting a branch of industry wherein we are un- 
doubtedly surpassed by Germany. 

I am convinced that I have found a precise, practical solution of the 
arduous problem which I proposed to myself — that of a process of 
manufacture, independent of season and locality, which should obviate 
the necessity of having recourse to the cosdy methods of cooling em- 
ployed in existing processes, and at the same time secure the preservation 
of its products for any length of time. 

These new studies are based on the same principles which guided me 
in my researches on wine, vinegar, and the silk-worm disease — principles, 
the applications of which are practically unlimited. The etiology of con- 
tagious diseases may, perhaps, receive from them an unexpected light. 

I need not hazard any prediction concerning the advantages likely to 
accrue to the brewing industry from the adoption of such a process of 
brewing as my study of the subject has enabled me to devise, and from 
an application of the novel facts upon which this process is founded. 
Time is the best appraiser of scientific work, and I am not unaware that 
an industrial discovery rarely produces all its fruit in the hands of its 
first inventor. 

I began my researches at Clermont-Ferrand, in the laboratory, and 
with the help, of my friend M. Duclaux, professor of chemistry at the 
Faculty of Sciences of that town. I continued them in Paris, and after- 
wards at the great brewery of Tourtel Brothers, of Tantonville, which 
is admitted to be the first in France. I heartily thank these gentlemen 
for their extreme kindness. I owe also a public tribute of gratitude to 
M. Kuhn, a skillful brewer of Chamalieres, near Clermont-Ferrand, as 
well as to M. Velten of Marseilles, and to MM. de Tassigny, of Reims, 
who have placed at my disposal their establishments and their products, 
with the most praiseworthy eagerness. 

L. Pasteur. 

Paris, June i, 1879. 



THE 

PHYSIOLOGICAL THEORY 

OF FERMENTATION 

§ I. On the Relations Existing Between Oxygen and Yeast 

IT is characteristic of science to reduce incessantly the number of 
unexplained phenomena. It is observed, for instance, that 
fleshy fruits are not liable to fermentation so long as their 
epidermis remains uninjured. On the other hand, they ferment 
very readily when they are piled up in heaps more or less open, and 
immersed in their saccharine juice. The mass becomes heated and 
swells; carbonic acid gas is disengaged, and the sugar disappears 
and is replaced by alcohol. Now, as to the question of the origin of 
these spontaneous phenomena, so remarkable in character as well 
as usefulness for man's service, modern knowledge has taught us 
that fermentation is the consequence of a development of vegetable 
cells the germs of which do not exist in the saccharine juices within 
fruits; that many varieties of these cellular plants exist, each giving 
rise to its own particular fermentation. The principal products of 
these various fermentations, although resembling each other in their 
nature, differ in their relative proportions and in the accessory sub- 
stances that accompany them, a fact which alone is sufficient to 
account for wide differences in the quality and commercial value 
of alcoholic beverages. 

Now that the discovery of ferments and their living nature, and 
our knowledge of their origin, may have solved the mystery of the 
spontaneous appearance of fermentations in natural saccharine 
juices, we may ask whether we must still regard the reactions that 
occur in these fermentations as phenomena inexplicable by the 
ordinary laws of chemistry. We can readily see that fermentations 
occupy a special place in the series of chemical and biological phe- 
nomena. What gives to fermentations certain exceptional characters 

275 



276 LOUIS PASTEUR 

of which we are only now beginning to suspect the causes, is the 
mode of life in the minute plants designated under the generic name 
of ferments, a mode of life which is essentially different from that 
in other vegetables, and from which result phenomena equally 
exceptional throughout the whole range of the chemistry of living 
beings. 

The least reflection will suffice to convince us that the alcoholic 
ferments must possess the faculty of vegetating and performing their 
functions out of contact with air. Let us consider, for instance, the 
method of vintage practised in the Jura. The bunches are laid at 
the foot of the vine in a large tub, and the grapes there stripped 
from them. When the grapes, some of which are uninjured, others 
bruised, and all moistened by the juice issuing from the latter, fill 
the tub — where they form what is called the vintage — they are con- 
veyed in barrels to large vessels fixed in cellars of a considerable 
depth. These vessels are not filled to more than three-quarters of 
their capacity. Fermentation soon takes place in them, and the 
carbonic acid gas finds escape through the bunghole, the diameter 
of which, in the case of the largest vessels, is not more than ten or 
twelve centimetres (about four inches). The wine is not drawn 
off before the end of two or three months. In this way it seems 
highly probable that the yeast which produces the wine under such 
conditions must have developed, to a great extent at least, out of 
contact with oxygen. No doubt oxygen is not entirely absent from 
the first; nay, its limited presence is even a necessity to the mani- 
festation of the phenomena which follow. The grapes are stripped 
from the bunch in contact with air, and the must which drops from 
the wounded fruit takes a little of this gas into solution. This 
small quantity of air so introduced into the must, at the commence- 
ment of operations, plays a most indispensable part, it being from 
the presence of this that the spores of ferments which are spread 
over the surface of the grapes and the woody part of the bunches 
derive the power of starting their vital phenomena.' This air, how- 

' It has been remarked in practice that fermentation is facilitated by leaving the 
grapes on the bunches. The reason of this has not yet been discovered. Still we have 
no doubt that it may be attributed, principally, to the fact that the interstices between 
the grapes, and the spaces which the bunch leaves throughout, considerably increase 
the volume of air placed at the service of the germs of ferment. 



THEORY OF FERMENTATION 277 

ever, especially when the grapes have been stripped from the bunches, 
is in such small proportion, and that which is in contact with the 
liquid mass is so promptly expelled by the carbonic acid gas, which 
IS evolved as soon as a little yeast has formed, that it will readily be 
admitted that most of the yeast is produced apart from the influence 
of oxygen, whether free or in solution. We shall revert to this fact, 
which is of great importance. At present we are only concerned in 
pointing out that, from the mere knowledge of the practices of 
certain localities, we are induced to believe that the cells of yeast, 
after they have developed from their spores, continue to live and 
multiply without the intervention of oxygen, and that the alcoholic 
ferments have a mode of life which is probably quite exceptional, 
since it is not generally met with in other species, vegetable or animal. 

Another equally exceptional characteristic of yeast and fermenta- 
tion in general consists in the small proportion which the yeast that 
forms bears to the sugar that decomposes. In all other known beings 
the weight of nutritive matter assimilated corresponds with the 
weight of food used up, any difference that may exist being com- 
paratively small. The hfe of yeast is entirely different. For a cer- 
tain weight of yeast formed, we may have ten times, twenty times, 
a hundred times as much sugar, or even more decomposed, as we 
shall experimentally prove by-and-by; that is to say, that whilst 
the proportion varies in a precise manner, according to conditions 
which we shall have occasion to specify, it is also greatly out of pro- 
portion to the weight of the yeast. We repeat, the life of no other 
being, under its normal physiological conditions, can show anything 
similar. The alcoholic ferments, therefore, present themselves to 
us as plants which possess at least two singular properties: they can 
live without air, that is without oxygen, and they can cause decom- 
position to an amount which, though variable, yet, as estimated by 
weight of product formed, is out of all proportion to the weight of 
their own substance. These are facts of so great importance, and so 
intimately connected with the theory of fermentation, that it is 
indispensable to endeavour to establish them experimentally, with 
all the exactness of which they will admit. 

The question before us is whether yeast is in reality an anaerobian^ 

2 Capable of livingi without free oxygen — a term invented by Pasteur. — ^Ed. 



278 LOUIS PASTEUR 

plant, and what quantities of sugar it may cause to ferment, under 
the various conditions under which we cause it to act. 

The following experiments were undertaken to solve this double 
problem : — ^We took a double-necked flask, of three litres (five pints) 
capacity, one of the tubes being curved and forming an escape for 
the gas; the other one, on the right hand side (Fig. i), being fur- 




FlG. I 



nished with a glass tap. We filled this flask with pure yeast water, 
sweetened with 5 per cent, of sugar candy, the flask being so full 
that there was not the least trace of air remaining above the tap or 
in the escape tube; this artificial wort had, however, been itself 
aerated. The curved tube was plunged in a porcelain vessel full of 
mercury, resting on a firm support. In the small cylindrical funnel 
above the tap, the capacity of which was from 10 cc. to 15 cc. (about 
half a fluid ounce) we caused to ferment, at a temperature of 20° 
or 25° C. (about 75° F.), five or six cubic centimetres of the sac- 
charine liquid, by means of a trace of yeast, which multiplied rapidly. 



THEORY OF FERMENTATION 279 

causing fermentation, and forming a slight deposit of yeast at the 
bottom of the funnel above the tap. We then opened the tap, and 
some of the liquid in the funnel entered the flask, carrying with it 
the small deposit of yeast, which was sufficient to impregnate the 
saccharine hquid contained in the flask. In this manner it is possible 
to introduce as small a quantity of yeast as we wish, a quantity the 
weight of which, we may say, is hardly appreciable. The yeast 
sown multipUes rapidly and produces fermentation, the carbonic 
gas from which is expelled into the mercury. In less than twelve 
days all the sugar had disappeared, and the fermentation had fin- 
ished. There was a sensible deposit of yeast adhering to the sides 
of the flask; collected and dried it weighed 2.25 grammes (34 grains). 
It is evident that in this experiment the total amount of yeast formed, 
if it required oxygen to enable it to live, could not have absorbed, 
at most, more than the volume which was originally held in solu- 
tion in the saccharine liquid, when that was exposed to the air 
before being introduced into the flask. 

Some exact experiments conducted by M. Raulin in our laboratory 
have established the fact that saccharine worts, like water, soon 
become saturated when shaken briskly with an excess of air, and 
also that they always take into solution a little less air than saturated 
pure water contains under the same conditions of temperature and 
pressure. At a temperature of 25° C. (77° F.), therefore, if we adopt 
the coefficient of the solubility of oxygen in water given in Bunsen's 
tables, we find that i litre (1% pints) of water saturated with air 
contains 5.5 cc. (0.3 cubic inch) of oxygen. The three litres of yeast- 
water in the flask, supposing it to have been saturated, contains less 
than 16.5 cc. (i cubic inch) of oxygen, or, in weight, less than 23 
milligrammes (0.35 grains). This was the maximum amount of 
oxygen, supposing the greatest possible quantity to have been ab- 
sorbed, that was required by the yeast formed in the fermentation 
of 150 grammes (4.8 Troy ounces) of sugar. We shall better under- 
stand the significance of this result later on. Let us repeat the 
foregoing experiment, but under altered conditions. Let us fill, as 
before, our flask with sweetened yeast-water, but let this first be 
boiled, so as to expel all the air it contains. To effect this we arrange 



aSo LOUIS PASTEUR 

our apparatus as represented in the accompanying sketch. (Fig. 2.) 
We place our flask, A, on a tripod above a gas flame, and in place 
of the vessel of mercury substitute a porcelain dish, under which 
we can put a gas flame, and which contains some fermentable, sac- 




FlG. 2 

charine liquid, similar to that with which the flask is filled. We 
boil the liquid in the flask and that in the basin simultaneously, and 
then let them cool down together, so that as the liquid in the flask 
cools some of the liquid is sucked from the basin into the flask. From 
a trial experiment which we conducted, determining the quandty 
of oxygen that remained in solution in the liquid after cooling, ac- 
cording to M. Schiitzenberger's valuable method, by means of 
hydrosulphite of soda,' we found that the three litres in the flask, 
treated as we have described, contained less than one milligramme 
(0.015 grain) of oxygen. At the same time we conducted another 
experiment, by way of comparison (Fig. 3). We took a flask, B, of 
larger capacity than the former one, which we filled about half with 
the same volume as before of a saccharine liquid of identically the 
same composition. This liquid had been previously freed from al- 
terative germs by boiling. In the funnel surmounting A, we put a 

' NaHSOo, now called Sodium hyposulphite. — D. C. R. 



THEORY OF FERMENTATION 




Fig. 3 



281 

few cubic centimetres of saccharine liquid in a state of fermentation, 
and when this small quantity of liquid was in full fermentation, and 
the yeast in it was young and vigorous, we 
opened the tap, closing it again immedi- 
ately, so that a little of the liquid and yeast 
still remained in the funnel. By this means 
we caused the liquid in A to ferment. We 
also impregnated the liquid in B with some 
yeast taken from the funnel of A. We then 
replaced the porcelain dish in which the 
curved escape tube of A had been plunged, 
by a vessel filled with mercury. The fol- 
lowing is a description of two of these 
comparative fermentations and the results 
they gave. 

The fermentable liquid was composed of 
yeast-water sweetened with 5 per cent, of 
sugar-candy; the ferment employed was 
sacchormyces pastorianus. 

The impregnation took place on January 20th. The flasks were 
placed in an oven at 25° (77° F.). 

Flas\ A, without air. 

January 21st. — Fermentation commenced; a little frothy liquid issued 
from the escape tube and covered the mercury. 

The following days, fermentation was active. Examining the yeast 
mixed with the froth that was expelled into the mercury by the evolution 
of carbonic acid gas, we find that it was very fine, young, and actively 
budding. 

February 3rd. — Fermentation still continued, showing itself by a 
number of little bubbles rising from the bottom of the liquid, which had 
settled bright. The yeast was at the bottom in the form of a deposit. 

February 7th. — Fermentation still continued, but very languidly. 

February 9th. — A very languid fermentation still went on, discernible 
in little bubbles rising from the bottom of the flask. 

Flas\ B, with air. 

January 21st. — A sensible development of yeast. 
The following days, fermentation was active, and there was an abun- 
dant froth on the surface of the liquid. 

February ist. — All symptoms of fermentation had ceased. 



282 LOUIS PASTEUR 

As the fermentation in A would have continued a long time, 
being so very languid, and as that in B had been finished for several 
days, we brought to a close our two experiments on February 9th. 
To do this we poured off the liquids in A and B, collecting the yeasts 
on tared filters. Filtration was an easy matter, more especially in the 
case of A. Examining the yeasts under the microscope, immediately 
after decantation, we found that both of them remained very pure. 
The yeast in A was in little clusters, the globules of which were 
collected together, and appeared by their well-defined borders to 
be ready for an easy revival in contact with air. 

As might have been expected, the liquid in Hask B did not contain 
the least trace of sugar; that in the flask A still contained some, as 
was evident from the non-completion of fermentation, but not 
more than 4.6 grammes (71 grains). Now, as each flask originally 
contained three litres of liquid holding in solution 5 per cent, of 
sugar, it follows that 150 grammes (2,310 grains) of sugar had fer- 
mented in the flask B, and 145.4 grammes (2,239.2 grains) in the 
flask A. The weights of yeast after drying at 100° C. (212° F.) 
were — 

For the flask B, with air. . . 1,970 grammes (30.4 grains). 
For the flask A, without air. .1,368 grammes'*. 

The proportions were i of yeast to 76 of fermented sugar in the 
first case, and i of yeast to 89 of fermented sugar in the second. 
From these facts the following consequences may be deduced: 

1. The fermentable liquid (flask B), which since it had been in 
contact with air, necessarily held air in solution, although not to 
the point of saturation, inasmuch as it had been once boiled to free 
it from all foreign germs, furnished a weight of yeast sensibly 
greater than that yielded by the liquid which contained no air at 
all (flask A) or, at least, which could only have contained an ex- 
ceedingly minute quantity. 

2. This same slightly aerated fermentable liquid fermented much 
more rapidly than the other. In eight or ten days it contained no 
more sugar; while the other, after twenty days, still contained an 
appreciable quantity. 

*This appears to be a misprint for 1.638 grammes==25.3 grains. — D. C. R. 



THEORY OF FERMENTATION 283 

Is this last fact to be explained by the greater quantity of yeast 
formed in B ? By no means. At first, when the air has access to the 
liquid, much yeast is formed and little sugar disappears, as we shall 
prove immediately; nevertheless the yeast formed in contact with 
the air is more active than the other. Fermentation is correlative 
first to the development of the globules, and then to the continued 
life of those globules once formed. The more oxygen these last 
globules have at their disposal during their formation, the more 
vigorous, transparent, and turgescent, and, as a consequence of this 
last quality, the more active they are in decomposing sugar. We 
shall hereafter revert to these facts. 

3. In the airless flask the proportion of yeast to sugar was ^; it 
was only 7^ in the flask which had air at first. 

The proportion that the weight of yeast bears to the weight of 
the sugar is, therefore, variable, and this variation depends, to a cer- 
tain extent, upon the presence of air and the possibility of oxygen 
being absorbed by the yeast. We shall presently show that yeast 
possesses the power of absorbing that gas and emitting carbonic 
acid, like ordinary fungi, that even oxygen may be reckoned 
amongst the number of food-stuffs that may be assimilated by this 
plant, and that this fixation of oxygen in yeast, as well as the oxida- 
tions resulting from it, have the most marked effect on the life of 
yeast, on the multiplication of its cells, and on their activity as fer- 
ments acting upon sugar, whether immediately or afterwards, apart 
from supplies of oxygen or air. 

In the preceding experiment, conducted without the presence of 
air, there is one circumstance particularly worthy of notice. This 
experiment succeeds, that is to say, the yeast sown in the medium 
deprived of oxygen develops, only when this yeast is in a state of 
great vigour. We have already explained the meaning of this last 
expression. But we wish now to call attention to a very evident fact 
in connection with this point. We impregnate a fermentable liquid; 
yeast develops and fermentation appears. This lasts for several days 
and then ceases. Let us suppose that, from the day when fermenta- 
tion first appears in the production of a minute froth, which grad- 
ually increases until it whitens the surface of the liquid, we take, 
every twenty-four hours, or at longer intervals, a trace of the yeast 



284 LOUIS PASTEUR 

deposited on the bottom of the vessel and use it for starting fresh 
fermentations. Conducting these fermentations all under precisely 
the same conditions of temperature, character and volume of liquid, 
let us continue this for a prolonged time, even after the original 
fermentation is finished. We shall have no difficulty in seeing that 
the first signs of action in each of our series of second fermentations 
appear always later and later in proportion to the length of time 
that has elapsed from the commencement of the original fermenta- 
tion. In other words, the time necessary for the development of the 
germs and the production of that amount of yeast sufficient to cause 
the first appearance of fermentation varies with the state of the im- 
pregnating cells, and is longer in proportion as the cells are further 
removed from the period of their formation. It is essential, in ex- 
periments of this kind, that the quantities of yeast successively taken 
should be as nearly as possible equal in weight or volume, since, 
ceteris paribus, fermentations manifest themselves more quickly the 
larger the quantity of yeast employed in impregnation. 

If we compare under the microscope the appearance and charac- 
ter of the successive quantities of yeast taken, we shall see plainly 
that the structure of the cells undergoes a progressive change. The 
first sample which we take, quite at the beginning of the original 
fermentation, generally gives us cells rather larger than those later 
on, and possessing a remarkable tenderness. Their walls are ex- 
ceedingly thin, the consistency and softness of their protoplasm is 
akin to fluidity, and their granular contents appear in the form of 
scarcely visible spots. The borders of the cells soon become more 
marked, a proof that their walls undergo a thickening; their pro- 
toplasm also becomes denser, and the granulations more distinct. 
Cells of the same organ, in the states of infancy and old age, should 
not differ more than the cells of which we are speaking, taken in 
their extreme states. The progressive changes in the cells, after they 
have acquired their normal form and volume, clearly demonstrate 
the existence of a chemical work of a remarkable intensity, during 
which their weight increases, although in volume they undergo no 
sensible change, a fact that we have often characterized as "the con- 
tinued life of cells already formed." We may call this work a 
process of maturation on the part of the cells, almost the same that 



THEORY OF FERMENTATION 285 

we see going on in the case of adult beings in general, which con- 
tinue to live for a long time, even after they have become incapable 
of reproduction, and long after their volume has become permanently 
fixed. 

This being so, it is evident, we repeat, that, to multiply in a fer- 
mentable medium, quite out of contact with oxygen, the cells of 
yeast must be extremely young, full of life and health, and still under 
the influence of the vital activity which they owe to the free oxygen 
which has served to form them, and which they have perhaps stored 
up for a time. When older, they reproduce themselves with much 
difficulty when deprived of air, and gradually become more languid; 
and if they do multiply, it is in strange and monstrous forms. A 
little older still, they remain absolutely inert in a medium deprived 
of free oxygen. This is not because they are dead; for in general 
they may be revived in a marvellous manner in the same liquid if 
it has been first aerated before they are sown. It would not surprise 
us to learn that at this point certain preconceived ideas suggest them- 
selves to the mind of an attentive reader on the subject of the causes 
that may serve to account for such strange phenomena in the life 
of these beings which our ignorance hides under the expressions of 
youth and age; this, however, is a subject which we cannot pause to 
consider here. 

At this point we must observe — for it is a matter of great im- 
portance — that in the operations of the brewer there is always a 
time when the yeasts are in this state of vigorous youth of which 
we have been speaking, acquired under the influence of free oxygen, 
since all the worts and the yeasts of commerce are necessarily 
manipulated in contact with air, and so impregnated more or less 
with oxygen. The yeast immediately seizes upon this gas and ac- 
quires a state of freshness and activity, which permits it to live 
afterwards out of contact with air, and to act as a ferment. Thus, 
in ordinary brewery practice, we find the yeast already formed in 
abundance even before the earliest external signs of fermentation 
have made their appearance. In this first phase of its existence, yeast 
lives chiefly like an ordinary fungus. 

From the same circumstances it is clear that the brewer's fer- 
mentations may, speaking quite strictly, last for an indefinite time. 



286 LOUIS PASTEUR 

in consequence of the unceasing supply of fresh wort, and from the 
fact, moreover, that the exterior air is constantly being introduced 
during the work, and that the air contained in the fresh worts keeps 
up the vital activity of the yeast, as the act of breathing keeps up the 
vigour and life of cells in all living beings. If the air could not renew 
itself in any way, the vital activity which the cells originally received, 
under its influence, would become more and more exhausted, and 
the fermentation eventually come to an end. 

We may recount one of the results obtained in other experiments 
similar to the last, in which, however, we employed yeast which 
was still older than that used for our experiment with flask A (Fig. 
2), and moreover took still greater precautions to prevent the pres- 
ence of air. Instead of leaving the flask, as well as the dish, to cool 
slowly, after having expelled all air by boiling, we permitted the 
liquid in the dish to continue boiling whilst the flask was being 
cooled by artificial means; the end of the escape tube was then taken 
out of the still boihng dish and plunged into the mercury trough. 
In impregnating the liquid, instead of employing the contents of 
the small cylindrical funnel whilst still in a state of fermentation, we 
waited until this was finished. Under these conditions, fermentation 
was still going on in our flask, after a lapse of three months. We 
stopped it and found that 0.255 gramme (3.9 grains) of yeast had 
been formed, and that 45 grammes (693 grains) of sugar had fer- 
mented, the ratio between the weights of yeast and sugar being 
thus ^fl^ = rr^- In this experiment the yeast developed with much 
difficulty, by reason of the conditions to which it had been subjected. 
In appearance the cells varied much, some were to be found large, 
elongated, and of tubular aspect, some seemed very old and were 
extremely granular, whilst others were more transparent. All of 
them might be considered abnormal cells. 

In such experiments we encounter another difficulty. If the yeast 
sown in the non-aerated fermentable liquid is in the least degree 
impure, especially if we use sweetened yeast-water, we may be sure 
that alcoholic fermentation will soon cease, if, indeed, it ever com- 
mences, and that accessory fermentations will go on. The vibrios of 
butyric fermentation, for instance, will propagate with remarkable 
facility under these circumstances. Clearly then, the purity of the 



THEORY OF FERMENTATION 287 

yeast at the moment o£ impregnation, and the purity of the Uquid 
in the funnel, are conditions indispensable to success. 

To secure the latter of these conditions, we close the funnel, as 
shown in Fig. 2, by means of a cork pierced with two holes, through 
one of which a short tube passes, to which a short length of india- 
rubber tubing provided with a glass stopper is attached; through 
the other hole a thin curved tube is passed. Thus fitted, the funnel 
can answer the same purposes as our double-necked flasks. A few 
cubic centimetres of sweetened yeast-water are put in it and boiled, 
so that the steam may destroy any germs adhering to the sides; and 
when cold the liquid is impregnated by means of a trace of pure 
yeast, introduced through the glass-stoppered tube. If these pre- 
cautions are neglected, it is scarcely possible to secure a successful 
fermentation in our flasks, because the yeast sown is immediately 
held in check by a development of anaerobian vibrios. For greater 
security, we may add to the fermentable liquid, at the moment when 
it is prepared, a very small quantity of tartaric acid, which will 
prevent the development of butyric vibrios. 

The variation of the ratio between the weight of the yeast and 
that of the sugar decomposed by it now claims special attention. 
Side by side with the experiments which 
we have just described, we conducted a 
third lot by means of the flask C (Fig. 
4), holding 4.7 litres (8V2 pints), and 
fitted up like the usual two-necked 
flasks, with the object of freeing the 
fermentable liquid from foreign germs, 
by boiling it to begin with, so that we 
might carry on our work under con- 
ditions of purity. The volume of yeast- 
water (containing 5 per cent, of sugar) 
was only 200 cc. (7 fl. oz.), and conse- 
quently, taking into account the capacity 
of the flask, it formed but a very thin 
layer at the bottom. On the day after impregnation the deposit of 
yeast was already considerable, and forty-eight hours afterwards 
the fermentation was completed. On the third day we collected the 




Fig. 4 



288 LOUIS PASTEUR 

yeast after having analyzed the gas contained in the flask. This 
analysis was easily accomplished by placing the flask in a hot-water 
bath, whilst the end of the curved tube was plunged under a cylinder 
of mercury. The gas contained 41.4 per cent, of carbonic acid, and, 
after the absorption, the remaining air contained: — 

Oxygen 19.7 

Nitrogen 80.3 

1 00.0 

Taking into consideration the volume of this flask, this shows a 
minimum of 50 cc. (3.05 cub. in.) of oxygen to have been absorbed 
by the yeast. The liquid contained no more sugar, and the weight 
of the yeast, dried at a temperature of 100° C. (212° F.), was 044 
grammes. The ratio between the weights of yeast and sugar is 
*T^~^T^- On this occasion, where we had increased the quantity 
of oxygen held in solution, so as to yield itself for assimilation at 
the beginning and during the earlier developments of the yeast, we 
found instead of the previous ratio of ^ that of -^. 

The next experiment was to increase the proportion of oxygen to 
a still greater extent, by rendering the diffusion of gas a more easy 
matter than in a flask, the air in which is in a state of perfect 



(E 



Fig. 5 

quiescence. Such a state of matters hinders the supply of oxygen, 
inasmuch as the carbonic acid, as soon as it is liberated, at once 
forms an immovable layer on the surface of the liquid, and so 
separates off the oxygen. To effect the purpose of our present ex- 
periment, we used flat basins having glass bottoms and low sides, 
also of glass, in which the depth of the liquid is not more than a 
few miUimetres (less than }4 inch [Fig. 5]). The following is one 
of our experiments so conducted: — On April i6th, i860, we sowed 
a trace of beer yeast ("high" yeast) in 200 cc. (7 fl. oz.) of a sac- 

^ 200 cc. of liquid were used, which, as containing 5 per cent., had in solution 
10 grammes of sugar. — D. C. R. 



THEORY OF FERMENTATION 289 

charine liquid containing 1.720 grammes (26.2 grains) of sugar- 
candy. From April i8th our yeast was in good condition and well 
developed. We collected it, after having added to the liquid a few 
drops of concentrated sulphuric acid, with the object of checking 
the fermentation to a great extent, and facilitating filtration. The 
sugar remaining in the filtered liquid, determined by Fehling's solu- 
tion, showed that 1.04 grammes (16 grains) of sugar had disappeared. 
The weight of the yeast, dried at 100° C. (212° F.), was 0.127 
gramme (2 grains), which gives us the ratio between the weight of 
the yeast and that of the fermented sugar -t-W^^fT) which is 
considerably higher than the preceding ones. 

We may still further increase this ratio by making our estimation 
as soon as possible after the impregnation, or the addition of the 
ferment. It will be readily understood why yeast, which is com- 
posed of cells that bud and subsequently detach themselves from 
one another, soon forms a deposit at the bottom of the vessels. In 
consequence of this habit of growth, the cells constantly covering 
each other prevents the lower layers from having access to the 
oxygen held in solution in the liquid, which is absorbed by the 
upper ones. Hence, these which are covered and deprived of this 
gas act on the sugar without deriving any vital benefit from the 
oxygen — a circumstance which must tend to diminish the ratio of 
which we are speaking. Once more repeating the preceding experi- 
ment, but stopping it as soon as we think that the weight of yeast 
formed may be determined by the balance (we find that this may 
be done twenty-four hours after impregnation with an inappreciable 
quantity of yeast), in this case the ratio between the weights of 
yeast and sugar is^g-J75^^^ = T- This is the highest ratio we have 
been able to obtain. 

Under these conditions the fermentation of sugar is extremely 
languid: the ratio obtained is very nearly the same that ordinary 
fungoid growths would give. The carbonic acid evolved is prin- 
cipally formed by the decompositions which result from the as- 
similation of atmospheric oxygen. The yeast, therefore, lives and 
performs its functions after the manner of ordinary fungi: so far 
it is no longer a ferment, so to say; moreover, we might expect to 
find it to cease to be a ferment at all if we could only surround each 



290 LOUIS PASTEUR 

cell separately with all the air that it required. This is what the 
preceding phenomena teach us; we shall have occasion to compare 
them later on with others which relate to the vital action exercised 
on yeast by the sugar o£ milk. 

We may here be permitted to make a digression. 

In his work on fermentations, which M. Schiitzenberger has re- 
cently published, the author criticises the deductions that we have 
drawn from the preceding experiments, and combats the explanation 
which we have given of the phenomena of fermentation.' It is an 
easy matter to show the weak point of M. Schiitzenberger's reason- 
ing. We determined the power of the ferment by the relation of 
the weight of sugar decomposed to the weight of the yeast pro- 
duced. M. Schiitzenberger asserts that in doing this we lay down 
a doubtful hypothesis, and he thinks that this power, which he terms 
fermentative energy, may be estimated more correctly by the quantity 
of sugar decomposed by the unit-weight of yeast in unit-time; more- 
over, since our experiments show that yeast is very vigorous when 
it has a sufficient supply of oxygen, and that, in such a case, it can 
decompose much sugar in a little time, M. Schiitzenberger concludes 
that it must then have great power as a ferment, even greater than 
when it performs its functions without the aid of air, since under 
this condition it decomposes sugar very slowly. In short, he is dis- 
posed to draw from our observations the very opposite conclusion 
to that which we arrived at. 

M. Schiitzenberger has failed to notice that the power of a fer- 
ment is independent of the time during which it performs its func- 
tions. We placed a trace of yeast in one litre of saccharine wort; it 
propagated, and all the sugar was decomposed. Now, whether the 
chemical action involved in this decomposition of sugar had re- 
quired for its completion one day, or one month, or one year, such 
a factor was of no more importance in this matter than the mechan- 
ical labour required to raise a ton of materials from the ground to 
the top of a house would be affected by the fact that it had taken 
twelve hours instead of one. The notion of time has nothing to do 
with the definition of work. M. Schiitzenberger has not perceived 

^International Science Series, vol. xx, pp. 179-182. London, 1876. — D. C. R. 



THEORY OF FERMENTATION 29 1 

that in Introducing the consideration of time into the definition of 
the power of a ferment, he must introduce at the same time, that 
of the vital activity of the cells vi'hich is independent of their charac- 
ter as a ferment. Apart from the consideration of the relation ex- 
isting between the weight of fermentable substance decomposed 
and that of ferment produced, there is no occasion to speak of fer- 
mentations or of ferments. The phenomena of fermentation and 
of ferments have been placed apart from others, precisely because, 
in certain chemical actions, that ratio has been out of proportion; 
but the time that these phenomena require for their accomplish- 
ment has nothing to do with either their existence proper, or with 
their power. The cells of a ferment may, under some circumstances, 
require eight days for revival and propagation, whilst, under other 
conditions, only a few hours are necessary; so that, if we introduce 
the notion of time into our estimate of their power of decomposition, 
we may be led to conclude that in the first case that power was en- 
tirely wanting, and that in the second case it was considerable, al- 
though all the time we are dealing with the same organism — the 
identical ferment. 

M. Schiitzenberger is astonished that fermentation can take place 
in the presence of free oxygen, if, as we suppose, the decomposition 
of the sugar is the consequence of the nutrition of the yeast, at the 
expense of the combined oxygen, which yields itself to the ferment. 
At all events, he argues, fermentation ought to be slower in the 
presence of free oxygen. But why should it be slower? We have 
proved that in the presence of oxygen the vital activity of the cells 
increases, so that, as far as rapidity of action is concerned, its power 
cannot be diminished. It might, nevertheless, be weakened as a 
ferment, and this is precisely what happens. Free oxygen imparts 
to the yeast a vital activity, but at the same time impairs its power 
as yeast — qud yeast, inasmuch as under this condition it approaches 
the state in which it can carry on its vital processes after the man- 
ner of an ordinary fungus; the mode of life, that is, in which the 
ratio between the weight of sugar decomposed and the weight of 
the new cells produced will be the same as holds generally among 
organisms which are not ferments. In short, varying our form of 



292 LOUIS PASTEUR 

expression a little, we may conclude with perfect truth, from the 
sum total of observed facts, that the yeast which lives in the presence 
of oxygen and can assimilate as much of that gas as is necessary to 
its perfect nutrition, ceases absolutely to be a ferment at all. Never- 
theless, yeast formed under these conditions and subsequently 
brought into the presence of sugar, out of the influence of air, would 
decompose more in a given time than in any other of its states. The 
reason is that yeast which has formed in contact with air, having the 
maximum of free oxygen that it can assimilate is fresher and pos- 
sessed of greater vital activity than that which has been formed 
without air or with an insufficiency of air. M. Schiitzenberger would 
associate this activity with the notion of time in estimating the 
power of the ferment; but he forgets to notice that yeast can only 
manifest this maximum of energy under a radical change of its life 
conditions; by having no more air at its disposal and breathing no 
more free oxygen. In other words, when its respiratory power be- 
comes null, its fermentative power is at its greatest. M. Schiitzen- 
berger asserts exactly the opposite (p. 151 of his work — Paris. 1875),' 
and so gratuitously places himself in opposition to facts. 

In presence of abundant air supply, yeast vegetates with extraor- 
dinary activity. We see this in the weight of new yeast, compara- 
tively large, that may be formed in the course 
of a few hours. The microscope still more 
clearly shows this activity in the rapidity of 
^ budding, and the fresh and active appearance 
of all the cells. Fig. 6 represents the yeast of 
Q, our last experiment at the moment when we 
^ stopped the fermentation. Nothing has been 

Fig. 6 i r ... 1, 1 . 

taken rrom imagmation, ail the groups have 
been faithfully sketched as they were.' 

In passing it is of interest to note how promptly the preceding 
results were turned to good account practically. In well-managed 
distilleries, the custom of aerating the wort and the juices to render 
them more adapted to fermentation, has been introduced. The 

'Page 182, English edition. 

* This figure is on a scale o£ 300 diameters, most of the figures in this work being 
of 400 diameters. 




THEORY OF FERMENTATION 293 

molasses mixed with water is permitted to run in thin threads 
through the air at the moment when the yeast is added. Manufac- 
tories have been erected in which the manufacture of yeast is almost 
exclusively carried on. The saccharine worts, after the addition of 
yeast, are left to themselves, in contact with air, in shallow vats of 
large superficial area, realizing thus on an immense scale the con- 
ditions of the experiments which we undertook in 1861, and which 
we have already described in determining the rapid and easy mul- 
tiplication of yeast in contact with air. 

The next experiment was to determine the volume of oxygen 
absorbed by a known quantity of yeast, the yeast living in contact 
with air, and under such conditions that the absorption of air was 
comparatively easy and abundant. 

