Unitarian Divine, Joseph Priestley (1733-1804). A series of important
observations was made by him in the seventies and eighties of the
eighteenth century. He showed that green growing plants would make
respired air again respirable, and that they gave off a respirable
gas. In 1774 he prepared Oxygen by heating certain oxides, though,
still hampered by the phlogiston theory, he failed to recognize the
nature of the oxygen he had produced. The conclusions of his striking
experiments on blood, which he showed to depend on this same agent for
its changes from venous to arterial, were similarly vitiated.
[Illustration:
FIG. 76. APPARATUS from Joseph Priestley’s _Experiments and
Observations on different Kinds of Air_, Birmingham, 1774. In the
background can be seen an experiment on the effect of combustion on
confined air. There are also two cylinders inverted over water in which
green plants are growing. In one of them the growing plant has given
off a gas (oxygen) which Priestley showed could support both combustion
and respiration. In the foreground under a bell-jar are some mice on
which Priestley performed respiratory experiments.
]
The real passage to the modern point of view in our knowledge of the
air was made by the brilliant French chemist Antoine Laurent Lavoisier
(1743-94). He made an extensive quantitative investigation of the
changes during breathing (Fig. 77), burning, and calcination. In the
course of these he discovered the true composition of respired air, and
showed how both Carbon dioxide and water are normal products of the act
of breathing. If clear grasp of the implication of discovery be made
the test, Lavoisier must be regarded as the discoverer of Oxygen.
Cavendish (1731-1810) had already discovered the composition of
water (1785). Lavoisier concluded that water and Carbon dioxide are
produced by the process of oxidation in the lungs, and that it is
this oxidization process, and not any innate quality of a mysterious
character in the body or in the blood, that is responsible for the
bodily heat. Lavoisier introduced much of the chemical nomenclature
that we still employ. So far as respiration is concerned, subsequent
research has added much to his standpoint. In the purely chemical
aspect, however, it has altered little, though we now know that the
tissues and not the lungs are the seat of oxidation.
[Illustration:
FIG. 77. LAVOISIER in his laboratory making experiments on breathing.
To the right Madame Lavoisier sits at a table, taking notes. Lavoisier
stands behind, directing. To the left is the subject of the experiment.
His face is covered with a mask provided with a valve. He is breathing
into the apparatus. An assistant feels his pulse while a second
assistant collects the respired air in a bell-jar inverted over a
trough.
From a contemporary sketch.
]
§ 6. _Morbid Anatomy becomes a Science._
The main intellectual movement of the seventeenth and eighteenth
centuries had been focused, so far as Medicine was concerned, on the
manner of working of the animal body, the department that we now term
Physiology. It was necessary to obtain clear concepts of the action of
the body in health before venturing into discussion of its action in
disease. Towards the end of the seventeenth century, an industrious
compiler had put together all the then published records of post-mortem
examinations up to his time. During the first part of the eighteenth
century many practitioners in Physic and in Surgery published
isolated cases or groups of cases connected with particular diseases.
Boerhaave regularly attended post-mortem examinations (p. 140). No
general pathological principles had, however, yet been elicited on a
scientific basis. The theories of disease such as those of Boerhaave
were perforce still mainly speculative, for there were no extensive
records of the correlation of symptoms during life with the appearances
of the organs of the body after death, the subject we now call ‘Morbid
Anatomy’. This gap was first effectively bridged by Morgagni.
Giovanni Battista Morgagni (1682-1771) was professor at Padua for no
less than fifty-six years. During this time he performed an enormous
number of post-mortem examinations, and made important contributions
to Descriptive Anatomy. In his seventy-ninth year, eleven years before
his death, there emerged from his enormous experience his work _On
the sites and causes of disease_. This classical treatise may still
be read with profit. Its leading feature is the very careful way in
which actual cases are recorded. The life-history of the patient, the
history of his disease, the events in connection with his final illness
and death, are all recounted with detail and care. The condition of
the organs at the post-mortem examination is minutely described and
an attempt is made to explain how the symptoms were the result of the
lesions. Morgagni is justly said to have introduced the ‘anatomical
concept’ into the practice of medicine. This concept is one of the main
elements in modern diagnosis, and a modern physician, in reflecting
on a case, considers first whether he is able to express the symptoms
in terms of lesion. There are many lesions of great importance and
frequent occurrence which Morgagni was the first to describe.
