Click on IMAGE to enlarge photos. Click on BLUE link to read articles.
In the early 1850's
there was a rush of designs for a new stethoscope that used both ears. This new
"binaural" ('bi-aural') instrument was felt to be the future of auscultation.
Actually, the idea for a binaural stethoscope was first introduced in 1829, just
ten years after the publication of Laennec's text illustrated his original
instrument. The idea belonged to Nicholas Comins, who devised a stethoscope that
he described as "a bent tube" that had several hinges, allowing the physician to
not have to assumeuncomfortable positions during the examination. He offered the
suggestion of making hisinstrument binaural, but there are only sketches of his instrument.
Arthur Leared presented a model of a "double" stethoscope made
of gutta-percha at the Great Exhibition in London in 1851 The first commercially marketed model was
that of Nathan Marsh of Cincinnati in 1851. His model was made of india rubber and contained the first
recorded diaphragm chest piece. However, it proved bulky and cumbersome,and quickly faded. The diaphragm would
not re-surface for 50 years.
In 1852, Dr. George Cammann of New York
produced the first recognized usable binaural
stethoscope. He was working as a physician at the Northern Dispensary in New York City and had
seen Marsh's model. He also had a model of a soft metal, multiple-tubed stethoscope made by
H. Landouzy in 1841, which was designed for two people to listen at the same time. And
Charles J. B. Williams claims to have made a binaural stethoscope with lead tubes in
1843. Cammann did not claim to have the original idea for a binaural stethoscope, only
to have developed a practical instrument that could be used in clinical practice.
Cammann had some help in designing his stethoscope and, interestingly, never
patented the stethoscope believing it should be freely available to physicians.
The stethoscope was named Cammann's Stethoscope by the manufacturer of the original instrument, George Tiemann.
Cammann's model was made with ivory earpieces
connected to metal tube that were held together by a simple hinge joint,
and tension was applied by way of an elastic band. Attached to these were two
tubes covered by wound silk. These converged into a hollow ball designed to
amplify the sound, and attached to the ball was a conical shaped, bell chest piece.
Prior to 1855
George Tiemann marked his medical instruments as Tiemann, after 1855 used the
mark G. Tiemann & Co. and later used the mark Tiemann & Co. The markings
on the models shown below help date these stethoscopes and are consistent with the
introduction of the Cammann stethoscope in 1852.
To the left is an original Cammann stethoscope, circa 1852. The yoke of the hinge joint is hand engraved Dr. Cammann's Stethoscope and the reverse is stamped Tiemann N[ew]. York. This initial model had a large and flaring ebony chestpiece and ivory earpieces. The flexible woven tubes were covered with velvet and were very short as compared to later models. This is one of the four oldest known examples, and one of only two to have the hand engraving shown above.
The Cammann stethoscope shown in the middle photo dates to 1855. The left side of the yoke of the hinge joint is stamped Dr. Cammann's Stethoscope, but is not hand engraved. The right side is stamped G. Tiemann & Co. Note that the wood bell does not have as large a flare and the velvet covered tubes are a little longer. This is the only example of this stethoscope known to exist.
On the right is Cammann stethoscope, circa 1860. The left side of the yoke is marked Dr. Cammann's Stethoscope but is not hand engraved. The right side is marked Tiemann & Co. Note that the flexible tubes are longer, not covered in velvet and are attached by gutta percha connectors to the binaural ear tubes. The two parts of the stethoscope could be detached for carrying and reattached for auscultation.
A Photo
of New York physician George P. Cammann, circa 1855, who
developed the binaural stethoscope while working
at the
Northern Dispensary. The Northern Dispensary was built in 1831 to
provide
medical care
to the "sick and poor"and was open from 1831
until 1989. The Dispensary is
the only building
in New York City that has two sides on one
street (Waverly Place) and one side on two streets (Christopher and Grove
Streets). The three sided building occupies the triangle formed by
those streets. Shown above are the photos of the
Northern Dispensary
in 1885 and 2006, looking the same as it did in 1852
when Dr. Cammann deveolped his stethoscope.
Notice the young
boy pausing on his bike, while trying to decide which fork
in
the Waverly Place
road to
take, which splits into a left and right street at the tip
of the Northern Dispensary triangle. Dr. Cammann was appointed to the Dispensary
in 1832 as an Attending Physician and worked there for
28 years until he resigned in 1859 and
then contiunued
to serve as
a Consulting
Physician until his death in 1863. Shown above are photos of pages
from the June 7, 1832 and October 7, 1859 minutes of the
Proceedings of the Trustees of the Northern Dispensary appointing Dr.