With this object we repeated the experiment that we performed 
with the large-bottomed flask (Fig. 4), employing a vessel shaped 
like Fig. B (Fig. 7), which is, in point of fact, the flask A with its 
neck drawn out and closed in a flame, after the introduction of a 





Fig. 7 

thin layer of some saccharine juice impregnated with a trace of 
pure yeast. The following are the data and results of an experiment 
of this kind. 

We employed 60 cc. (about 2 fluid ounces) of yeast-water, sweet- 
ened with two per cent, of sugar and impregnated with a trace of 
yeast. After having subjected our vessel to a temperature of 25° C. 
(77° F.) in an oven for fifteen hours, the drawn-out point was 
brought under an inverted jar filled with mercury and the point 
broken ofE. A portion of the gas escaped and was collected in the 
jar. For 25 cc. of this gas we found, after absorption by potash, 20.6, 
and after absorption by pyrogallic acid, 17.3. Taking into account 



294 LOUIS PASTEUR 

the volume which remained free in the flask, which held 315 cc, 
there was a total absorption o£ 14.5 cc. (0.88 cub. in.) of oxygen.* 
The weight of the yeast, in a state of dryness, was 0.035 gramme. 

It follows that in the production of 35 milligrammes (0.524 grain) 
of yeast there was an absorption of 14 or 15 cc. (about % cub. in.) 
of oxygen, even supposing that the yeast was formed entirely under 
the influence of that gas: this is equivalent to not less than 414 cc. 
for I gramme of yeast (or about 33 cubic inches for every 20 
grains) .'° 

Such is the large volume of oxygen necessary for the development 
of one gramme of yeast when the plant can assimilate this gas after 
the manner of an ordinary fungus. 

Let us now return to the first experiment described in the para- 
graph on page 278 in which a flask of three litres capacity was filled 
with fermentable liquid, which, when caused to ferment, yielded 
2.25 grammes of yeast, under circumstances where it could not 
obtain a greater supply of free oxygen than 16.5 cc. (about one 
cubic inch). According to what we have just stated, if this 2.25 
grammes (34 grains) of yeast had not been able to live without 
oxygen, in other words, if the original cells had been unable to 
multiply otherwise than by absorbing free oxygen, the amount of 
that gas required could not have been less than 2.25X414 cc, that 
is, 931.5 cc. (56.85 cubic inches). The greater part of the 2.25 

'It may be useful for the non-scientific reader to put it thus: that the 25 cc. which 
escaped, being a fair sample of the whole gas in the flask, and containing (i) 
25 — 20.6^4.4 cc, absorbed by potash and therefore due to carbonic acid, and (2) 
20.6— 17.3=:3.3 cc, absorbed by pyrogallate, and therefore due to oxygen, and the 
remaining 17.3 cc. being nitrogen, the whole gas in the flask, which has a capacity 
of 312 cc, will contain oxygen in the above proportion and therefore its amount may 
be determined, provided we know the total gas in the flask before opening. On the 
other hand we know that air normally contains approximately, 1-5 its volume of 
oxygen, the rest being nitrogen, so that, by ascertaining the diminution of the pro- 
portion in the flask, we can find how many cubic centimeters have been absorbed by 
the yeast. The author, however, has not given all the data necessary for accurate 
calculation. — D. C. R. 

"•This number is probably too small; it is scarcely possible that the increase of 
weight in the yeast, even under the exceptional conditions of the experiment described, 
was not to some extent at least due to oxidation apart from free oxygen, inasmuch as 
some of the cells were covered by others. The increased weight of the yeast is always 
due to the action of two distinct modes of vital energy — activity, namely, in presence 
and activity in absence of air. We might endeavour to shorten the duration of the 
experiment still further, in which case we would still more assimilate the life of the 
yeast to that of ordinary moulds. 



THEORY OF FERMENTATION 295 

grammes, therefore, had evidently been produced as the growth of 
an anaerobian plant. 

Ordinary fungi likewise require large quantities of oxygen for 
their development, as we may readily prove by cultivating any 
mould in a closed vessel full of air, and then taking the weight of 
plant formed and measuring the volume of oxygen absorbed. To 
do this, we take a Hask of the shape shown in Fig. 8, capable of 
holding about 300 cc. (10'/^ fluid ounces), and contain- 
ing a liquid adapted to the life of moulds. We boil 
this liquid, and seal the drawn-out point after the steam 
has expelled the air wholly or in part; we then open the 
flask in a garden or in a room. Should a fungus-spore 
enter the flask, as will invariably be the case in a certain 
number of flasks out of several used in the experiment, 
except under special circumstances, it will develop there 
and gradually absorb all the oxygen contained in the 
air of the flask. Measuring the volume of this air, and 
weighing, after drying, the amount of plant formed, we 
find that for a certain quantity of oxygen absorbed we 
have a certain weight of mycelium, or of mycelium together with 
its organs of fructification. In an experiment of this kind, in which 
the plant was weighed a year after its development, we found for 
0.008 gramme (0.123 grain) of mycehum, dried at 100° C. (212° F.), 
an absorption that amounted to not less than 43 cc. (2.5 cubic inches) 
of oxygen at 25° C. These numbers, however, must vary sensibly 
with the nature of the mould employed, and also with the greater or 
less activity of its development, because the phenomena is compli- 
cated by the presence of accessory oxidations, such as we find in the 
case of mycoderma vini and aceti, to which cause the large absorp- 
tion of oxygen in our last experiment may doubtless be attributed." 

" In these experiments, in which the moulds remain for a long time in contact 
with a saccharine wort out of contact with oxygen — the oxygen being promptly 
absorbed by the vital action of the plant (see our Mimo'ire sur les Generations dites 
Spontanhs, p. 54, note) — there is no doubt that an appreciable quantity of alcohol 
is formed because the plant does not immediately lose its vital activity after the 
absorption of oxygen. 

A 300-cc. (lo-oz.) flask, containing 100 cc. of must, after the air in it had been 
expelled by boiling, was opened and immediately re-closed on August 15th, 1873. 
A fungoid growth — a unique one, of greenish-grey colour — developed from spon- 
taneous impregnation, and decolorized the liquid, which originally was of a yellowish- 




296 LOUIS PASTEUR 

The conclusions to be drawn from the whole of the preceding 
facts can scarcely admit of doubt. As for ourselves, we have no 
hesitation in finding them the foundation of the true theory of 
fermentation. In the experiments which we have described, fermen- 
tation by yeast, that is to say, by the type of ferments properly so 
called, is presented to us, in a word, as the direct consequence of the 
processes of nutrition, assimilation and life, when these are carried 
on without the agency of free oxygen. The heat required in the 
accomplishment of that work must necessarily have been borrowed 
from the decomposition of the fermentable matter, that is from the 
saccharine substance which, like other unstable substances, liberates 
heat in undergoing decomposition. Fermentation by means of yeast 
appears, therefore, to be essentially connected with the property 
possessed by this minute cellular plant of performing its respiratory 
functions, somehow or other, with oxygen existing combined in 
sugar. Its fermentative power — which power must not be confounded 
with the fermentative activity or the intensity of decomposition in a 
given time — varies considerably between two limits, fixed by the 
greatest and least possible access to free oxygen which the plant has 
in the process of nutrition. If we supply it with a sufficient quantity 
of free oxygen for the necessities of its life, nutrition, and respiratory 
combustions, in other words, if we cause it to live after the manner 
of a mould, properly so called, it ceases to be a ferment, that is, the 
ratio between the weight of the plant developed and that of the 
sugar decomposed, which forms its principal food, is similar in 
amount to that in the case of fungi." On the other hand, if we 
deprive the yeast of air entirely, or cause it to develop in a saccharine 
medium deprived of free oxygen, it will multiply just as if air were 



brown. Some large crystals, sparkling like diamonds, of neutral tartrate of lime, 
were precipitated. About a year afterwards, long after the death of the plant, we 
examined this liquid. It contained 0.3 gramme (4.6 grains) of alcohol, and 0.053 
gramme (0.8 grain) of vegetable matter, dried at 100° C. (212° F.). We ascertained 
that the spores of the fungus were dead at the moment when the flask was opened. 
When sown, they did not develop in the least degree. 

'^ We find in M. Raulin's note that "the minimum ratio between the weight of 
sugar and the weight of organized matter, that is, the weight of fungoid growth which 
it helps to form, may be expressed as ^^ = 3.1." Jules Raulin, Etudes chimiques 
sur la vigitation. Recherches sur le diveloppement d'unc mucedinee dans un milieu 
artificiel, p. 192. Paris, 1870. We have seen in the case of yeast that this ratio may 
be as low as f . 



THEORY OF FERMENTATION 297 

present, although with less activity, and under these circumstances 
its fermentative character will be most marked; under these circum- 
stances, moreover, we shall find the greatest disproportion, all other 
conditions being the same, between the weight of yeast formed and 
the weight of sugar decomposed. Lastly, if free oxygen occurs in 
varying quantities, the ferment-power of the yeast may pass through 
all the degrees comprehended between the two extreme limits of 
which we have just spoken. It seems to us that we could not 
have a better proof of the direct relation that fermentation bears 
to life, carried on in the absence of free oxygen, or with a quan- 
tity of that gas insufficient for all the acts of nutrition and assimila- 
tion. 

Another equally striking proof of the truth of this theory is the 
fact previously demonstrated that the ordinary moulds assume the 
character of a ferment when compelled to live without air, or with 
quantities of air too scant to permit of their organs having around 
them as much of that element as is necessary for their life as aerobian 
plants. Ferments, therefore, only possess in a higher degree a char- 
acter which belongs to many common moulds, if not to all, and 
which they share, probably, more or less, with all living cells, namely 
the power of living either an aerobian or anaerobian life, according 
to the conditions under which they are placed. 

It may be readily understood how, in their state of aerobian life, 
the alcoholic ferments have failed to attract attention. These fer- 
ments are only cultivated out of contact with air, at the bottom of 
liquids which soon become saturated with carbonic acid gas. Air is 
only present in the earlier developments of their germs, and without 
attracting the attention of the operator, whilst in their state of 
anaerobian growth their life and acdon are of prolonged duration. 
We must have recourse to special experimental apparatus to enable 
us to demonstrate the mode of life of alcoholic ferments under the 
influence of free oxygen; it is their state of existence apart from air, 
in the depths of liquids, that attracts all our attention. The results 
of their action are, however, marvellous, if we regard the products 
resulting from them, in the important industries of which they 
are the life and soul. In the case of ordinary moulds, the opposite 
holds good. What we want to use special experimental apparatus 



298 LOUIS PASTEUR 

for with them, is to enable us to demonstrate the possibiUty of their 
continuing to Uve for a time out of contact with air, and all our 
attention, in their case, is attracted by the facility with which they 
develop under the influence of oxygen. Thus the decomposition of 
saccharine liquids, which is the consequence of the life of fungi 
without air, is scarcely perceptible, and so is of no practical impor- 
tance. Their aerial life, on the other hand, in which they respire and 
accomplish their process of oxidation under the influence of free 
oxygen is a normal phenomenon, and one of prolonged duration 
which cannot fail to strike the least thoughtful of observers. We are 
convinced that a day will come when moulds will be utilised in 
certain industrial operations, on account of their power in destroying 
organic matter. The conversion of alcohol into vinegar in the 
process of acetification and the production of gallic acid by the action 
of fungi on wet gall nuts, are already connected with this kind of 
phenomena." On this last subject, the important work of M. Van 
Tieghem {Annates Scientifiques de I'Ecole Normale, vol. vi.) may 
be consulted. 

The possibility of living without oxygen, in the case of ordinary 
moulds, is connected with certain morphological modifications which 
are more marked in proportion as this faculty is itself more devel- 
oped. These changes in the vegetative forms are scarcely perceptible, 
in the case of penicillium and mycoderma vini, but they are very 
evident in the case of aspergillus, consisting of a marked tendency on 
the part of the submerged mycelial filaments to increase in diameter, 
and to develop cross partitions at short intervals, so that they some- 
times bear a resemblance to chains of conidia. In mucor, again, they 
are very marked, the inflated filaments which, closely interwoven, 
present chains of cells, which fall off and bud, gradually producing 
a mass of cells. If we consider the matter carefully, we shall see that 
yeast presents the same characteristics. * * * * 

'^ We shall show, some day, that the processes of oxidation due to growth of fungi 
cause, in certain decompositions, liberation of ammonia to a considerable extent, and 
that by regulating their action we might cause them to extract the nitrogen from a 
host of organic debris, as also, by checking the production of such organisms, we 
might considerably increase the proportion of nitrates in the artificial nitrogenous 
substances. By cultivating the various moulds on the surface of damp bread in a 
current of air we have obtained an abundance of ammonia, derived from the decom- 
position of the albuminoids effected by the fungoid life. The decomposition of 
asparagus and several other animal or vegetable substances has given similar results. 



THEORY OF FERMENTATION 299 

It is a great presumption in favor of the truth of theoretical ideas 
when the resuhs of experiments undertaken on the strength of those 
ideas are confirmed by various facts more recently added to science, 
and when those ideas force themselves more and more on our minds, 
in spite of a prima facie improbability. This is exactly the character 
of those ideas which we have just expounded. We pronounced them 
in 1861, and not only have they remained unshaken since, but they 
have served to foreshadow neW facts, so that it is much easier to 
defend them in the present day than it was to do so fifteen years 
ago. We first called attention to them in various notes, which we 
read before the Chemical Society of Paris, notably at its meetings 
of April i2th and June 28th, 1861, and in papers in the Comptes 
rendus de l' Academic des Sciences. It may be of some interest to 
quote here, in its entirety, our communication of June 28th, 1861, 
entitled, "Influences of Oxygen on the Development of Yeast and 
on Alcoholic Fermentation," which we extract from the Bulletin 
de la Societe Chimique de Paris: — 

"M. Pasteur gives the result of his researches on the fermentation 
of sugar and the development of yeast-cells, according as that fermen- 
tation takes place apart from the influence of free oxygen or in 
contact vvdth that gas. His experiments, however, have nothing in 
common with those of Gay-Lussac, which were performed with the 
juice of grapes crushed under conditions where they would not be 
affected by air, and then brought into contact with oxygen. 

"Yeast, when perfectly developed, is able to bud and grow in a 
saccharine and albuminous liquid, in the complete absence of 
oxygen or air. In this case but Httle yeast is formed, and a com- 
paratively large quantity of sugar disappears — sixty or eighty parts 
for one of yeast formed. Under these conditions fermentation is 
very sluggish. 

"If the experiment is made in contact with the air, and with a 
great surface of liquid, fermentation is rapid. For the same quantity 
of sugar decomposed much more yeast is formed. The air with 
which the liquid is in contact is absorbed by the yeast. The yeast 
develops very actively, but its fermentative character tends to dis- 
appear under these conditions; we find, in fact, that for one part of 
yeast formed, not more than from four to ten parts of sugar are 



300 LOUIS PASTEUR 

transformed. The fermentative character of this yeast nevertheless 
continues, and produces even increased effects, if it is made to act 
on sugar apart from the influence of free oxygen. 

"It seems, therefore, natural to admit that when yeast functions 
as a ferment by living apart from the influence of air, it derives 
oxygen from the sugar, and that this is the origin of its fermentative 
character. 

"M. Pasteur explains the fact of the immense activity at the com- 
mencement of fermentations by the influence of the oxygen of the 
air held in solution in the liquids, at the time when the action com- 
mences. The author has found, moreover, that the yeast of beer 
sown in an albuminous liquid, such as yeast-water, still multiplies, 
even when there is not a trace of sugar in the liquid, provided always 
that atmospheric oxygen is present in large quantities. When 
deprived of air, under these conditions, yeast does not germinate 
at all. The same experiments may be repeated with albuminous 
liquid, mixed with a solution of non-fermentable sugar, such 
as ordinary crystallized milk-sugar. The results are precisely the 
same. 

"Yeast formed thus in the absence of sugar does not change its 
nature; it is still capable of causing sugar to ferment, if brought to 
bear upon that substance apart from air. It must be remarked, how- 
ever, that the development of yeast is effected with great difficulty 
when it has not a fermentable substance for its food. In short, the 
yeast of beer acts in exactly the same manner as an ordinary plant, 
and the analogy would be complete if ordinary plants had such an 
affinity for oxygen as permitted them to breathe by appropriating 
this element from unstable compounds, in which case, according to 
M. Pasteur, they would appear as ferments for those substances. 

"M. Pasteur declares that he hopes to be able to realize this result, 
that is to say, to discover the conditions under which certain inferior 
plants may live apart from air in the presence of sugar, causing 
that substance to ferment as the yeast of beer would do." 

This summary and the preconceived views that it set forth have 
lost nothing of their exactness; on the contrary, time has strength- 
ened them. The surmises of the last two paragraphs have received 



THEORY OF FERMENTATION 3OI 

valuable confirmation from recent observations made by Messrs. 
Lechartier and Bellamy, as well as by ourselves, an account of vi^hich 
we must put before our readers. It is necessary, however, before 
touching upon this curious feature in connection with fermentations 
to insist on the accuracy of a passage in the preceding summary; 
the statement, namely, that yeast could multiply in an albuminous 
liquid, in which it found a non-fermentable sugar, milk-sugar, for 
example. The following is an experiment on this point : — On August 
15th, 1875, we sowed a trace of yeast in 150 cc. (rather more than 
5 fluid ounces) of yeast-water, containing 2V2 per cent, of milk- 
sugar. The solution was prepared in one of our double-necked 
flasks, with the necessary precautions to secure the absence of germs, 
and the yeast sown was itself perfectly pure. Three months after- 
wards, November 15th, 1875, we examined the liquid for alcohol; 
it contained only the smallest trace; as for the yeast (which had 
sensibly developed), collected and dried on a filter paper, it weighed 
0.050 gramme (0.76 grain). In this case we have the yeast multi- 
plying without giving rise to the least fermentation, like a fungoid 
growth, absorbing oxygen, and evolving carbonic acid, and there is 
no doubt that the cessation of its development in this experiment was 
due to the progressive deprivation of oxygen that occurred. As soon 
as the gaseous mixture in the flask consisted entirely of carbonic 
acid and nitrogen, the vitality of the yeast was dependent on, and 
in proportion to, the quantity of air which entered the flask in con- 
sequence of variations of temperature. The question now arose, was 
this yeast, which had developed wholly as an ordinary fungus, still 
capable of manifesting the character of a ferment? To settle this 
point we had taken the precaution on August 15th, 1875, of pre- 
paring another flask, exactly similar to the preceding one in every 
respect, and which gave results identical with those described. We 
decanted this November 15th, pouring some wort on the deposit of 
the plant, which remained in the flask. In less than five hours from 
the time we placed it in the oven, the plant started fermentation in 
the wort, as we could see by the bubbles of gas rising to form patches 
on the surface of the liquid. We may add that yeast in the medium 
which we have been discussing will not develop at all without air. 



302 LOUIS PASTEUR 

The importance o£ these results can escape no one; they prove 
clearly that the fermentative character is not an invariable phenome- 
non of yeast-life, they show that yeast is a plant which does not 
differ from ordinary plants, and which manifests its fermentative 
power solely in consequence of particular conditions under which 
it is compelled to live. It may carry on its life as a ferment or not, 
and after having lived without manifesting the slightest symptom of 
fermentative character, it is quite ready to manifest that character 
when brought under suitable conditions. The fermentative property, 
therefore, is not a f>ower peculiar to cells of a special nature. It is 
not a permanent character of a particular structure, like, for instance, 
the property of acidity or alkalinity. It is a peculiarity dependent 
on external circumstances and on the nutritive conditions of the 
organism. 

§ II. Fermentation in Saccharine Fruits Immersed in Carbonic 

Acid Gas 

The theory which we have, step by step, evolved, on the subject 
of the cause of the chemical phenomena of fermentation, may claim 
a character of simplicity and generality that is well worthy of atten- 
tion. Fermentation is no longer one of those isolated and mysterious 
phenomena which do not admit of explanation. It is the consequence 
of a peculiar vital process of nutrition which occurs under certain 
conditions, differing from those which characterize the life of all 
ordinary beings, animal or vegetable, but by which the latter may 
be affected, more or less, in a way which brings them, to some extent 
within the class of ferments, properly so called. We can even con- 
ceive that the fermentative character may belong to every organized 
form, to every animal or vegetable cell, on the sole condition that 
the chemico-vital acts of assimilation and excretion must be capable 
of taking place in that cell for a brief period, longer or shorter it 
may be, without necessity for recourse to supplies of atmospheric 
oxygen; in other words, the cell must be able to derive its needful 
heat from the decomposition of some body which yields a surplus 
of heat in the process. 

As a consequence of these conclusions it should be an easy matter 



THEORY OF FERMENTATION 303 

to show, in the majority of Hving beings, the manifestation of the 
phenomena of fermentation; for there are, probably, none in which 
all chemical action entirely disappears, upon the sudden cessation of 
life. One day, when we were expressing these views in our labora- 
tory, in the presence of M. Dumas, who seemed inclined to admit 
their truth, we added: "We should like to make a wager that if we 
were to plunge a bunch of grapes into carbonic acid gas, there 
would be immediately produced alcohol and carbonic acid gas, in 
consequence of a renewed action starting in the interior cells of the 
grapes, in such a way that these cells would assume the functions of 
yeast cells. We will make the experiment, and when you come 
to-morrow" — it was our good fortune to have M. Dumas working in 
our laboratory at that time — "we will give you an account of the 
result." Our predictions were realized. We then endeavoured to 
find, in the presence of M. Dumas, who assisted us in our endeavour, 
cells of yeast in the grapes; but it was quite impossible to discover 
any.' 

Encouraged by this result, we undertook fresh experiments on 
grapes, on a melon, on oranges, on plums, and on rhubarb leaves, 
gathered in the garden of the Ecole Normale, and, in every case, 

' To determine the absence of cells of ferment in fruits that have been immersed 
in carbonic acid gas, we must first of all carefully raise the pellicle of the fruit, taking 
care that the subjacent parenchyma does not touch the surface of the pellicle, since 
the organized corpuscles existing on the exterior of the fruit might introduce an error 
into our microscopical observations. Experiments on grapes have given us an explana- 
tion of a fact generally known, the cause of which, however, had hitherto escaped our 
knowledge. We all know that the taste and aroma of the vintage, that is, of the 
grapes stripped from the bunches and thrown into tubs, where they get soaked in the 
juice that issues from the wounded specimens, are very different from the taste and 
aroma of an uninjured bunch. Now grapes that have been immersed in an atmosphere 
of carbonic acid gas have exactly the flavour and smell of the vintage; the reason is 
that, in the vintage tub, the grapes are immediately surrounded by an atmosphere 
of carbonic acid gas, and undergo, in consequence, the fermentation peculiar to grapes 
that ha\'e been plunged in this gas. These facts deserve to be studied from a practical 
point of view. It would be interesting, for example, to learn what difference there 
would be in the quality of two wines, the grapes of which, in the one case, had been 
perfecdy crushed, so as to cause as great a separation of the cells of the parenchyma 
as possible; in the other case, left, for the most part, whole, as in the case in the 
ordinary vintage. The first wine would be deprived of those fixed and fragrant prin- 
ciples produced by the fermentation of which we have just spoken, when the grapes 
are immersed in carbonic acid gas. By such a comparison as that which we suggest 
we should be able to form a priori judgment on the merits of the new system, which 
has not been carefully studied, although already widely adopted, of milled, cylindrical 
crushers, for pressing the vintage. 



304 LOUIS PASTEUR 

our substance, when immersed in carbonic acid gas, gave rise to the 
production of alcohol and carbonic acid. We obtained the following 
surprising results from some prunes de Monsieur:^ — On July 21, 
1872, we placed twenty-four of these plums under a glass bell, which 
we immediately filled with carbonic acid gas. The plums had been 
gathered on the previous day. By the side of the bell we placed other 
twenty-four plums, which were left there uncovered. Eight days 
afterwards, in the course of which time there had been a considerable 
evolution of carbonic acid from the bell, we withdrew the plums and 
compared them with those which had been left exposed to the air. 
The difference was striking, almost incredible. Whilst the plums 
which had been surrounded with air (the experiments of Berard 
have long since taught us that, under this latter condition, fruits 
absorb oxygen from the air and emit carbonic acid gas in almost 
equal volume) had become very soft and watery and sweet, the 
plums taken from under the jar had remained very firm and hard, 
the flesh was by no means watery, but they had lost much sugar. 
Lastly, when submitted to distillation, after crushing, they yielded 
6.5 grammes (99.7 grains) of alcohol, more than i per cent, of the 
total weight of the plums. What better proof than these facts could 
we have of the existence of a considerable chemical action in the 
interior of fruit, an action which derives the heat necessary for 
its manifestation from the decomposition of the sugar present in the 
cells? Moreover, and this circumstance is especially worthy of our 
attention, in all these experiments we found that there was a libera- 
tion of heat, of which the fruits and other organs were the seat, 
as soon as they were plunged in the carbonic acid gas. This heat 
is so considerable that it may at times be detected by the hand, if the 
two sides of the bell, one of which is in contact with the objects, are 
touched alternately. It also makes itself evident in the formation 
of little drops on those parts of the bell which are less directly exposed 

^ We have sometimes found small quantities of alcohol in fruits and other vegetable 
organs, surrounded with ordinary air, but always in small proportion, and in a 
manner which suggested its accidental character. It is easy to understand how, in the 
thickness of certain fruits, certain parts of those fruits might be deprived of air, under 
which circumstances they would have been acting under conditions similar to those 
under which fruits act when wholly immersed in carbonic acid gas. Moreover, it 
would be useful to determine whether alcohol is not a normal product of vegeta- 
tion. 



THEORY OF FERMENTATION 305 

to the influence of the heat resulting from the decomposition of 
the sugar of the cells.' 

In short, fermentation is a very general phenomenon. It is life 
without air, or life without free oxygen, or, more generally still, it is 
the result of a chemical process accomplished on a fermentable 
substance capable of producing heat by its decomposition, in which 
process the entire heat used up is derived from a part of the heat 
that the decomposition of the fermentable substance sets free. The 
class of fermentations properly so called, is, however, restricted by 
the small number of substances capable of decomposing with the 
production of heat, and at the same time of serving for the nourish- 
ment of lower forms of life, when deprived of the presence and 
action of air. This, again, is a consequence of our theory, which is 
well worthy of notice. 

The facts that we have just mentioned in reference to the forma- 
tion of alcohol and carbonic acid in the substance of ripe fruits, 
under special conditions, and apart from the action of ferment, are 
already known to science. They were discovered in 1869 by M. 
Lechartier, formerly a pupil in the Ecole Normale Superieure, and 
his coadjutor, M. Bellamy.* In 1821, in a very remarkable work, 
especially when we consider the period when it appeared, Berard 
demonstrated several important propositions in connection with the 
maturation of fruits: 

I. All fruits, even those that are still green, and likewise even 
those that are exposed to the sun, absorb oxygen and set free an 
almost equal volume of carbonic acid gas. This is a condition of 
their proper ripening. 

' In these studies of plants living immersed in carbonic acid gas, we have come 
across a fact which corroborates those which we have already given in reference to 
the facility with which lactic and viscous ferments, and, generally speaking, those 
which we have termed the disease ferments of beer, develop when deprived of air, and 
which shows, consequently, how very marked their aerobian character is. If we 
immerse beet-roots or turnips in carbonic acid gas, we produce well-defined fermenta- 
tions in those roots. Their whole surface readily permits the escape of the highly 
acid liquids, and they become filled with lactic, viscous, and other ferments. This 
shows us the great danger which may result from the use of pits, in which the beet- 
roots are preserved, when the air is not renewed, and that the original oxygen is 
expelled by the vital processes of fungi or other deoxidizing chemical actions. We 
have directed the attention of the manufacturers of beet-root sugar to this point. 

* Lechartier and Bellamy, Comptes rendus de I'Acadimie dcs Sciences, vol., Ixix., 
pp., 366 and 466, 1869. 



306 LOUIS PASTEUR 

II. Ripe fruits placed in a limited atmosphere, after having 
absorbed all the oxygen and set free an almost equal volume of 
carbonic acid, continue to emit that gas in notable quantity, even 
when no bruise is to be seen — "as though by a kind of fermentation," 
as Berard actually observes — and lose their saccharine particles, a cir- 
cumstance which causes the fruits to appear more acid, although the 
actual weight of their acid may undergo no augmentation whatever. 

In this beautiful work, and in all subsequent ones of which the 
ripening of fruits has been the subject, two facts of great theoretical 
value have escaped the notice of the authors; these are the two 
facts which Messrs. Lechartier and Bellamy pointed out for the 
first time, namely, the production of alcohol and the absence of 
cells of ferments. It is worthy of remark that these two facts, as we 
have shown above, were actually fore-shadowed in the theory of 
fermentation that we advocated as far back as 1861, and we are 
happy to add that Messrs. Lechartier and Bellamy, who at first had 
prudently drawn no theoretical conclusions from their work, now 
entirely agree with the theory we have advanced.^ Their mode of 
reasoning is very different from that of the savants with whom we 
discussed the subject before the Academy, on the occasion when the 
communication which we addressed to the Academy in October, 
1872, attracted attention once more to the remarkable observations 
of Messrs. Lechartier and Bellamy.^ M. Fremy, in particular, was 
desirous of finding in these observations a confirmation of his views 
on the subject of hemi-organism, and a condemnation of ours, not- 
withstanding the fact that the preceding explanations, and, more 

^ Those gentlemen express themselves thus: "In a note presented to the Academy in 
November, 1872, we published certain experiments which showed that carbonic acid 
and alcohol may be produced in fruits kept in a closed vessel, out of contact with 
atmospheric oxygen, without our being able to discover alcoholic ferment in the 
interior of those fruits. 

"M. Pasteur, as a logical deduction from the principle which he has established in 
connection with the theory of fermentation, considers that the formation of alcohol 
may be attributed to the fact that the physical and chemical processes of life in the 
cells of fruit continue under new conditions, in a manner similar to those of the cells 
of ferment. Experiments, continued during 1872, 1873, and 1874, on different fruits 
have furnished results all of which seem to us to harmonize with this proposition, and 
to establish it on a firm basis of proof." — Comptes rendus, vol. Ixxix p. 949, 1874. 

^ Pasteur, Vaites nouveaux pour servir a la connaissance de la thiorie dc! fermen- 
tations proprement dites. {Comptes rendus de I' Academic des Sciences, vol. Ixxv., p. 
784.) See in the same volume the discussion that followed; also, Pasteur, Note sur la 
production de I'alcool par les fruits, same volume, p. 1054, in which we recount the 
observations anterior to our own, made by Messrs. Lechartier and Bellamy in 1869. 



THEORY OF FERMENTATION 307 

particularly our Note of 1861, quoted word for word in the pre- 
ceding section, furnish the most conclusive evidence in favor of 
those ideas which we advocate. Indeed, as far back as 1861 we 
pointed out very clearly that if we could find plants able to live 
when deprived of air, in the presence of sugar, they would bring 
about a fermentation of that substance, in the same manner that 
yeast does. Such is the case with the fungi already studied; such, 
too, is the case with the fruits employed in the experiments of 
Messrs. Lechartier and Bellamy, and in our own experiments, the 
results of which not only confirm those obtained by these gentle- 
men, but even extend them, in so far as we have shown that fruits, 
when surrounded with carbonic acid gas immediately produce 
alcohol. When surrounded with air, they live in their aerobian state 
and we have no fermentation; immersed immediately afterwards 
in carbonic acid gas, they now assume their anaerobian state, and 
at once begin to act upon the sugar in the manner of ferments, and 
emit heat. As for seeing in these facts anything like a confirmation 
of the theory of hemi-organism, imagined by M. Fremy, the idea 
of such a thing is absurd. The following, for instance, is the theory 
of the fermentation of the vintage, according to M. Fremy.' 
"To speak here of alcoholic fermentation alone,"' our author 

' Comptes rendus, meeting of January 1 5th, 1 872. 

' As a matter of fact, M. Fremy applies his theory of hemi-organism, not only to the 
alcoholic fermentation of grape juice, but to all other fermentations. The following 
passage occurs in one of his notes (Comptes rendus de l' Academic, vol. Ixxv., p. 979, 
October 28th, 1872): 

"Experiments on Germinated Barley. — ^The object of these was to show that when 
barley, left to itself in sweetened water, produces in succession alcoholic, lactic, butyric, 
and acetic fermentations, these modifications are brought about by ferments which 
are produced inside the grains themselves, and not by atmospheric germs. More than 
forty different experiments were devoted to this part of my work." 

Need we add that this assertion is based on no substantial foundation? The cells 
belonging to the grains of barley, or their albuminous contents, never do produce cells 
of alcoholic ferment, or of lactic ferment, or butyric vibrios. Whenever those ferments 
appear, they may be traced to germs of those organisms, diffused throughout the 
interior of the grains, or adhering to the exterior surface, or existing in the water 
employed, or on the side of the vessels used. There are many ways of demonstrating 
this, of which the following is one: Since the results of our experiments have shown 
that sweetened water, phosphates, and chalk very readily give rise to lactic and butyric 
fermentations, what reason is there for supposing that if we substitute grains of 
barley for chalk, the lactic and butyric ferments will spring from those grains, in 
consequence of a transformation of their cells and albuminous substances? Surely 
there is no ground for maintaining that they are produced by hemi-organism, since a 
medium composed of sugar, or chalk, or phosphates of ammonia, potash, or magnesia 
contains no albuminous substances. This is an indirect but irresistible argument against 
the hemi-organism theory. 



308 LOUIS PASTEUR 

says, "I hold that in the production of wine it is the juice of the 
fruit itself that, in contact with air, produces grains of ferment, 
by the transformation of the albuminous matter; Pasteur, on the 
other hand, maintains that the fermentation is produced by germs 
existing outside of the grapes." 

Now what bearing on this purely imaginary theory can the fact 
have, that a whole fruit, immersed in carbonic acid gas, immediately 
produces alcohol and carbonic acid ? In the preceding passage which 
we have borrowed from M. Fremy, an indispensable condition of 
the transformation of the albuminous matter is the contact with 
air and the crushing of the grapes. Here, however, we are dealing 
with uninjured fruits in contact with carbonic acid gas. Our theory, 
on the other hand, which, we may repeat, we have advocated since 
1861, maintains that ill cells become fermentative when their vital 
action is protracted in the absence of air, which are precisely the 
conditions that hold in the experiments on fruits immersed in car- 
bonic acid gas. The vital energy is not immediately suspended 
in their cells, and the latter are deprived of air. Consequently, 
fermentation must result. Moreover, we may add, if we destroy the 
fruit, or crush it before immersing it in the gas, it no longer produces 
alcohol or fermentation of any kind, a circumstance that may be 
attributed to the fact of the destruction of vital action in the crushed 
fruit. On the other hand, in what way ought this crushing to 
affect the hypothesis of hemi-organism ? The crushed fruit ought to 
act quite as well, or even better than that which is uncrushed. In 
short, nothing can be more directly opposed to the theory of the 
mode of manifestation of that hidden force to which the name of 
hemi-organism has been given, than the discovery of the production 
of these phenomena of fermentation in fruits surrounded with 
carbonic acid gas; whilst the theory, which sees in fermentation a 
consequence of vital energy in absence of air, finds in these facts 
the strictest confirmation of an express prediction, which from the 
first formed an integral part of its statement. 

We should not be justified in devoting further time to opinions 
which are not supported by any serious experiment. Abroad, as 
well as in France, the theory of the transformation of albuminous 
substances into organized ferments had been advocated long before 



THEORY OF FERMENTATION 309 

it had been taken up by M. Fremy. It no longer commands the 
slightest credit, nor do any observers of note any longer give it the 
least attention; it might even be said that it has become a subject 
o£ ridicule. 