The task which Morgagni had undertaken was worthily continued by the
Scot, Matthew Baillie (1761-1823), nephew, pupil, and heir of William
Hunter (p. 165). Baillie was a successful London practitioner. He
followed a new and convenient method in arranging his work according to
organs instead of by symptoms, as Morgagni had done. Baillie performed
post-mortem examinations on several men of eminence, among them Dr.
Johnson, whose lung he describes (see Fig. 78).
The task of naked-eye pathological anatomy, effectively begun by
Morgagni, was effectively completed by Karl Rokitansky of Vienna
(1804-78). His work (1842-6) was based on an experience extending
over 30,000 post-mortems! Though disfigured by a bizarre theory,
it left but few gaps for subsequent workers. From now on, the
science of Pathology was to be prosecuted in a new spirit and with
new instruments. Even in his own day Rokitansky was something of an
anachronism, with his pure naked-eye anatomy hardly ever involving
experimental evidence on the one hand or the findings of the microscope
on the other.
[Illustration:
FIG. 78. PART OF THE LUNG OF DR. SAMUEL JOHNSON, from a drawing
published by Matthew Baillie. Johnson was a fat, unwieldy man, with
a great barrel chest, who suffered for many years from shortness of
breath. These are common associations with the pathological condition
known as _Emphysema_, in which the lungs, which are normally of fine
spongy texture, become full of abnormally large cavities, so that, as
Baillie remarks, they come ‘to resemble the air cells of the lungs of
amphibious animals’ (cf. Fig. 45, p. 116). In the figure B represents
the external part of the lung and A its cut surface. On the cut surface
the large cellular structure can be seen. The very dark points are the
orifices of cut branches of the pulmonary vessels.
]
§ 7. _Clinical Methods and Instruments._
The great teachers of the earlier eighteenth century, though better
equipped as regards knowledge than their predecessors, had hardly any
better means of diagnosis. Pulse-measurers and thermometers such as
those of Sanctorius and Galileo (p. 109) had proved impracticable by
the bedside. The microscope had not yet entered into Clinical Medicine.
Chemical analysis as applied to disease had proved, as yet, of little
value.
The first efficient instrument of precision to merit clinical
adoption was the ‘pulse watch’, by Sir John Floyer (1649-1734), an
English provincial physician. It was introduced as early as 1707 as a
‘Physician’s Pulse Watch’ and was an instrument constructed to go for
just one minute. At that time the making of a twenty-four hours watch
with a seconds-hand presented great mechanical difficulties. Floyer’s
invention was not widely adopted at the time. Attempts were also made
to introduce a thermometer into practice, but again the construction of
suitable instruments proved impossible.
Effective pulse watches and clinical thermometers did not penetrate
into the general practice of Medicine till well into the nineteenth
century. Two instrumental advances of first-class importance to
Medicine were, however, introduced during the later eighteenth century.
These were the methods of Percussion and Stethoscopy.
Percussion of the surface of the body yields notes of varying degrees
of resonance. Its application has proved of great value to the
physician in outlining the position of the organs and of lesions,
especially those of the chest. It was invented by Leopold Auenbrugger
(1722-1809), a Viennese physician who first introduced it in 1761. Like
the thermometer, it was very slow in entering the general practice of
Medicine.
Auenbrugger deserves great credit for his invention, but he did not
work out its application with anything like the completeness that
the Breton physician, René Théophile Hyacinthe Laënnec (1781-1826),
applied to his ‘stethoscope’ (1819). Laënnec’s instrument was of the
uni-tubular type that is now seldom seen. At first, indeed, he used a
mere roll of paper. His idea was rapidly diffused into every country.