Cammann to the Dispensary and thanking Dr. Cammann for his faithful service to the Dispensary,
respectively. He was also a member of the St. James Episcopal Church, Fordham and
one of the church's four Royal Bavarian Stained Glass Windows portraying Saints John
and Peter healing of a man by the Jerusalem Temple's Beautiful Gate, installed
when
the church
was built on its present site in 1864-65, was in
memory of Dr. Cammann for his humanitarianism. The window dedication reads "In Memory
of Geo. P. Camann M.D. dec. Feb. 14. 1863."
( Dr. Cammann photo
courtesy of the Burns Archive, Nothern Dispensary minutes courtesy of
the New York University Archives, Northern Dispensary photo by Jefferson
Siegel and stained glass window photo courtesy of St. James
Episcopal Church, Fordham).
To the far left is Cammann
stethoscope with elastic band, which was the original tension mechanism designed
by Dr. Cammann, W.F. Ford & Co, circa 1870. Next is Cammann stethoscope with
spring tension mechanism, circa 1880 and a Cammann stethoscope with
Ford's patented wire spring tension mechanism to hold ear peices
together, Hazard, Harzard & Co, circa 1890. On the far right is a Cammann
stethoscope with screw tension mechanism, Sharp & Smith, circa
1880.
The Cammann stethoscope usually came in a carrying
case, although most of these were lost over time. The cases are more difficult
to find than the actual stethoscopes at this point. Various examples of such
cases are shown below.
Cammann stethoscope in its original tin case, circa 1870.
Cammann stethoscope, circa 1880, marked Dr. Cammann Stethoscope, Tiemann & Co. and its leather case. The tooled leather case is marked Dr. John Hatton (1838-1898) who graduated the Iowa University Medical College in 1870 and practiced in Des Moines.
Cammann stethoscope in its original cardboard box, circa 1890. The label is marked Cammann Stethoscope, with elastic rubber band tension spring, Chas. Truax, Greene & Co., Chicago Illinois.
As was the case
with Laennec's model, Cammann's was not embraced completely for quite some time.
It was not until Austin Flint (who had previously spoken against the binaural in
1856) endorsed it in 1866 that it became widely used. During the later half of
the 19th century, well educated physicians used advances in medical technology
to aid their ability to diagnose diseases in their patients. The stethoscope
became the main symbol of the highly skilled physician and often came as a set
with a pleximeter and percussion hammer.
A photo
dated May 1889 of a physician in his office with a medical text on his lap,
surrounded by medical equipment including a Bauch & Lomb microscope and
Cammann stethoscope on his desk. The use of the microscope and stethoscope by
physicians represents the advances in technology applied to the practice of
medicine in the nineteenth century.
The
Harvard Medical School (HMS) was founded in 1782 as the
Massachusettes Medical College
in Cambridge. John Warren, Professor of Anatomy and Surgery, and
one of the three original medical college faculty, was instrumetal in moving the school
to Boston. As there was no hospital in Boston at that time, teaching medical students
was devoid of clinical experience. In 1811, his son, John Collins Warren,
was a leader in establishing the Massachusetts General Hospital (MGH),
the third oldest hospital in the United States. Like most hospitals
founded in the 19th century, MGH was intended to care for the
poor. In 1869, a progressive curriculum was instituted at the
school, new departments of basic and clinical
sciences were established, a three-year degree program was introduced, and the
apprenticeship system was eliminated. Harvard Medical School became a
professional school of Harvard University, setting the United States standard
for the organization of medical education within a
university.
Pictured above is the Bulfinch Buiding of MGH, circa 1880,
with its famous ether dome on top of the buiding. Ether was first used for
anesthesia during surgery at the MGH in 1846. The fumes rose to the top of
the dome shaped ceiling of the surgical theater, enabling surgeons to
remain awake while performing surgery on their sleeping patients. Harvard Hall,
the original home of the HMS, was located adjacent to MGH from 1846 through
1883. In 1886, Reginald H. Fitz, Visiting Physician at MGH and the Shattuck Professor of Anatomical Pathology
at HMS, published his seminal paper on "Perforating Inflammation of the Vermiform Appendix; with special
reference to its early diagnosis and treatment". For the first
time the term appendicitis was used to describe that most
inflammatory disease of the right lower quadrant of the abdomen was caused by inflammation of
the appendix and that treatmant was early surgical removal of the inflammed
appendix.