An attempt has also been made to prove that we have contra- 
dicted ourselves, inasmuch as in i860 we published our opinion that 
alcoholic fermentation can never occur without a simultaneous 
occurrence of organization, development, and multiplication of 
globules; or continued life, carried on from globules already formed." 
Nothing, however, can be truer than that opinion, and at the present 
moment, after fifteen years of study devoted to the subject since the 
publication to which we have referred, we need no longer say, "we 
think," but instead, "we affirm," that it is correct. It is, as a matter 
of fact, to alcoholic fermentation, properly so called, that the charge 
to which we have referred relates — to that fermentation which yields, 
besides alcohol, carbonic acid, succinic acid, glycerine, volatile acids, 
and other products. This fermentation undoubtedly requires the 
presence of yeast-cells under the conditions that we have named. 
Those who have contradicted us have fallen into the error of sup- 
posing that the fermentation of fruits is an ordinary alcoholic fer- 
mentation, identical with that produced by beer yeast, and that, 

'Pasteur, Memoirc sur la fermentation alcoolique, i860; Annates de C/timie et 
de Physique. The word globules is here used for cells. In our researches we have 
always endeavoured to prevent any confusion of ideas. We stated at the beginning of 
our Memoir of i860 that: "We apply the term alcoholic to that fermentation which 
sugar undergoes under the influence of the ferment known as beer yeast." This is, 
the fermentation which produces wine and all alcoholic beverages. This, too, is 
regarded as the type for a host of similar phenomena designated, by general usage, 
under the generic name of fermentation, and qualified by the name of one of the 
essential products of the special phenomenon under observation. Bearing in mind 
this fact in reference to the nomenclature that we have adopted, it will be seen that 
the expression alcoholic fermentation cannot be applied to every phenomenon of 
fermentation in which alcohol is produced, inasmuch as there may be a number of 
phenomena having this character in common. If we had not at starting defined that 
particular one amongst the number of very distinct phenomena, which, to the exclu- 
sion of the others, should bear the name of alcoholic fermentation, we should 
inevitably have given rise to a confusion of language that would soon pass from words 
to ideas, and tend to introduce unnecessary complexity into researches which are 
already, in themselves, sufficiently complex to necessitate the adoption of scrupulous 
care to prevent their becoming still more involved. It seems to us that any further 
doubt as to the meaning of the words alcoholic fermentation, and the sense in which 
they are employed, is impossible, inasmuch as Lavoisier, Gay-Lussac, and Th^nard 
have applied this term to the fermentation of sugar by means of beer yeast. It would 
be both dangerous and unprofitable to discard the example set by these illustrious 
masters, to whom we are indebted for our earliest knowledge of this subject. 



310 LOUIS PASTEUR 

consequently, the cells of that yeast must, according to our own theory, 
be always present. There is not the least authority for such a suppo- 
sition. When we come to exact quantitative estimations — and these 
are to be found in the figures supplied by Messrs. Lechartier and 
Bellamy — it will be seen that the proportions of alcohol and carbonic 
acid gas produced in the fermentation of fruits differ widely from 
those that we find in alcoholic fermentations properly so called, as 
must necessarily be the case since in the former the fermentation is 
effected by the cells of a fruit, but in the latter by cells of ordinary 
alcoholic ferment. Indeed we have a strong conviction that each 
fruit would be found to give rise to special action, the chemical 
equation of which would be different from that in the case of other 
fruits. As for the circumstance that the cells of these fruits cause 
fermentation without multiplying, this comes under the kind of 
activity which we have already distinguished by the expression con- 
tinuous life in cells already formed. 

We will conclude this section with a few remarks on the subject 
of equations of fermentations, which have been suggested to us prin- 
cipally in attempts to explain the results derived from the fermen- 
tation of fruits immersed in carbonic acid gas. 

Originally, when fermentations were put amongst the class of 
decompositions by contact-action, it seemed probable, and, in fact, 
was believed, that every fermentation has its own well-defined equa- 
tion which never varied. In the present day, on the contrary, it must 
be borne in mind that the equation of a fermentation varies essen- 
tially with the conditions under which that fermentation is accom- 
plished, and that a statement of this equation is a problem no less 
complicated than that in the case of the nutrition of a living being. 
To every fermentation may be assigned an equation in a general 
sort of way, an equation, however, which, in numerous points of 
detail, is liable to the thousand variations connected with the phe- 
nomena of life. Moreover, there will be as many distinct fermenta- 
tions brought about by one ferment as there are fermentable sub- 
stances capable of supplying the carbon element of the food of that 
same ferment, in the same way that the equation of the nutrition 
of an animal will vary with the nature of the food which it con- 
sumes. As regards fermentation producing alcohol, which may be 



THEORY OF FERMENTATION 3II 

effected by several different ferments, there will be as in the case 
of a given sugar, as many general equations as there are ferments, 
whether they be ferment-cells properly so called, or cells of the 
organs of living beings functioning as ferments. In the same way 
the equation of nutrition varies in the case of different animals 
nourished on the same food. And it is from the same reason that 
ordinary wort produces such a variety of beers when treated with 
the numerous alcoholic ferments which we have described. These 
remarks are applicable to all ferments alike; for instance, butyric 
ferment is capable of producing a host of distinct fermentations, in 
consequence of its ability to derive the carbonaceous part of its food 
from very different substances, from sugar, or lactic acid, or glycer- 
ine, or mannite, and many others. 

When we say that every fermentation has its own peculiar fer- 
ment, it must be understood that we are speaking of the fermentation 
considered as a whole, including all the accessory products. We do 
not mean to imply that the ferment in question is not capable of 
acting on some other fermentable substance and giving rise to 
fermentation of a very different kind. Moreover, it is quite erroneous 
to suppose that the presence of a single one of the products of a 
fermentation implies the co-existence of a particular ferment. If, 
for example, we find alcohol among the products of a fermentation, 
or even alcohol and carbonic acid gas together, this does not prove 
that the ferment must be an alcoholic ferment, belonging to alcoholic 
fermentations, in the strict sense of the term. Nor, again, does the 
mere presence of lactic acid necessarily imply the presence of lactic 
ferment. As a matter of fact, different fermentations may give rise 
to one or even several identical products. We could not say with 
certainty, from a purely chemical point of view, that we were deal- 
ing, for example, with an alcoholic fermentation properly so called, 
and that the yeast of beer must be present in it, if we had not first 
determined the presence of all the numerous products of that par- 
ticular fermentation under conditions similar to those under which 
the fermentation in question had occurred. In works on fermenta- 
tion the reader will often find those confusions against which we 
are now attempting to guard him. It is precisely in consequence of 
not having had their attention drawn to such observations that some 



312 LOUIS PASTEUR 

have imagined that the fermentation in fruits immersed in carbonic 
acid gas is in contradiction to the assertion which we originally made 
in our Memoir on alcoholic fermentation published in i860, the exact 
words of which we may here repeat: — "The chemical phenomena 
of fermentation are related essentially to a vital activity, beginning 
and ending with the latter; we believe that alcoholic fermentation 
never occurs" — we were discussing the question of ordinary alcoholic 
fermentation produced by the yeast of beer — "without the simul- 
taneous occurrence of organization, development, and multiplication 
of globules, or continued life, carried on by means of the globules 
already formed. The general results of the present Memoir seem to 
us to be in direct opposition to the opinions of MM. Liebig and 
Berzelius." These conclusions, we repeat, are as true now as they 
ever were, and are as applicable to the fermentation of fruits, of 
which nothing was known in i860, as they are to the fermentation 
produced by the means of yeast. Only, in the case of fruits, it is 
the cells of the parenchyma that function as ferment, by a continu- 
ation of their activity in carbonic acid gas whilst in the other case 
the ferment consists of cells of yeast. 

There should be nothing very surprising in the fact that fermen- 
tation can originate in fruits and form alcohol without the presence 
of yeast, if the fermentation of fruits were not confounded com- 
pletely with alcoholic fermentation yielding the same products and 
in the same proportions. It is through the misuse of words that the 
fermentation of fruits has been termed alcoholic, in a way which has 
misled many persons.'" In this fermentation, neither alcohol nor 
carbonic acid gas exists in those proportions in which they are found 
in fermentation produced by yeast; and, although we may determine 
in it the presence of succinic acid, glycerine, and a small quantity of 
volatile acids" the relative proportions of these substances will be 

'" See, for example, the communications of MM. Colin and Poggiale, and the dis- 
cussion on them, in the Bulletin de I' Academic de Medecine, March 2d, 9th, and 30th, 
and February i6th and 23rd, 1875. 

" We have elsewhere determined the formation of minute quantities of volatile 
acids in alcoholic fermentation. M. Bechamp, who studied these, recognized several 
belonging to the series of fatty acids, acetic acid, butyric acid, &c. "The presence 
of succinic acid is not accidental, but constant; if we put aside volatile acids that form 
in quantities which we may call infinitely small, we may say that succinic acid is the 
only normal acid of alcoholic fermentation." — Pasteur, Comptes rendus de I'Acadimie, 
vol. xlvii., p. 224, 1858. 



THEORY OF FERMENTATION 313 

different from what they are in the case of alcoholic fermenta- 
tion. 

§ III. Reply to Certain Critical Observations of the German 
Naturalists, Oscar Brefeld and Moritz Traube 

The essential point of the theory of fermentation which we have 
been concerned in proving in the preceding paragraphs may be 
briefly put in the statement that ferments properly so called con- 
stitute a class of beings possessing the faculty of living out of contact 
with free oxygen; or, more concisely still, we may say that fermen- 
tation is a result of life without air. 

If our affirmation were inexact, if ferment cells did require for 
their growth or for their increase in number or weight, as all other 
vegetable cells do, the presence of oxygen, whether gaseous or held 
in solution in liquids, this new theory would lose all value, its 
very raison d'etre would be gone, at least as far as the most important 
part of fermentations is concerned. This is precisely what M. Oscar 
Brefeld has endeavoured to prove in a Memoir read to the Physico- 
Medical Society of Wurzburg on July 26th, 1873, in which, although 
we have ample evidence of the great experimental skill of its author, 
he has nevertheless, in our opinion, arrived at conclusions entirely 
opposed to fact. 

"From the experiments which I have just described," he says, "it 
follows, in the most indisputable manner, that a ferment cannot 
increase without free oxygen. Pasteur's supposition that a ferment, 
unlike all other living organisms, can live and increase at the expense 
of oxygen held in combination, is, consequently, altogether wanting 
in any solid basis of experimental proof. Moreover, since, according 
to the theory of Pasteur, it is precisely this faculty of living and 
increasing at the expense of the oxygen held in combination that 
constitutes the phenomenon of fermentation, it follows that the 
whole theory, commanding though it does such general assent, is 
shown to be untenable; it is simply inaccurate." 

The experiments to which Dr. Brefeld alludes, consisted in keep- 
ing under continued study with the microscope, in a room specially 
prepared for the purpose, one or more cells of ferment in wort in an 
atmosphere of carbonic acid gas free from the least traces of free 



314 LOUIS PASTEUR 

oxygen. We have, however, recognized the fact that the increase 
of a ferment out of contact with air is only possible in the case of a 
very young specimen; but our author employed brewer's yeast taken 
after fermentation, and to this fact we may attribute the non-success 
of his growths. Dr. Brefeld, without knowing it, operated on yeast 
in one of the states in which it requires gaseous oxygen to enable 
it to germinate again. A perusal of what we have previously written 
on the subject of the revival of yeast according to its age will show 
how widely the time required for such revival may vary in different 
cases. What may be perfectly true of the state of a yeast to-day may 
not be so to-morrow, since yeast is continually undergoing modifica- 
tions. We have already shown the energy and activity with which a 
ferment can vegetate in the presence of free oxygen, and we have 
pointed out the great extent to which a very small quantity of oxygen 
held in solution in fermenting liquids can operate at the beginning 
of fermentation. It is this oxygen that produces revival in the cells 
of the ferment and enables them to resume the faculty of germinat- 
ing and condnuing their life, and of multiplying when deprived 
of air. 

In our opinion, a simple reflection should have guarded Dr. 
Brefeld against the interpretation which he has attached to his 
observations. If a cell of ferment cannot bud or increase without 
absorbing oxygen, either free or held in solution in the liquid, the 
ratio between the weight of the ferment formed during fermen- 
tation and that of oxygen used up must be constant. We had, 
however, clearly established, as far back as 1861, the fact that this 
ratio is extremely variable, a fact, moreover, which is placed beyond 
doubt by the experiments described in the preceding section. 
Though but small quantities of oxygen are absorbed, a considerable 
weight of ferment may be generated; whilst if the ferment has 
abundance of oxygen at its disposal, it will absorb much, and the 
weight of yeast formed will be still greater. The ratio between the 
weight of ferment formed and that of sugar decomposed may pass 
through all stages within certain very wide limits, the variations 
depending on the greater or less absorption of free oxygen. And 
in this fact, we believe, lies one of the most essential supports of 
the theory which we advocate. In denouncing the impossibility, as 



THEORY OF FERMENTATION 315 

he considered it, of a ferment living without air or oxygen, and so 
acting in defiance of that law which governs all Uving beings, 
animal or vegetable, Dr. Brefeld ought also to have borne in mind 
the fact which we have pointed out, that alcoholic yeast is not the 
only organized ferment which lives in an anaerobian state. It is 
really a small matter that one more ferment should be placed in 
a list of exceptions to the generality of living beings, for whom 
there is a rigid law in their vital economy which requires for 
continued life a continuous respiration, a continuous supply of free 
oxygen. Why, for instance, has Dr. Brefeld omitted the facts bearing 
on the life of the vibrios of butyric fermentation? Doubtless he 
thought we were equally mistaken in these: a few actual experi- 
ments would have put hira right. 

These remarks on the criticisms of Dr. Brefeld are also applicable 
to certain observations of M. Moritz Traube's, although, as regards 
the principal object of Dr. Bref eld's attack, we are indebted to M. 
Traube for our defence. This gentleman maintained the exactness 
of our results before the Chemical Society of Berlin, proving by 
fresh experiments that yeast is able to live and multiply without 
the intervention of oxygen. "My researches," he said, "confirm in 
an indisputable manner M. Pasteur's assertion that the multipli- 
cation of yeast can take place in media which contain no trace of 
free oxygen. . . . M. Brefeld's assertion to the contrary is erroneous." 
But immediately afterwards M. Traube adds: "Have we here a 
confirmation of Pasteur's theory? By no means. The results of my 
experiments demonstrate on the contrary that this theory has no 
true foundation." What were these results? Whilst proving that 
yeast could live without air, M. Traube, as we ourselves did, found 
that it had great difficulty in living under these conditions; indeed 
he never succeeded in obtaining more than the first stages of true 
fermentation. This was doubtless for the two following reasons: 
first, in consequence of the accidental production of secondary and 
diseased fermentations which frequently prevent the propagation of 
alcoholic ferment; and, secondly, in consequence of the original 
exhausted condition of the yeast employed. As long ago as 1861, 
we pointed out the slowness and difficulty of the vital action of 
yeast when deprived of air; and a little way back, in the preceding 



3l6 LOUIS PASTEUR 

section, we have called attention to certain fermentations that can- 
not be completed under such conditions without going into the 
causes of these peculiarities. M. Traube expresses himself thus: 
"Pasteur's conclusion, that yeast in the absence of air is able to 
derive the oxygen necessary for its development from sugar, is 
erroneous; its increase is arrested even when the greater part of the 
sugar still remains undecomposed. It is in a mixture of albuminous 
substances that yeast, when deprived of air, finds the materials for 
its development." This last assertion of M. Traube's is entirely dis- 
proved by those fermentation experiments in which, after sup- 
pressing the presence of albuminous substances, the action, never- 
theless, went on in a purely inorganic medium, out of contact with 
air, a fact, of which we shall give irrefutable proofs/ 

§ IV. Fermentation of Dextro-Tartrate of Lime* 

Tartrate of lime, in spite of its insolubility in water, is capable 
of complete fermentation in a mineral medium. 

If we put some pure tartrate of lime, in the form of a granu- 
lated, crystalline powder, into pure water, together with some sul- 
phate of ammonia and phosphates of potassium and magnesium, 
in very small proportions, a spontaneous fermentation will take 
place in the deposit in the course of a few days, although no germs 

■ Traube's conceptions are governed by a theory of fermentation entirely his own, 
a hypothetical one, as he admits, of which the following is a brief summary: "We 
have no reason to doubt," Traube says, "that the protoplasm of vegetable cells is 
itself, or contains within it, a chemical ferment which causes the alcoholic fermen- 
tation of sugar; its efficacy seems closely connected with the presence of the cell, 
inasmuch as, up to the present time, we have discovered no means of isolating it 
from the cells with success. In the presence of air this ferment oxidizes sugar by 
bringing oxygen to bear upon it; in the absence of air it decomposes the sugar by tak- 
ing away oxygen from one group of atoms of the molecule of sugar and bringing it 
to act upon other atoms; on the one hand yielding a product of alcohol by reduction, 
on the other hand a product of carbonic acid gas by oxidation." 

Traube supposes that this chemical ferment exists in yeast and in all sweet fruits, 
but only when the cells are intact, for he has proved for himself that thoroughly 
crushed fruits give rise to no fermentation whatever in carbonic acid gas. In this 
respect this imaginary chemical ferment would differ entirely from those which we 
call soluble ferments, since diastase, emulsine, &c., may be easily isolated. 

For a full account of the views of Brefeld and Traube, and the discussion which 
they carried on on the subject of the results of our cxjieriments, our readers may 
consult the Journal of the Chemical Society of Berlin, vii., p. 872. The numbers for 
September and December, 1874, in the same volume, contain the replies of the 
two authors. 

^ See Pasteur, Comptes rendu! de V Academic des Sciences, vol. Ivi., p. 416. 



THEORY OF FERMENTATION 317 

of ferment have been added. A living, organized ferment, of the 
vibrionic type, filiform, with tortuous motions, and often of im- 
mense length, forms spontaneously by the development of some 
germs derived in some way from the inevitable particles of dust 
floating in the air or resting on the surface of the vessels or material 
which we employ. The germs of the vibrios concerned in putre- 
faction are diffused around us on every side, and, in all probability, 
it is one or more of these germs that develop in the medium in 
question. In this way they effect the decomposition of the tartrate, 
from which they must necessarily obtain the carbon of their food 
without which they cannot exist, while the nitrogen is furnished by 
the ammonia of the ammoniacal salt, the mineral principles by the 
phosphate of potassium and magnesium, and the sulphur by the 
sulphate of ammonia. How strange to see organization, life, and 
motion originating under such conditions! Stranger still to think 
that this organization, life, and motion are effected without the par- 
ticipation of free oxygen. Once the germ gets a primary impulse 
on its living career by access of oxygen, it goes on reproducing 
indefinitely, absolutely without atmospheric air. Here then we 
have a fact which it is important to establish beyond the possibility 
of doubt, that we may prove that yeast is not the only organized 
ferment able to live and multiply when out of the influence of free 
oxygen. 

Into a flask, like that represented in Fig. 9, of 2.5 litres (about 
four pints) in capacity, we put: 

Pure, crystallized, neutral tartrate of lime 100 grammes 

Phosphate of ammonia i 

magnesium i 

potassium 0.5 

Sulphate of ammonia ■ 0.5 

(i gramme =15.43 grains) 

To this we added pure distilled water,. so as entirely to fill the 
flask. 

In order to expel all the air dissolved in the water and adhering 
to the solid substances, we first placed our flask in a bath of chloride 
of calcium in a large cylindrical white iron pot set over a flame. 
The exit-tube of the flask was plunged in a test tube of Bohemian 



3l8 LOUIS PASTEUR 

glass three-quarters full of distilled water, and also heated by a 
flame. We boiled the liquids in the flask and test-tube for a suflScient 
time to expel all the air contained in them. We then withdrew 
the heat from under the test-tube, and immediately afterwards 
covered the water which it contained with a layer of oil and then 
permitted the whole apparatus to cool down. 

Next day we applied a finger to the open extremity of the exit- 
tube, which we then plunged in a vessel of mercury. In this par- 



FiG. 9 

ticular experiment which we are describing, we permitted the flask 
to remain in this state for a fortnight. It might have remained there 
for a century without ever manifesting the least sign of fermen- 
tation, the fermentation of the tartrate being a consequence of life, 
and life after boiling no longer existed in the flask. When it was 
evident that the contents of the flask were perfectly inert, we impreg- 
nated them rapidly, as follows: all the liquid contained in the 
exit-tube was removed by means of a fine caoutchouc tube, and 
replaced by about i c. (about 17 minims) of liquid and deposit 
from another flask, similar to the one we have just described, but 
which had been fermenting spontaneously for twelve days; we lost 
no time in refilling completely the exit-tube with water which had 



THEORY OF FERMENTATION 319 

been first boiled and then cooled down in carbonic acid gas. This 
operation lasted only a few minutes. The exit-tube was again 
plunged under mercury. Subsequently the tube was not moved 
from under the mercury, and as it formed part of the flask, and 
there was neither cork nor india-rubber, any introduction of air 
was consequently impossible. The small quantity of air introduced 
during the impregnation was insignificant and it might even be 
shown that it injured rather than assisted the growth of the organ- 
isms, inasmuch as these consisted of adult individuals which had 
lived without air and might be liable to be damaged or even 
destroyed by it. Be this as it may, in a subsequent experiment we 
shall find the possibility removed of any aeration taking place in 
this way, however infinitesimal, so that no doubts may linger on 
this subject. 

The following days the organisms multiplied, the deposit of tar- 
trate gradually disappeared, and a sensible ferment action was mani- 
fest on the surface, and throughout the bulk of the liquid. The 
deposit seemed lifted up in places, and was covered with a layer 
of dark-grey colour, puffed up, and having an organic and gelati- 
nous appearance. For several days, in spite of this action in the 
deposit, we detected no disengagement of gas, except when the 
flask was slightly shaken, in which case rather large bubbles adher- 
ing to the deposit rose, carrying with them some solid particles, 
which quickly fell back again, whilst the bubbles diminished in 
size as they rose, from being partially taken into solution, in conse- 
quence of the liquid not being saturated. The smallest bubbles had 
even time to dissolve completely before they could reach the surface 
of the liquid. In -course of time the liquid was saturated, and the 
tartrate was gradually displaced by mammillated crusts, or clear, 
transparent crystals of carbonate of lime at the bottom and on the 
sides of the vessel. 

The impregnation took place on February loth, and on March 
15th the liquid was nearly saturated. The bubbles then began to 
lodge in the bent part of the exit-tube, at the top of the flask. A, 
glass measuring-tube containing mercury was now placed with its 
open end over the point of the exit-tube under the mercury in the 
trough, so that no bubble might escape. A steady evolution of gas 



320 LOUIS PASTEUR 

went on from the 17th to the 18th, 17.4 cc. (1.06 cubic inches) 
having been collected. This was proved to be nearly absolutely pure 
carbonic acid, as indeed might have been suspected from the fact 
that the evolution did not begin before a distinct saturation of the 
liquid was observed.' 

The liquid, which was turbid on the day after its impregnation, 
had, in spite of the liberation of gas, again become so transparent 
that we could read our handwriting through the body of the flask. 
Notwithstanding this, there was still a very active operation going 
on in the deposit, but it was confined to that spot. Indeed, the 
swarming vibrios were bound to remain there, the tartrate of lime 
being still more insoluble in water saturated with carbonate of lime 
than it is in pure water. A supply of carbonaceous food, at all 
events, was absolutely wanting in the bulk of the liquid. Every 
day we continued to collect and analyze the total amount of gas 
disengaged. To the very last it was composed of pure carbonic acid 
gas. Only during the first few days did the absorption by the con- 
centrated potash leave a very minute residue. By April 26th all 
liberation of gas had ceased, the last bubbles having risen in the 
course of April 23rd. The flask had been all the time in the oven, 
at a temperature between 25° C. and 28° C. (77° F. and 83° F.). 
The total volume of gas collected was 2.135 litres (130.2 cubic 
inches) . To obtain the whole volume of gas formed we had to add 
to this what was held in the liquid in the state of acid carbonate 
of lime. To determine this we poured a portion of the liquid from 
the flask into another flask of similar shape, but smaller, up to the 
gaugemark on the neck.'' This smaller flask had been previously 
filled with carbonic acid. The carbonic acid of the fermented liquid 
was then expelled by means of heat, and collected over mercury. 
In this way we found a volume of 8.322 litres (508 cubic inches) 
of gas in solution, which, added to the 2.135 litres, gave a total of 
10.457 litres (638.2 cubic inches) at 20° and 760 mm., which, calcu- 
lated to 0° C. and 760 mm. atmospheric pressure (32° F. and 30 

' Carbonic acid being considerably more soluble than other gases possible under 
the circumstances. — Ed. 

* We had to avoid filling the small flask completely, for fear of causing some of the 
liquid to pass on to the surface of the mercury in the measuring tube. The liquid 
condensed by boiling forms pure water, the solvent affinity of which for carbonic acid, 
at the temperature we employ, is well known. 



THEORY OF FERMENTATION 32 1 

inches) gave a weight of 19.700 grammes (302.2 grains) of carbonic 
acid. 

Exactly half of the lime in the tartrate employed got used up in 
the soluble salts formed during fermentation; the other half was 
partly precipitated in the form of carbonate of lime, partly dissolved 
in the liquid by the carbonic acid. The soluble salts seemed to us 
to be a mixture or combination of i equivalent of metacetate of 
lime, with 2 equivalents of the acetate, for every 10 equivalents of 
carbonic acid produced, the whole corresponding to the fermen- 
tation of 3 equivalents of neutral tartrate of lime.^ This point, how- 
ever, is worthy of being studied with greater care: the present state- 
ment of the nature of the products formed is given with all reserve. 
For our point, indeed, the matter is of little importance, since the 
equation of the fermentation does not concern us. 

After the completion of fermentation there was not a trace of 
tartrate of lime remaining at the bottom of the vessel: it had dis- 
appeared gradually as it got broken up into the different products 
of fermentation, and its place was taken by some crystallized car- 
bonate of lime — the excess, namely, which had been unable to 
dissolve by the action of the carbonic acid. Associated, moreover, 
with this carbonate of lime there was a quantity of some kind of 
animal matter, which, under the microscope, appeared to be com- 
posed of masses of granules mixed with very fine filaments of vary- 
ing lengths, studded with minute dots, and presenting all the 
characteristics of a nitrogenous organic substance.* That this was 

* The following is a curious consequence of these numbers and of the nature of the 
products of this fermentation. The carbonic acid liberated being quite pure, especially 
when the liquid has been boiled to expel all air from the flask, and capable of perfect 
solution, it follows that the volume of liquid being sufficient and the weight of tartrate 
suitably chosen — we may set aside tartrate of lime in an insoluble, crystalline powder, 
along with phosphates at the bottom of a closed vessel full of water, and find soon 
afterwards in their place carbonate of lime, and in the liquid soluble salts of lime, 
with a mass of organic matter at the bottom, without any liberation of gas or appear- 
ance of fermentation ever taking place, except as far as the vital action and transforma- 
tion in the tartrate are concerned. It is easy to calculate that a vessel or flask of five 
litres (rather more than a gallon) would be large enough for the accomplishment of 
this remarkable and singularly quiet transformation, in the case of 50 grammes (767 
grains) of tartrate of lime. 

^ We treated the whole deposit with dilute hydrochloric acid, which dissolved the 
carbonate of lime, and the insoluble phosphates of calcium and magnesium; after- 
wards filtering the liquid through a weighed filter paper. Dried at 100° C. (212° F.), 
the weight of the organic matter thus obtained was 0.54 gramme (8.3 grains), which 
was rather more than jjiyth of the weight of fermentable matter. 




322 LOUIS PASTEUR 

really the ferment is evident enough from all that we have already 
said. To convince ourselves more thoroughly of the fact, and at 
the same time to enable us to observe the mode of activity of the 
organism, we instituted the following supplementary observation. 
Side by side with the experiment just described, we conducted a 
similar one, which we intermitted after the fermentation was some- 
what advanced, and about half of the tartrate 
dissolved. Breaking off with a file the exit- 
tube at the point where the neck began to 
narrow off, we took some of the deposit from 
the bottom by means of a long straight piece 
of tubing, in order to bring it under micro- 
scopical examination. We found it to consist 
'°' '° of a host of long filaments of extreme tenuity, 

their diameter being about nrWth of a millimetre (0.000039 in.); 
their length varied, in some cases being as much as -/j-th of a milli- 
metre (0.0019 i"^-)' ^ crowd of these long vibrios were to be seen 
creeping slowly along, with a sinuous movement, showing three, 
four, or even five flexures. The filaments that were at rest had the 
same aspect as these last, with the exception that -they appeared 
punctuate, as though composed of a series of granules arranged in 
irregular order. No doubt these were vibrios in which vital action 
had ceased, exhausted specimens which we may compare with the 
old granular ferment of beer, whilst those in motion may be com- 
pared with young and vigorous yeast. The absence of movement in 
the former seems to prove that this view is correct. Both kinds 
showed a tendency to form clusters, the compactness of which 
impeded the movements of those which were in motion. Moreover, 
it was noticeable that the masses of these latter rested on tartrate 
not yet dissolved, whilst the granular clusters of the others rested 
directly on the glass, at the bottom of the flask, as if, having decom- 
posed the tartrate, the only carbonaceous food at their disposal, they 
had then died on the spot where we captured them, from inability 
to escape, precisely in consequence of that state of entanglement 
which they combined to form, during the period of their active 
development. Besides these we observed vibrios of the same 
diameter, but of much smaller length, whirling round with great 



THEORY OF FERMENTATION 323 

rapidity, and darting backwards and forwards; these were probably 
identical with the longer ones, and possessed greater freedom o£ 
movement, no doubt in consequence of their shortness. Not one 
of these vibrios could be found throughout the mass of the liquid. 

We may remark that as there was a somewhat putrid odour 
from the deposit in which the vibrios swarmed, the action must 
have been one of reduction, and no doubt to this fact was due the 
greyish coloration of the deposit. We suppose that the substances 
employed, however pure, always contain some trace of iron, which 
becomes converted into the sulphide, the black colour of which 
would modify the originally white deposit of insoluble tartrate and 
phosphate. 

But what is the nature of these vibrios? We have already said 
that we believe that they are nothing but the ordinary vibrios of 
putrefaction, reduced to a state of extreme tenuity by the special 
conditions of nutrition involved in the fermentable medium used; 
in a word, we think that the fermentation in question might be 
called putrefaction of tartrate of lime. It would be easy enough to 
determine this point by growing the vibrios of such fermentation 
in media adapted to the production of the ordinary forms of vibrio; 
but this is an experiment which we have not ourselves tried. 

One word more on the subject of these curious beings. In a 
great many of them there appears to be something like a clear spot, 
a kind of bead, at one of their extremities. This is an illusion 
arising from the fact that the extremity of these vibrios is curved, 
hanging downwards, thus causing a greater refraction at that 
particular point, and leading us to think that the diameter is greater 
at that extremity. We may easily undeceive ourselves if we watch 
the movements of the vibrio, when we will readily recognize the 
bend, especially as it is brought into the vertical plane passing over 
the rest of the filament. In this way we will see the bright spot, the 
head, disappear, and then reappear. 

The chief inference that it concerns us to draw from the preceding 
facts is one which cannot admit of doubt, and which we need not 
insist on any further — namely that vibrios, as met with in the 
fermentation of neutral tartrate of lime, are able to live and multiply 
when entirely deprived of air. 



324 LOUIS PASTEUR 

■^ V. — Another Example of Life Without Air — Fermentation 
OF Lactate of Lime 

As another example o£ life without air, accompanied by fermen- 
tation properly so called, we may lastly cite the fermentation of 
lactate of lime in a mineral medium. 

In the experiment described in the last paragraph, it will be 
remembered that the ferment liquid and the germs employed in 
its impregnation came in contact with air, although only for a 
very brief time. Now, notwithstanding that we possess exact obser- 
vations which prove that the diffusion of oxygen and nitrogen in 
a liquid absolutely deprived of air, so far from taking place rapidly, 
is, on the contrary, a very slow process indeed; yet we were anxious 
to guard the experiment that we are about to describe from the 
slightest possible trace of oxygen at the moment of impregnation. 

We employed a liquid prepared as follows: Into from 9 to 10 
litres (somewhat over 2 gallons) of pure water the following salts' 
were introduced successively, viz: 

Pure lactate of lime 225 grammes 

Phosphate of ammonia 0.75 " 

Phosphate of potassium 0.4 " 

Sulphate of magnesium 0.4 " 

Sulphate of ammonia 0.2 " 

(i gramme= 15.43 grains) 

On March 23rd, 1875, we filled a 6 litre (about 11 pints) flask, 
of the shape represented in Fig. ii, and placed it over a heater. 
Another flame was placed below a vessel containing the same liquid, 
into which the curved tube of the flask plunged. The liquids in 
the flask and in the basin were raised to boiling together, and kept 
in this condition for more than half-an-hour, so as to expel all the 
air held in solution. The liquid was several times forced out of the 
flask by the steam, and sucked back again; but the portion which 
re-entered the flask was always boiling. On the following day when 

• should the solution of lactate of lime be turbid, it may be clarified by filtration, 
after previously adding a small quantity of phosphate of ammonia, which throws down 
phosphate of lime. It is only after this process of clarification and filtration that the 
phosphates of the formula are added. The solution soon becomes turbid if left in 
contact with air, in consequence of the spontaneous formation of bacteria. 



THEORY OF FERMENTATION 325 

the flask had cooled, we transferred the end of the dehvery tube to 
a vessel full of mercury and placed the whole apparatus in an oven 
at a temperature varying between 25° C. and 30° C. (77° F. and 
86° F.) ; then, after having refilled the small cylindrical tap-funnel 
with carbonic acid, we passed into it with all necessary precautions 
10 cc. (0.35 fl. oz.) of a liquid similar to that described, which had 




Fig. II 



been already in active fermentation for several days out of con- 
tact with air and now swarmed with vibrios. We then turned the 
tap of the funnel, until only a small quantity of liquid was left, 
just enough to prevent the access of air. In this way the impreg- 
nation was accomplished without either the ferment-liquid or the 
ferment-germs having been brought in contact, even for the shortest 
space, with the external air. The fermentation, the occurrence of 
which at an earlier or later period depends for the most part on 
the condition of the impregnating germs, and the number intro- 
duced in the act, in this case began to manifest itself by the appear- 
ance of minute bubbles from March 29th. But not until April 
9th did we observe bubbles of larger size rise to the surface. From 



326 LOUIS PASTEUR 

that date onward they continued to come in increasing number, 
from certain points at the bottom of the flask, where a deposit of 
earthy phosphates existed; and at the same time the hquid, which 
for the first few days remained perfectly clear, began to grow turbid 
in consequence of the development of vibrios. It was on the same 
day that we first observed a deposit on the sides of carbonate of 
lime in crystals. 

It is a matter of some interest to notice here that, in the mode of 
procedure adopted, everything combined to prevent the interference 
of air. A portion of the liquid expelled at the beginning of the 
experiment, partly because of the increased temperature in the oven 
and partly also by the force of the gas, as it began to be evolved 
from the fermentative action, reached the surface of the mercury, 
where, being the most suitable medium we know for the growth of 
bacteria, it speedily swarmed with these organisms.^ In this way any 
passage of air, if such a thing were possible, between the mercury 
and the sides of the delivery-tube was altogether prevented, since 
the bacteria would consume every trace of oxygen which might 
be dissolved in the liquid lying on the surface of the mercury. 
Hence it is impossible to imagine that the slightest trace of oxygen 
could have got into the liquid in the flask. 

Before passing on we may remark that in this ready absorption 
of oxygen by bacteria we have a means of depriving fermentable 
liquids of every trace of that gas with a facility and success equal 
or even greater than by the preliminary method of boiling. Such 
a solution as we have described, if kept at summer heat, without any 
previous boiling, becomes turbid in the course of twenty-four hours 
from a spontaneous development of bacteria; and it is easy to prove 

^The naturalist Cohn, of Breslau, who published an excellent work on bacteria in 
1872, described, after Mayer, the composition of a liquid peculiarly adapted to the 
propagation of these organisms, which it would be well to compare for its utility in 
studies of this kind with our solution of lactate and phosphates. The following 
b Cohn's formula: 

Distilled water 20 cc. (0.7 fl. oz.) 