But Laënnec did far more than introduce a useful and convenient device
into Medicine. He explored with extraordinary skill the physical signs
in the chest which correspond to a large number of diseases. The major
part of our chest-lore and much of the technique and nomenclature of
chest examination come direct from him. Despite continual bad health
and the shortness of his life, Laënnec’s brilliance and devotion to
duty at a hospital in Paris enabled him to transmit his views and
methods to many other physicians, both French and foreign. He is
unquestionably among the greatest physicians of all time. Clinical
medicine assumes with him a completely modern aspect. In reading his
work one feels that, had he been called in consultation by a medical
man of our own day, the two would have been able to understand each
other perfectly, after only a little adjustment and explanation.
[Illustration: FIGS. 79-82. LAËNNEC’S WOODEN STETHOSCOPE, from his work
of 1819, _On Instrumental Auscultation_.
FIG. 79 is the complete instrument.
FIG. 80 is the instrument in section.
FIG. 81 is the ear-piece unscrewed.
FIG. 82 is the detachable chest-piece terminating in a thin metal tube.
]
§ 8. _Surgery and Obstetrics._
During the eighteenth century the improved knowledge of Normal and
Pathological Anatomy was a great aid to the surgeon. The technique of
Surgery was certainly improved. Operations were now being performed
with success that could not before have been attempted. Nevertheless
few important new principles were introduced until long after the
nineteenth century had dawned. It is indeed probable that as a means
of life-saving Surgery had an almost inappreciable effect on vital
statistics until the advent of Anaesthesia and Antiseptics. Even the
greatest surgeon of the eighteenth century, John Hunter, introduced no
fundamental new surgical principles. True, the names of many surgeons
of the period have become associated with operations invented or
introduced by them, but it was not till after the advent of antiseptic
methods that these were practised with full success. There are but two
surgical matters in which advances of great significance can be said to
have been made. These were the treatment of Venereal Disease and the
treatment of Labor.
Syphilis, which existed in Europe in the later Middle Ages, had
usually been confused with Leprosy and other conditions (p. 98). Its
treatment by Mercury had been practised at least as early as the
fifteenth century, perhaps as an inheritance from the Arabic-speaking
physicians. During the sixteenth and seventeenth centuries various
other remedies were tried (Fig. 33); much quackery arose around them.
In the eighteenth century the accumulated experience of generations
returned again to Mercury. Satisfactory methods of administration were
evolved and the treatment became standardized. It hardly changed until
the twentieth century.
[Illustration:
FIG. 83. LYING-IN SCENE in the sixteenth century from a contemporary
work on midwifery. Drinking and feasting is going on in the room where,
in addition to the patient, there are two men, five women, and two
children. A dog chews a bone on the floor, cooking is in progress in
the adjoining room. Food and drink is being forced on the unfortunate
patient herself. The whole scene, which is intended to portray an
upper-class household, suggests carousal, disorder, and dirt, as well
as ignorance of the most elementary principles of hygiene.
]
The treatment and care of women in Labor made considerable progress
during the period of which we are treating. We have seen how there were
advances even during the sixteenth century (p. 93) by such a writer as
Paré. Works on obstetrics intended for women were often printed in the
sixteenth century in France, England and Germany. Scientific obstetric
works were produced especially in France in the second half of
the seventeenth century. The obstetric forceps was known, but was
still a family secret. At the time and for long after, there was a
great objection on the part of pregnant women to treatment by men.
The midwives were for the most part ignorant, dirty, unskilful and
superstitious, and the loss of life and health that resulted from
their mishandling was enormous. The objection to the ‘man midwife’ was
only gradually overcome, though his advent was unquestionably attended
by a fall in the mortality. About the middle of the eighteenth century,
moreover, the obstetric forceps came into wider use. One of the ablest
and most successful of the obstetric physicians was William Hunter
(1718-83), the brother of John Hunter.
[Illustration: Early obstetric instruments.
FIG. 84 is the very dangerous and brutal _Speculum matricis_ used to
force open the mouth of the womb in cases of difficult labor. A similar
instrument has been used since antiquity to dilate wounds.
FIG. 85 is an even more terrible and powerful instrument, the
_Apertorium_, provided with a sharp edge by means of which the mouth of
the womb was violently cut or torn.
In the seventeenth century less heroic measures began to be used, and
the obstetric forceps was introduced.