THE HUSE COLLECTION
Unique collection from Dr. Charles Archelaus
Huse's medical office circa 1884 in Worcester, Massachusettes.
Displayed is his Cammann stethoscope,
surgical instrument kit, urethral silver catheters,
patient records, patient receipts, letter from the Dudley
& Sheppard instrument company dated 1877 where Dr. Huse purchased his
medical instruments, medical student ticket to Harvard Medical School dated 1879-80, and sign
from his office in Worcester. Dr. Huse was
born on
August 7, 1855
in Worcester, graduated Brown University in 1878 and Harvard Medical
School in 1881. After graduation from Harvard, he served as the
Boston Board of Health Assistant Port Physician
for 14 months stationed at Deer Island.. In the summer
of 1882, he moved back to his home town of Worcester and established his practice of
medicine and surgery. He was a member of the Massachusetts Medical Society
from 1882-1884. Dr. Huse died prematurely at age 29 from "peritonitis" after a nine
day illness on July 3, 1884, just two years prior to the publication
of the classic paper by his former Harvard Professor, Dr. Fitz, identifying the cause of most cases
of peritionitis as the rupture of an inflammed appendix. The Huse antique medical collection represents a
truly unique look into the practice of medicine in the late 19th
century.
On the left
is a potrait cdv photo of
Charles A. Huse as a student at Brown University circa 1878 and on the
right is a cabinet photo of him with his clasmates at Harvard Medical
School circa 1881. Huse is sitting on the steps of
Harvard Hall in the center of his class
photograph.
Bellevue Hospital in New York City is the nation's oldest public hospital. It was
founded in 1736 as the Alms House, a six bed infirmary for the poor, and was
located at the site of the current City Hall in lower Manhattan. In 1794, the
Belle Vue farm on Manhattan's East Side was used to quarantine victims of the
yellow fever epidemic in New York City. In 1811, the Kips
Bay farm, just north of Belle Vue, was purchased by the city for a larger almshouse. McKim,
Mead & White designed the Bellevue Hospital buildings
between 1908 and 1939 that stand today on the land of the Belle Vue
and Kips Bay farms on First Avenue and 27th Street. The Bellevue Medical College
was established in 1861 and the first School of Nursing in
the nation based on Florence Nightingale's philosophy was opened in 1873 at Bellevue. In
1841, the University Medical College was established as the Medical Department
of the University of New York on First Avenue and 26th Street. The College
changed its name to New York University in 1896. In 1898, Bellevue Medical College and
University Medical College of New York University consolidated as the University and
Bellevue Hospital Medical College, ultimately changing its name to New York
University School of Medicine in 1960. Bellevue Hospital remains today the nation's premier public
hospital and continues its long tradition of serving as a primary teaching
hospital of NYU Medical Center.
On the left is a photo of the Unversity College of
Medicine (NYU), 1886. On the right is
a photo of Bellevue Hospital, 1886.
These photos are taken from the "University of the City of
New York / Medical Department / Forty-Sixth Annual Announcement of Lectures and
Catalogue / Session 1886-87 /New York: 1886"
Photo of Women's Ward 20 at Bellevue Hospital
in New York City, circa 1888.
The photo has a legend identifying the
hospital, ward, physicians and nurses bearing the mark of the Bellevue Hospital
Photography Department, NY City. The enlarged photo on the right shows Dr.
Nammack holding a Cammann stethoscope in his left hand, Dr. Tingley taking
notes, presumaby of Dr. Nammack's ausculatory findings and nurse Ried with an
open chart. Note that Dr. Nammack is also holding his patient's hand, perhaps to
reassure her, as he discusses his observations.
Dr.
William H. Nammack was a 1886 graduate of Bellevue Medical College and was one
of four "successful candidates for appointment in the Bellevue Hospital "
and served as a House Physician on the 3rd Medical Division at Bellevue
Hospital in 1887. Dr. Nammack was a physician and surgeon who originally
practiced general medicine at 11 Rutgers Street in New York City. He ultimately
practiced in Far Rockaway and aslo served as the Coroner of Queens for a
number of years. His son Griswold D. Nammack, grandson Griswold P.D.