Phosphate of potassium o.i gramme (1.5 grains) 

Sulphate of magnesium o.i " " 

Tribasic phosphate of lime o.oi " (0.15 grain) 

Tartrate of ammonia 0.2 " (3 grains) 

This liquid, the author says, has a feeble acid reaction and forms a perfectly 
clear solution. 



THEORY OF FERMENTATION 327 

that they absorb all the oxygen held in solution.^ If we completely 
fill a flask of a few litres capacity (about a gallon) (Fig. 9) with 
the liquid described, taking care to have the delivery-tube also 
filled, and its opening plunged under mercury, and, forty-eight hours 
afterwards by means of a chloride of calcium bath, expel from the 
liquid on the surface of the mercury all the gas which it holds in 
solution, this gas, when analyzed, will be found to be composed 
of a mixture of nitrogen and carbonic acid gas, without the least 
trace of oxygen. Here, then, we have an excellent means of depriv- 
ing the fermentable liquid of air; we simply have completely to 
fill a flask with the liquid, and place it in the oven, merely avoid- 
ing any addition of butyric vibrios, before the lapse of two or three 
days. We may wait even longer; and then, if the liquid does 
become impregnated spontaneously with vibrio germs, the liquid, 
which at first was turbid from the presence of bacteria, will become 
bright again, since the bacteria, when deprived of life, or, at least, 
of the power of moving, after they have exhausted all the oxygen 
in solution, will fall inert to the bottom of the vessel. On several 
occasions we have determined this interesting fact, which tends to 
prove that the butyric vibrios cannot be regarded as another form 
of bacteria, inasmuch as, on the hypothesis of an original relation 
between the two productions, butyric fermentation ought in every 
case to follow the growth of bacteria. 

We may also call attention to another striking experiment, well 
suited to show the effect of differences in the composition of the 
medium upon the propagation of microscopic beings. The fermen- 
tation which we last described commenced on March 27th and 
continued until May loth; that to which we are now to refer, how- 
ever, was completed in four days, the liquid employed being similar 
in composition and quantity to that employed in the former experi- 
ment. On April 23, 1875, we filled a flask of the same shape as that 
represented in Fig. ii, and of similar capacity, viz., 6 litres, with a 
liquid composed as described at page 324. This liquid had been 
previously left to itself for five days in large open flasks, in conse- 
quence of which it had developed an abundant growth of bacteria. 

'On the rapid absorption of oxygen by bacteria, see also our Memoire of 1872, sur 
les Generations dites Spontanees, especially the note on page 78. 



328 LOUIS PASTEUR 

On the fifth day a few bubbles, rising from the bottom of the 
vessels, at long intervals, betokened the commencement of butyric 
fermentation, a fact, moreover, confirmed by the microscope, in the 
appearance of the vibrios of this fermentation in specimens of the 
liquid taken from the bottom of the vessels, the middle of its mass, 
and even in the layer on the surface that was swarming with bacteria. 
We transferred the liquid so prepared to the 6-litre flask arranged 
over the mercury. By evening a tolerably active fermentation had 
begun to manifest itself. On the 24th this fermentation was pro- 
ceeding with astonishing rapidity, which continued during the 25th 
and 26th. During the evening of the 26th it slackened, and on the 
27th all signs of fermentation had ceased. This was not, as might 
be supposed, a sudden stoppage due to some unknown cause; the 
fermentation was actually completed, for when we examined the 
fermented liquid on the 28th we could not find the smallest quantity 
of lactate of lime. If the needs of industry should ever require the 
production of large quantities of butyric acid, there would, beyond 
doubt, be found in the preceding fact valuable information in 
devising an easy method of preparing that product in abundance.* 

Before we go any further, let us devote ome attention to the 
vibrios of the preceding fermentations. 

On May 27th, 1862, we completely filled a flask capable of holding 
2.780 litres (about five pints) with the solution of lactate and phos- 
phates.'' We refrained from impregnating it with any germs. The 

^ In what way are we to account for so great a difference between the two fermen- 
tations that we have just described? Probably it was owing to some modification 
effected in the medium by the previous life of the bacteria, or to the special character 
of the vibrios used in impregnation. Or, again, it might have been due to the action 
of the air, which, under the conditions of our second experiment, was not absolutely 
eliminated, since we took no precaution against its introduction at the moment of 
filling our flask, and this would tend to facilitate the multiplication of anaerobian 
vibrios, just as, under similar conditions, would have been the case if we had been 
dealing with a fermentation by ordinary yeast. 

* In this case the liquid was composed as follows : A saturated solution of lactate of 
lime, at a temperature of 25° C. (77° F.), was prepared, containing for every 100 cc. 
(3^ fl. oz.) 25.65 grammes (394 grains) of the lactate, CsHsOsCaO (neiv notation, 
CeHioCflOs). This solution was rendered very clear by the addition of i gramme of 
phosphate of ammonia and subsequent filtration. For a volume of 8 litres (14 pints) 
of this clear saturated solution we used (i gramme^i5.43 grains): 

Phosphate of ammonia 2 grammes 

Phosphate of potassium i 

Phosphate of magnesium i " 

Sulphate of ammonia 0.5 " 



THEORY OF FERMENTATION 329 

liquid became turbid from a development of bacteria and then 
underwent butyric fermentation. By June 9th the fermentation had 
become sufficiently active to enable us to collect in the course of 
twenty-four hours, over mercury, as in all our experiments, about 
100 cc. (about 6 cubic inches) of gas. By June nth, judging from 
the volume of gas liberated in the course of twenty-four hours, the 
activity of the fermentation had doubled. We examined a drop of 
the turbid liquid. Here are the notes accompanying the sketch 
(Fig. 12) as they stand in our note-book: "A swarm « n 

of vibrios, so active in their movements that the eye \/ u5 
has great difficulty in following them. They may be " ^ ilpV^f 
seen in pairs throughout the field, apparently making f 'i" " 
efforts to separate from each other. The connection F'°- '^ 
would seem to be by some invisible, gelatinous thread, which yields 
so far to their efforts that they succeed in breaking away from actual 
contact, but yet are, for a while, so far restrained that the move- 
ments of one have a visible effect on those of the other. By and 
by, however, we see a complete separation effected, and each moves 
on its separate way with an activity greater than it ever had be- 
fore." 

One of the best methods that can be employed for the micro- 
scopical examination of these vibrios, quite out of contact with air, 
is the following. After butyric fermentation has been going on for 
several days in a flask (Fig. 13), w:e connect this flask by an india- 
rubber tube with one of the flattened bulbs previously described, 
which we then place on the stage of the microscope (Fig. 13). 
When we wish to make an observation we close, under the mercury, 
at the point b, the end of the drawn-out and bent delivery-tube. 
The continued evolution of gas soon exerts such a pressure within 
the flask, that when we open the tap r, the liquid is driven into the 
bulb //, until it becomes quite full and the liquid flows over into 
the glass V. In this manner we may bring the vibrios under obser- 
vation without their coming into contact with the least trace of 
air, and with as much success as if the bulb, which takes the place 
of an object glass, had been plunged into the very centre of the 
flask. The movements and fissiparous multiplication of the vibrios 
may thus be seen in all their beauty, and it is indeed a most interest- 



330 LOUIS PASTEUR 

ing sight. The movements do not immediately cease when the 
temperature is suddenly lowered, even to a considerable extent, 
15° C. (59° F.) for example; they are only slackened. Neverthe- 
less, it is better to observe them at the temperatures most favourable 
to fermentation, even in the oven where the vessels employed in the 




Fig. 13 



experiment are kept at a temperature between 25° C. and 30° C. 
(77° F. and 86° F.). 

We may now continue our account of the fermentation which 
we were studying when we made this last digression. On June 17th 
that fermentation produced three times as much gas as it did on 
June nth, when the residue of hydrogen, after absorption by potash, 
was 72.6 per cent.; whilst on the 17th it was only 49.2 per cent. Let 
us again discuss the microscopic aspect of the turbid liquid at this 




THEORY OF FERMENTATION 33 1 

Stage. Appended is the sketch we made (Fig. 14) and our notes on 
it: "A most beautiful object: vibrios all in motion, advancing or 
undulating. They have grovv^n considerably in bulk and length 
since the nth; many of them are joined together in long sinuous 
chains, very mobile at the articulations, visibly 
less active and more wavering in proportion 
to the number that go to form the chain, 
of the length of the individuals." This descrip- 
tion is applicable to the majority of the vibrios 
which occur in cyhndrical rods and are homo- 
geneous in aspect. There are others, of rare 
occurrence in chains, which have a clear cor- 
puscle, that is to say, a portion more refrac- 
tive than other parts of the segments, at one of their extremities. 
Sometimes the foremost segment has the corpuscle at one end, some- 
times the other. The long segments of the commoner kind attain 
a length of from 10 to 30 and even 45 thousandths of a millimetre. 
Their diameter is from i'/2 to 2, very rarely 3, thousandths of a 
millimetre.^ 

On June 28th, fermentation was quite finished; there was no 
longer any trace of gas, nor any lactate in solution. All the infusoria 
were lying motionless at the bottom of the flask. The liquid 
clarified by degrees, and in the course of a few days became quite 
bright. Here we may inquire, were these motionless infusoria, 
which from complete exhaustion of the lactate, the source of the 
carbonaceous part of their food, were now lying inert at the bottom 
of the fermenting vessel — were they dead beyond the power of 
revival.? ' The following experiment leads us to believe that they 
were not perfectly lifeless, and that they might behave in the same 

' I millimetxe^o.039 inch: hence the dimensions indicated will be — ^length, from 
0.00039 to 0.00117, or even 0.00176 in.; diameter, from 0.000058 to 0.000078, rarely 
0.000 1 17 in. — D. C. R. 

' The carbonaceous supply, as we remarked, had failed them, and to this failure 
the absence of vital action, nutrition, and multiplication was attributable. The liquid, 
however, contained butyrate of lime, a salt possessing properties similar to those of 
the lactate. Why could not this salt equally well support the life of the vibrios.? The 
explanation of the difficulty seems to us to lie simply in the fact that lactic acid 
produces heat by its decomposition, whilst butyric acid does not, and the vibrios 
seem to require heat during the chemical process of their nutrition. 



332 LOUIS PASTEUR 

manner as the yeast of beer, which, after it has decomposed all the 
sugar in a fermentable liquid, is ready to revive and multiply in a 
fresh saccharine medium. On April 22nd, 1875, we left in the oven 
at a temperature of 25° C. (77° F.) a fermentation of lactate of 
lime that had been completed. The delivery tube of the flask A, 
(Fig. 15), in which it had taken place, had never been withdrawn 
from under the mercury. We kept the liquid under observation 




Fig. 15 

daily, and saw it gradually become brighter; this went on for 
fifteen days. We then filled a similar flask, B, with the solution of 
lactate, which we boiled, not only to kill the germs of vibrios 
which the liquid might contain, but also to expel the air that it 
held in solution. When the flask, B, had cooled, we connected the 
two flasks, avoiding the introduction of air,* after having slightly 
shaken the flask. A, to stir up the deposit at the bottom. There was 
then a pressure due to carbonic acid at the end of the delivery tube 
of this latter flask, at the point a, so that on opening the taps r and 
s, the deposit at the bottom of flask A was driven over into flask B, 
which in consequence was impregnated with the deposit of a 
fermentation that had been completed fifteen days before. Two 

' To do this it is sufficient, first, to fill the curved ends of the stopcocked tubes 
of the flasks, as well as the india-rubber tube c c which connects them, with boiling 
water that contains no air. 



THEORY OF FERMENTATION 333 

days after impregnation the flask B began to show signs of fermen- 
tation. It follows that the deposit of vibrios of a completed butyric 
fermentation may be kept, at least for a certain time, without losing 
the power of causing fermentation. It furnishes a butyric ferment, 
capable of revival and action in a suitable fresh fermentable medium. 
The reader who has attentively studied the facts which we have 
placed before him cannot, in our opinion, entertain the least doubt 
on the subject of the possible multiplication of the vibrios of a 
fermentation of lactate of lime out of contact with atmospheric 
oxygen. If fresh proofs of this important proposition were necessary, 
they might be found in the following observations, from which it 
may be inferred that atmospheric oxygen is capable of suddenly 
checking a fermentation produced by butyric vibrios, and rendering 
them absolutely motionless, so that it cannot be necessary to enable 
them to live. On May 7th, 1862, we placed in the oven a flask 
holding 2.580 litres (4'/^ pints), and filled with the solution of lactate 
of lime and phosphates, which we had impregnated on the 9th with 
two drops of a liquid in butyric fermentation. In the course of a 
few days fermentation declared itself: on the iBth it was active; on 
the 30th it was very active. On June ist it yielded hourly 35 cc. 
(2.3 cubic inches) of gas, containing ten per cent, of hydrogen. 
On the 2nd we began the study of the action of air on the vibrios 
of this fermentation. To do this we cut off the delivery-tube on a 
level with its point of junction to the flask, then with a 50 cc. pipette 
we took out that quantity (i54 fl- oz.) of liquid which was, of 
course, replaced at once by air. We then reversed the flask with the 
opening under the mercury, and shook it every ten minutes for more 
than an hour. Wishing to make sure, to begin with, that the oxygen 
had been absorbed we connected under the mercury the beak of the 
flask by means of a thin india-rubber tube filled with water, with a 
small flask, the neck of which had been drawn out and was filled 
with water; we then raised the large flask with the smaller kept 
above it. A Mohr's cHp, which closed the india-rubber tube, and 
which we then opened, permitted the water contained in the small 
flask to pass into the large one, whilst the gas, on the contrary, 
passed upwards from the large flask into the small one. We analyzed 
the gas immediately, and found that, allowing for the carbonic acid 



334 LOUIS PASTEUR 

and hydrogen, it did not contain more than 14.2 per cent, of oxygen, 
which corresponds to an absorption of 6.6 cc, or of 3.3 cc. (0.2 cubic 
inch) of oxygen for the 50 cc. (3.05 cubic inches) of air employed. 
Lastly, we again established connection by an india-rubber tube 
between the flasks, after having seen by microscopical examination 
that the movements of the vibrios were very languid. Fermentation 
had become less vigorous without having actually ceased, no doubt 
because some portions of the liquid had not been brought into con- 
tact with the atmospheric oxygen, in spite of the prolonged shaking 
that the flask had undergone after the introduction of the air. What- 
ever the cause might have been, the significance of the phenomenon 
is not doubtful. To assure ourselves further of the effect of air on 
the vibrios, we half filled two test tubes with the fermenting liquid 
taken from another fermentation which had also attained its maxi- 
mum of intensity, into one of which we passed a current of air, into 
the other carbonic acid gas. In the course of half an hour, all the 
vibrios in the aerated tube were dead, or at least motionless, and 
fermentation had ceased. In the other tube, after three hours' 
•exposure to the effects of the carbonic acid gas, the vibrios were still 
very active, and fermentation was going on. 

There is a most simple method of observing the deadly effect of 
atmospheric air upon vibrios. We have seen in the microscopical 
examination made by means of the apparatus represented in Fig. 13, 
how remarkable were the movements of the vibrios when abso- 
lutely deprived of air, and how easy it was to discern them. We will 
repeat this observation, and at the same time make a comparative 
study of the same liquid under the microscope in the ordinary way, 
that is to say, by placing a drop of the liquid on an object-glass, 
and covering it with a thin glass slip, a method which must neces- 
sarily bring the drop into contact with air, if only for a moment. 
It is surprising what a remarkable difference is observed immedi- 
ately between the movements of the vibrios in the bulb and those 
under the glass. In the case of the latter, we generally see all move- 
ment at once cease near the edges of the glass, where the drop of 
liquid is in direct contact with the air; the movements continue for 
a longer or shorter time about the centre, in proportion as the air 
is more or less intercepted by the vibrios at the circumference of 



THEORY OF FERMENTATION 335 

the liquid. It does not require much skill in experiments of this 
kind to enable one to see plainly that immediately after the glass 
has been placed on the drop, which has been affected all over by 
atmospheric air, the whole of the vibrios seem to languish and to 
manifest symptoms of illness — we can think of no better expression 
to explain what we see taking place — and that they gradually recover 
their activity about the centre, in proportion as they find themselves 
in a part of the medium that is less affected by the presence of 
oxygen. 

Some of the most curious facts are to be found in connection 
with an observation, the correlative and inverse of the foregoing, 
on the ordinary aerobian bacteria. If we examine below the micro- 
scope a drop of liquid full of these organisms under a coverslip, 
we very soon observe a cessation of motion in all the bacteria which 
lie in the central portion of the liquid, where the oxygen rapidly 
disappears to supply the necessities of the bacteria existing there; 
whilst, on the other hand, near the edges of the cover-glass the 
movements are very active, in consequence of the constant supply 
of air. In spite of the speedy death of the bacteria beneath the 
centre of the glass, we see life prolonged there if by chance a bubble 
of air has been enclosed. All round this bubble a vast number of 
bacteria collect in a thick, moving circle, but as soon as all the 
oxygen of the bubble has been absorbed they fall apparently life- 
less, and are scattered by the movement of the liquid.^ 

We may here be permitted to add, as a purely historical matter, 
that it was these two observations just described, made successively 
one day in 1861, on vibrios and bacteria, that first suggested to us 
the idea of the possibility of life without air, and caused us to think 
that the vibrios which we met so frequently in our lactic fermen- 
tations must be the true butyric ferment. 

We may pause to consider an interesting question in reference to 

the two characters under which vibrios appear in butyric fermen- 

* We find this fact, which we published as long ago as 1863, confirmed in a work of 
H. Hoffmann's, published in 1869 under the title of Mimoire sur les bactiries, which 
has appeared in French (Annales dcs Sciences naturelles, 5th series, vol. ix.). On 
this subject we may cite an observation that has not yet been published. Aerobian 
bacteria lose all power of movement when suddenly plunged into carbonic acid gas; 
they recover it, however, as if they had only been suffering from anasthesia, as soon 
as they are brought into the air again. 



336 LOUIS PASTEUR 

tations. What is the reason that some vibrios exhibit refractive 
corpuscles, generally of a lenticular form, such as we see in Fig. 14. 
We are strongly inclined to believe that these corpuscles have to 
do with a special mode of reproduction in the vibrios, common 
alike to the anaerobian forms which we are studying, and the 
ordinary aerobian forms in which also the corpuscles of which we 
are speaking may occur. The explanation of the phenomenon, from 
our point of view, would be that, after a certain number of fissip- 
arous generations, and under the influence of variations in the 
composition of the medium, which is constantly changing through 
fermentation as well as through the active life of the vibrios them- 
selves, cysts, which are simply the refractive corpuscles, form along 
them at different points. From these gemmules we have ultimately 
produced vibrios, ready to reproduce others by the process of trans- 
verse division for a certain time, to be themselves encysted, later on. 
Various observations incline us to believe that, in their ordinary 
form of minute, soft, exuberant rods, the vibrios perish when sub- 
mitted to desiccation, but when they occur in corpuscular or encysted 
form they possess unusual powers of resistance and may be brought 
to the state of dry dust and be wafted about by winds. None of the 
matter which surrounds the corpuscle or cyst seems to take part in 
the preservation of the germ, when the cyst is formed, for it is all 
re-absorbed, gradually leaving the cyst bare. The cysts appear as 
masses of corpuscles, in which the most practiced eye cannot detect 
anything of an organic nature, or anything to remind one of the 
vibrios which produced them; nevertheless, these minute bodies are 
endowed with a latent vital action, and only await favourable con- 
ditions to develop long rods of vibrios. We are not, it is true, in a 
position to adduce any very forcible proofs in support of these 
opinions. They have been suggested to us by experiments, none of 
which, however, have been absolutely decisive in their favour. We 
may cite one of our observations on this subject. 

In a fermentation of glycerine in a mineral medium — the glycerine 
was fermenting under the influence of butyric vibrios — after we had 
determined the, we may say, exclusive presence of lenticular vibrios, 
with refractive corpuscles, we observed the fermentation, which for 
some unknown reason had been very languid, suddenly become 



THEORY OF FERMENTATION 337 

extremely active, but now through the influence of the ordinary 
vibrios. The gemmules with briUiant corpuscles had almost dis- 
appeared; we could see but very few, and those now consisted of 
the refractive bodies alone, the bulk of the vibrios accompanying 
them having undergone some process of re-absorption. 

Another observation which still more closely accords with this 
hypothesis is given in our work on silk-worm disease (vol. i, p. 256). 
We there demonstrated that, when we place in water some of the 
dust formed of desiccated vibrios, containing a host of these refrac- 
tive corpuscles, in the course of a very few hours large vibrios appear, 
well-developed rods fully grown, in which the brilliant points are 
absent; whilst in the water no process of development from smaller 
vibrios is to be discerned, a fact which seems to show that the former 
had issued fully grown from the refractive corpuscles, just as we see 
colpoda issue with their adult aspect from the dust of their cysts. 
This observation, we may remark, furnishes one of the best proofs 
that can be adduced against the spontaneous generation of vibrios 
or bacteria, since it is probable that the same observation applies 
to bacteria. It is true that we cannot say of mere points of dust 
examined under the microscope, that one particular germ belongs to 
vibrio, another to bacterium; but how is it possible to doubt that 
the vibrios issue, as we see them, from an ovum of some kind, a 
cyst, or germ, of determinate character, when, after having placed 
some of those indeterminate motes of dust into clean water, we 
suddenly see, after an interval of not more than one or two hours, 
an adult vibrio crossing the field of the microscope, without our 
having been able to detect any intermediate state between its birth 
and adolescence? 

It is a question whether differences in the aspect and nature of 
vibrios, which depend upon their more or less advanced age, or are 
occasioned by the influence of certain conditions on the medium in 
which they propagate, do not bring about corresponding changes 
in the course of the fermentation and the nature of its products. 
Judging at least from the variations in the proportions of hydrogen 
and carbonic acid gas produced in butyric fermentations, we are 
inclined to think that this must be the case; nay, more, we find 
that hydrogen is not even a constant product in these fermentations. 



338 LOUIS PASTEUR 

We have met with butyric fermentations of lactate of lime which 
did not yield the minutest trace of hydrogen, or anything besides 
carbonic acid. Fig. 16 represents the vibrios which we observed in 
<v a a fermentation of this kind. They present no 



^'a ^^jj^ special features. Butyl alcohol is, according to our 



^j'*«^^fi4^ observations, an ordinary product, although it 



y^J^^ft^ "°^"^^"°"^' '"^ orumary prouucc, aiinouga 11 

**> n ^'^V ''^ varies and is by no means a necessary concomitant 

J^/n ^ "^ °°^ of these fermentations. It might be supposed, since 

'«^^^\^1^ butylic alcohol may be produced, and hydrogen be 

^ ^ </ in deficit, that the proportion of the former of 

Fig. 16 these products would attain its maximum when 

the latter assumed a minimum. This, however, is by no means 

the case; even in those few fermentations that we have met with 

in which hydrogen was absent, there was no formation of butylic 

alcohol. 

From a consideration of all the facts detailed in this section we 
can have no hesitation in concluding that, on the one hand, in 
cases of butyric fermentation, the vibrios which abound in them and 
constitute their ferment, hve without air or free oxygen; and that, 
on the other hand, the presence of gaseous oxygen operates preju- 
diciaUy against the movements and activity of those vibrios. But 
now, does it follow that the presence of minute quantities of air 
brought into contact with a liquid undergoing butyric fermentation 
would prevent the continuance of that fermentation or even exercise 
any check upon it ? We have not made any direct experiments upon 
this subject; but we should not be surprised to find that, so far 
from hindering, air may, under such circumstances, facilitate the 
propagation of the vibrios and accelerate fermentation. This is 
exactly what happens in the case of yeast. But how could we recon- 
cile this, supposing it were proved to be the case, with the fact just 
insisted on as to the danger of bringing the butyric vibrios into 
contact with air? It may be possible that life without air results 
from habit, whilst death through air may be brought about by a 
sudden change in the conditions of the existence of the vibrios. The 
following remarkable experiment is well-known: A bird is placed 
in a glass jar of one or two litres (60 to 120 cubic inches) in capacity 



THEORY OF FERMENTATION 339 

which is then closed. After a time the creature shows every sign 
of intense uneasiness and asphyxia long before it dies; a similar 
bird of the same size is introduced into the jar; the death of the 
latter takes place instantaneously, whilst the life of the former may 
still be prolonged under these conditions for a considerable time, 
and there is no difficulty even in restoring the bird to perfect health 
by taking it out of the jar. It seems impossible to deny that we 
have here a case of the adaptation of an organism to the gradual 
contamination of the medium; and so it may likewise happen that 
the anaerobian vibrios of a butyric fermentation, which develop and 
multiply absolutely without free oxygen, perish immediately when 
suddenly taken out of their airless medium, and that the result 
might be different if they had been gradually brought under the 
action of air in small quantities at a time. 

We are compelled here to admit that vibrios frequently abound 
in liquids exposed to the air, and that they appropriate the atmos- 
pheric oxygen, and could not withstand a sudden removal from its 
influence. Must we, then, believe that such vibrios are absolutely 
different from those of butyric fermentations? It would, perhaps, 
be more natural to admit that in the one case there is an adaptation 
to life with air, and in the other case an adaptation to life without 
air; each of the varieties perishing when suddenly transferred from 
its habitual condition to that of the other, whilst by a series of 
progressive changes one might be modified into the other.'" We 
know that in the case of alcoholic ferments, although these can 
actually live without air, propagation is wonderfully assisted by the 
presence of minute quantities of air ; and certain experiments which 
we have not yet published lead us to believe that, after having lived 
without air, they cannot be suddenly exposed with impunity to the 
influence of large quantities of oxygen. 

We must not forget, however, that aerobian torulae and anaero- 
bian ferments present an example of organisms apparently identical, 
in which, however, we have not yet been able to discover any ties 
of a common origin. Hence we are forced to regard them as a dis- 

'" These doubts might be easily removed by putting the matter to the test of direct 
experiment. 



340 LOUIS PASTEUR 

tinct species; and so it is possible that there may Hkewise be aerobian 
and anaerobian vibrios without any transformation of the one into 
the other. 

The question has been raised whether vibrios, especially those 
which we have shown to be the ferment of butyric and many other 
fermentations, are in their nature, animal or vegetable. M. Ch. 
Robin attaches great importance to the solution of this question, 
of which he speaks as follows:" "The determination of the nature, 
whether animal or vegetable, of organisms, either as a whole or in 
respect to their anatomical parts, assimilative or reproductive, is a 
problem which has been capable of solution for a quarter of a 
century. The method has been brought to a state of remarkable 
precision, experimentally, as well as in its theoretical aspects, since 
those who devote their attention to the organic sciences consider it 
indispensable in every observation and experiment to determine 
accurately, before anything else, whether the object of their study is 
animal or vegetable in its nature, whether adult or otherwise. To 
neglect this is as serious an omission for such students as for chemists 
would be the neglecting to determine whether it is nitrogen or 
hydrogen, urea or stearine, that has been extracted from a tissue, 
or which it is whose combinations they are studying in this or 
that chemical operation. Now, scarcely any one of those who study 
fermentations, properly so-called, and putrefactions, ever pay any 
attention to the preceding data. . . . Among the observers to whom 
I allude, even M, Pasteur is to be found, who, even in his most 
recent communications, omits to state definitely what is the nature 
of many of the ferments which he has studied, with the exception, 
however, of those which belong to the cryptogamic group called 
torulaceae. Various passages in his work seem to show that he con- 
siders the cryptogamic organisms called bacteria, as well as those 
known as vibrios, as belonging to the animal kingdom (see Bulletin 
de V Academic de Medecine, Paris, 1875, pp. 249, 251, especially 256, 
266, 267, 289, and 290). These would be very different, at least 
physiologically, the former being anaerobian, that is to say, requiring 

" Robin, Sur la nature des fermentations, &c. (Journal de I'Acadimie et de la 
Physiologie, July and August, 1875, p. 386). 



THEORY OF FERMENTATION 34 1 

no air to enable them to live, and being killed by oxygen, should it 
be dissolved in the liquid to any considerable extent." 

We are unable to see the matter in the same light as our learned 
colleague does; to our thinking, we should be labouring under a 
great delusion were we to suppose "that it is quite as serious an 
omission not to determine the animal or vegetable nature of a fer- 
ment as it would be to confound nitrogen with hydrogen or urea 
with stearine." The importance of the solutions of disputed ques- 
tions often depends on the point of view from which these are 
regarded. As far as the result of our labours is concerned, we 
devoted our attention to these two questions exclusively: i. Is the 
ferment, in every fermentation properly so called, an organized 
being? 2. Can this organized being live without air? Now, what 
bearing can the question of the animal or vegetable nature of the 
ferment, of the organized being, have upon the investigation of 
these two problems ? In studying butyric fermentation, for example, 
we endeavoured to establish these two fundamental points; i. The 
butyric ferment is a vibrio. 2. This vibrio may dispense with air 
in its life, and, as a matter of fact, does dispense with it in the act of 
producing butyric fermentation. We did not consider it at all neces- 
sary to pronounce any opinion as to the animal or vegetable nature 
of this organism, and, even up to the present moment, the idea that 
vibrio is an animal and not a plant is in our minds, a matter of 
sentiment rather than of conviction. 

M. Robin, however, would have no difficulty in determining the 
limits of the two kingdoms. According to him, "every variety of 
cellulose is, we may say, insoluble in ammonia, as also are the repro- 
ductive elements of plants, whether male or female. Whatever 
phase of evolution the elements which reproduce a new individual 
may have reached, treatment with this reagent, either cold or raised 
to boiling, leaves them absolutely intact under the eyes of the 
observer, except that their contents, from being partially dissolved, 
become more transparent. Every vegetable whether microscopic 
or not, every mycelium and every spore, thus preserves in its entirety 
its special characteristics of form, volume and structural arrange- 
ments; whilst in the case of microscopic animals, or the ova and 



342 LOUIS PASTEUR 

microscopic embryos of different members of the animal kingdom, 
the very opposite is the case." 

We should be glad to learn that the employment of a drop of 
ammonia would enable us to pronounce an opinion with this degree 
of confidence on the nature of the lowest microscopic beings; but 
is M. Robin absolutely correct in his assumptions ? That gentleman 
himself remarks that spermatozoa, which belong to animal organ- 
isms, are insoluble in ammonia, the effect of which is merely to 
make them paler. If a difference of action in certain reagents, in 
ammonia, for example, were sufficient to determine the limits of 
the animal and vegetable kingdoms, might we not argue that there 
must be a very great and natural difference between moulds and 
bacteria, inasmuch as the presence of a small quantity of acid in 
the nutritive medium facilitates the growth and propagation of the 
former, whilst it is able to prevent the life of bacteria and vibrios? 
Although as is well known, movement is not an exclusive char- 
acteristic of animals, yet we have always been inclined to regard 
vibrios as animals, on account of the peculiar character of their 
movements. How greatly they differ in this respect from the dia- 
tomacae, for example! When the vibrio encounters an obstacle it 
turns, or after assuring itself by some visual effort or other that it 
cannot overcome it, it retraces its steps. The colpoda — undoubted 
infusoria — behave in an exactly similar manner. It is true one may 
argue that the zoospores of certain cryptogamia exhibit similar 
movements; but do not these zoospores possess as much of an 
animal nature as do the spermatozoa? As far as bacteria are con- 
cerned, when, as already remarked, we see them crowd round a 
bubble of air in a liquid to prolong their life, oxygen having failed 
them everywhere else, how can we avoid believing that they are 
animated by an instinct for life, of the same kind that we find in 
animals? M. Robin seems to us to be wrong in supposing that it 
is possible to draw any absolute line of separation between the 
animal and vegetable kingdoms. The settlement of this line how- 
ever, we repeat again, no matter what it may be, has no serious 
bearing upon the questions that have been the subject of our 
researches. 

In like manner the difficulty which M. Robin has raised in object- 



THEORY OF FERMENTATION 343 

ing to the employment of the word germ, when we cannot specify 
whether the nature of that germ is animal or vegetable, is in many 
respects an unnecessary one. In all the questions which we have 
discussed, whether we were speaking of fermentation or spontaneous 
generation, the word germ has been used in the sense of origin of 
living organism. If Liebig, for example, said of an albuminous sub- 
stance that it gave birth to ferment, could we contradict him more 
plainly than by replying "No; ferment is an organized being, the 
germ of which is always present, and the albuminous substance 
merely serves by its occurrence to nourish the germ and its successive 
generations" ? 

In our Memoir of 1862, on so called spontaneous generations, 
would it not have been an entire mistake to have attempted to assign 
specific names to the microscopic organisms which we met with in 
the course of our observations? Not only would we have met with 
extreme difficulty in the attempt, arising from the state of extreme 
confusion which even in the present day exists in the classification 
and nomenclature of these microscopic organisms, but we should 
have been forced to sacrifice clearness in our work besides; at all 
events, we should have wandered from our principal object, which 
was the determination of the presence or absence of life in general, 
and had nothing to do with the manifestation of a particular kind 
of life in this or that species, animal or vegetable. Thus we have 
systematically employed the vaguest nomenclature, such as mucors, 
torulae, bacteria, and vibrios. There was nothing arbitrary in our 
doing this, whereas there is much that is arbitrary in adopting a 
definite system of nomenclature, and applying it to organisms but 
imperfectly known, the differences or resemblances between which 
are only recognizable through certain characteristics, the true signi- 
fication of which is obscure. Take, for example, the extensive array 
of widely different systems which have been invented during the 
last few years for the species of the genera bacterium and vibrio in 
the works of Cohn, H. Hoffmann, Hallier, and Billroth. The con- 
fusion which prevails here is very great, although we do not of 
course by any means place these different works on the same footing 
as regards their respective merits. 

M. Robin is, however, right in recognizing the impossibility of 



344 LOUIS PASTEUR 

maintaining in the present day, as he formerly did, "That fermen- 
tation is an exterior phenomenon, going on outside cryptogamic 
cells, a phenomenon of contact. It is probably," he adds, "an interior 
and molecular action at work in the innermost recesses of the sub- 
stance of each cell." From the day when we first proved that it is 
possible for all organized ferments, properly so called, to spring up 
and multiply from their respective germs, sown, whether consciously 
or by accident, in a mineral medium free from organic and nitrog- 
enous matters other than ammonia, in which medium the ferment- 
able matter alone is adapted to provide the ferment with whatever 
carbon enters into its composition, from that time forward the 
theories of Liebig, as well as Berzelius, which M. Robin formerly 
defended, have had to give place to others more in harmony with 
facts. We trust that the day will come when M. Robin will like- 
wise acknowledge that he has been in error on the subject of the 
doctrine of spontaneous generation, which he continues to afSrm, 
without adducing any direct proofs in support of it, at the end of 
the article to which we have been here replying. 

We have devoted the greater part of this chapter to the establish- 
ing with all possible exactness the extremely important physiological 
fact of life without air, and its correlation to the phenomena of 
fermentations properly so called — that is to say, of those which are 
due to the presence of microscopic cellular organisms. This is the 
chief basis of the new theory that we propose for the explanation 
of these phenomena. The details into which we have entered were 
indispensable on account of the novelty of the subject no less than 
on account of the necessity we were under of combating the criti- 
cisms of the two German naturalists, Drs. Oscar Brefeld and Traube, 
whose works had cast some doubts on the correctness of the facts 
upon which we had based the preceding propositions. We have 
much pleasure in adding that at the very moment we were revising 
the proofs of this chapter, we received from M. Brefeld an essay, 
dated Berlin, January, 1876, in which, after describing his later 
experimental researches, he owns with praiseworthy frankness that 
Dr. Traube and he were both of them mistaken. Life without air 
is now a proposition which he accepts as perfectly demonstrated. 
He has witnessed it in the case of mucor racemosus and has also 



THEORY OF FERMENTATION 345 

verified it in the case of yeast. "If," he says, "after the results of 
my previous researches, which I conducted with all possible exact- 
ness, I was inclined to consider Pasteur's assertion as inaccurate and 
to attack them, I have no hesitation now in recognizing them as 
true, and in proclaiming the service which Pasteur has rendered to 
science in being the first to indicate the exact relation of things in 
the phenomenon of fermentation." In his later researches. Dr. Bre- 
feld has adopted the method which we have long employed for 
demonstrating the life and multiplication of butyric vibrios in the 
entire absence of air, as well as the method of conducting growths 
in mineral media associated with fermentable substance. We need 
not pause to consider certain other secondary criticisms of Dr. 
Brefeld. A perusal of the present work will, we trust, convince him 
that they are based on no surer foundation than were his former 
criticisms. 