FIG. 86 shows a pair of obstetric forceps as used in the seventeenth
century. The instrument is the direct ancestor of that now in use,
which, however, is a vast improvement upon it. The obstetric forceps
was invented by a member of an hereditary family of man midwives, at
the beginning of the seventeenth century. The nature of the instrument
was long kept a secret. This particular instrument was found by
accident in 1813, having been hidden under the floor by a member of the
family of the inventor.
]
Despite the absence of any great new principle in the surgery of the
period, there can be no doubt that a new spirit was introduced by
John Hunter (1728-93). His complex and interesting character demands
better treatment than it has yet received. As an investigator his
powers were superb, but, like Leonardo, he was handicapped at every
turn by literary incoherence. Nevertheless, with him Surgery begins
to appear, at last, as a real Science and not as a mere applied Art.
Hunter brought to bear on the subject a mind stored with ideas drawn
from Comparative Anatomy and Pathology. Quick to detect analogy, shrewd
in his scientific judgments, tireless and unsparing of himself in his
pursuit of truth, a victim of disease self-inflicted in the service of
science to which he was tragically a martyr in his death, he shows as
a heroic figure, rendered no less heroic by some very human failings.
Fully to appreciate so incoherent a writer, it is unfortunately
necessary to wade through many works written in his own clumsy and
ill-arranged manner. To gain any real idea of this great personality we
must consult the writings of his contemporary colleagues.
So far as actual advances are concerned, two may be connected with
Hunter’s name. Firstly, in the treatment of the deadly condition known
as ‘Aneurysm’ he introduced a method of operation which is still in
vogue. Secondly, he enormously improved the method of making and
ordering a museum. His monument is the Hunterian Museum in London,
based on his specimens of which many may still be seen there. The
museums of Natural History, as now constituted in all civilized
countries, have been influenced by, if they have not been derived from,
that which he literally gave his life’s blood to found. He was right
when he said musingly in his illness, ‘You will not easily find another
John Hunter.’
[Illustration:
FIG. 87. JOHN HUNTER’S COUNTRY HOUSE at Earl’s Court, Kensington,
before its demolition in 1886. This house was in the country in
Hunter’s day, though its site is now a busy part of London. For many
years he used it as a laboratory and menagerie, and much of his best
work was done there.
]
§ 9. _The Beginnings of the Science of Vital Statistics._
Attempts to combat widespread disease and to improve the public
health are to be found in the history of all civilizations, both
ancient and modern. Nevertheless, the rational method cannot come into
operation until it has exact data upon which to work. Such data may
be numerically expressed, a fact first appreciated by the versatile
English physician and inventor, Sir William Petty (1623-87), who is
usually regarded as the father of the science of Political Economy. In
1662, and on many subsequent occasions, he joined a friend in issuing
_Natural and Political Observations upon the Bills of Mortality_ of
London. In this work he endeavored to deduce population, death-rates,
disease prevalence, and other matters of vital statistics from the
crude figures of the day. He was fully aware of the imperfection of his
materials, and on this account he urged the necessity of providing a
system and a government department for the collection of trustworthy
statistics. In his _Political Arithmetick_ (1683), the basic work of
modern Economics, he displays ideas of a very modern character. Among
these is his view that the true wealth of a country is to be sought in
its efficient man power.
A number of Petty’s fellow members of the Royal Society began to take
interest in statistics. Chief among these was Edmund Halley, the
astronomer (1656-1742). Toward the end of the century (1693) Halley
produced a mass of statistics on the chances of life at various ages,
designed for the estimation of the price of annuities. During the
eighteenth century numerous writers devoted themselves to similar
investigations. An important contributor to the mathematical basis
of vital statistics was the French Huguenot and friend of Newton,
Abraham de Moivre (1667-1754). His _Doctrine of Chances_ (1715) and
his _Annuities upon Lives_ (1725) are important contributions to the
subject. His celebrated hypothesis that among a body of persons over
a certain age the successive annual decrease by death may be esteemed
as nearly equal (that ‘the decrements of life are in arithmetical
progression’) was under discussion for a century, but is now accepted.
