ILLUSTRATED CATALOGUE
ELECTRO-MEDICAL  INSTRUMENTS,
MANUFACTURED A^D SOLD
     THOMAS HALL,
 (SUCCESSOR TO PALMER <Ss HALLJ

    ELECTEICIAN,

MANUFACTURER AND IMPORTER OF

     MAGNETIC  GALVANIC,
TELEGRAPHIC INSTRUMENTS.
/
WC.-S—
1901
     BOSTON, MASS.
No. 168 WASHINGTON"!1
         1859. 
 
PREFACE  TO  CATALOGUE.
  The  manufacturing of Magnetic  and Galvanic Instru-
ments was first commenced in this country by Mr. Daniel
Davis, Jr., in the year 1836.  Previous to that time, all the
Galvanic Instruments used  in this country were imported
from Europe.  Mr. Davis, having had an old induction coil
to repair, saw the principle  upon which it acted, and made
one for  amusement, with some improvement upon the one
he repaired.  He found  a ready sale for it.  This induced
him to engage in the manufacture of them.  At that time
they were very rough and inconvenient  instruments, com-
pared with those we now make.  They were very seldom
used for medical purposes.   The mode of breaking the cur-
rent was by means of a ratchet placed on the top or by the
side of  the coil.  This was a great  objection to them for
medical  purposes, as the shocks came very irregularly; this
was remedied by the invention and adoption of the vibrat-
ing armatures in connection with  the secondary coils con-
trived by  Mr. Davis. It is now universally used for this
purpose both in this country and Europe.   By this in-
genious  arrangement  the  instruments  are self-operating, and
the current is extremely fine.  Making induction  coils led
to making models for motive  power,  and various  pieces
of apparatus to illustrate galvanism and electro-magnetism.
The  adoption of this branch of physical science in our col-
leges  and  schools created a constant  demand for this class
of instruments, so that we  now manufacture over five hun-
dred distinct instruments adapted to this branch of studies. 
PREFACE TO CATALOGUE.
For several years they were used only for illustrating the
principles of galvanism, &c, there not being any practical
use for them except being occasionally used for medical pur-
poses.  Like most new theories in medical science, this agent
was extremely slow in coming into use among the medical
profession.   One of the greatest obstacles in the way of  this
agent was, that there were no books on this subject whereby
a physician could inform himself how  to apply electricity to
various diseases.   This defect is remedied  now to a great
extent; there are some  very valuable  works  on  medical
electricity, by some of the  first physicians  in Europe  and
America.  Among the most prominent stand the names of
Golding Bird, of England, M. Duchenne and M. Becquerel,
of France, Middeldorpf, of  Germany,  and Dr. W. F. Chan-
ning, of this  city.  This last gentleman  has paid  especial
attention to  electricity as a therapeutic  agent, having con-
structed and devised a great many new and useful instru-
ments in this department.   We are greatly  indebted to  him
for his  suggestions and advice  in  the -construction of the
various instruments described in the following catalogue.
Many  of them, and  the manner of applying them,  are
original with him.
   Having been engaged with Mr. Davis in the manufacture
of these instruments from  1840 until his retirement from
business in 1849, and  subsequently successor to him in the
firm of Palmer  & Hall, until 1857;  having had  eighteen
years'  experience, and possessing great  facilities  and  con-
veniences for the manufacture of instruments in this line,—
it is my intention that no efforts on my part shall  be want-
ing to sustain the previous high reputation of these instru-
ments, or to render them unsurpassed by those of any other
maker.
                                  THOMAS HALL. 
HALL'S  CATALOGUE.
  Persons ordering will please state the number and price
of instruments.
  All instruments carefully packed  and warranted, with
cost of box added to bill.
INSTRUMENTS.
  No. 1.  Single Coil Instrument, in black walnut box,
with draw to contain directors, wire, &c, large size, de-
Pig. 1.
209
99999999999999999999999999999999999999999999999999� 
2
hall's  catalogue
signed for physicians' use, containing ground stopple bottles
for solutions.   This  instrument  is  thoroughly  made, and
beautifully finished.   Price, $20.00.
  No. 2.   Double  Coil Instrument, same  size as Fig. 1,
with the addition of a quantity coil and graduated battery'
Price, $25.00.                                         J
  No. 3.  Same size as Fig. 1, silver plated.  Price, $25.
  No. 4.  Double Coil Instrument, silver plated.  $30.00.
Fig. 5.
  No. 5.   Dr. Page's  Portable  Battery.   This  is  very
powerful for its size.   It is contained in a  black walnut
box, 5 inches high, 7 wide, and 9 long.   It consists  of coil, 
          OF  ELECTRO-MEDICAL  INSTRUMENTS.         3