To bring one's self to believe in a truth that has just dawned 
upon one is the first step towards progress; to persuade others is 
the second. There is a third step, less useful perhaps, but highly 
gratifying nevertheless, which is, to convince one's opponents. 

We therefore, have experienced great satisfaction in learning that 
we have won over to our ideas an observer of singular ability, on a 
subject which is of the utmost importance to the physiology of cells. 

§ VI. Reply to the Critical Observations of Liebig, 
Published in 1870.' 

In the Memoir which we published, in i860, on alcoholic fer- 
mentation, and in several subsequent works, we were led to a dif- 
ferent conclusion on the causes of this very remarkable phenomenon 
from that which Liebig had adopted. The opinions of Mitscherlich 
and Berzelius had ceased to be tenable in the presence of the new 
facts which we had brought to light. From that time we felt sure 
that the celebrated chemist of Munich had adopted our conclusions, 
from the fact that he remained silent on this question for a long 
time, although it had been until then the constant subject of his 
study, as is shown by all his works. Suddenly there appeared in the 

' Liebig, Sur la fermentation et la source ie la force musculaire {Annates de Chimie 
et de Physique, 4th series, vol. xxiii., p. 5, 1870). 



346 LOUIS PASTEUR 

Annales de Chimie et de Physique a long essay, reproduced from a 
lecture delivered by him before the Academy of Bavaria in 1868 and 
1869. In this Liebig again maintained, not, however, without certain 
modifications, the views which he had expressed in his former pub- 
lications, and disputed the correctness of the principal facts enun- 
ciated in our Memoir of i860, on which were based the arguments 
against his theory. 

"I had admitted," he says, "that the resolution of fermentable 
matter into compounds of a simpler kind must be traced to some 
process of decomposition taking place in the ferment, and that the 
action of this same ferment on the fermentable matter must continue 
or cease according to the prolongation or cessation of the alteration 
produced in the ferment. The molecular change in the sugar, 
would, consequently, be brought about by the destruction or modifi- 
cation of one or more of the component parts of the ferment, and 
could only take place through the contact of the two substances. 
M. Pasteur regards fermentation in the following light : The chemi- 
cal action of fermentation is essentially a phenomenon correlative 
with a vital action, beginning and ending with it. He believes that 
alcoholic fermentation can never occur without the simultaneous 
occurrence of organization, development, and multiplication of 
globules, or continuous life, carried on from globules already formed. 
But the idea that the decomposition of sugar during fermentation is 
due to the development of the cellules of the ferment, is in contra- 
diction with the fact that the ferment is able to bring about the fer- 
mentation of a pure solution of sugar. The greater part of the 
ferment is composed of a substance that is rich in nitrogen and con- 
tains sulphur. It contains, moreover, an appreciable quantity of 
phosphates, hence it is difficult to conceive how, in the absence of 
these elements in a pure solution of sugar undergoing fermentation, 
the number of cells is capable of any increase." 

Notwithstanding Liebig's belief to the contrary, the idea that the 
decomposition of sugar during fermentation is intimately connected 
with a development of the cellules of the ferment, or a prolongation 
of the life of cellules already formed, is in no way opposed to the 
fact that the ferment is capable of bringing about the fermentation 
of a pure solution of sugar. It is manifest to any one who has studied 



THEORY OF FERMENTATION 347 

such fermentation with the microscope, even in those cases where 
the sweetened water has been absolutely pure, that ferment-cells do 
multiply, the reason being that the cells carry with them all the 
food-supplies necessary for the life of the ferment. They may be 
observed budding, at least many of them, and there can be no doubt 
that those which do not bud still continue to live; life has other 
ways of manifesting itself besides development and cell-proliferation. 

If we refer to the figures on page 81 of our Memoir of i860. 
Experiments D, E, F, H, I, we shall see that the weight of yeast, 
in the case of the fermentation of a pure solution of sugar, undergoes 
a considerable increase, even without taking into account the fact 
that the sugared water gains from the yeast certain soluble parts, 
since in the experiments just mentioned, the weights of solid yeast, 
washed and dried at 100° C. (212° F.), are much greater than those 
of the raw yeast employed, dried at the same temperature. 

In these experiments we employed the following weights of yeast, 
expressed in grammes (i gramme=i5.43 grains) : 

(0 2-313 

(2) 2.626 

(3) 1-198 

(4) 0-699 

(5) 0-326 

(6) 0.476 

which became, after fermentation, we repeat, without taking into 
account the matters which the sugared water gained from the yeast: 







grammes. 




grains 


(l) 2.486 


Increase 0.173 


= 


2.65 


(2) 2.963 


u 


0.337 


= 


5.16 


(3) 1-700 


tt 


0.502 


= 


7-7 


(4) 0.712 


<c 


0.013 


= 


0.2 


(5) 0-335 


<c 


0.009 


= 


0.14 


(6) 0.590 


<c 


0.114 


^ 


1-75 



Have we not in this marked increase in vveight a proof of life, or, 
to adopt an expression which may be preferred, a proof of a pro- 
found chemical work of nutrition and assimilation .'' 

We may cite on this subject one of our earlier experiments, which 
is to be found in the Comptes rendus de I'Academie for the year 
1857, and which clearly shows the great influence exerted on fer- 



348 LOUIS PASTEUR 

mentation by the soluble portion that the sugared water takes up 
from the globules of ferment: 

"We take two equal quantities of fresh yeast that have been 
washed very freely. One of these we cause to ferment in water con- 
taining nothing but sugar, and, after removing from the other all 
its soluble particles — by boiling it in an excess of water and then 
filtering it to separate the globules — we add to the filtered liquid as 
much sugar as was used in the first case along with a mere trace 
of fresh yeast insufficient, as far as its weight is concerned, to affect 
the results of our experiment. The globules which we have sown 
bud, the liquid becomes turbid, a deposit of yeast gradually forms, 
and, side by side with these appearances, the decomposition of the 
sugar is effected, and in the course of a few hours manifests itself 
clearly. These results are such as we might have anticipated. The 
following fact, however, is of importance. In effecting by these 
means the organization into globules of the soluble part of the yeast 
that we used in the second case, we find that a considerable quantity 
of sugar is decomposed. The following are the results of our experi- 
ment; 5 grammes of yeast caused the fermentation of 12.9 grammes 
of sugar in six days, at the end of which time it was exhausted. The 
soluble portion of a like quantity of 5 grammes of the same yeast 
caused the fermentation of 10 grammes of sugar in nine days, after 
which the yeast developed by the sowing was likewise exhausted." 

How is it possible to maintain that, in the fermentation of water 
containing nothing but sugar, the soluble portion of the yeast does 
not act, either in the production of new globules or the perfection 
of old ones, when we see, in the preceding experiment, that after this 
nitrogenous and mineral portion has been removed by boiling, it 
immediately serves for the production of new globules, which, under 
the influence of the sowing of a mere trace of globules, causes the 
fermentation of so much sugar ? ^ 

In short, Liebig is not justified in saying that the solution of 

^ It is important that we should here remark that, in the fermentation of pure solu- 
tion of sugar by means of yeast, the oxygen originally dissolved in the water, as well 
as that appropriated by the globules of yeast in their contact with air, has a consider- 
able effect on the activity of the fermentation. As a matter of fact, if we pass a 
strong current of carbonic acid through the sugared water and the water in which 
the yeast has been treated, the fermentation will be rendered extremely sluggish, and 
the few new cells of yeast which form will assume strange and abnormal aspects. In- 



THEORY OF FERMENTATION 349 

pure sugar, caused to ferment by means o£ yeast, contains none of 
the elements needed for the growth of yeast, neither nitrogen, sul- 
phur, nor phosphorus, and that, consequently, it should not be 
possible, by our theory, for the sugar to ferment. On the contrary, 
the solution does contain all these elements, as a consequence of the 
introduction and presence of the yeast. 

Let us proceed without examination of Liebig's criticisms: 

"To this," he goes on to say, "must be added the decomposing 
action which yeast exercises on a great number of substances, and 
which resembles that which sugar undergoes. I have shown that 
malate of lime ferments readily enough through the action of yeast, 
and that it splits up into three other calcareous salts, namely, the 
acetate, the carbonate and the succinate. If the action of yeast con- 
sists in its increase and multiplication, it is difficult to conceive this 
action in the case of malate of lime and other calcareous salts of 
vegetable acids." 

This statement, with all due deference to the opinion of our illus- 
trious critic, is by no means correct. Yeast has no action on malate 
of lime, or on other calcareous salts formed by vegetable acids. 
Liebig had previously, much to his own satisfaction, brought for- 
ward urea as being capable of transformation into carbonate of 
ammonia during alcoholic fermentation in contact with yeast. This 
has been proved to be erroneous. It is an error of the same kind 
that Liebig again brings forward here. In the fermentation of which 
he speaks (that of malate of lime), certain spontaneous ferments 
are produced, the germs of which are associated with the yeast, and 
develop in the mixture of yeast and malate. The yeast merely serves 
as a source of food for these new ferments without taking any direct 
part in the fermentations of which we are speaking. Our researches 
leave no doubt on this point, as is evident from the observations on 
the fermentation of tartrate of lime previously given. 

It is true that there are circumstances under which yeast brings 
about modifications in different substances. Doebereiner and Mit- 



deed this might have been expected, for we have seen that yeast, when somewhat 
old, is incapable of development or of causing fermentation even in a fermentable 
medium containing all the nutritive principles of yeast if the liquid has been deprived 
of air; much more should we expect this to be the case in pure sugared water, likewise 
deprived of air. 



350 LOUIS PASTEUR 

scherlich, more especially, have shown that yeast imparts to water a 
soluble material, which liquefies cane-sugar and produces inversion 
in it by causing it to take up the elements of water, just as diastase 
behaves to starch or emulsin to amygdalin. 

M. Berthelot also has shown that this substance may be isolated 
by precipitating it with alcohol, in the same way as diastase is pre- 
cipitated from its solutions.' These are remarkable facts, which 

' DoEEEREiNER, Joumol dc Chimie de Schweigger, vol. xii., p. 129, and Journal de 
Pharmacie, vol. i., p. 342. 

MiTscHERLicH, Monatshmchte d. Kon. Preuss. Al(ad. d. Wissen, zii Berlin, and 
Rapports annucls de Berzelius, Paris, 1843, 3rd year. On the occasion of a communi- 
cation on the inversion of cane-sugar by H. Rose, published in 1840, M. Mitscherlich 
observed: "The inversion of cane-sugar in alcoholic fermentation is not due to the 
globules of yeast, but to a soluble matter in the water v^ith which they mix. The 
liquid obtained by straining off the ferment on a filter paper possesses the property 
of converting cane-sugar into uncrystallizable sugar." 

Berthelot, Comptes rendus de I'Acadimie, Meeting of May 28th, i860. M. 
Berthelot confirms the preceding experiment of Mitscherlich, and proves, moreover, 
that the soluble matter of which the author speaks may be precipitated with alcohol 
without losing its invertive power. 

M. Bdchamp has applied Mitscherlich's observation, concerning the soluble fermen- 
tative part of yeast, to fungoid growths, and has made the interesting discovery that 
fungoid growths, like yeast, yield to water a substance that inverts sugar. When the 
production of fungoid growths is prevented by means of an antiseptic, the inversion 
of sugar does not take place. 

We may here say a few words respecting M. B(5champ's claim to priority of dis- 
covery. It is a well-known fact that we were the first to demonstrate that living 
ferments might be completely developed if their germs were placed in pure water 
together with sugar, ammonia, and phosphates. Relying on this established fact, that 
moulds are capable of development in sweetened water in which, according to M. 
Bechamp, they invert the sugar, our author asserts that he has proved that "living 
organized ferments may originate in media which contain no albuminous substances." 
(See Comptes rendus, vol. Ixxv., p. 1519.) To be logical, M. Bechamp might say that 
he has proved that certain moulds originate in pure sweetened water without nitrogen 
or phosphates or other mineral elements, for such a deduction might very well be 
drawn from his work, in which we do not find the least expression of astonishment 
at the possibility of moulds developing in pure water containing nothing but sugar 
without other mineral or organic principles. 

M. B<5champ's first note on the inversion of sugar was published in 1855. In it we 
find nothing relating to the influence of moulds. His second, in which that influence 
is noticed, was published in January, 1858, that is, subsequently to our work on lactic 
fermentation, which appeared in November, 1857. In that work we established for 
the first time that the lactic ferment is a living, organized being, that albuminous 
substances have no share in the production of fermentation, and that they only serve 
as the food of the ferment. M. Bechamp's note was even subsequent to our first work 
on alcoholic fermentation, which appeared on December 21st, 1857. It is since the 
appearance of these two works of ours that the preponderating influence of the life 
of microscopic organism in the phenomena of fermentation has been better understood. 
Immediately after their appearance M. Bechamp, who from 1855 had made no 
observation on the action of fungoid growths on sugar, although he had remarked 
their presence, modified his former conclusions. {Comptes rendus, January 4th, 
1858.) 



THEORY OF FERMENTATION 35 1 

are, however, at present but vaguely connected with the alcohoHc 
fermentation of sugar by means of yeast. The researches in which 
we have proved the existence of special forms of living ferments in 
many fermentations, which one might have supposed to have been 
produced by simple contact action, had established beyond doubt the 
existence of profound differences between those fermentations, 
which we have distinguished as fermentations proper, and the 
phenomena connected with soluble substances. The more we 
advance, the more clearly we are able to detect these differences. 
M. Dumas has insisted on the fact that the ferments of fermentation 
proper multiply and reproduce themselves in the process whilst the 
others are destroyed.'' Still more recently M. Miintz has shown that 
chloroform prevents fermentations proper, but does not interfere 
with the action of diastase {Comptes rendus, 1875). M. Bouchardat 
had already established the fact that hydrocyanic acids, salts of mer- 
cury, ether, alcohol, creosote, and the oils of turpentine, lemon, cloves, 
and mustard destroy or check alcoholic fermentations, whilst in no 
way interfering with the glucoside fermentations {Anncdes de 
Chitnie et de Physique, 3rd series, vol. xiv., 1845). We may add in 
praise of M. Bouchardat's sagacity, that that skilful observer has 
always considered these results as a proof that alcoholic fermentation 
is dependent on the life of the yeast-cell, and that a distinction should 
be made between the two orders of fermentation. 

M. Paul Bert, in his remarkable studies on the influence of baro- 
metric pressure on the phenomena of life, has recognized the fact 
that compressed oxygen is fatal to certain ferments, whilst under 
similar conditions it does not interfere with the action of those sub- 
stances classed under the name of soluble ferments, such as diastase 
(the ferment which inverts cane sugar), emulsin and others. During 
their stay in compressed air, ferments proper ceased their activity, 
nor did they resume it, even after exposure to air at ordinary pres- 
sures, provided the access of germs was prevented. 

We now come to Liebig's principal objection, with which he con- 

* "There are two classes of ferments; the first, of which the yeast of beer may be 
taken as the type, perpetuate and renew themselves if they can find in the liquid in 
which they produce fermentation food enough for their wants; the second, of which 
diastase is the type, always sacrifice themselves in the exercise of their activity." 
(Dumas, Comptes rendus de I'Academie, vol. Ixxv., p. 277, 1872.) 



352 LOUIS PASTEUR 

eludes his ingenious argument, and to which no less than eight or 
nine pages of the Annales are devoted. 

Our author takes up the question of the possibility of causing 
yeast to grow in sweetened water, to which a salt of ammonia and 
some yeast-ash have been added — a fact which is evidently incom- 
patible with his theory that a ferment is always an albuminous sub- 
stance on its way to decomposition. In this case the albuminous 
substance does not exist; we have only the mineral substances which 
will serve to produce it. We know that Liebig regarded yeast, and, 
generally speaking, any ferment whatever, as being a nitrogenous, 
albuminous substance which, in the same way as emulsin, for ex- 
ample, possesses the power of bringing about certain chemical 
decompositions. He connected fermentation with the easy decom- 
position of that albuminous substance, and imagined that the phe- 
nomenon occurred in the following manner: "The albuminous 
substance on its way to decomposition possesses the power of com- 
municating to certain other bodies that same state of mobility by 
which its own atoms are already affected; and through its contact 
with other bodies it imparts to them the power of decomposing or 
of entering into other combinations." Here Liebig failed to per- 
ceive that the ferment, in its capacity of a living organism, had any- 
thing to do with the fermentation. 

This theory dates back as far as 1843. In 1846 Messrs. Boutron 
and Fremy, in a Memoir on lactic fermentation, published in the 
Annales de Chimie et de Physique, strained the conclusions deducible 
from it to a most unjustifiable extent. They asserted that one and 
the same nitrogenous substance might undergo various modifica- 
tions in contact with air, so as to become successively alcoholic, 
lactic, butyric, and other ferments. There is nothing more convenient 
than purely hypothetical theories, theories which are not the neces- 
sary consequences of facts; when fresh facts which cannot be recon- 
ciled with the original hypothesis are discovered, new hypotheses 
can be tacked on to the old ones. This is exactly what Liebig and 
Fremy have done, each in his turn, under the pressure of our 
studies, commenced in 1857. In 1864 Fremy devised the theory of 
hemi-organism , which meant nothing more than that he gave up 
Liebig's theory of 1843, together with the additions which Boutron 



THEORY OF FERMENTATION 353 

and he had made to it in 1846; in other words, he abandoned the 
idea of albuminous substances being ferments, to take up another 
idea, that albuminous substances in contact with air are peculiarly 
adapted to undergo organization into new beings — that is, the liv- 
ing ferments which we had discovered — and that the ferments of 
beer and of the grape have a common origin. 

This theory of hemi-organism was word for word the antiquated 
opinion of Turpin. * * * The public, especially a certain section 
of the public, did not go very deeply into an examination of the 
subject. It was the period when the doctrine of spontaneous genera- 
tion was being discussed with much warmth. The new word hemi- 
organism, which was the only novelty in M. Fremy's theory, 
deceived people. It was thought that M. Fremy had really discov- 
ered the solution of the question of the day. It is true that it was 
rather difficult to understand the process by which an albuminous 
substance could become all at once a living and budding cell. This 
difficulty was solved by M. Fremy, who declared that it was the 
result of some power that was not yet understood, the power of 
"organic impulse."^ 

Liebig, who, as well as M. Fremy, was compelled to renounce his 
original opinions concerning the nature of ferments, devised the 
following obscure theory (Memoir by Liebig, 1870, already cited) : 

"There seems to be no doubt as to the part which the vegetable 
organism plays in the phenomenon of fermentation. It is through 
it alone that an albuminous substance and sugar are enabled to 
unite and form this particular combination, this unstable form 
under which alone, as a component part of the mycodenm, they 
manifest an action on sugar. Should the mycoderm cease to grow, 
the bond which unites the constituent parts of the cellular contents 
is loosened, and it is through the motion produced therein that the 
cells of yeast bring about a disarrangement or separation of the 
elements of the sugar into molecules." 

One might easily believe that the translator for the Annales has 
made some mistake, so great is the obscurity of this passage. 

Whether we take this new form of the theory or the old one, 
neither can be reconciled at all with the development of yeast and 

'Fremy, Comples rendtis de VAcadkmie, vol. Iviii., pp. 1065, 1864. 



354 LOUIS PASTEUR 

fermentation in a saccharine mineral medium, for in the latter 
experiment fermentation is correlative to the life of the ferment and 
to its nutrition, a constant change going on between the ferment 
and its food-matters, since all the carbon assimilated by the ferment 
is derived from sugar, its nitrogen from ammonia and phosphorus 
from the phosphates in solution. And even all said, what purpose 
can be served by the gratuitous hypothesis of contact-action or com- 
municated motion? The experiment of which we are speaking is 
thus a fundamental one; indeed, it is its possibility that constitutes 
the most effective point in the controversy. No doubt Liebig might 
say, "but it is the motion of life and of nutrition which constitutes 
your experiment, and this is the communicated motion that my 
theory requires." Curiously enough, Liebig does endeavour, as a 
matter of fact, to say this, but he does so timidly and incidentally: 
"From a chemical point of view, which point of view I would not 
willingly abandon, a vital action is a phenomenon of motion, and, 
in this double sense of life M. Pasteur's theory agrees with my own, 
and is not in contradiction with it (page 6)." This is true. Else- 
where Liebig says: 

"It is possible that the only correlation between the physiological 
act and the phenomenon of fermentation is the production, in the 
Uving cell, of the substance which, by some special property analogous 
to that by which emulsin exerts a decomposing action on salicin and 
amygdalin, may bring about the decomposition of sugar into other 
organic molecules; the physiological act, in this view, would be 
necessary for the production of this substance, but would have 
nothing else to do with the fermentation (page lo)." To this, again, 
we have no objection to raise. 

Liebig, however, does not dwell upon these considerations, which 
he merely notices in passing, because he is well aware that, as far 
as the defence of his theory is concerned, they would be mere eva- 
sions. If he had insisted on them, or based his opposition solely 
upon them, our answer would have been simply this : "If you do not 
admit with us that fermentation is correlated with the life and 
nutrition of the ferment, we agree upon the principal point. So 
agreeing, let us examine, if you will, the actual cause of fermentation; 



THEORY OF FERMENTATION 355 

— this is a second question, quite distinct from the first. Science is 
built up of successive solutions given to questions of ever increasing 
subtlety, approaching nearer and nearer towards the very essence 
of phenomena. If we proceed to discuss together the question of 
how living, organized beings act in decomposing fermentable sub- 
stances, we will be found to fall out once more on your hypothesis 
of communicated motion, since according to our ideas, the actual 
cause of fermentation is to be sought, in most cases, in the fact of 
life without air, which is the characteristic of many ferments." 

Let us briefly see what Liebig thinks of the experiment in which 
fermentation is produced by the impregnation of a saccharine min- 
eral medium, a result so greatly at variance with his mode of view- 
ing the question.^ After deep consideration he pronounces this 
experiment to be inexact, and the result ill-founded. Liebig, how- 
ever, was not one to reject a fact without grave reasons for doing 
so, or with the sole object of evading a troublesome discussion. "I 
have repeated this experiment," he says, "a great number of times, 
with the greatest possible care, and have obtained the same results 
as M. Pasteur, excepting as regards the formation and increase of 
the ferment." It was, however, the formation and increase of the 
ferment that constituted the point of the experiment. Our discus- 
sion was, therefore, distinctly limited to this: Liebig denied that 
the ferment was capable of development in a saccharine mineral 
medium, whilst we asserted that this development did actually take 
place, and was comparatively easy to prove. In 1871 we replied to 
M. Liebig before the Paris Academy of Sciences in a Note, in which 
we offered to prepare in a mineral medium, in the presence of a 
commission to be chosen for the purpose, as great a weight of fer- 
ment as Liebig could reasonably demand.' We were bolder than 
we should, perhaps, have been in 186a; the reason was that our 
knowledge of the subject had been strengthened by ten years of 
renewed research. Liebig did not accept our proposal, nor did he 
even reply to our Note. Up to the time of his death, which took 

'See our Memoir of i860 {Annales de Chimie et de Physique, vol. Iviii., p. 61, 
and following, especially pp. 69 and 70, where the details of the experiment will be 
found). 

^Pasteur, Comptes rendus de I'Aeademie des Sciences, vol. Ixxiii., pp. 1419, 1871. 



356 LOUIS PASTEUR 

place on April i8th, 1873, he wrote nothing more on the subject.' 
When we published, in i860, the details of the experiment in 
question, we pointed out at some length the difficulties of conduct- 
ing it successfully, and the possible causes of failure. We called 
attention particularly to the fact that saccharine mineral media are 
much more suited for the nutrition of bacteria, lactic ferment, and 
other lowly forms, than they are to that of yeast, and in consequence 
readily become filled with various organisms from the spontaneous 
growth of germs derived from the particles of dust floating in the 
atmosphere. The reason why we do not observe the growth of 
alcoholic ferments, especially at the commencement of the experi- 
ments, is because of the unsuitableness of those media for the life 
of yeast. The latter may, nevertheless, form in them subsequent to 
this development of other organized forms, by reason of the modifica- 
tion produced in the original mineral medium by the albuminous 
matters that they introduce into it. It is interesting to peruse, in our 
Memoir of i860, certain facts of the same kind relating to fer- 
mentation by means of albumens — that of the blood for example, 
from which, we may mention incidentally, we were led to infer the 
existence of several distinct albumens in the serum, a conclusion 
which, since then, has been confirmed by various observers, notably 
by M. Bechamp. Now, in his experiments on fermentation in 
sweetened water, with yeast-ash and a salt of ammonia, there is no 
doubt that Liebig had failed to avoid those difficulties which are 
entailed by the spontaneous growth of other organisms than yeast. 
Moreover, it is possible that, to have established the certainty of 
this result, Liebig should have had recourse to a closer microscopical 
observation than from certain passages in his Memoir he seems to 

'In his Memoir of 1870, Liebig made a remarkable admission: "My late friend 
Pelouze," he says, "had communicated to me nine years ago certain results of M. 
Pasteur's researches on fermentation. I told him that just then I was not disposed to 
alter my opinion on the cause of fermentation, and that if it were possible, by means 
of ammonia, to produce or multiply the yeast in fermenting liquors, industry would 
soon avail itself of the fact, and that I would wait to see if it did so; up to the present 
time, however, there had not been the least change in the manufacture of yeast." We 
do not know what M. Pelouze's reply was; but it is not difhcult to conceive so 
sagacious an observer remarking to his illustrious friend that the possibility of deriving 
pecuniary advantage from the wide application of a new scientific fact had never 
been regarded as the criterion of the exactness of that fact. We could prove, moreover, 
by the undoubted testimony of very distinguished practical men, notably by that of 
M. Pezeyre, director of distilleries, that upon this point also Liebig was mistaken. 



THEORY OF FERMENTATION 357 

have adopted. We have little doubt that his pupils could tell us 
that Liebig did not even employ that instrument without which 
any exact study of fermentation is not merely difficult but well- 
nigh impossible. We ourselves, for the reasons mentioned, did not 
obtain a simple alcoholic fermentation any more than Liebig did. 
In that particular experiment, the details of which we gave in our 
Memoir of i860, we obtained lactic and alcoholic fermentation to- 
gether; an appreciable quantity of lactic acid formed and arrested 
the propagation of the lactic and alcoholic ferments, so that more 
than half of the sugar remained in the liquid without fermenting. 
This, however, in no way detracted from the correctness of the con- 
clusion which we deduced from the experiment, and from other 
similar ones; it might even be said that, from a general and philo- 
sophical point of view — which is the only one of interest here — the 
result was doubly satisfactory, inasmuch as we demonstrated that 
mineral media were adapted to the simultaneous development of 
several organized ferments instead of only one. The fortuitous asso- 
ciation of different ferments could not invalidate the conclusion that 
all the nitrogen of the cells of the alcoholic and lactic ferments was 
derived from the nitrogen in the ammoniacal salts, and that all the 
carbon of those ferments was taken from the sugar, since, in the 
medium employed in our experiment, the sugar was the only sub- 
stance that contained carbon. Liebig carefully abstained from notic- 
ing this fact, which would have been fatal to the very groundwork 
of his criticisms, and thought that he was keeping up the appearance 
of a grave contradiction by arguing that we had never obtained a 
simple alcoholic fermentation. It would be unprofitable to dwell 
longer upon the subject of the difficulties which the propagation of 
yeast in a saccharine mineral medium formerly presented. As a 
matter of fact, the progress of our studies has imparted to the ques- 
tion an aspect very different from that which it formerly wore; it 
was this circumstance which emboldened us to offer, in our reply 
to Liebig before the Academy of Sciences in 1871, to prepare, in a 
saccharine mineral medium, in the presence of a commission to be 
appointed by our opponent, any quantity of ferment that he might 
require, and to effect the fermentation of any weight of sugar what- 
soever. 



358 LOUIS PASTEUR 

Our knowledge of the facts detailed in the preceding chapter 
concerning pure ferments, and their manipulation in the presence 
of pure air, enables us completely to disregard those causes of em- 
barrassment that result from the fortuitous occurrence of the germs 
of organisms different in character from the ferments introduced 
by the air or from the sides of vessels, or even by the ferment itself. 

Let us once more take one of our double-necked flasks, which we 
will suppose is capable of containing three or four litres (six to eight 
pints) . 

Let us put into it the following: 

Pure distilled water. 

Sugar candy 200 grammes 

Bitartrate of potassium i.o " 

ammonia 0.5 

Sulphate of ammonia 1.5 

Ash of yeast i .5 

(i gramme= 15.43 grains) 

Let us boil the mixture, to destroy all germs of organisms that 
may exist in the air or liquid or on the sides of the flask, and then 
permit it to cool, after having placed, by way of extra precaution, a 
small quantity of asbestos in the end of the fine curved tube. Let us 
next introduce a trace of ferment into the liquid, through the other 
neck, which, as we have described, is terminated by a small piece 
of india-rubber tube closed with a glass stopper. 

Here are the details of such an experiment: — 

On December 9th, 1873, we sowed some pure ferment — sac- 
charomyces pastorianus. From December 11, that is, within so short 
a time as forty-eight hours after impregnation, we saw a multitude 
of extremely minute bubbles rising almost continuously from the 
bottom, indication that at this point the fermentation had com- 
menced. On the following days, several patches of froth appeared 
on the surface of the liquid. We left the flask undisturbed in the 
oven, at a temperature of 25° C. (77° F.) On April 24, 1874, we 
tested some of the liquid, obtained by means of the straight tube, 
to see if it still contained any sugar. We found that it contained 
less than two grammes, so that 198 grammes (4.2 oz. Troy) had 
already disappeared. Some time afterwards the fermentation came 



THEORY OF FERMENTATION 359 

to an end; we carried on the experiment, nevertheless, until April 
18, 1875. 

There was no development of any organism absolutely foreign 
to the ferment, which was itself abundant, a circumstance that, 
added to the persistent vitality of the ferment, in spite of the un- 
suitableness of the medium for its nutrition, permitted the perfect 
completion of fermentation. There was not the minutest quantity 
of sugar remaining. The total weight of ferment, after washing 
and drying at 100° C. (212° F.), was 2.563 grammes (39.5 grains). 

In experiments of this kind, in which the ferment has to be 
weighed, it is better not to use any yeast-ash that cannot be dissolved 
completely, so as to be capable of easy separation from the ferment 
formed. Raulin's liquid' may be used in such cases with success. 

All the alcoholic ferments are not capable to the same extent of 
development by means of phosphates, ammoniacal salts, and sugar, 
There are some whose development is arrested a longer or shorter 
time before the transformation of all the sugar. In a series of com- 
parative experiments, 200 grammes of sugar-candy being used in 
each case, we found that whilst saccharomyces pastorianus effected 
a complete fermentation of the sugar, the caseous ferment did not 
decompose more than two-thirds, and the ferment we have desig- 
nated new "high" ferment not more than one-fifth: and keeping 
the flasks for a longer time in the oven had no effect in increasing 
the proportions of sugar fermented in these two last cases. 

We conducted a great number of fermentations in mineral media, 
in consequence of a circumstance which it may be interesting to 

' M. Jules Raulin has published a well-known and remarkable work on the discovery 
of the mineral medium best adapted by its composition to the life of certain fungoid 
growths; he has given a formula for the composition of such a medium. It is this 
that we call here "Raulin's liquid" for abbreviation. 

Water 1,500 

Sugar candy 70 

Tartaric acid 4 

Nitrate of ammonia 4 

Phosphate of ammonia , 0.6 

Carbonate of potassium 0.6 

Carbonate of magnesia 0.4 

Sulphate of ammonia 0.25 

Sulphate of zinc 0.07 

Sulphate of iron 0.07 

Silicate of potassium 0.07 

— ^J. Raulin, Paris, Victor Masson, 1870, Thise pour le doctorat. 



360 LOUIS PASTEUR 

mention here. A person who was working in our laboratory as- 
serted that the success of our experiments depended upon the im- 
purity of the sugar-candy which we employed, and that if this sugar 
had been pure — much purer than was the ordinary, white, commer- 
cial sugar-candy, which up to that time we had always used — the 
ferment could not have multiplied. The persistent objections of 
our friend, and our desire to convince him, caused us to repeat all 
our previous experiments on the subject, using sugar of great purity, 
which had been specially prepared for us, with the utmost care, by 
a skilful confectioner, Seugnot. The result only confirmed our 
former conclusions. Even this did not satisfy our obstinate friend, 
who went to the trouble of preparing some pure sugar for himself, 
in little crystals, by repeated crystallizations of carefully selected 
commercial sugar-candy; he then repeated our experiments himself. 
This time his doubts were overcome. It even happened that the 
fermentations with the perfectly pure sugar instead of being slow 
were very active, when compared with those which we had con- 
ducted with the commercial sugar-candy. 

We may here add a few words on the non-transformation of 
yeast into penicillium glaucum. 

If at any time during fermentation we pour off the fermenting 
liquid, the deposit of yeast remaining in the vessel may continue 
there, in contact with air, without our ever being able to discover 
the least formation of penicillium glaucum in it. We may keep a 
current of pure air constantly passing through the flask; the experi- 
ment will give the same result. Nevertheless, this is a medium 
peculiarly adapted to the development of this mould, inasmuch as 
if we were to introduce merely a few spores of penicillium an abun- 
dant vegetation of that growth will afterwards appear on the de- 
posit. The descriptions of Messrs. Turpin, Hoffmann, and Trecul 
have, therefore, been based on one of these illusions which we meet 
with so frequently in microscopical observations. 

When we laid these facts before the Academy,'" M. Trecul pro- 
fessed his inability to comprehend them:" "According to M. Pas- 

*" Pasteur, Comptes rendus de I'Academie, vol. Ixxviii., pp. 213-216. 
"Trecul, Comptes rendus de I'Acadimie, vol. Ixxviii., pp. 217, 218. 



THEORY OF FERMENTATION 361 

teur," he said, "the yeast of beer is anaerobian, that is to say, it lives 
in a liquid deprived of free oxygen; and to become mycoderma or 
penicillium it is above all things necessary that it should be placed 
in air, since, without this, as the name signifies, an aerobian being 
cannot exist. To bring about the transformation of the yeast of beer 
into mycoderma cerevisiae or into penicillium glaucum we must 
accept the conditions under which these two forms are obtained. If 
M. Pasteur will persist in keeping his yeast in media which are in- 
compatible with the desired modification, it is clear that the results 
which he obtains must always be negative." 

Contrary to this perfectly gratuitous assertion of M. Trecul's we 
do not keep our yeast in media which are calculated to prevent its 
transformation into penicillium. As we have just seen, the principal 
aim and object of our experiment was to bring this minute plant 
into contact with air, and under conditions that would allow the 
penicillium to develop with perfect freedom. We conducted our 
experiments exactly as Turpin and Hoffmann conducted theirs, 
and exactly as they stipulate that such experiments should be con- 
ducted — with the one sole difference, indispensable to the correct- 
ness of our observations, that we carefully guarded ourselves against 
those causes of error which they did not take the least trouble to 
avoid. It is possible to produce a ready entrance and escape of pure 
air in the case of the double-necked flasks which we have so often 
employed in the course of this work, without having recourse to 
the continuous passage of a current of air. Having made a file-mark 
on the thin curved neck at a distance of two or three centimetres 
(an inch) from the flask, we must cut round the neck at this point 
with a glazier's diamond, and then remove it, taking care to cover 
the opening immediately with a sheet of paper which has been 
passed through the flame, and which we must fasten with a thread 
round the part of the neck still left. In this manner we may in- 
crease or prolong the fructification of fungoid growths, or the life 
of the aerobian ferments in our flasks. 