In 1761 a Prussian clergyman, J. P. Süssmilch (1707-82), produced an
extraordinary theological work, _The Divine Ordinance manifested in the
Human Race through Birth, Death, and Propagation_. Its object was to
exhibit God’s design in the constancy of the numerical relationships
of vital statistics. Despite the motive--somewhat unpromising for a
scientific treatise--the work is of great historic and scientific
importance, for it was based upon a vast mass of statistics and showed
a great advance in method. It stressed the importance of accurate data
and the necessity for numerous observations, if reliable conclusions
were to be drawn. From the time of the publication of the work of
Süssmilch, the statistical study of population advanced rapidly. The
basis of statistics was greatly improved by the introduction of the
census system which was put into action in England in 1801.
The science of vital statistics was placed on a firm foundation by the
Belgian astronomer Lambert Quetelet (1796-1874). His principal work,
_On Man and on the Development of his Faculties, An Essay on Social
Physics_, contains an account of his statistical researches on the
development of the physical and intellectual qualities of man and on
the ‘average man’ both physically and intellectually considered. He
followed this in 1848 by his treatise, _On the Social System and the
Laws which govern it_. In it he shows how the numbers representing the
individual qualities of man may be grouped round the numbers referring
to the average man in a way corresponding to the principles of the
theory of probabilities. This conception, elaborated and further
analyzed, has formed the basis of all subsequent researches in vital
statistics.
§ 10. _Military, Naval, and Prison Medicine._
The eighteenth century saw some of Petty’s principles put into
practice. There was, as yet, but one section of public life in which
scientific principles of preventive medicine could be applied. Only
in the Army and Navy were the sufferers from disease under adequate
control and observation, and only there were proper statistics of
sickness and health available. Thus, many of the most important
movements in Preventive Medicine during the eighteenth century, both
in England and other countries, were initiated by naval and military
surgeons.
Among military medical reformers an important place is taken by a
Scottish pupil of Boerhaave, Sir John Pringle (1707-82). He had a large
military experience in the British army, occupied a position of great
influence, and was able to get many of his views and reforms generally
accepted. Pringle was among the first to see the importance of ordinary
putrefactive processes in the production of disease, and quite the
first to apply these principles in hospitals and camps. Important
conclusions on these matters were published in his _Experiments upon
Septic and Antiseptic Substances, with Remarks relating to their Use
in the Theory of Medicine_, which appeared in 1750. He identified
‘gaol fever’ or typhus with ‘hospital fever’. He laid down important
rules for the hygiene of camps which involved avoidance of marshes,
proper drainage, and adequate latrines. His most permanent service
was probably his suggestion that army hospitals should be regarded
as neutral, and be mutually protected by belligerents. This great
physician is a good illustration of the ‘new humanity’ which came into
public life in the eighteenth century. In much of that movement one may
feel the influence of that most humane of physicians, Hermann Boerhaave
(pp. 140-1).
Hardly less important than the work of Pringle for the Army was that
of his brother Scot, James Lind (1716-94), for the Navy. Lind was a
pupil’s pupil of Boerhaave. He had a long naval experience and in 1753
wrote an important work on Scurvy, then a very common and fatal disease
at sea. He demonstrated how this might be prevented by the adequate use
of fresh fruit or, when this was not available, of lemon juice. Fresh
water had always been a difficulty of sea voyages. Lind arranged for
sea-water to be distilled for the purpose. He introduced rules for the
prevention of typhus on ships, and made great improvements in naval
hygiene. His essay of 1757 _On the most effectual means of preserving
the Health of Seamen_ is a classic. He also wrote an important _Essay
on Diseases of Europeans in Hot Climates_, which opened the campaign
for the conquest of the tropics (p. 270).
Lind, like Pringle, is one of a type that is very fully represented
in the eighteenth century. A worthy representative of that school
was Captain James Cook (1728-79), the explorer, who adopted Lind’s
principles. He established a record in one of his voyages to the South
Seas. The voyage lasted three and a half years, and many hardships had
to be endured, but out of 118 men only one died, and he was consumptive
when he embarked from England. Of a different type was the Manchester
health reformer, Thomas Percival (1740-1804), who worked to introduce
the reforms of Pringle and Lind into civilian life. The work of
Percival leads on naturally to Southwood Smith and Chadwick (pp. 193-5).