Nammack, and nephew Charles H. Nammack were also all surgeons affiliated with
Bellevue Hospital. Dr. Nammack's great grandson Thomas Nammack is the Headmaster
of The Montclair Kimberley Academy, Monclair, New Jersey, and provided this
history of the Nammack family.
Dr. Witter Kinney Tingley was also a
graduate of Bellevue in 1886 and another of the four graduates to serve as a
House Physician on the 3d Medical Division in 1887-1888. Dr. Tingley
practiced General Medicine in Norwich, Connecticut and served as President of
the Norwich Medical Association in 1890. He was one of the incorporaters of and
Visiting Physician to Backus Hospital in 1892. Dr. Tinlgley was the nephew of
Elijah Clark Kinney who served as House Physician on the Bellevue 4th
Medical Division in 1859.
Dr. Robert Alexander Murray was a
graduate of University Medical College (NYU) in 1873 and a House Physician
on the 2d Medical Division from 1874-1875. Dr. Murray practiced General Medicine and
specialized in Disease of Women at 235 West 23d Street
, New York City. He served as Attending Physician, Diseases of Women, at the Northwestern Dispensary,
New York City, from 1876-1883 and Assistant Professor of Obstetrics
at University Medical College (NYU) from 1876-1886. He also served
as an Instructor in Obstetrics, New York Polyclinic from 1887-1888. Dr.
Murray authored various articles on obsterical subjects in medical
journals.
Ms. Ried, Autisdale and Chase were Nurses at Bellevue
Hospital.
Another photo of Rounds at Bellevue Hospital from the Bellevue Hospital Photography
Department, circa 1891. Similar to the previous photo, one physician
is using a Cammann Stethoscope to auscultate the heart of a young patient,
while another takes notes of the physical diagnostic findings and a nurse holds
an open chart.
( Photo courtesy of the
NYU School of Medicine Archives )
|
READ DR. CAMMANN'S SON'S ADDRESS REGARDING HIS MODIFICATION OF HIS FATHER'S STETHOSCOPE |
The screw mechanism became a great
success and would be included in the models that followed for many
years.
Knight's Stethoscope with two bells and a Flint Pleximeter
and Percussion Hammer that is shown with its original wood carrying box, Codman
& Shurtleff, Boston, circa 1880. On the left the instruments are
shown out of the box and on the right placed inside the
box. The bells were interchangeable in that each could be screwed on and
off the body of the stethoscope depending on the choice of the
physician.
A unique modification of the Cammann bell was
Ware's model. This model was a practical adaption of the bell in which a
smaller bell
could be screwed into the larger bell such that the larger bell
never had to be removed. The smaller bell was utilized for a more precise localization of sound
during auscultation, most especially during auscultation of the heart. 
A
Knight's Stethoscope with Ware's bell, circa 1870s, that belonged to Sir
William Osler while he was a student and later a faculty member at the McGill
School of Medicne. Dr. Osler's stethoscope was obtained from his grand niece,
Marian Grace Francis, who found it among Dr.Osler's dissecting equipment
in the Francis household. Marian
Grace was the daughter of
William Willoughby Francis, the son of Osler's cousin Marian Osler Francis.
The Francis household was a home away from home for Dr. Osler while
he was at McGill
and he was very close to her children and especially to his
godson, William, who was most often referred to as his nephew. William W. Francis was the
cataloger of the Osler library and the first librarian of the Osler
Library at McGill. This stethoscope is rare in and of itself because
of the Ware's bell, not to mention the provevnace through the
Francis family to one of medicine's most revered physicians, Sir William Osler. The photo of
Dr. Osler was taken in the 1870s when he was a member of the medical faculty at
McGill and physician and the first pathologist at Montreal General
Hopsital. Dr. Osler was an ardent "student" of pathology in the
great tradition of Laennec and others who applied their post-mortem findings to better understand
the pathophysiology of disease. Thus Dr. Osler's grand niece finding his stethoscope among his pathologic
dissecting equipment is not
suprising.
The first medical school
building of McGill School of Medicine shown on the left opened in 1872, just
after Dr. Osler graduated form McGill. The photo on the right is Montreal
General Hopsital, circa 1872. "When I began clinical work in 1870, the Montreal
General Hospital was an old coccus and rat-ridden building, but with two
valuable assets for the students-much acute disease and a group of keen
teachers" (William Osler, "The Medical Clinic",
British Medical Journal, January 3, 1914).