What we have said of penicillium glaucum will apply equally to 
mycoderma cerevisiae. Notwithstanding that Turpin and Trecul 
may assert to the contrary, yeast, in contact with air as it was under 



362 LOUIS PASTEUR 

the conditions o£ the experiment just described, will not yield myco- 
derma vini or mycoderma cerevisiae any more than it will peni- 
cillium. 

The experiments described in the preceding paragraphs on the 
increase of organized ferments in mineral media of the composition 
described, are of the greatest physiological interest. Amongst other 
results, they show that all the proteic matter of ferments may be 
produced by the vital activity of the cells, which, apart altogether 
from the influence of light or free oxygen (unless indeed, we are 
dealing with aerobian moulds which require free oxygen), have the 
power of developing a chemical activity between carbo-hydrates, 
ammoniacal salts, phosphates, and sulphates of potassium and mag- 
nesium. It may be admitted with truth that a similar effect obtains 
in the case of the higher plants, so that in the existing state of science 
we fail to conceive what serious reason can be urged against our 
considering this effect as general. It would be perfectly logical to 
extend the results of which we are speaking to all plants, and to 
believe that the proteic matter of vegetables, and perhaps of animals 
also, is formed exclusively by the activity of the cells operating upon 
the ammoniacal and other mineral salts of the sap or plasma of the 
blood, and the carbo-hydrates, the formation of which, in the case 
of the higher plants, requires only the concurrence of the chemical 
impulse of green light. 

Viewed in this manner, the formation of the proteic substances, 
would be independent of the great act of reduction of carbonic acid 
gas under the influence of light. These substances would not be 
built up from the elements of water, ammonia, and carbonic acid 
gas, after the decomposition of this last; they would be formed 
where they are found in the cells themselves, by some process of 
union between the carbo-hydrates imported by the sap, and the 
phosphates of potassium and magnesium and salts of ammonia. 
Lastly, in vegetable growth, by means of a carbo-hydrate and a 
mineral medium, since the carbo-hydrate is capable of many varia- 
tions, and it would be difficult to understand how it could be split 
up into its elements before serving to constitute the proteic sub- 
stances, and even cellulose substances, as these are carbo-hydrates. 
We have commenced certain studies in this direction. 



THEORY OF FERMENTATION 363 

If solar radiation is indispensable to the decomposition o£ carbonic 
acid and the building up of the primary substances in the case of 
higher vegetable life, it is still possible that certain inferior organisms 
may do without it and nevertheless yield the most complex sub- 
stances, fatty or carbo-hydrate, such as cellulose, various organic 
acids, and proteic matter; not, however, by borrowing their carbon 
from the carbonic acid which is saturated with oxygen, but from 
other matters still capable of acquiring oxygen, and so of yielding 
heat in the process, such as alcohol and acetic acid, for example, to 
cite merely carbon compounds most removed from organization. 
As these last compounds, and a host of others equally adapted to 
serve as the carbonaceous food of mycoderms and the mucedines, 
may be produced synthetically by means of carbon and the vapour 
of water, after the methods that science owes to Berthelot, it follows 
that, in the case of certain inferior beings, life would be possible even 
if it should be that the solar light was extinguished.'^ 

'2 See on this subject the verbal observations which we addressed to the Academy 
of Sciences at its meetings of April loth and 24th, 1876. 



THE GERM THEORY 

AND ITS APPLICATIONS TO 
MEDICINE AND SURGERY' 

THE Sciences gain by mutual support. When, as the result 
of my first communications on the fermentations in 1857- 
1858, it appeared that the ferments, properly so-called, are 
living beings, that the germs of microscopic organisms abound in 
the surface of all objects, in the air and in water; that the theory of 
spontaneous generation is chimerical; that wines, beer, vinegar, the 
blood, urine and all the fluids of the body undergo none of their 
usual changes in pure air, both Medicine and Surgery received fresh 
stimulation. A French physician, Dr. Davaine, was fortunate 
in making the first application of these principles to Medicine, in 
1863. 

Our researches of last year, left the etiology of the putrid disease, 
or septicemia, in a much less advanced condition than that of an- 
thrax. We had demonstrated the probability that septicemia depends 
upon the presence and growth of a microscopic body, but the abso- 
lute proof of this important conclusion was not reached. To demon- 
strate experimentally that a microscopic organism actually is the 
cause of a disease and the agent of contagion, I know no other way, 
in the present state of Science, than to subject the microbe (the new 
and happy term introduced by M. Sedillot) to the method of culti- 
vation out of the body. It may be noted that in twelve successive 
cultures, each one of only ten cubic centimeters volume, the original 
drop will be diluted as if placed in a volume of Huid equal to the 
total volume of the earth. It is just this form of test to which M. 
Joubert and I subjected the anthrax bacteridium.'' Having culti- 

' Read before the French Academy of Sciences, April 29th, 1878. Published in 
Comptes rendus de V Academic dcs Sciences, Ixxxvi., pp. 1037-43. 

^ In making the translation, it seems wiser to adhere to Pasteur's nomenclature. 
Bacillus anthracis would be the term employed to-day. — Translator. 

364 



THE GERM THEORY 365 

vated it a great number of times in a sterile fluid, each culture being 
started with a minute drop from the preceding, we then demon- 
strated that the product of the last culture was capable of further 
development and of acting in the animal tissues by producing an- 
thrax with all its symptoms. Such is — as we beHeve — the indisputable 
proof that anthrax is a bacterial disease. 

Our researches concerning the septic vibrio had not so far been 
convincing, and it was to fill up this gap that we resumed our experi- 
ments. To this end, we attempted the cultivation of the septic vibrio 
from an animal dead of septicemia. It is worth noting that all of 
our first experiments failed, despite the variety of culture media we 
employed — urine, beer yeast water, meat water, etc. Our culture 
media were not sterile, but we found — most commonly — a micro- 
scopic organism showing no relationship to the septic vibrio, and 
presenting the form, common enough elsewhere, of chains of ex- 
tremely minute spherical granules possessed of no virulence what- 
ever.' This was an impurity, introduced, unknown to us, at the 
same time as the septic vibrio; and the germ undoubtedly passed 
from the intestines — always inflamed and distended in septicemic 
animals — into the abdominal fluids from which we took our original 
cultures of the septic vibrio. If this explanation of the contamina- 
tion of our cultures was correct, we ought to find a pure culture of 
the septic vibrio in the heart's blood of an animal recently dead of 
septicemia. This was what happened, but a new difficulty presented 
itself; all our cultures remained sterile. Furthermore this sterility 
was accompanied by loss in the culture media of (the original) 
virulence. 

It occurred to us that the septic vibrio might be an obligatory 
anaerobe and that the sterility of our inoculated culture fluids might 
be due to the destruction of the septic vibrio by the atmospheric 
oxygen dissolved in the fluids. The Academy may remember that I 
have previously demonstrated facts of this nature in regard to the 
vibrio of butyric fermentation, which not only lives without air but 
is killed by the air. 

It was necessary therefore to attempt to cultivate the septic vibrio 

'It Is quite possible that Pasteur was here dealing with certain septicemic strepto- 
cocci that are now known to lose their virulence with extreme rapidity under 
artificial cultivation. — ^Translator. 



366 LOUIS PASTEUR 

either in a vacuum or in the presence of inert gases — such as carbonic 
acid. 

Results justified our attempt; the septic vibrio grew easily in a 
complete vacuum, and no less easily in the presence of pure carbonic 
acid. 

These results have a necessary corollary. If a fluid containing septic 
vibrios be exposed to pure air, the vibrios should be killed and all 
virulence should disappear. This is actually the case. If some 
drops of septic serum be spread horizontally in a tube and in a very 
thin layer, the fluid will become absolutely harmless in less than half 
a day, even if at first it was so virulent as to produce death upon 
the inoculation of the smallest portion of a drop. 

Furthermore all the vibrios, which crowded the liquid as motile 
threads, are destroyed and disappear. After the action of the air, 
only fine amorphous granules can be found, unfit for culture as well 
as for the transmission of any disease whatever. It might be said that 
the air burned the vibrios. 

If it is a terrifying thought that life is at the mercy of the multi- 
plication of these minute bodies, it is a consoling hope that Science 
will not always remain powerless before such enemies, since for 
example at the very beginning of the study we find that simple 
exposure to air is sufficient at times to destroy them. 

But, if oxygen destroys the vibrios, how can septicemia exist, since 
atmospheric air is present everywhere? How can such facts be 
brought in accord with the germ theory? How can blood, exposed 
to air, become septic through the dust the air contains ? 

All things are hidden, obscure and debatable if the cause of the 
phenomena be unknown, but everything is clear if this cause be 
known. What we have just said is true only of a septic fluid con- 
taining adult vibrios, in active development by fission : conditions are 
different when the vibrios are transformed into their germs,^ that 
is into the glistening corpuscles first described and figured in my 
studies on silk-worm disease, in dealing with worms dead of the 
disease called "flacherie." Only the adult vibrios disappear, burn up, 

* By the terms "germ" and "germ corpuscles," Pasteur undoubtedly means "spores," 
but the change is not made, in accordance with note 2, p. 364 — Translator. 



THE GERM THEORY 367 

and lose their virulence in contact with air: the germ corpuscles, 
under these conditions, remain always ready for new cultures, and 
for new inoculations. 

All this however does not do away with the difficulty of under- 
standing how septic germs can exist on the surface of objects, float- 
ing in the air and in water. 

Where can these corpuscles originate? Nothing is easier than the 
production of these germs, in spite of the presence of air in contact 
with septic fluids. 

If abdominal serous exudate containing septic vibrios actively 
growing by fission be exposed to the air, as we suggested above, but 
with the precaution of giving a substantial thickness to the layer, 
even if only one centimeter be used, this curious phenomenon will 
appear in a few hours. The oxygen is absorbed in the upper layers 
of the fluid — as is indicated by the change of color. Here the vibrios 
are dead and disappear. In the deeper layers, on the other hand, 
towards the bottom of this centimeter of septic fluid we suppose to 
be under observation, the vibrios continue to multiply by fission — 
protected from the action of oxygen by those that have perished 
above them: little by little they pass over to the condition of germ 
corpuscles with the gradual disappearance of the thread forms. So 
that instead of moving threads of varying length, sometimes greater 
than the field of the microscope, there is to be seen only a number of 
glittering points, lying free or surrounded by a scarcely perceptible 
amorphous mass.'' Thus is formed, containing the latent germ life, 
no longer in danger from the destructive action of oxygen, thus, I 
repeat, is formed the septic dust, and we are able to understand what 
has before seemed so obscure; we can see how putrescible fluids can 
be inoculated by the dust of the air, and how it is that putrid diseases 
are permanent in the world. 

The Academy will permit me, before leaving these interesting 
results, to refer to one of their main theoretical consequences. At 

*In our note of July i6th, 1877, it is stated that the septic vibrio is not destroyed 
by the oxygen o£ the air nor by oxygen at high tension, but that under these conditions 
it is transformed into germ corpuscles. This is, however, an incorrect interpretation 
of facts. The vibrio is destroyed by oxygen, and it is only where it is in a thick layer 
that it is transformed to germ-corpuscles in the presence of oxygen and that its 
virulence is preserved. 



368 LOUIS PASTEUR 

the very beginning of these researches, for they reveal an entirely 
new field, what must be insistently demanded ? The absolute proof 
that there actually exist transmissible, contagious, infectious diseases 
of which the cause lies essentially and solely in the presence of micro- 
scopic organisms. The proof that for at least some diseases, the con- 
ception of spontaneous virulence must be forever abandoned — as 
well as the idea of contagion and an infectious element suddenly 
originating in the bodies of men or animals and able to originate 
diseases which propagate themselves under identical forms: and all 
of those opinions fatal to medical progress, which have given rise 
to the gratuitous hypotheses of spontaneous generation, of albu- 
minoid ferments, of hemiorganisms, of archebiosis, and many other 
conceptions without the least basis in observation. What is to be 
sought for in this instance is the proof that along with our vibrio 
there does not exist an independent virulence belonging to the sur- 
rounding fluids or solids, in short that the vibrio is not merely an 
epiphenomenon of the disease of which it is the obligatory accom- 
paniment. What then do we see, in the results that I have just 
brought out? A septic fluid, taken at the moment that the vibrios 
are not yet changed into germs, loses its virulence completely upon 
simple exposure to the air, but preserves this virulence, although 
exposed to air on the simple condition of being in a thick layer for 
some hours. In the first case, the virulence once lost by exposure to 
air, the liquid is incapable of taking it on again upon cultivation: 
but, in the second case, it preserves its virulence and can propagate, 
even after exposure to air. It is impossible, then, to assert that there 
is a separate virulent substance, either fluid or solid, existing, apart 
from the adult vibrio or its germ. Nor can it be supposed that there 
is a virus which loses its virulence at the moment that the adult 
vibrio dies; for such a substance should also lose its virulence when 
the vibrios, changed to germs, are exposed to the air. Since the viru- 
lence persists under these conditions it can only be due to the germ 
corpuscles — the only thing present. There is only one possible 
hypothesis as to the existence of a virus in solution, and that is that 
such a substance, which was present in our experiment in non-fatal 
amounts, should be continuously furnished by the vibrio itself, 
during its growth in the body of the living animal. But it is of 



THE GERM THEORY 369 

little importance since the hypothesis supposes the forming and 
necessary existence of the vibrio.^ 

I hasten to touch upon another series of observations which are 
even more deserving the attention of the surgeon than the preced- 
ing: I desire to speak of the effects of our microbe of pus when 
associated with the septic vibrio. There is nothing more easy to 
superpose — as it were — two distinct diseases and to produce what 
might be called a septicemic purulent infection, or a purulent septi- 
cemia. Whilst the microbe-producing pus, when acting alone, gives 
rise to a thick pus, white, or sometimes with a yellow or bluish tint, 
not putrid, diffused or enclosed by the so-called pyogenic membrane, 
not dangerous, especially if localized in cellular tissue, ready, if the 
expression may be used for rapid resorption; on the other hand the 
smallest abscess produced by this organism when associated with the 
septic vibrio takes on a thick gangrenous appearance, putrid, green- 
ish and infiltrating the softened tissues. In this case the microbe of 
pus carried so to speak by the septic vibrio, accompanies it through- 
out the body: the highly-inflamed muscular tissues, full of serous 
fluid, showing also globules of pus here and there, are like a knead- 
ing of the two organisms. 

By a similar procedure the effects of the anthrax bacteridium and 
the microbe of pus may be combined and the two diseases may be 
superposed, so as to obtain a purulent anthrax or an anthracoid 
purulent infection. Care must be taken not to exaggerate the pre- 
dominance of the new microbe over the bacteridium. If the microbe 
be associated with the latter in sufficient amount it may crowd it out 
completely — prevent it from growing in the body at all. Anthrax 
does not appear, and the infection, entirely local, becomes merely an 
abscess whose cure is easy. The microbe-producing pus and the 
septic vibrio (not)' being both anaerobes, as we have demonstrated, 
it is evident that the latter will not much disturb its neighbor. Nutri- 
ent substances, fluid or solid, can scarcely be deficient in the tissues 
from such minute organisms. But the anthrax bacteridium is exclu- 
sively aerobic, and the proportion of oxygen is far from being equally 

'The regular limits oblige me to omit a portion of my speech. 

'There is undoubtedly a mistake in the original. Pasteur could not have meant 
to say that both bacteria are anaerobes. The word "not" is introduced to correct the 
error. — ^Translator. 



370 LOUIS PASTEUR 

distributed throughout the tissues: innumerable conditions can di- 
minish or exhaust the supply here and there, and since the microbe- 
producing pus is also aerobic, it can be understood how, by using a 
quantity slightly greater than that of the bacteridium it might easily 
deprive the latter of the oxygen necessary for it. But the explana- 
tion of the fact is of little importance: it is certain that under some 
conditions the microbe we are speaking of entirely prevents the 
development of the bacteridium. 

Summarizing — it appears from the preceding facts that it is 
possible to produce at will, purulent infections with no elements of 
putrescence, putrescent purulent infections, anthracoid purulent in- 
fections, and finally combinations of these types of lesions varying 
according to the proportions of the mixtures of the specific organisms 
made to act on the living tissues. 

These are the principal facts I have to communicate to the Acad- 
emy in my name and in the names of my collaborators, Messrs. 
Joubert and Chamberland. Some weeks ago (Session of the nth 
of March last) a member of the Section of Medicine and Surgery, 
M. Sedillot, after long meditation on the lessons of a brilliant career, 
did not hesitate to assert that the successes as well as the failures of 
Surgery find a rational explanation in the principles upon which the 
germ theory is based, and that this theory would found a new Sur- 
gery — already begun by a celebrated English surgeon. Dr. Lister,' 
who was among the first to understand its fertility. With no pro- 
fessional authority, but with the conviction of a trained experimenter, 
I venture here to repeat the words of an eminent confrere. 
* See Lord Lister's paper in the present volume. — Ed. 



ON THE EXTENSION OF 
THE GERM THEORY 

TO THE ETIOLOGY OF CERTAIN 
COMMON DISEASES' 

WHEN I began the studies now occupying my attention,' 
I was attempting to extend the germ theory to certain 
common diseases. I do not know when I can return to 
that work. Therefore in my desire to see it carried on by others, I 
take the Uberty of presenting it to the pubHc in its present condition. 

I. Furuncles. In May, 1879, one of the workers in my laboratory 
had a number of furuncles, appearing at short intervals, sometimes 
on one part of the body and sometimes on another. Constantly 
impressed with the thought of the immense part played by micro- 
scopic organisms in Nature, I queried whether the pus in the fu- 
runcles might not contain one of these organisms whose presence, 
development, and chance transportation here and there in the tissues 
after entrance would produce a local inflammation, and pus forma- 
tion, and might explain the recurrence of the illness during a longer 
or shorter time. It was easy enough to subject this thought to the 
test of experiment. 

First observation. — On June second, a puncture was made at the 
base of the small cone of pus at the apex of a furuncle on the nape 
of the neck. The fluid obtained was at once sowed in the presence 
of pure air — of course with the precautions necessary to exclude any 
foreign germs, either at the moment of puncture, at the moment of 
sowing in the culture fluid, or during the stay in the oven, which was 
kept at the constant temperature of about 35° C. The next day, the 
culture fluid had become cloudy and contained a single organism, 

' Read before the French Academy of Sciences, May 3, 1880. Published in Comptes 
rendus de I'Academie des Sciences, xc, pp. 1033—44. 

2 In 1880. Especially engaged in the study of chicken cholera and the attenuation 
of virulence. — ^Translator. 

371 



372 LOUIS PASTEUR 

consisting o£ small spherical points arranged in pairs, sometimes in 
fours, but often in irregular masses. Two fluids were preferred in 
these experiments — chicken and yeast bouillon. According as one or 
the other was used, appearances varied a little. These should be 
described. With the yeast water, the pairs of minute granules are 
distributed throughout the liquid, which is uniformly clouded. But 
with the chicken bouillon, the granules are collected in little masses 
which line the walls and bottom of the flasks while the body of the 
fluid remains clear, unless it be shaken: in this case it becomes 
uniformly clouded by the breaking up of the small masses from the 
walls of the Hasks. 

Second observation. — On the tenth of June a new furuncle made 
its appearance on the right thigh of the same person. Pus could 
not yet be seen under the skin, but this was already thickened and 
red over a surface the size of a franc. The inflamed part was washed 
with alcohol, and dried with blotting paper passed through the flame 
of an alcohol lamp. A puncture at the thickened portion enabled 
us to secure a small amount of lymph mixed with blood, which 
was sowed at the same time as some blood taken from the finger of 
the hand. The following days, the blood from the finger remained 
absolutely sterile: but that obtained from the center of the forming 
furuncle gave an abundant growth of the same small organism 
as before. 

Third observation. — The fourteenth of June, a new furuncle ap- 
peared on the neck of the same person. The same examination, the 
same result, that is to say the development of the microscopic organ- 
ism previously described and complete sterility of the blood of the 
general circulation, taken this time at the base of the furuncle outside 
of the inflamed area. 

At the time of making these observations I spoke of them to Dr. 
Maurice Reynaud, who was good enough to send me a patient who 
had had furuncles for more than three months. On June thirteenth 
I made cultures of the pus from a furuncle of this man. The next 
day there was a general cloudiness of the culture fluids, consisting 
entirely of the preceding parasite, and of this alone. 

Fourth observation. — June fourteenth, the same individual showed 
me a newly forming furuncle in the left axilla: there was wide- 



EXTENSION OF THE GERM THEORY 373 

spread thickening and redness of the skin, but no pus was yet appar- 
ent. An incision at the center of the thickening showed a small 
quantity of pus mixed with blood. Sowing, rapid growth for twenty- 
four hours and the appearance of the same organism. Blood from 
the arm at a distance from the furuncle remained completely ster- 
ile. 

June 17, the examination of a fresh furuncle on the same indi- 
vidual gave the same result, the development of a pure culture of the 
same organism. 

Fifth observation. — July twenty-first, Dr. Maurice Reynaud in- 
formed me that there was a woman at the Lariboisiere hospital with 
multiple furuncles. As a matter of fact her back was covered with 
them, some in active suppuration, others in the ulcerating stage. 
I took pus from all of these furuncles that had not opened. After 
a few hours, this pus gave an abundant growth in cultures. The 
same organism, without admixture, was found. Blood from the 
inflamed base of the furuncle remained sterile. 

In brief, it appears certain that every furuncle contains an aerobic 
microscopic parasite, to which is due the local inflammation and the 
pus formation that follows. 

Culture fluids containing the minute organism inoculated under 
the skin of rabbits and guinea-pigs produce abscesses generally small 
in size and that promptly heal. As long as healing is not complete 
the pus of the abscesses contains the microscopic organism which 
produced them. It is therefore living and developing, but its propa- 
gation at a distance does not occur. These cultures of which I speak, 
when injected in small quantities in the jugular vein of guinea-pigs 
show that the minute organism does not grow in the blood. The day 
after the injection they cannot be recovered even in cultures. I seem 
to have observed as a general principle, that, provided the blood 
corpuscles are in good physiological condition it is difficult for 
aerobic parasites to develop in the blood. I have always thought that 
this is to be explained by a kind of struggle between the affinity of 
the blood corpuscles for oxygen and that belonging to the parasite 
in cultures. Whilst the blood corpuscles carry off, that is, take pos- 
session of all the oxygen, the life and development of the parasite 
become extremely difficult or impossible. It is therefore easily elimi- 



374 LOUIS PASTEUR 

nated, digested, if one may use the phrase. I have seen these facts 
many times in anthrax and chicken-cholera, diseases both of which 
are due to the presence of an aerobic parasite. 

Blood cultures from the general circulation being always sterile 
in these experiments, it would seem that under the conditions of 
the furuncular diathesis, , the minute parasite does not exist in the 
blood. That it cannot be cultivated for the reason given, and that 
it is not abundant is evident; but, from the sterility of the cultures 
reported (five only) it should not be definitely concluded that the 
little parasite may not, at some time, be taken up by the blood and 
transplanted from a furuncle when it is developing to another part 
of the body, where it may be accidentally lodged, may develop and 
produce a new furuncle. I am convinced that if, in cases of furuncu- 
lar diathesis, not merely a few drops but several grams of blood from 
the general circulation could be placed under cultivation frequent 
successful growths would be obtained.' In the many experiments I 
have made on the blood in chicken-cholera, I have frequently demon- 
strated that repeated cultures from droplets of blood do not show an 
even development even where taken from the same organ, the 
heart for example, and at the moment when the parasite begins its 
existence in the blood, which can easily be understood. Once even, 
it happened that only three out of ten chickens died after inocula- 
tion with infectious blood in which the parasite had just begun to 
appear, the remaining seven showed no symptoms whatever. In 
fact, the microbe, at the moment of beginning its entrance into the 
blood may exist singly or in minute numbers in one droplet and 
not at all in its immediate neighbor. I believe therefore that it would 
be extremely instructive in furunculosis, to find a patient willing to 
submit to a number of punctures in different parts of the body away 
from formed or forming furuncles, and thus secure many cultures, 
simultaneous or otherwise, of the blood of the general circulation. 
I am convinced that among them would be found growths of the 
micro-organism of furuncles. 

II. On Osteomyelitis. Single observation. I have but one observa- 
tion relating to this severe disease, and in this Dr. Lannelongue took 

'This prediction is fully carried out in the present day successful use of consider- 
able amounts of blood in cultures and the resultant frequent demonstrations o£ 
bacteria present in the circulation in many infections. — Translator. 



EXTENSION OF THE GERM THEORY 375 

the initiative. The monograph on osteomyehtis published by this 
learned practitioner is well known, with his suggestion of the pos- 
sibility of a cure by trephining the bone and the use of antiseptic 
washes and dressings. On the fourteenth of February, at the request 
of Dr. Lannelongue I went to the Sainte-Eugenie hospital, where 
this skillful surgeon was to operate on a little girl of about twelve 
years of age. The right knee was much swollen, as well as the 
whole leg below the calf and a part of the thigh above the knee. 
There was no external opening. Under chloroform, Dr. Lanne- 
longue made a long incision below the knee which let out a large 
amount of pus; the tibia was found denuded for a long distance. 
Three places in the bone were trephined. From each of these, quan- 
tities of pus flowed. Pus from inside and outside the bone was col- 
lected with all possible precautions and was carefully examined and 
cultivated later. The direct microscopic study of the pus, both inter- 
nal and external, was of extreme interest. It was seen that both 
contained large numbers of the organism similar to that of furuncles, 
arranged in pairs, in fours and in packets, some with sharp clear 
contour, others only faintly visible and with very pale outUnes. The 
external pus contained many pus corpuscles, the internal had none 
at all. It was like a fatty paste of the furuncular organism. Also, it 
may be noted, that growth of the small organism had begun in less 
than six hours after the cultures were started. Thus I saw, that it 
corresponded exactly with the organism of furuncles. The diameter 
of the individuals was found to be one one-thousandth of a milli- 
meter. If I ventured to express myself so I might say that in this 
case at least the osteomyelitis was really a furuncle of the bone mar- 
row.* It is undoubtedly easy to induce osteomyelitis artificially in 
living animals. 

III. On puerperal fever. — First observation. On the twelfth of 
March, 1878, Dr. Hervieux was good enough to admit me to his 
service in the Maternity to visit a woman delivered some days before 
and seriously ill with puerperal fever. The lochia were extremely 
fetid. I found them full of micro-organisms of many kinds. A 
small amount of blood was obtained from a puncture on the index 
finger of the left hand, (the finger being first properly washed and 
*This has been demonstrated, as is well known. — ^Translator. 



376 LOUIS PASTEUR 

dried with a sterile towel,) and then sowed in chicken bouillon. The 
culture remained sterile during the following days. 

The thirteenth, more blood was taken from a puncture in the 
finger and this time growth occurred. As death took place on the 
sixteenth of March at six in the morning, it seems that the blood 
contained a microscopic parasite at least three days before. 

The fifteenth of March, eighteen hours before death, blood from 
a needle-prick in the left foot was used. This culture also was fer- 
tile. 

The first culture, of March thirteenth, contained only the organ- 
ism of furuncles; the next one, that of the fifteenth, contained an 
organism resembling that of f urunculosis, but which always differed 
enough to make it easy usually to distinguish it. In this way; whilst 
the parasite of furuncles is arranged in pairs, very rarely in chains of 
three or four elements, the new one, that of the culture of the 
fifteenth, occurs in long chains, the number of cells in each being 
indefinite. The chains are flexible and often appear as little tangled 
packets like tangled strings of pearls. 

The autopsy was performed on the seventeenth at two o'clock. 
There was a large amount of pus in the peritoneum. It was sowed 
with all possible precautions. Blood from the basilic and femoral 
veins was also sowed. So also was pus from the mucous surface 
of the uterus, from the tubes, and finally that from a lymphatic in 
the uterine wall. These are the results of these cultures: in all there 
were the long chains of cells just spoken of above, and nowhere 
any mixture of other organisms, except in the culture from the peri- 
toneal pus, which, in addition to the long chains, also contained the 
small pyogenic vibrio which I describe under the name organism 
of pus in the Note I published with Messrs. Joubert and Chamber- 
land on the thirtieth of April, iSyS.'^ 

Interpretation of the disease and of the death. — After confinement, 
the pus that always naturally forms in the injured parts of the uterus 
instead of remaining pure becomes contaminated with microscopic 
organisms from outside, notably the organism in long chains and 
the pyogenic vibrio. These organisms pass into the peritoneal cavity 
through the tubes or by other channels, and some of them into the 

' See preceding paper. 



EXTENSION OF THE GERM THEORY 'i,']'] 

blood, probably by the lymphatics. The resorption of the pus, always 
extremely easy and prompt when it is pure, becomes impossible 
through the presence of the parasites, whose entrance must be pre- 
vented by all possible means from the moment of confinement. 

Second observation. — The fourteenth of March, a woman died of 
puerperal fever at the Lariboisiere hospital; the abdomen was dis- 
tended before death. 

Pus was found in abundance by a peritoneal puncture and was 
sowed; so also was blood from a vein in the arm. The culture of pus 
yielded the long chains noted in the preceding observation and also 
the small pyogenic vibrio. The culture from the blood contained only 
the long chains. 

Third observation. — The seventeenth of May, 1879, a woman, 
three days past confinement, was ill, as well as the child she was 
nursing. The lochia were full of the pyogenic vibrio and of the or- 
ganism of furuncles, although there was but a small proportion of the 
latter. The milk and the lochia were sowed. The milk gave the or- 
ganism in long chains of granules, and the lochia only the pus organ- 
ism. The mother died, and there was no autopsy. 

On May twenty-eighth, a rabbit was inoculated under the skin 
of the abdomen with five drops of the preceding culture of the 
pyogenic vibrio. The days following an enormous abscess formed 
which opened spontaneously on the fourth of June. An abundantly 
cheesy pus came from it. About the abscess there was extensive 
induration. On the eighth of June, the opening of the abscess was 
larger, the suppuration active. Near its border was another abscess, 
evidently joined with the first, for upon pressing it with the finger, 
pus flowed freely from the opening in the first abscess. During the 
whole of the month of June, the rabbit was sick and the abscesses 
suppurated, but less and less. In July they closed; the animal was 
well. There could only be felt some nodules under the skin of the 
abdomen. 

What disturbances might not such an organism carry into the 
body of a parturient woman, after passing into the peritoneum, the 
lymphatics or the blood through the maternal placenta! Its presence 
is much more dangerous than that of the parasite arranged in chains. 
Furthermore, its development is always threatening, because, as said 



378 LOUIS PASTEUR 

in the work already quoted (April, 1878) this organism can be easily 
recovered from many ordinary waters. 

I may add that the organism in long chains, and that arranged in 
pairs are also extremely widespread, and that one of their habitats is 
the mucous surfaces of the genital tract.° 

Apparently there is no puerperal parasite, properly speaking. I 
have not encountered true septicemia in my experiments: but it ought 
to be among the puerperal affections. 

Fourth observation. — On June fourteenth, at the Lariboisiere, a 
woman was very ill following a recent confinement: she was at the 
point of death: in fact she did die on the fourteenth at midnight. 
Some hours before death pus was taken from an abscess on the 
arm, and blood from a puncture in a finger. Both were sowed. On 
the next day (the fifteenth) the flask containing the pus from the 
abscess was filled with long chains of granules. The flask containing 
the blood was sterile. The autopsy was at ten o'clock on the morn- 
ing of the sixteenth. Blood from a vein of the arm, pus from the 
uterine walls and that from a collection in the synovial sac of the 
knee were all placed in culture media. All showed growth, even 
the blood, and they all contained the long strings of granules. The 
peritoneum contained no pus. 

Interpretation of the disease and o£ the death. — ^The injury of the 
uterus during confinement as usual furnished pus, which gave a 
lodging place for the germs of the long chains of granules. These, 
probably through the lymphatics, passed to the joints and to some 
other places, thus being the origin of the metastatic abscesses which 
produced death. 

Fifth observation. — On June seventeenth, M. Doleris, a well- 
known hospital interne, brought to me some blood, removed with 
the necessary precautions, from a child dead immediately after birth, 
whose mother, before confinement had had febrile symptoms with 
chills. This blood, upon cultivation, gave an abundance of the pyo- 
genic vibrio. On the other hand, blood taken from the mother on 
the morning of the eighteenth (she had died at one o'clock that 

' when, by the procedure I elsewhere described, urine is removed in a pure con- 
dition by the urethra from the bladder, if any chance growth occurs through some 
error of technic, it is the two organisms of which I have been spealcing that are 
almost exclusively present. 



EXTENSION OF THE GERM THEORY 379 

morning) showed no development whatever, on the nineteenth nor 
on following days. The autopsy on the mother took place on the 
nineteenth. It is certainly worthy of note that the uterus, peritoneum 
and intestines showed nothing special, but the liver was full of 
metastatic abscesses. At the exit of the hepatic vein from the liver 
there was pus, and its walls were ulcerated at this place. The pus 
from the liver abscesses was filled with the pyogenic vibrio. Even the 
liver tissues, at a distance from the visible abscesses, gave abundant 
cultures of the same organism. 

Interpretation of the disease and of the death. — ^The pyogenic 
vibrio, found in the uterus, or which was perhaps already in the 
body of the mother, since she suffered from chills before confine- 
ment, produced metastatic abscesses in the liver and, carried to the 
blood of the child, there induced one of the forms of infection called 
purulent, which caused its death. 

Sixth observation. — The eighteenth of June, 1879, M. Doleris in- 
formed me that a woman confined some days before at the Cochin 
Hospital, was very ill. On the twentieth of June, blood from a 
needle-prick in the finger was sowed; the culture was sterile. On July 
fifteenth, that is to say twenty-five days later, the blood was tried 
again. Still no growth. There was no organism distinctly recog- 
nizable in the lochia: the woman was nevertheless, they told me, 
dangerously ill and at the point of death. As a matter of fact, she 
did die on the eighteenth of July at nine in the morning: as may be 
seen, after a very long illness, for the first observations were made 
over a month before: the illness was also very painful, for the patient 
could make no movement without intense suffering. 

An autopsy was made on the nineteenth at ten in the morning, 
and was of great interest. There was purulent pleurisy with a con- 
siderable pocket of pus, and purulent false membranes on the walls 
of the pleura. The Uver was bleached, fatty, but of firm consistency, 
and with no apparent metastatic abscesses. The uterus, of small size, 
appeared healthy; but on the external surface whitish nodules filled 
with pus were found. There was nothing in the peritoneum, which 
was not inflamed; but there was much pus in the shoulder joints and 
the symphysis pubis. 

The pus from the abscesses, upon cultivation, gave the long chains 



380 LOUIS PASTEUR 

of granules — not only that of the pleura, but that from the shoulders 
and a lymphatic of the uterus as well. An interesting thing, but 
easily understood, was that the blood from a vein in the arm and 
taken three-quarters of an hour after death was entirely sterile. Noth- 
ing grew from the Fallopian tubes nor the broad ligaments. 

Interpretation of the disease and of the death. — The pus found in 
the uterus after conjfinerhent became infected with germs of micro- 
scopic organisms which grew there, then passed into the uterine 
lymphatics, and from there went on to produce pus in the pleura 
and in the articulations. 

Seventh observation. — On June eighteenth, M. Doleris informed 
me that a woman had been confined at the Cochin Hospital five days 
before and that fears were entertained as to the results of an opera- 
tion that had been performed, it having been necessary to do an 
embryotomy. The lochia were sowed on the i8th; there was not 
the slightest trace of growth the next day nor the day after. With- 
out the least knowledge of this woman since the eighteenth, on the 
twentieth I ventured to assert that she would get well. I sent to 
inquire about her. This is the text of the report: "The woman is 
doing extremely well; she goes out tomorrow." 

Interpretation of the facts. — The pus naturally formed on the sur- 
face of the injured parts did not become contaminated with organ- 
isms brought from without. Natura medicatrix carried it off, that 
is to say the vitality of the mucous surfaces prevented the develop- 
ment of foreign germs. The pus was easily resorbed, and recovery 
took place. 

I beg the Academy to permit me, in closing, to submit certain 
definite views, which I am strongly inclined to consider as legitimate 
conclusions from the facts I have had the honor to communicate 
to it. 

Under the expression puerperal fever are grouped very different 
diseases,^ but all appearing to be the result of the growth of common 
organisms which by their presence infect the pus naturally formed 
on injured surfaces, which spread by one means or another, by the 
blood or the lymphatics, to one or another part of the body, and there 

' Interesting as the starting point of the conception of diseases according to the 
etiological factor, not by groups of symptoms. — Translator. 



EXTENSION OF THE GERM THEORY 38 1 

induce morbid changes varying with the condition of the parts, the 
nature of the parasite, and the general constitution of the subject. 

Whatever this constitution, does it not seem that by taking 
measures opposing the production of these common parasitic organ- 
isms recovery would usually occur, except perhaps when the body 
contains, before confinement, microscopic organisms, in contami- 
nated internal or external abscesses, as was seen in one striking 
example (fifth observation). The antiseptic method I beheve likely 
to be sovereign in the vast majority of cases. It seems to me that 
immediately after confinement the application of antiseptics should 
be begun. Carbolic acid can render great service, but there is another 
antiseptic, the use of which I am strongly inclined to advise, this is 
boric acid in concentrated solution, that is, four per cent, at the ordi- 
nary temperature. This acid, whose singular influence on cell life 
has been shown by M. Dumas, is so slightly acid that it is alkaline 
to certain test papers, as was long ago shown by M. Chevreul, 
besides this it has no odor like carbolic acid, which odor often dis- 
turbs the sick. Lastly, its lack of hurtful effects on mucous mem- 
branes, notably of the bladder, has been and is daily demonstrated 
in the hospitals of Paris. The following is the occasion upon which 
it was first used. The Academy may remember that I stated before 
it, and the fact has never been denied, that ammoniacal urine is 
always produced by a microscopic organism, entirely similar in many 
respects to the organism of furuncles. Later, in a joint investigation 
with M. Joubert, we found that a solution of boric acid was easily 
fatal to these organisms. After that, in 1877, I induced Dr. Guyon, 
in charge of the genito-urinary clinic at the Necker hospital, to try 
injections of a solution of boric acid in affections of the bladder. I 
am informed by this skillful practitioner that he has done so, and 
daily observes good results from it. He also tells me that he performs 
no operation of lithotrity without the use of similar injections. I 
recall these facts to show that a solution of boric acid is entirely 
harmless to an extremely delicate mucous membrane, that of the 
bladder, and that it is possible to fill the bladder with a warm solution 
of boric acid without even inconvenience. 

To return to the confinement cases. Would it not be of great 
service to place a warm concentrated solution of boric acid, and 



382 LOUIS PASTEUR 

compresses, at the bedside of each patient; which she could renew 
frequently after saturating with the solution, and this also after con- 
finement. It would also be acting the part of prudence to place the 
compresses, before using, in a hot air oven at 150° C, more than 
enough to kill the germs of the common organisms.* 

Was I justified in calling this communication "On the extension 
of the germ theory to the etiology of certain common diseases?" I 
have detailed the facts as they have appeared to me and I have men- 
tioned interpretations of them: but I do not conceal from myself 
that, in medical territory, it is difficult to support one's self wholly 
on subjective foundations. I do not forget that Medicine and Veteri- 
nary practice are foreign to me. I desire judgment and criticism upon 
all my contributions. Little tolerant of frivolous or prejudiced con- 
tradiction, contemptuous of that ignorant criticism which doubts on 
principle, I welcome with open arms the militant attack which has a 
method in doubting and whose rule of conduct has the motto 
"More light." 

It is a pleasure once more to acknowledge the helpfulness of the 
aid given me by Messrs. Chamberland and Roux during the studies 
I have just recorded. I wish also to acknowledge the great assistance 
of M. Doleris. 

' The adoption of precautions, similar to those here suggested, has resulted in the 
practically complete disappearance of puerperal fever. — Translator. 



PREJUDICES WHICH HAVE 

RETARDED THE PROGRESS 

OF GEOLOGY 

UNIFORMITY IN THE SERIES 

OF PAST CHANGES 

IN THE ANIMATE 

AND INANIMATE WORLD 

BY 
SIR CHARLES LYELL 



INTRODUCTORY NOTE 

Sir Charles Lyell was born near Kirriemuir, Forfarshire, Scotland, 
on November 14, 1797. He graduated from Exeter College, Oxford, in 
1819, and proceeded to the, study of law. Although he practised for a 
short time, he was much hampered in this profession, as in all his work, 
by weak eyesight; and after the age of thirty he devoted himself chiefly 
to science. 

Lyell's father was a botanist of some distinction, and the son seems to 
have been interested in natural history from an early age. While still an 
undergraduate he made geological journeys in Scotland and on the Con- 
tinent of Europe, and throughout his life he upheld by precept and 
example the importance of travel for the geologist. 

The first edition of his "Principles of Geology" was published in 1830; 
and the phrase used in the sub-title, "an attempt to explain the former 
changes of the earth's surface, by reference to causes now in action," 
strikes the keynote of his whole work. All his life he continued to urge 
this method of explanation in opposition to the hypotheses, formerly 
much in vogue, which assumed frequent catastrophes to account for 
geologic changes. The chapters here printed give his own final statement 
of his views on this important issue. 

Lyell's scientific work received wide recognition: he was more than 
once President of the Geological Society, in 1864 was President of the 
British Association, was knighted in 1848, and made a baronet in 1864. 
He possessed a broad general culture, and his home was a noted center 
of the intellectual life of London. He twice came to the United States 
to le;ture, and created great interest. On his death, on February 22, 1875, 
he was buried in Westminster Abbey. - 

Persistent as were Lyell's efforts for the establishment of his main 
theory, he remained remarkably open-minded; and when the evolutionary 
hypothesis was put forward he became a warm supporter of it. Darwin 
in his autobiography thus sums up Lyell's achievement: "The science of 
geology is enormously indebted to Lyell — ^more so, as I believe, than to 
any other man who ever lived." 



THE PROGRESS OF GEOLOGY' 



Prepossessions in regard to the Duration of Past Time — Prejudices Aris- 
ing from our Peculiar Position as Inhabitants of the Land — Others 
Occasioned by our not seeing Subterranean Changes now in Progress 
— All these Causes Combine to make the Former Course of Nature 
appear Different from the Present — Objections to the Doctrine that 
Causes Similar in Kind and Energy to those now Acting, have 
Produced the Former Changes of the Earth's Surface Considered 

IF WE reflect on the history of the progress of geology * * * 
we perceive that there have been great fluctuations of opinion 
respecting the nature of the causes to which all former changes 
of the earth's surface are referable. The first observers conceived 
the monuments which the geologist endeavours to decipher to relate 
to an original state of the earth, or to a period when there were 
causes in activity, distinct, in a kind and degree, from those now 
constituting the economy of nature. These views were gradually 
modified, and some of them entirely abandoned, in proportion as 
observations were multiplied, and the signs of former mutations were 
skilfully interpreted. Many appearances, which had for a long time 
been regarded as indicating mysterious and extraordinary agency, 
were finally recognised as the necessary result of the laws now gov- 
erning the material world; and the discovery of this unlooked-for 
conformity has at length induced some philosophers to infer, that, 
during the ages contemplated in geology, there has never been any 
interruption to the agency of the same uniform laws of change. The 
same assemblage of general causes, they conceive, may have been 
sufficient to produce, by their various combinations, the endless 
diversity of effects, of which the shell of the earth has preserved the 
memorials; and, consistently with these principles, the recurrence 
of analogous changes is expected by them in time to come. 

' The text of the two following papers is taken from the 1 1 th edition of Lyell's 
Principles of Geology, the last edition revised by the author, 

383 



386 SIR CHARLES LYELL 

Whether we coincide or not in this doctrine we must admit that 
the gradual progress o£ opinion concerning the succession of phe- 
nomena in very remote eras, resembles, in a singular manner, that 
which has accompanied the growing intelligence of every people, in 
regard to the economy of nature in their own times. In an early state 
of advancement, when a greater number of natural appearances are 
unintelligible, an eclipse, an earthquake, a flood, or the approach 
of a comet, with many other occurrences afterwards found to belong 
to the regular course of events, are regarded as prodigies. The same 
delusion prevails as to moral phenomena, and many of these are 
ascribed to the intervention of demons, ghosts, witches, and other 
immaterial and supernatural agents. By degrees, many of the enig- 
mas of the moral and physical world are explained, and, instead of 
being due to extrinsic and irregular causes, they are found to depend 
on fixed and invariable laws. The philosopher at last becomes con- 
vinced of the undeviating uniformity of secondary causes; and, 
guided by his faith in this principle, he determines the probability 
of accounts transmitted to him of former occurrences, and often 
rejects the fabulous tales of former times, on the ground of their 
being irreconcilable with the experience of more enlightened ages. 

Prepossessions in regard to the duration of past time. — ^As a belief 
in the want of conformity in the cause by which the earth's crust has 
been modified in ancient and modern periods was, for a long time, 
universally prevalent, and that, too, amongst men who were con- 
vinced that the order of nature had been uniform for the last several 
thousand years, every circumstance which could have influenced their 
minds and given an undue bias to their opinions deserves particular 
attention. Now the reader may easily satisfy himself, that, however 
undeviating the course of nature may have been from the earUest 
epochs, it was impossible for the first cultivators of geology to come 
to such a conclusion, so long as they were under a delusion as to the 
age of the world, and the date of the first creation of animate beings. 
However fantastical some theories of the sixteenth century may now 
appear to us, — however unworthy of men of great talent and sound 
judgment, — we may rest assured that, if the same misconception now 
prevailed in regard to the memorials of human transactions, it would 
give rise to a similar train of absurdities. Let us imagine, for ex- 



THE PROGRESS OF GEOLOGY 387 

ample, that Champollion, and the French and Tuscan literati when 
engaged in exploring the antiquities of Egypt, had visited that coun- 
try with a firm belief that the banks of the Nile were never peopled 
by the human race before the beginning of the nineteenth century, 
and that their faith in this dogma was as difficult to shake as the 
opinion of our ancestors, that the earth was never the abode of 
living beings until the creation of the present continents, and of the 
species now existing, — ^it is easy to perceive what extravagant sys- 
tems they would frame, while under the influence of this delusion, 
to account for the monuments discovered in Egypt. The sight of 
the pyramids, obelisks, colossal statues, and ruined temples, would 
fill them with such astonishment, that for a time they would be as 
men spell-bound — wholly incapable of reasoning with sobriety. They 
might incline at first to refer the construction of such stupendous 
works to some superhuman powers of the primeval world. A system 
might be invented resembling that so gravely advanced by Manetho, 
who relates that a dynasty of gods originally ruled in Egypt, of whom 
Vulcan, the first monarch, reigned nine thousand years; after whom 
came Hercules and other demigods, who were at last succeeded by 
human kings. 

When some fanciful speculations of this kind had amused their 
imaginations for a time, some vast repository of mummies would be 
discovered, and would immediately undeceive those antiquaries who 
enjoyed an opportunity of personally examining them; but the preju- 
dices of others at a distance, who were not eye-witnesses of the whole 
phenomena, would not be so easily overcome. The concurrent report 
of many travellers would, indeed, render it necessary for them to 
accommodate ancient theories to some of the new facts, and much 
wit and ingenuity would be required to modify and defend their 
old positions. Each new invention would violate a greater number 
of known analogies; for if a theory be required to embrace some false 
principle, it becomes more visionary in proportion as facts are multi- 
plied, as would be the case if geometers were now required to form 
an astronomical system on the assumption of the immobility of 
the earth. 

Amongst other fanciful conjectures concerning the history of 
Egypt, we may suppose some of the following to be started. 'As the 



388 SIR CHARLES LYELL 

banks of the Nile have been so recently colonized for the first time, 
the curious substances called mummies could never in reality have 
belonged to men. They may have been generated by some plastic 
virtue residing in the interior of the earth, or they may be abortions 
of Nature produced by her incipient efforts in the work of creation. 
For if deformed beings are sometimes born even now^, vk^hen the 
scheme of the universe is fully developed, many more may have 
been "sent before their time scarce half made up," when the planet 
itself was in the embryo state. But if these notions appear to derogate 
from the perfection of the Divine attributes, and if these mummies 
be in all their parts true representations of the human form, may we 
not refer them to the future rather than the past? May we not be 
looking into the womb of Nature, and not her grave ? May not these 
images be like the shades of the unborn in Virgil's Elysium — the 
archetypes of men not yet called into existence?' 

These speculations, if advocated by eloquent writers, would not 
fail to attract many zealous votaries, for they would relieve men 
from the painful necessity of renouncing preconceived opinions. 
Incredible as such scepticism may appear, it has been rivalled by 
many systems of the sixteenth and seventeenth centuries, and among 
others by that of the learned Falloppio, who, as we have seen (p. 33), 
regarded the tusks of fossil elephants as earthly concretions, and the 
pottery of fragments of vases in the Monte Testaceo, near Rome, as 
works of nature, and not of art. But when one generation had passed 
away, and another, not compromised to the support of antiquated 
dogmas, had succeeded, they would review the evidence afforded by 
mummies more impartially, and would no longer controvert the pre- 
liminary question, that human beings had lived in Egypt before the 
nineteenth century : so that when a hundred years perhaps had been 
lost, the industry and talents of the philosopher would be at last 
directed to the elucidation of points of real historical importance. 

But the above arguments are aimed against one only of many 
prejudices with which the earlier geologists had to contend. Even 
when they conceded that the earth had been peopled with animate 
beings at an earlier period than was at first supposed, they had no 
conception that the quantity of time bore so great a proportion to 
the historical era as is now generally conceded. How fatal every error 



THE PROGRESS OF GEOLOGY 389 

as to the quantity of time must prove to the introduction of rational 
views concerning the state of things in former ages, may be con- 
ceived by supposing the annals of the civil and military transactions 
of a great nation to be perused under the impression that they oc- 
curred in a period of one hundred instead of two thousand years. 
Such a portion of history would immediately assume the air of a 
romance; the events would seem devoid of credibility, and incon- 
sistent with the present course of human affairs. A crowd of inci- 
dents would follow each other in thick succession. Armies and fleets 
would appear to be assembled only to be destroyed, and cities built 
merely to fall in ruins. There would be the most violent transitions 
from foreign or intestine war to periods of profound peace, and the 
works effected during the years of disorder or tranquillity would 
appear alike superhuman in magnitude. 

He who should study the monuments of the natural world under 
the influence of a similar infatuation, must draw a no less exagger- 
ated picture of the energy and violence of causes, and must experi- 
ence the same insurmountable difficulty in reconciling the former 
and present state of nature. If we could behold in one view all the 
volcanic cones thrown up in Iceland, Italy, Sicily, and other parts 
of Europe, during the last five thousand years, and could see the 
lavas which have flowed during the same period; the dislocations, 
subsidences, and elevations caused during earthquakes; the lands 
added to various deltas, or devoured by the sea, together with the 
effects of devastation by floods, and imagine that all these events 
had happened in one year, we must form most exalted ideas of the 
activity of the agents, and the suddenness of the revolutions. If 
geologists, therefore, have misinterpreted the signs of a succession 
of events, so as to conclude that centuries were implied where the 
characters indicated thousands of years, and thousands of years where 
the language of Nature signified millions, they could not, if they 
reasoned logically from such false premises, come to any other con- 
clusion than that the system of the natural world had undergone a 
complete revolution. 

We should be warranted in ascribing the erection of the great 
pyramid to superhuman power, if we were convinced that it was 
raised in one day; and if we imagine, in the same manner, a conti- 



390 SIR CHARLES LYELL 

nent or mountain-chain to have been elevated during an equally 
small fraction of the time which was really occupied in upheaving 
it, we might then be justified in inferring, that the subterranean 
movements were once far more energetic than in our own times. We 
know that during one earthquake the coast of Chili may be raised 
for a hundred miles to the average height of about three feet. A 
repetition of two thousand shocks, of equal violence, might produce 
a mountain-chain one hundred miles long, and six thousand feet 
high. Now, should one or two only of these convulsions happen in 
a century, it would be consistent with the order of events experienced 
by the Chilians from the earliest times: but if the whole of them 
were to occur in the next hundred years, the entire district must be 
depopulated, scarcely any animals or plants could survive, and the 
surface would be one confused heap of ruin and desolation. 

One consequence of undervaluing greatly the quantity of past 
time, is the apparent coincidence which it occasions of events neces- 
sarily disconnected, or which are so unusual, that it would be incon- 
sistent with all calculation of chances to suppose them to happen at 
one and the same time. When the unlooked-for association of such 
rare phenomena is witnessed in the present course of nature, it 
scarcely ever fails to excite a suspicion of the preternatural in those 
minds which are not firmly convinced of the uniform agency of 
secondary causes; — as if the death of some individual in whose fate 
they are interested happens to be accompanied by the appearance of 
a luminous meteor, or a comet, or the shock of an earthquake. It 
would be only necessary to multiply such coincidences indefinitely, 
and the mind of every philosopher would be disturbed. Now it 
would be diiScult to exaggerate the number of physical events, many 
of them most rare and unconnected in their nature, which were 
imagined by the Woodwardian hypothesis to have happened in the 
course of a few months: and numerous other examples might be 
found of popular geological theories, which require us to imagine 
that a long succession of events happened in a brief and almost 
momentary period. 

Another liability to error, very nearly allied to the former, arises 
from the frequent contact of geological monuments referring to very 
distant periods of time. We often behold, at one glance, the 



THE PROGRESS OF GEOLOGY 39 1 

effects of causes which have acted at times incalculably remote, and 
yet there may be no striking circumstances to mark the occurrence 
of a great chasm in the chronological series of Nature's archives. 
In the vast interval of time which may really have elapsed between 
the results of operations thus compared, the physical condition of the 
earth may, by slow and insensible modifications, have become entirely 
altered; one or more races of organic beings may have passed away, 
and yet have left behind, in the particular region under contempla- 
tion, no trace of their existence. 

To a mind unconscious of these intermediate events, the passage 
from one state of things to another must appear so violent, that the 
idea of revolutions in the system inevitably suggests itself. The 
imagination is as much perplexed by the deception, as it might be 
if two distant points in space were suddenly brought into imme- 
diate proximity. Let us suppose, for a moment, that a philosopher 
should lie down to sleep in some arctic wilderness, and then be 
transferred by a power, such as we read of in tales of enchantment, 
to a valley in a tropical country, where, on awaking, he might find 
himself surrounded by birds of briUiant plumage, and all the luxuri- 
ance of animal and vegetable forms of which Nature is so prodigal 
in those regions. The most reasonable supposition, perhaps, which 
he could make, if by the necromancer's art he were placed in such 
a situation, would be, that he was dreaming; and if a geologist form 
theories under a similar delusion, we cannot expect him to preserve 
more consistency in his speculations, than in the train of ideas in an 
ordinary dream. 

It may afford, perhaps, a more lively illustration of the principle 
here insisted upon, if I recall to the reader's recollection the legend of 
the Seven Sleepers. The scene of that popular fable was placed in 
the two centuries which elapsed between the reign of the emperor 
Decius and the death of Theodosius the younger. In that interval 
of time (between the years 249 and 450 of our era) the union of the 
Roman empire had been dissolved, and some of its fairest provinces 
overrun by the barbarians of the north. The seat of government had 
passed from Rome to Constantinople, and the throne from a pagan 
persecutor to a succession of Christian and orthodox princes. The 
genius of the empire had been humbled in the dust, and the altars 



392 SIR CHARLES LYELL 

of Diana and Hercules were on the point of being transferred to 
Catholic saints and martyrs. The legend relates, 'that when Decius 
was still persecuting the Christians, seven noble youths of Ephesus 
concealed themselves in a spacious cavern in the side of an adjacent 
mountain, where they were doomed to perish by the tyrant, who gave 
orders that the entrance should be firmly secured with a pile of huge 
stones. They immediately fell into a deep slumber, which was 
miraculously prolonged, without injuring the powers of life, during 
a period of 187 years. At the end of that time the slaves of Adolius, 
to whom the inheritance of the mountain had descended, removed 
the stones to supply materials for some rustic edifice: the light of 
the sun darted into the cavern, and the seven sleepers were permitted 
to awake. After a slumber, as they thought, of a few hours, they 
were pressed by the calls of hunger, and resolved that Jamblichus, 
one of their number, should secretly return to the city to purchase 
bread for the use of his companions. The youth could no longer 
recognize the once familiar aspect of his native country, and his sur- 
prise was increased by the appearance of a large cross triumphantly 
erected over the principal gate of Ephesus. His singular dress and 
obsolete language confounded the baker, to whom he offered an 
ancient medal of Decius as the current coin of the empire; and 
Jamblichus, on the suspicion of a secret treasure, was dragged before 
the judge. Their mutual enquiries produced the amazing discovery, 
that two centuries were almost elapsed since Jamblichus and his 
friends had escaped from the rage of a pagan tyrant.' 

This legend was received as authentic throughout the Christian 
world before the end of the sixth century, and was afterwards intro- 
duced by Mahomet as a divine revelation into the Koran, and from 
hence was adopted and adorned by all the nations from Bengal to 
Africa who professed the Mahometan faith. Some vestiges even of a 
similar tradition have been discovered in Scandinavia. 'This easy 
and universal belief,' observes the philosophical historian of the 
Decline and Fall, 'so expressive of the sense of mankind, may be 
ascribed to the genuine merit of the fable itself. We imperceptibly 
advance from youth to age, without observing the gradual, but inces- 
sant, change of human aiJairs; and even, in our larger experience of 
history, the imagination is accustomed, by a perpetual series of 



THE PROGRESS OF GEOLOGY 393 

causes and effects, to unite the most distant revolutions. But if the 
interval between two memorable eras could be instantly annihilated ; 
if it were possible, after a momentary slumber of two hundred years, 
to display the new world to the eyes of a spectator who still retained 
a lively and recent impression of the old, his surprise and his reflec- 
tions would furnish the pleasing subject of a philosophical romance.' ^ 

Prejudices arising from our peculiar position as inhabitants of 
the land. — The sources of prejudice hitherto considered may be 
deemed peculiar for the most part to the infancy of the science, but 
others are common to the first cultivators of geology and to our- 
selves, and are all singularly calculated to produce the same decep- 
tion, and to strengthen our belief that the course of Nature in the 
earlier ages differed widely from that now established. Although 
these circumstances cannot be fully explained without assuming some 
things as proved, which it has been my object elsewhere to demon- 
strate,' it may be well to allude to them briefly in this place. 

The first and greatest difficulty, then, consists in an habitual un- 
consciousness that our position as observers is essentially unfavour- 
able, when we endeavour to estimate the nature and magnitude of 
the changes now in progress. In consequence of our inattention to 
this subject, we are liable to serious mistakes in contrasting the pres- 
ent with former states of the globe. As dwellers on the land, we 
inhabit about a fourth part of the surface; and that portion is almost 
exclusively a theatre of decay, and not of reproduction. We know, 
indeed, that new deposits are annually formed in seas and lakes, 
and that every year some new igneous rocks are produced in the 
bowels of the earth, but we cannot watch the progress of their forma- 
tion, and as they are only present to our minds by the aid of reflec- 
tion, it requires an effort both of the reason and the imagination to 
appreciate duly their importance. It is, therefore, not surprising that 
we estimate very imperfectly the result of operations thus unseen 
by us; and that, when analogous results of former epochs are pre- 
sented to our inspection, we cannot immediately recognise the anal- 
ogy. He who has observed the quarrying of stone from a rock, and 
has seen it shipped for some distant port, and then endeavours to 

' Gibbon, Decline and Fall, chap, xxxiii. 

'Elements of Geology, 6th edit., 1865; and Student's Elements, 1871. 



394 SIR CHARLES LYELL 

conceive what kind of edifice will be raised by the materials, is in 
the same predicament as a geologist, who, while he is confined to the 
land, sees the decomposition of rocks, and the transportation of 
matter by rivers to the sea, and then endeavours to picture to himself 
the new strata which Nature is building beneath the waters. 

Prejudices arising from our not seeing subterranean changes. — 
Nor is his position less unfavourable when, beholding a volcanic 
eruption, he tries to conceive what changes the column of lava has 
produced, in its passage upwards, on the intersected strata; or what 
form the melted matter may assume at great depths on cooling; or 
what may be the extent of the subterranean rivers and reservoirs of 
liquid matter far beneath the surface. It should, therefore, be remem- 
bered, that the task imposed on those who study the earth's history 
requires no ordinary share of discretion; for we are precluded from 
collating the corresponding parts of the system of things as it exists 
now, and as it existed at former periods. If we were inhabitants 
of another element — ^if the great ocean were our domain, instead of 
the narrow limits of the land, our difficulties would be considerably 
lessened; while, on the other hand, there can be little doubt, although 
the reader may, perhaps, smile at the bare suggestion of such an idea, 
that an amphibious being, who should possess our faculties, would 
still more easily arrive at sound theoretical opinions in geology, 
since he might behold, on the one hand, the decomposition of rocks 
in the atmosphere, or the transportation of matter by running water; 
and, on the other, examine the deposition of sediment in the sea, 
and the imbedding of animal and vegetable remains in new strata. 
He might ascertain, by direct observation, the action of a moun- 
tain torrent, as well as of a marine current; might compare the prod- 
ucts of volcanos poured out upon the land with those ejected beneath 
the waters; and might mark, on the one hand, the growth of the 
forest, and, on the other, that of the coral reef. Yet, even with these 
advantages, he would be liable to fall into the greatest errors, when 
endeavouring to reason on rocks of subterranean origin. He would 
seek in vain, within the sphere of his observation, for any direct 
analogy to the process of their formation, and would therefore be in 
danger of attributing them, wherever they are upraised to view, to 
some 'primeval state of nature.' 



THE PROGRESS OF GEOLOGY 395 

But if we may be allowed so far to indulge the imagination, as to 
suppose a being entirely confined to the nether world — ^some 'dusky 
melancholy sprite,' like Umbriel, who could 'flit on sooty pinions to 
the central earth,' but who was never permitted to 'sully the fair face 
of light,' and emerge into the regions of water and of air; and if 
this being should busy himself in investigating the structure of the 
globe, he might frame theories the exact converse of those usually 
adopted by human philosophers. He might infer that the stratified 
rocks, containing shells and other organic remains, were the oldest 
of created things, belonging to some original and nascent state of 
the planet. 'Of these masses,' he might say, 'whether they consist of 
loose incoherent sand, soft clay, or solid stone, none have been 
formed in modern times. Every year some of them are broken 
and shattered by earthquakes, or melted by volcanic fire; and when 
they cool down slowly from a state of fusion, they assume a new and 
more crystalline form, no longer exhibiting that stratified disposition 
and those curious impressions and fantastic markings, by which they 
were previously characterised. This process cannot have been carried 
on for an indefinite time, for in that case all the stratified rocks would 
long ere this have been fused and crystallised. It is therefore probable 
that the whole planet once consisted of these mysterious and curi- 
ously bedded formations at a time when the volcanic fire had not yet 
been brought into activity. Since that period there seems to have 
been a gradual development of heat; and this augmentation we may 
expect to continue till the whole globe shall be in a state of fluidity, 
or shall consist, in those parts which are not melted, of volcanic and 
crystalline rocks.' 

Such might be the system of the Gnome at the very time that the 
followers of Leibnitz, reasoning on what they saw on the outer sur- 
face, might be teaching the opposite doctrine of gradual refrigeration, 
and averring that the earth had begun its career as a fiery comet, 
and might be destined hereafter to become a frozen mass. The tenets 
of the schools of the nether and the upper world would be directly 
opposed to each other, for both would partake of the prejudices in- 
evitably resulting from the continual contemplation of one class of 
phenomena to the exclusion of another. Man observes the annual de- 
composition of crystalline and igneous rocks, and may sometimes see 



39^ SIR CHARLES LYELL 

their conversion into stratified deposits; but he cannot witness the 
reconversion of the sedimentary into the crystalline by subterranean 
heat. He is in the habit of regarding all the sedimentary rocks as 
more recent than the unstratified, for the same reason that we may 
suppose him to fall into the opposite error if he saw the origin of the 
igneous class only. 

For more than two centuries the shelly strata of the Subapennine 
hills afforded matter of speculation to the early geologists of Italy, 
and few of them had any suspicion that similar deposits were then 
forming in the neighbouring sea. Some imagined that the strata, so 
rich in organic remains, instead of being due to secondary agents, 
had been so created in the beginning of things by the fiat of the 
Almighty. Others, as we have seen, ascribed the imbedded fossil 
bodies to some plastic power which resided in the earth in the early 
ages of the world. In what manner were these dogmas at length 
exploded? The fossil relics were carefully compared with their liv- 
ing analogues, and all doubts as to their organic origin were eventu- 
ally dispelled. So, also, in regard to the nature of the containing 
beds of mud, sand, and limestone: those parts of the bottom of the 
sea were examined where shells are now becoming annually en- 
tombed in new deposits. Donati explored the bed of the Adriatic, 
and found the closest resemblance between the strata there forming, 
and those which constituted hills above a thousand feet high in 
various parts of the Italian peninsula. He ascertained by dredging 
that living testacea were there grouped together in precisely the 
same manner as were their fossil analogues in the inland strata; and 
while some of the recent shells of the Adriatic were becoming in- 
crusted with calcareous rock, he observed that others had been newly 
buried in sand and clay, precisely as fossil shells occur in the Sub- 
apennine hills. 

In like manner, the volcanic rocks of the Vicentin had been 
studied in the beginning of the last century; but no geologist sus- 
pected, before the time of Arduino, that these were composed of 
ancient submarine lavas. During many years of controversy, the 
popular opinion inclined to a belief that basalt and rocks of the same 
class had been precipitated from a chaotic fluid, or an ocean which 
rose at successive periods over the continents, charged with the com- 



THE PROGRESS OF GEOLOGY 397 

ponent elements of the rocks in question. Few will now dispute 
that it would have been difficult to invent a theory more distant 
from the truth; yet we must cease to wonder that it gained so 
many proselytes, when we remember that its claims to probability 
arose partly from the very circumstance of its confirming the assumed 
want of analogy between geological causes and those now in action. 
By what train of investigations were geologists induced at length 
to reject these views, and to assent to the igneous origin of the trap- 
pean formations? By an examination of volcanos now active, and 
by comparing their structure and the composition of their lavas with 
the ancient trap rocks. 

The establishment, from time to time, of numerous points of 
identification, drew at length from geologists a reluctant admission, 
that there was more correspondence between the condition of the 
globe at remote eras and now, and more uniformity in the laws 
which have regulated the changes of its surface, than they at first 
imagined. If, in this state of the science, they still despaired of 
reconciling every class of geological phenomena to the operations of 
ordinary causes, even by straining analogy to the utmost limits of 
credibility, we might have expected, at least, that the balance of 
probability would now have been presumed to incline towards the 
close analogy of the ancient and modern causes. But, after repeated 
experience of the failure of attempts to speculate on geological 
monuments, as belonging to a distinct order of things, new sects 
continued to persevere in the principles adopted by their predecessors. 
They still began, as each new problem presented itself, whether 
relating to the animate or inanimate world, to assume an original 
and dissimilar order of nature; and when at length they approxi- 
mated, or entirely came round to an opposite opinion, it was always 
with the feeling, that they were conceding what they had been 
justified a priori in deeming improbable. In a word, the same men 
who, as natural philosophers, would have been most incredulous 
respecting any extraordinary deviations from the known course of 
nature, if reported to have happened in their own time, were equally 
disposed, as geologists, to expect the proofs of such deviations at 
every period of the past. * * * * 



UNIFORMITY OF CHANGE 
II 

Supposed Alternate Periods of Repose and Disorder — Observed Facts in 
which this Doctrine has Originated — These may be Explained by 
Supposing a Uniform and Uninterrupted Series of Changes — Three- 
fold Consideration of this Subject: First, in Reference to the Laws 
which Govern the Formation of Fossiliferous Strata, and the Shift- 
ing of the Areas of Sedimentary Deposition; Secondly, in Reference 
to the Living Creation, Extinction of Species, and Origin of New 
Animals and Plants; Thirdly, in Reference to the Changes Produced 
in the Earth's Crust by the Continuance of Subterranean Movements 
in Certain Areas, and their Transference after Long Periods to New 
Areas — On the Combined Influence of all these Modes and Causes 
of Change in Producing Breaks and Chasms in the Chain of Records 
— Concluding Remarks on the Identity of the Ancient and Present 
System of Terrestrial Changes. 

ORIGIN of the doctrine of alternate periods of repose and 
disorder. — ^It has been truly observed, that when we arrange 
the fossiliferous formations in chronological order, they 
constitute a broken and defective series of monuments: we pass 
without any intermediate gradations from systems of strata which 
are horizontal, to other systems which are highly inclined — from 
rocks of peculiar mineral composition to others which have a 
character wholly distinct — from one assemblage of organic remains 
to another, in which frequently nearly all the species, and a large 
part of the genera, are different. These violations of continuity are 
so common as to constitute in most regions the rule rather than the 
exception, and they have been considered by many geologists as 
conclusive in favour of sudden revolutions in the inanimate and 
animate world. We have already seen that according to the specula- 
tions of some writers, there have been in the past history of the planet 
alternate periods of tranquillity and convulsion, the former enduring 
for ages, and resembling the state of things now experienced by man; 
the other brief, transient, and paroxysmal, giving rise to new moun- 

398 



UNIFORMITY OF CHANGE 399 

tains, seas, and valleys, annihilating one set of organic beings, and 
ushering in the creation of another. 

It will be the object of the present chapter to demonstrate that 
these theoretical views are not borne out by a fair interpretation of 
geological monuments. It is true that in the solid framework of the 
globe we have a chronological chain of natural records, many links 
of which are wanting: but a careful consideration of all the phe- 
nomena leads to the opinion that the series was originally defective — 
that it has been rendered still more so by time — that a great part of 
what remains is inaccessible to man, and even of that fraction which 
is accessible nine-tenths or more are to this day unexplored. 

The readiest way, perhaps, of persuading the reader that we may 
dispense with great and sudden revolutions in the geological order 
of events is by showing him how a regular and uninterrupted series 
of changes in the animate and inanimate world must give rise to 
such breaks in the sequence, and such unconformability of stratified 
rocks, as are usually thought to imply convulsions and catastrophes. 
It is scarcely necessary to state that the order of events thus assumed 
to occur, for the sake of illustration, should be in harmony with all 
the conclusions legitimately drawn by geologists from the structure 
of the earth, and must be equally in accordance with the changes 
observed by man to be now going on in the living as well as in 
the inorganic creation. It may be necessary in the present state of 
science to supply some part of the assumed course of nature hypo- 
thetically; but if so, this must be done without any violation of 
probability, and always consistently with the analogy of what is 
known both of the past and present economy of our system. 
Although the discussion of so comprehensive a subject must carry 
the beginner far beyond his depth, it will also, it is hoped, stimulate 
his curiosity, and prepare him to read some elementary treatises on 
geology with advantage, and teach him the bearing on that science 
of the changes now in progress on the earth. At the same time it 
may enable him the better to understand the intimate connection 
between the Second and Third Books of this work, one of which is 
occupied with the changes of the inorganic, the latter with those of 
the organic creation. 

In pursuance, then, of the plan above proposed, I will consider in 



400 SIR CHARLES LYELL 

this chapter, first, the laws which regulate the denudation of strata 
and the deposition of sediment; secondly, those which govern the 
fluctuation in the animate world; and thirdly, the mode in which 
subterranean movements affect the earth's crust. 