Dr.Olser once said he hoped his tombstone would say
only,"He brought medical students into the wards for bedside teaching." And his
most noteable statement to his students at the bedside of patients was
"Listen to your patient, he is telling you the diagnosis",
emphasizing the impotance of taking a thorough history.
There was still a desire to improve the sound
conduction through the tubes. Around 1882, Bartlett designed a stethoscope that
used metal ear-tubes with silk covered rubber tubes leading to a wooden
chest piece. This model was also called "Bartlett's Laennec" stethoscope and was
an ingenious design. Truax describes Bartlett's Laennec model as "The Laennec
stethoscope, devised by Bartlett, belongs to the heavier class of stethoscopes,
the instrument throughout being stronger that those of the ordinary Cammann
pattern... a heavy spring, somewhat similar to the pattern of Knight."
Bartlett's
Stethoscope shown on the left was a heavier version of the Knight
model, circa 1880.
Bell's Stethoscope, circa 1875, has an all metal chest piece with rubber
rim in this adaptation of the Knight model.
TheCammann stethoscope on the right has an
unusual horn bell, brass ear tubes and ivory ear tips and is marked
H.G. Kern, Philadelphia, circa 1860.
There were
many different modifications to Cammann's original instrument. Scott Alison came
up with a 'Differential Stethoscope' that consisted of two independent chest
pieces, and was designed to allow the listener to compare the sounds of two
areas of the chest. This instrument was also found to be impractical because it
muffled certain sounds. Most references list this piece as circa 1885, but it
was actually first illustrated in the John Weiss & Son catalog in
1863.
Alison's Differential Stethoscope is displayed
on the left, circa 1860. The close up shows the ebony bell chest pieces. It is
signed "Ferguson, London."
On the far right is an example of a modern
differential stethoscope with metal diaphragm chest pieces, circa 2000 and
next to it is a differential Stethoscope with plastic bell chest pieces, circa
1930.
In 1885, Charles Denison came out with an entirely new
model, based on Bartlett's. His was based on the idea of funneling sound to the
ears, much like the monaurals. His earpieces were made of hard rubber which led
into woven tubes and a large chest piece. It came with three interchangeable
chest pieces for hearing different types of sounds. The tension between the
earpieces was accomplished by a clever screw mechanism.Denison's
model was widely accepted. So widely, that many makers began marketing inferior
pieces of the "Denison Stethoscope." Denison became outraged at the poor quality
of stethoscope being manufactured with his name. He delivered a powerful speech
in which he stated precisely how his stethoscope was to be made, condemned the
makers of poor instruments, and praised one American company for their quality
craftsmanship.
Denison's Stethoscope, circa
1885.
Left example with multiple size bells, courtesy of the
Mutter Museum. Right examples in this collection, shown without and with
large bell.
Davis modification of the Cammann Stethoscope which incorporated a wire metal tension spring between the metal ear tubes. In this early model, the wood chest bell was attached to the ear piece by a flexible tube which inserted into the wooden ball connecting the ear piece, circa 1880.On the right is a later model Davis stethoscope with simple bell and metal tension mechanism between ear pieces, circa 1890 .
On the left is a Matthews
stethoscope with detachable chest piece and ear tubes for easy portability,
circa 1882. Shown on the
right is a
very unusal
folding stethoscope with ivory ear pieces and a unique bell that is a smaller
version of the original Cammann bell with a insertable plug designed after the
William's plug, circa 1890. This two piece bell is made of wood and allowed the
auscultator to change the size of the bell by inserting or removing the
plug.
Convenience came in several ways. Longer tubes added more flexibility, but other
methods were used as well. Around 1880, Lynch's stethoscope was marketed, which
folded onto itself and thus greatly reduced it's length. Sheppard's model
(1890), by contrast,
folded the earpieces together reducing the width of the instrument.
Lynch's folding stethoscope, circa 1880. This piece folds top to bottom as shown on the right. Sheppard's folding stethoscope in its original box shown on the right. This piece folds in half. On the left is the top of the cardboard box which is marked "Sheppard's Stethoscope / patented July 7th, 1890."