Uniformity of change considered, first, in reference to denudation 
and sedimentary deposition. — First, in regard to the laws governing 
the deposition of new strata. If we survey the surface of the globe, 
we immediately perceive that it is divisible into areas of deposition 
and non-deposition; or, in other words, at any given time there are 
spaces which are the recipients, others which are not the recipients, 
of sedimentary matter. No new strata, for example, are thrown 
down on dry land, which remains the same from year to year; 
whereas, in many parts of the bottom of seas and lakes, mud, sand, 
and pebbles are annually spread out by rivers and currents. There 
are also great masses of limestone growing in some seas, chiefly 
composed of corals and shells, or, as in the depths of the Atlantic, 
of chalky mud made up of foraminifera and diatomaceae. 

As to the dry land, so far from being the receptacle of fresh 
accessions of matter, it is exposed almost everywhere to waste away. 
Forests may be as dense and lofty as those of Brazil, and may swarm 
with quadrupeds, birds, and insects, yet at the end of thousands of 
years one layer of black mould a few inches thick may be the sole 
representative of those myriads of trees, leaves, flowers, and fruits, 
those innumerable bones and skeletons of birds, quadrupeds, and 
reptiles, which tenanted the fertile region. Should this land be at 
length submerged, the waves of the sea may wash away in a few 
hours the scanty covering of mould, and it may merely impart a 
darker shade of colour to the next stratum of marl, sand, or other 
matter newly thrown down. So also at the bottom of the ocean 
where no sediment is accumulating, seaweed, zoophytes, fish, and 
even shells, may multiply for ages and decompose, leaving no vestige 
of their form or substance behind. Their decay, in water, although 
more slow, is as certain and eventually as complete as in the open 
air. Nor can they be perpetuated for indefinite periods in a fossil 
state, unless imbedded in some matrix which is impervious to water, 
or which at least does not allow a free percolation of that fluid, 
impregnated, as it usually is, with a slight quantity of carbonic or 



UNIFORMITY OF CHANGE 4OI 

Other acid. Such a free percolation may be prevented either by the 
mineral nature of the matrix itself, or by the superposition of an 
impermeable stratum; but if unimpeded, the fossil shell or bone will 
be dissolved and removed, particle after particle, and thus entirely 
effaced, unless petrifaction or the substitution of some mineral for 
the organic matter happen to take place. 

That there has been land as well as sea at all former geological 
periods, we know from the fact that fossil trees and terrestrial plants 
are imbedded in rocks of every age, except those which are so ancient 
as to be very imperfectly known to us. Occasionally lacustrine and 
fluviatile shells, or the bones of amphibious or land reptiles, point 
to the same conclusion. The existence of dry land at all periods of 
the past implies, as before mentioned, the partial deposition of 
sediment, or its limitation to certain areas; and the next point to 
which I shall call the reader's attention is the shifting of these areas 
from one region to another. 

First, then, variations in the site of sedimentary deposition are 
brought about independently of subterranean movements. There is 
always a slight change from year to year, or from century to century. 
The sediment of the Rhone, for example, thrown into the Lake of 
Geneva, is now conveyed to a spot a mile and a half distant from 
that where it accumulated in the tenth century, and six miles from 
the point where the delta began originally to form. We may look 
forward to the period when this lake will be filled up, and then the 
distribution of the transported matter will be suddenly altered, for 
the mud and sand brought down from the Alps will thenceforth, 
instead of being deposited near Geneva, be carried nearly 200 miles 
southwards, where the Rhone enters the Mediterranean. 

In the deltas of large rivers, such as those of the Ganges and 
Indus, the mud is first carried down for many centuries through one 
arm, and on this being stopped up it is discharged by another, and 
may then enter the sea at a point 50 or 100 miles distant from its 
first receptacle. The direction of marine currents is also liable to be 
changed by various accidents, as by the heaping up of new sand- 
banks, or the wearing away of cliffs and promontories. 

But, secondly, all these causes of fluctuation in the sedimentary 
areas are entirely subordinate to those great upward or downward 



402 SIR CHARLES LYELL 

movements of land, which will presently be spoken of, as prevailing 
over large tracts of the globe. By such elevation or subsidence certain 
spaces are gradually submerged, or made gradually to emerge: in 
the one case sedimentary deposition may be suddenly renewed after 
having been suspended for one or more geological periods, in the 
other as suddenly made to cease after having continued for ages. 

If deposition be renewed after a long interval, the new strata will 
usually differ greatly from the sedimentary rocks previously formed 
in the same place, and especially if the older rocks have suffered 
derangement, which implies a change in the physical geography 
of the district since the previous conveyance of sediment to the same 
spot. It may happen, however, that, even where the two groups, the 
superior and the inferior, are horizontal and conformable to each 
other, they may still differ entirely in mineral character, because, 
since the origin of the older formation, the geography of some 
distant country has been altered. In that country rocks before con- 
cealed may have become exposed by denudation; volcanos may have 
burst out and covered the surface with scoriz and lava; or new lakes, 
intercepting the sediment previously conveyed from the upper 
country, may have been formed by subsidence; and other fluctua- 
tions may have occurred, by which the materials brought down 
from thence by rivers to the sea have acquired a distinct mineral 
character. 

It is well known that the stream of the Mississippi is charged with 
sediment of a different colour from that of the Arkansas and Red 
Rivers, which are tinged with red mud, derived from rocks of 
porphyry and red gypseous clays in 'the far west.' The waters of 
the Uruguay, says Darwin, draining a granitic country, are clear 
and black, those of the Parana, red.' The mud with which the 
Indus is loaded, says Burnes, is of a clayey hue, that of the Chenab, 
on the other hand, is reddish, that of the Sutlej is more pale.^ The 
same causes which make these several rivers, sometimes situated 
at no great distance the one from the other, to differ greatly in the 
character of their sediment, will make the waters draining the same 
country at different epochs, especially before and after great revolur 

'Darwin's Journal, p. 163, and edit., p. 139. 
^Journ. Roy. Geograph. Sec., vol. iii., p. 142. 



UNIFORMITY OF CHANGE 4O3 

tions in physical geography, to be entirely dissimilar. It is scarcely 
necessary to add that marine currents will be affected in an analogous 
manner in consequence o£ the formation of new shoals, the emer- 
gence of new islands, the subsidence of others, the gradual waste of 
neighbouring coasts, the growth of new deltas, the increase of coral 
reefs, volcanic eruptions, and other changes. 

Uniformity of change considered, secondly, in reference to the 
living creation. — Secondly, in regard to the vicissitudes of the living 
creation, all are agreed that the successive groups of sedimentary 
strata found in the earth's crust are not only dissimilar in mineral 
composition for reasons above alluded to, but are likewise distin- 
guishable from each other by their organic remains. The general 
inference drawn from the study and comparison of the various 
groups, arranged in chronological order, is this: that at successive 
periods distinct tribes of animals and plants have inhabited the land 
and waters, and that the organic types of the newer formations are 
more analogous to species now existing than those of more ancient 
rocks. If we then turn to the present state of the animate creation, 
and enquire whether it has now become fixed and stationary, we 
discover that, on the contrary, it is in a state of continual flux— that 
there are many causes in action which tend to the extinction of 
species, and which are conclusive against the doctrine of their un- 
limited durability. 

There are also causes which give rise to new varieties and races 
in plants and animals, and new forms are continually supplanting 
others which had endured for ages. But natural history has been 
successfully cultivated for so short a period, that a few examples 
only of local, and perhaps but one or two of absolute, extirpation of 
sjjecies can as yet be proved, and these only where the interference 
of man has been conspicuous. It will nevertheless appear evident, 
from the facts and arguments detailed in the chapters which treat of 
the geographical distribution of species in the next volume, that 
man is not the only exterminating agent; and that, independently of 
his intervention, the annihilation of species is promoted by the 
multiplication and gradual diffusion of every animal or plant. It 
will also appear that every alteration in the physical geography and 
climate of the globe cannot fail to have the same tendency. If we 



404 SIR CHARLES LYELL 

proceed still farther, and enquire whether new species are substituted 
from time to time for those which die out, we find that the successive 
introduction of new forms appears to have been a constant part of 
the economy of the terrestrial system, and if we have no direct proof 
of the fact it is because the changes take place so slowly as not to 
come within the period of exact scientific observation. To enable 
the reader to appreciate the gradual manner in which a passage may 
have taken place from an extinct fauna to that now living, I shall 
say a few words on the fossils of successive Tertiary periods. When 
we trace the series of formations from the more ancient to the more 
modern, it is in these Tertiary deposits that we first meet with assem- 
blages of organic remains having a near analogy to the fauna of 
certain parts of the globe in our own time. In the Eocene, or oldest 
subdivisions, some few of the testacea belong to existing species, 
although almost all of them, and apparently all the associated verte- 
brata, are now extinct. These Eocene strata are succeeded by a great 
number of more modern deposits, which depart gradually in the 
character of their fossils from the Eocene type, and approach more 
and more to that of the living creation. In the present state of sci- 
ence, it is chiefly by the aid of shells that we are enabled to arrive 
at these results, for of all classes the testacea are the most generally 
diffused in a fossil state, and may be called the medals principally 
employed by nature in recording the chronology of past events. In 
the Upper Miocene rocks (No. 5 of the table, p. 135) we begin to 
find a considerable number, although still a minority, of recent 
species, intermixed with some fossils common to the preceding, or 
Eocene, epoch. We then arrive at the Pliocene strata, in which 
species now contemporary with man begin to preponderate, and in 
the newest of which nine-tenths of the fossils agree with species 
still inhabiting the neighbouring sea. It is in the Post-Tertiary 
strata, where all the shells agree with species now living, that we 
have discovered the first or earliest known remains of man associated 
with the bones of quadrupeds, some of which are of extinct spe- 
cies. 

In thus passing from the older to the newer members of the Ter- 
tiary system, we meet with many chasms, but none which separate 
entirely, by a broad line of demarcation, one state of the organic 



UNIFORMITY OF CHANGE 405 

world from another. There are no signs of an abrupt termination 
of one fauna and flora, and the starting into Ufe of new and wholly 
distinct forms. Although we are far from being able to demonstrate 
geologically an insensible transition from the Eocene to the Miocene, 
or even from the latter to the recent fauna, yet the more we enlarge 
and perfect our general survey, the more nearly do we approximate 
to such a continuous series, and the more gradually are we con- 
ducted from times when many of the genera and nearly all the 
species were extinct, to those in which scarcely a single species 
flourished which we do not know to exist at present. Dr. A. Philippi, 
indeed, after an elaborate comparison of the fossil tertiary shells of 
Sicily with those now living in the Mediterranean, announced, as 
the result of his examination, that there are strata in that island 
which attest a very gradual passage from a period when only thirteen 
in a hundred of the shells were like the species now living in the sea, 
to an era when the recent species had attained a proportion of ninety- 
five in a hundred. There is, therefore, evidence, he says, in Sicily 
of this revolution in the animate world having been effected 'with- 
out the intervention of any convulsion or abrupt changes, certain 
species having from time to time died out, and others having been 
introduced, until at length the existing fauna was elaborated.' 

In no part of Europe is the absence of all signs of man or his 
works, in strata of comparatively modern date, more striking than 
in Sicily. In the central parts of that island we observe a lofty table- 
land and hills, sometimes rising to the height of 3,000 feet, capped 
with a limestone, in which from 70 to 85 per cent, of the fossil 
testacea are specifically identical with those now inhabiting the 
Mediterranean. These calcareous and other argillaceous strata of 
the same age are intersected by deep valleys which appear to have 
been gradually formed by denudation, but have not varied mate- 
rially in width or depth since Sicily was first colonised by the Greeks. 
The limestone, moreover, which is of so late a date in geological 
chronology, was quarried for building those ancient temples of 
Girgenti and Syracuse, of which the ruins carry us back to a remote 
era in human history. If we are lost in conjectures when speculating 
on the ages required to lift up these formations to the height of 
several thousand feet above the sea, and to excavate the valleys, how 



406 SIR CHARLES LYELL 

much more remote must be the era when the same rocks were 
gradually formed beneath the waters! 

The intense cold of the Glacial period was spoken of in the tenth 
chapter. Although we have not yet succeeded in detecting proofs 
of the origin of man antecedently to that epoch, we have yet found 
evidence that most of the testacea, and not a few of the quadrupeds, 
which preceded, were of the same species as those which followed 
the extreme cold. To whatever local disturbances this cold may 
have given rise in the distribution of species, it seems to have done 
little in effecting their annihilation. We may conclude therefore, 
from a survey of the tertiary and modern strata, which constitute a 
more complete and unbroken series than rocks of older date, that 
the extinction and creation of species have been, and are, the result 
of a slow and gradual change in the organic world. 

Uniformity of change considered, thirdly, in reference to subter- 
ranean movements. — Thirdly, to pass on to the last of the three topics 
before proposed for discussion, the reader will find, in the account 
given in the Second Book, Vol. II., of the earthquakes recorded in 
history, that certain countries have from time immemorial, been 
rudely shaken again and again; while others, comprising by far the 
largest part of the globe, have remained to all appearance motionless. 
In the regions of convulsion rocks have been rent asunder, the surface 
has been forced up into ridges, chasms have opened, or the ground 
throughout large spaces has been permanently lifted up above or 
let down below its former level. In the regions of tranquillity some 
areas have remained at rest, but others have been ascertained, by a 
comparison of measurements made at different periods, to have 
risen by an insensible motion, as in Sweden, or to have subsided 
very slowly, as in Greenland. That these same movements, whether 
ascending or descending, have continued for ages in the same direc- 
tion has been established by historical or geological evidence. Thus 
we find on the opposite coasts of Sweden that brackish water 
deposits, like those now forming in the Baltic, occur on the eastern 
side, and upraised strata filled with purely marine shells, now proper 
to the ocean, on the western coast. Both of these have been lifted up 
to an elevation of several hundred feet above high-water mark. The 
rise within the historical period has not amounted to many yards, 



UNIFORMITY OF CHANGE 407 

but the greater extent o£ antecedent upheaval is proved by the occur- 
rence in inland spots, several hundred feet high, of deposits filled 
with fossil shells of species now living either in the ocean or the 
Baltic. 

It must in general be more difficult to detect proofs of slow and 
gradual subsidence than of elevation, but the theory which accounts 
for the form of circular coral reefs and lagoon islands, and which 
will be explained in the concluding chapter of this work, will satisfy 
the reader that there are spaces on the globe, several thousand miles 
in circumference, throughout which the downward movement has 
predominated for ages, and yet the land has never, in a single 
instance, gone down suddenly for several hundred feet at once. Yet 
geology demonstrates that the persistency of subterranean move- 
ments in one direction has not been perpetual throughout all past 
time. There have been great oscillations of level, by which a surface 
of dry land has been submerged to a depth of several thousand feet, 
and then at a period long subsequent raised again and made to 
emerge. Nor have the regions now motionless been always at rest; 
and some of those which are at present the theatres of reiterated 
earthquakes have formerly enjoyed a long continuance of tranquil- 
lity. But, although disturbances have ceased after having long pre- 
vailed, or have recommenced after a suspension for ages, there has 
been no universal disruption of the earth's crust or desolation of the 
surface since times the most remote. The non-occurrence of such a 
general convulsion is proved by the perfect horizontality now re- 
tained by some of the most ancient fossiliferous strata throughout 
wide areas. 

That the subterranean forces have visited different parts of the 
globe at successive periods is inferred chiefly from the unconforma- 
bility of strata belonging to groups of different ages. Thus, for 
example, on the borders of Wales and Shropshire, we find the slaty 
beds of the ancient Silurian system inclined and vertical, while the 
beds of the overlying carboniferous shale and sandstone are hori- 
zontal. All are agreed that in such a case the older set of strata had 
suffered great disturbance before the deposition of the newer or 
carboniferous beds, and that these last have never since been vio- 
lently fractured, nor have ever been bent into folds, whether by 



408 SIR CHARLES LYELL 

sudden or continuous lateral pressure. On the other hand, the more 
ancient or Silurian group suffered only a local derangement, and 
neither in Wales nor elsewhere are all the rocks of that age found 
to be curved or vertical. 

In various parts of Europe, for example, and particularly near Lake 
Wener in the south of Sweden, and in many parts of Russia, the 
Silurian strata maintain the most perfect horizontality; and a similar 
observation may be made respecting limestones and shales of like 
antiquity in the great lake district of Canada and the United States. 
These older rocks are still as flat and horizontal as when first 
formed; yet, since their origin, not only have most of the actual 
mountain-chains been uplifted, but some of the very rocks of which 
those mountains are composed have been formed, some of them by 
igneous and others by aqueous action. 

It would be easy to multiply instances of similar unconforma- 
bility in formations of other ages; but a few more will suffice. The 
carboniferous rocks before alluded to as horizontal on the borders 
of Wales are vertical in the Mendip hills in Somersetshire, where the 
overlying beds of the New Red Sandstone are horizontal. Again, 
in the Wolds of Yorkshire the last-mentioned sandstone supports on 
its curved and inclined beds the horizontal Chalk. The Chalk again 
is vertical on the flanks of the Pyrenees, and the tertiary strata repose 
unconformably upon it. 

As almost every country supplies illustrations of the same phe- 
nomena, they who advocate the doctrine of alternate periods of dis- 
order and repose may appeal to the facts above described, as proving 
that every district has been by turns convulsed by earthquakes and 
then respited for ages from convulsions. But so it might with equal 
truth be affirmed that every part of Europe has been visited alter- 
nately by winter and summer, although it has always been winter 
and always summer in some part of the planet, and neither of these 
seasons has ever reigned simultaneously over the entire globe. They 
have been always shifting from place to place; but the vicissitudes 
which recur thus annually in a single spot are never allowed to inter- 
fere with the invariable uniformity of seasons throughout the whole 
planet. 

So, in regard to subterranean movements, the theory of the per- 



UNIFORMITY OF CHANGE 4O9 

petual uniformity of the force which they exert on the earth's crust 
is quite consistent with the admission of their alternate development 
and suspension for long and indefinite periods within limited geo- 
graphical areas. 

If, for reasons before stated, we assume a continual extinction 
of species and appearance of others on the globe, it will then follow 
that the fossils of strata formed at two distant periods on the same 
spot will differ even more certainly than the mineral composition 
of those strata. For rocks of the same kind have sometimes been 
reproduced in the same district after a long interval of time; whereas 
all the evidence derived from fossil remains is in favour of the 
opinion that species which have once died out have never been 
reproduced. The submergence, then, of land must be often attended 
by the commencement of a new class of sedimentary deposits, char- 
acterized by a new set of fossil animals and plants, while the recon- 
version of the bed of the sea into land may arrest at once and for 
an indefinite time the formation of geological monuments. Should 
the land again sink, strata will again be formed; but one or many 
entire revolutions in animal or vegetable life may have been com- 
pleted in the interval. 

As to the want of completeness in the fossiliferous series, which 
may be said to be almost universal, we have only to reflect on what 
has been already said of the laws governing sedimentary deposition, 
and those which give rise to fluctuations in the animate world, to be 
convinced that a very rare combination of circumstances can alone 
give rise to such a superposition and preservation of strata as will 
bear testimony to the gradual passage from one state of organic life 
to another. To produce such strata nothing less will be requisite than 
the fortunate coincidence of the following conditions: first, a never- 
failing supply of sediment in the same region throughout a period 
of vast duration; secondly, the fitness of the deposit in every part for 
the permanent preservation of imbedded fossils; and, thirdly, a 
gradual subsidence to prevent the sea or lake from being filled up 
and converted into land. 

It will appear in the chapter on coral reefs, that, in certain parts 
of the Pacific and Indian Oceans, most of these conditions, if not all, 
are complied with, and the constant growth of coral, keeping pace 



410 SIR CHARLES LYELL 

with the sinking of the bottom of the sea, seems to have gone on so 
slowly, for such indefinite periods, that the signs of a gradual change 
in organic life might probably be detected in that quarter of the 
globe if we could explore its submarine geology. Instead of the 
growth of coralline limestone, let us suppose, in some other place, 
the continuous deposition of fluviatile mud and sand, such as the 
Ganges and Brahmapootra have poured for thousands of years into 
the Bay of Bengal. Part of this bay, although of considerable depth, 
might at length be filled up before an appreciable amount of change 
was effected in the fish, moUusca, and other inhabitants of the sea 
and neighbouring land. But if the bottom be lowered by sinking at 
the same rate that it is raised by fluviatile mud, the bay can never 
be turned into dry land. In that case one new layer of matter may 
be superimposed upon another for a thickness of many thousand 
feet, and the fossils of the inferior beds may differ greatly from those 
entombed in the uppermost, yet every intermediate gradation may 
be indicated in the passage from an older to a newer assemblage of 
species. Granting, however, that such an unbroken sequence of 
monuments may thus be elaborated in certain parts of the sea, and 
that the strata happen to be all of them well adapted to preserve 
the included fossils from decomposition, how many accidents must 
still concur before these submarine formations will be laid open to 
our investigation! The whole deposit must first be raised several 
thousand feet, in order to bring into view the very foundation; and 
during the process of exposure the superior beds must not be entirely 
swept away by denudation. 

In the first place, the chances are nearly as three to one against the 
mere emergence of the mass above the waters, because nearly three- 
fourths of the globe are covered by the ocean. But if it be upheaved 
and made to constitute part of the dry land, it must also, before 
it can be available for our instruction, become part of that area 
already surveyed by geologists. In this small fraction of land already 
explored, and still very imperfectly known, we are required to find a 
set of strata deposited under peculiar conditions, and which, having 
been originally of limited extent, would have been probably much 
lessened by subsequent denudation. 

Yet it is precisely because we do not encounter at every step the 



UNIFORMITT OF CHANGE 4II 

evidence of such gradations from one state of the organic world to 
another, that so many geologists have embraced the doctrine of 
great and sudden revolutions in the history of the animate world. 
Not content with simply availing themselves, for the convenience of 
classification, of those gaps and chasms which here and there inter- 
rupt the continuity of the chronological series, as at present known, 
they deduce, from the frequency of these breaks in the chain of 
records, an irregular mode of succession in the events themselves, 
both in the organic and inorganic world. But, besides that some 
links of the chain which once existed are now entirely lost and others 
concealed from view, we have good reason to suspect that it was 
never complete originally. 

It may undoubtedly be said that strata have been always forming 
somewhere, and therefore at every moment of past time Nature has 
added a page to her archives; but, in reference to this subject, it 
should be remembered that we can never hope to compile a con- 
secutive history by gathering together monuments which were 
originally detached and scattered over the globe. For, as the species 
of organic beings contemporaneously inhabiting remote regions are 
distinct, the fossils of the first of several periods which may be pre- 
served in any one country, as in America for example, will have no 
connection with those of a second period found in India, and will 
therefore no more enable us to trace the signs of a gradual change in 
the living creation, than a fragment of Chinese history will fill up a 
blank in the political annals of Europe. 

The absence of any deposits of importance containing recent shells 
in Chili, or anywhere on the western coast of South America, natur- 
ally led Mr. Darwin to the conclusion that 'where the bed of the sea 
is either stationary or rising, circumstances are far less favourable 
than where the level is sinking to the accumulation of conchiferous 
strata of sufficient thickness and extension to resist the average vast 
amount of denudation.' ' In like manner the beds of superficial 
sand, clay, and gravel, with recent shells, on the coasts of Norway 
and Sweden, where the land has risen in Post-tertiary times, are so 
thin and scanty as to incline us to admit a similar proposition. We 
may in fact assume that in all cases where the bottom of the sea has 

'Darwin's S. America, pp. 136, 139. 



412 SIR CHARLES LYELL 

been undergoing continuous elevation, the total thickness of sedi- 
mentary matter accumulating at depths suited to the habitation of 
most of the species of shells can never be great, nor can the deposits 
be thickly covered by superincumbent matter, so as to be consolidated 
by pressure. When they are upheaved, therefore, the waves on the 
beach will bear down and disperse the loose materials; whereas, if 
the bed of the sea subsides slowly, a mass of strata, containing abun- 
dance of such species as live at moderate depths, may be formed and 
may increase in thickness to any amount. It may also extend hori- 
zontally over a broad area, as the water gradually encroaches on the 
subsiding land. 

Hence it will follow that great violations of continuity in the 
chronological series of fossiliferous rocks will always exist, and the 
imperfection of the record, though lessened, will never be removed 
by future discoveries. For not only will no deposits originate on the 
dry land, but those formed in the sea near land, which is undergoing 
constant upheaval, will usually be too slight in thickness to endure 
for ages. 

In proportion as we become acquainted with larger geographical 
areas, many of the gaps, by which a chronological table, Hke that 
given at page 135, is rendered defective, will be removed. We were 
enabled by aid of the labours of Prof. Sedgwick and Sir Roderick 
Murchison, to intercalate, in 1838, the marine strata of the Devonian 
period, with their fossil shells, corals, and fish, between the Silurian 
and Carboniferous rocks. Previously the marine fauna of these last- 
mentioned formations wanted the connecting links which now 
render the passage from the one to the other much less abrupt. In 
like manner the Upper Miocene has no representative in England, 
but in France, Germany, and Switzerland it constitutes a most 
instructive link between the living creation and the middle of the 
great Tertiary period. Still we must expect, for reasons before stated, 
that chasms will for ever continue to occur, in some parts of our 
sedimentary series. 

Concluding remar\s on the consistency of the theory of gradual 
change with the existence of great brea\s in the series.— To return 
to the general argument pursued in this chapter, it is assumed, for 
reasons above explained, that a slow change of species is in simul- 



UNIFORMITY OF CHANGE 413 

taneous operation everywhere throughout the habitable surface of 
sea and land; whereas the fossilisation of plants and animals is con- 
fined to those areas where new strata are produced. These areas, as 
we have seen, are always shifting their position, so that the fossilising 
process, by means of which the commemoration of the particular 
state of the organic world, at any given time, is effected, may be 
said to move about, visiting and revisiting different tracts in suc- 
cession. 

To make still more clear the supposed working of this machinery, 
I shall compare it to a somewhat analogous case that might be 
imagined to occur in the history of human affairs. Let the mortality 
of the population of a large country represent the successive extinc- 
tion of species, and the births of new individuals the introduction of 
new species. While these fluctuations are gradually taking place 
everywhere, suppose commissioners to be appointed to visit each 
province of the country in succession, taking an exact account of the 
number, names, and individual peculiarities of all the inhabitants, 
and leaving in each district a register containing a record of this 
information. If, after the completion of one census, another is imme- 
diately made on the same plan, and then another, there will at last 
be a series of statistical documents in each province. When those 
belonging to any one province are arranged in chronological order, 
the contents of such as stand next to each other will differ according 
to the length of the intervals of time between the taking of each 
census. If, for example, there are sixty provinces, and all the registers 
are made in a single year and renewed annually, the number of 
births and deaths will be so small, in proportion to the whole of the 
inhabitants, during the interval between the compiling of two con- 
secutive documents, that the individuals described in such documents 
will be nearly identical; whereas, if the survey of each of the sixty 
provinces occupies all the commissioners for a whole year, so that 
they are unable to revisit the same place until the expiration of sixty 
years, there will then be an almost entire discordance between the 
persons enumerated in two consecutive registers in the same prov- 
ince. There are, undoubtedly, other causes, besides the mere quantity 
of time, which may augment or diminish the amount of discrepancy. 
Thus, at some periods a pestilential disease may have lessened the 



414 SIR CHARLES LYELL 

average duration of human life; or a variety of circumstances may 
have caused the births to be unusually numerous, and the population 
to multiply; or a province may be suddenly colonised by persons 
migrating from surrounding districts. 

These exceptions may be compared to the accelerated rate of fluctu- 
ations in the fauna and flora of a particular region, in which the 
climate and physical geography may be undergoing an extraordinary 
degree of alteration. 

But I must remind the reader that the case above proposed has 
no pretensions to be regarded as an exact parallel to the geological 
phenomena which I desire to illustrate; for the commissioners are 
supposed to visit the different provinces in rotation; whereas the 
commemorating processes by which organic remains become fossil- 
ised, although they are always shifting from one area to the other, 
are yet very irregular in their movements. They may abandon and 
revisit many spaces again and again, before they once approach 
another district; and, besides this source of irregularity, it may often 
happen that, while the depositing process is suspended, denudation 
may take place, which may be compared to the occasional destruction 
by fire or other causes of some of the statistical documents before 
mentioned. It is evident that where such accidents occur the want 
of continuity in the series may become indefinitely great, and that 
the monuments which follow next in succession will by no means 
be equidistant from each other in point of time. 

If this train of reasoning be admitted, the occasional distinctness 
of the fossil remains, in formations immediately in contact, would 
be a necessary consequence of the existing laws of sedimentary 
deposition and subterranean movement, accompanied by a constant 
dying-out and renovation of species. 

As all the conclusions above insisted on are directly opposed to 
opinions still popular, I shall add another comparison, in the hope of 
preventing any possible misapprehension of the argument. Suppose 
we had discovered two buried cities at the foot of Vesuvius, immedi- 
ately superimposed upon each other, with a great mass of tuff and 
lava intervening, just as Portici and Resina, if now covered with 
ashes, would overlie Herculaneum. An antiquary might possibly be 
entitled to infer, from the inscriptions on public edifices, that the 



UNIFORMITY OF CHANGE 415 

inhabitants of the inferior and older city were Greeks, and those of 
the modern towns Italians. But he would reason very hastily if he 
also concluded from these data, that there had been a sudden change 
from the Greek to the Italian language in Campania. But if he 
afterwards found three buried cities, one above the other, the inter- 
mediate one being Roman, while, as in the former example, the 
lowest was Greek and the uppermost Italian, he would then per- 
ceive the fallacy of his former opinion, and would begin to suspect 
that the catastrophes, by which the cities were inhumed might have 
no relation whatever to the fluctuations in the language of the inhabi- 
tants; and that, as the Roman tongue had evidently intervened 
between the Greek and Italian, so many other dialects may have been 
spoken in succession, and the passage from the Greek to the Italian 
may have been very gradual, some terms growing obsolete, while 
others were introduced from time to time. 

If this antiquary could have shown that the volcanic paroxysms 
of Vesuvius were so governed as that cities should be buried one 
above the other, just as often as any variation occurred in the lan- 
guage of the inhabitants, then, indeed, the abrupt passage from a 
Greek to a Roman, and from a Roman to an Italian city, would 
afford proof of fluctuations no less sudden in the language of the 
people. 

So, in Geology, if we could assume that it is part of the plan of 
Nature to preserve, in every region of the globe, an unbroken series 
of monuments to commemorate the vicissitudes of the organic crea- 
tion, we might infer the sudden extirpation of species, and the 
simultaneous introduction of others, as often as two formations in 
contact are found to include dissimilar organic fossils. But we must 
shut our eyes to the whole economy of the existing causes, aqueous, 
igneous, and organic, if we fail to perceive that such is not the plan 
of Nature. 

I shall now conclude the discussion of a question with which we 
have been occupied since the beginning of the fifth chapter — namely, 
whether there has been any interruption, from the remotest periods, 
of one uniform and continuous system of change in the animate and 
inanimate world. We were induced to enter into that enquiry by 
reflecting how much the progress of opinion in Geology had been 



41 6 SIR CHARLES LYELL 

influenced by the assumption that the analogy was sHght in kind, 
and still more slight in degree, between the causes which produced 
the former revolutions of the globe, and those now in every-day 
operation. It appeared clear that the earlier geologists had not only 
a scanty acquaintance with existing changes, but were singularly 
unconscious of the amount of their ignorance. With the presumption 
naturally inspired by this unconsciousness, they had no hesitation in 
deciding at once that time could never enable the existing powers 
of nature to work out changes of great magnitude, still less such 
important revolutions as those which are brought to light by Geol- 
ogy. They therefore felt themselves at liberty to indulge their 
imaginations in guessing at what might be, rather than enquiring 
what is; in other words, they employed themselves in conjecturing 
what might have been the course of Nature at a remote period, 
rather than in the investigation of what was the course of Nature 
in their own times. 

It appeared to them far more philosophical to speculate on the 
possibilities of the past, than patiently to explore the realities of the 
present; and having invented theories under the influence of such 
maxims, they were consistently unwilling to test their validity by 
the criterion of their accordance with the ordinary operations of 
Nature. On the contrary, the claims of each new hypothesis to 
credibility appeared enhanced by the great contrast, in kind or inten- 
sity, of the causes referred to and those now in operation. 

Never was there a dogma more calculated to foster indolence, and 
to blunt the keen edge of curiosity, than this assumption of the 
discordance between the ancient and existing causes of change. It 
produced a state of mind unfavourable in the highest degree to the 
candid reception of the evidence of those minute but incessant alter- 
ations which every part of the earth's surface is undergoing, and by 
which the condition of its living inhabitants is continually made to 
vary. The student, instead of being encouraged with the hope of 
interpreting the enigmas presented to him in the earth's structure — 
instead of being prompted to undertake laborious enquiries into the 
natural history of the organic world, and the complicated effects of 
the igneous and aqueous causes now in operation — was taught to 
despond from the first. Geology, it was affirmed, could never rise 



UNIFORMITY OF CHANGE 417 

to the rank of an exact science; the greater number of phenomena 
must for ever remain inexplicable, or only be partially elucidated by 
ingenious conjectures. Even the mystery which invested the subject 
was said to constitute one of its principal charms, affording, as it 
did, full scope to the fancy to indulge in a boundless field of specu- 
lation. 

The course directly opposed to this method of philosophising con- 
sists in an earnest and patient enquiry, how far geological appear- 
ances are reconcilable with the effect of changes now in progress, 
or which may be in progress in regions inaccessible to us, but of 
which the reality is attested by volcanos and subterranean move- 
ments. It also endeavours to estimate the aggregate result of ordinary 
operations multiplied by time, and cherishes a sanguine hope that 
the resources to be derived from observation and experiment, or 
from the study of Nature such as she now is, are very far from 
being exhausted. For this reason all theories are rejected which 
involve the assumption of sudden and violent catastrophes and 
revolutions of the whole earth, and its inhabitants — theories which 
are restrained by no reference to existing analogies, and in which a 
desire is manifested to cut, rather than patiently to untie, the Gordian 
knot. 

We have now, at least, the advantage of knowing, from experience, 
that an opposite method has always put geologists on the road that 
leads to truth — suggesting views which, although imperfect at first, 
have been found capable of improvement, until at last adopted by 
universal consent; while the method of speculating on a former 
distinct state of things and causes has led invariably to a multitude 
of contradictory systems, which have been overthrown one after the 
other — have been found incapable of modification — and which have 
often required to be precisely reversed. 

The remainder of this work will be devoted to an investigation 
of the changes now going on in the crust of the earth and its inhabi- 
tants. The importance which the student will attach to such 
researches will mainly depend on the degree of confidence which 
he feels in the principles above expounded. If he firmly believes in 
the resemblance or identity of the ancient and present system of 
terrestrial changes, he will regard every fact collected respecting the 



41 8 SIR CHARLES LYELL 

cause in diurnal action as affording him a key to the interpretation 
of some mystery in the past. Events which have occurred at the 
most distant periods in the animate and inanimate world will be 
acknowledged to throw light on each other, and the deficiency of 
our information respecting some of the most obscure parts of the 
present creation will be removed. For as, by studying the external 
configuration of the existing land and its inhabitants, we may restore 
in imagination the appearance of the ancient continents which have 
passed away, so may we obtain from the deposits of ancient seas 
and lakes an insight into the nature of the subaqueous processes now 
in operation, and of many forms of organic life which, though now 
existing, are veiled from sight. Rocks, also, produced by subter- 
ranean fire in former ages, at great depths in the bowels of the earth, 
present us, when upraised by gradual movements, and exposed to 
the light of heaven, with an image of those changes which the deep- 
seated volcano may now occasion in the nether regions. Thus, 
although we are mere sojourners on the surface of the planet, chained 
to a mere point in space, enduring but for a moment of time, the 
human mind is not only enabled to number worlds beyond the 
unassisted ken of mortal eye, but to trace the events of indefinite 
ages before the creation of our race, and is not even withheld from 
penetrating into the dark secrets of the ocean, or the interior of the 
solid globe; free, like the spirit which the poet described as ani- 
mating the universe. 



ire per omnes 

Terrasque, tractusque maris, ccElumque profundum.* 

* "To go through all lands, and the tracts of the ocean, and the boundless heaven."