The next landmark improvement was the invention of the
'Ford's Bell' chest piece in 1885. This simple model was made of steel with
either gutta-percha, ebony, or even ivory at the base. It funneled sound into
two tubes, usually made of rubber, which led to the earpieces.
Three
examples of early Ford's bell stethoscopes with a simple metal band tension
mechanism holding the ear tubes together. On the left the Ford's bell
is made of ebony, circa 1890. In the middle the Ford's bell chest piece is made
of ivory with,circa 1895. On the right the Ford's bell is made of
metal, circa 1895.
Three examples of binaural stethoscopes with interesting tension mechanisms to hold ear tubes together.
On the
left is a Down Brothers stethoscope with finger rest, interesting screw spring
tension mechanism, ivory ear tips and Ford bell made of ivory, circa 1900. The
ivory bell unscrews to creat a smaller bell for the examination of children. In
the middle is a binaural stethoscope marked Gallante, circa 1890. The wood chest
piece and ear tips are typical of French binaurals of this period. Note the
spring tension mecahnism between the ear pieces. The right photo shows
a Holborn stethoscope with a slender, wood bell typically used for
children, Herschel's locking mechanism with lever and ivory ear tips, circa
1900.
The left
three examples areDown Brothers stethoscopes with Ford's bells made from
differnet materials.
On the left
the stethoscope has a finger rest and Ford bell made of aluminum, circa
1920. In the middle is a folding stethoscope with the mark of the "British Army"
with ivory Ford bell and wood ear pieces, circa 1910. On the right is a folding stethoscope with an
anti-chill, rubber cushioned Ford bell, circa
1910.
Binaural
stethoscopes with flexible rubber tubes to connect the ear pieces to the
chest piece, circa 1880.
The
example on the left is Chinese and has ivory ear pieces and a reversible ivory
chest piece. Each end of the reversible chest piece was a different size and
shape, presumably to examine different parts of the body. The middle ivory
example is Japanese.
The one on the right has a gutta percha chest
piece.
Examples of two American Phonendoscopes made by G.Pilling & Co. On the left the phonendoscope is in its original velvet lined, wood box, circa 1909. The photo in the middle is another phonendoscope in its original metal case with the chest piece in the case and its extension screwed onto the top for carrying. To the right the stethoscope is put together for auscultation with the ear pieces made of gutta-percha attached by flexible tubes with metal ends to the chest piece and the extension tube screwed into the diaphragm of the chest piece.
Three examples of phonendoscopes made in Europe. On the left is a model with an adjustable valve to vary the intensity of sound made by Osker Skaller A.G. of Berlin. In the middle is a German model with gutta percha ear pieces and on the right a similar French model with glass ear pieces, circa 1900. All the phonendoscopes are displayed in their original, velvet lined, leather covered,carrying cases.
Schreiber's Stetheskop made of metal, circa 1900.
As shown from left
to right, it could be set up as a monaural or by sliding the chestpiece down the
stem to expose the shaft, a phonendoscope chestpiece could be attached to the
stem. A close up of the phonendoscope chestpiece is shown on the far
right.
Wincarnis stethoscope, circa
1890. On the right the stethoscope chest piece is shown in its original case. On
the left the flexible tubes with ivory ear pieces and the chest piece taken
apart are displayed. Note the plastic diaphragm against which either of the two
wooden disks would rest
Marsh's Stethoscope, or Marsh's
Stethophone, is a very interesting invention. It comes with a small dial on the
back which has a pointer and the letters 'L,' 'S,' and 'W' engraved on it. These
stood for 'Loud,' 'Soft,' and 'Weak,' respectively. The examiner would dial in
the type of sound he
was listening to in order to be able to hear it
better.
Marsh's Stethophone, circa 1896
This is one of two examples
known. The other is in the collection of the Armed Forces Institute of
Pathology.
Magniphone Stethoscope, circa
1900.
The piece below is very interesting in that it combines the binaural ear piece of a stethoscope with a very long tube and wide bell charcteristic of a hearing aid or conversation tube. In fact, this piece is neither a stethoscope or hearing aid, but rather a "re-educative binaural tube to enable the patient to read or speak to himself and thus stimulate the dormant auditory centre by natural means of the voice" in order to treat middle ear deafness (Mayer&Phelps, circa 1931)
Re-educative
scope, circa 1931.
We are always interested in acquiring new items for the collection. If you have any items for sale or question please do not hesitate to contact us.