5  inches  long and  two inches in  diameter, with  square.
battery, handles, and flexible wires.   Price, $12.00.

   Directions. — 1.  Connect the wires  as  represented in
the cut.
   2.  The solution to be used in this battery, is  one of sul-
phate of copper, (blue vitriol,) containing about two ounces
of blue vitriol  to a pint of water.  To prepare it, a saturated
solution is first made, and to this solution is  then added as
much more water.
   3.  The zinc plate becomes coated in the battery, so that
it  is necessary to clean it after using it, whenever the metal
has become thickly furred.   The coating should be removed
each time, so  as to expose again the bright  surface of the
zinc.
   4.  If the electro-magnetic apparatus will not operate, see
first if any spark is  perceptible on rubbing the  extremities
of the wires from the battery together.  If not,  the battery
is  in fault. This may  be owing to a sediment of copper at
the bottom of  the battery, making a  connection between the
zinc and copper, or to the zinc being somewhere in metallic
contact with the copper; or it may be owing to the foulness
of the zinc plate, or to the weakness of the copper solution,
which in that  case will have lost its color.
   5.  A bundle of iron wires is shown in  the cut within the
inner helix.   This  can be removed  at  pleasure, and the
sdiock thus regulated.
   6.  The positive pole  may be determined from the nega-
tive by taking the handle-directors in the hands, the negative
always being felt the most sensibly. 
4
hall's catalogue
                        Fig. 6.


  No. 6.  Coil and Battery,  in box, for family use.   A
very convenient form, including handles and wire.  Price,
$10.00.
Fig. 7.
  No. 7.  Double  Helix and Vibrating Electrotome, with
battery and handles.   Neatly mounted on rosewood base.
Price, $8, $10, and $12.00.
  No. 8.  Small Coil, in neat rosewood box, with
and handles.  Price, $8.00. 
OF  ELECTRO-MEDICAL INSTRUMENTS.
5
                        Fig. 9.

  No. 9.  Compound Electrotome with Clockwork.  This
is a very powerful instrument, and is  used principally to
illustrate the  induction current in colleges  and  medical
schools.  Price, $20.00.
  No.  10.   Horizontal  Compound Electrotome.   This is
the same as Fig. 9, with the exception of being horizontal.
The current is broken by clockwork, attached to wires dip-
            1* 
6
HALL'S  CATALOGUE
                        Fig. 10.

ping into  mercury cups.  When the battery is connected,
there is a bright spark in the glass cup, sufficient to light
up a small room.   Price, $20.00.
  No. 11.  This  instrument  is enclosed in a black walnut
box, with  handles, battery, and wires.  The battery is com-
posed of zinc and platinum,  and is  excited with sulphuric
acid.  The instrument is entirely enclosed from the battery,
so as to avoid all fumes  and dirt arising from the battery.
This  battery  needs  no cleaning,  being always  ready for
action.  Price, $14.00.
  Instruments used for the application of Galvanism in the
Extraction of Teeth.
  No. 12, Represents helix, with handles and wires com-
plete.   In order to  operate  the  instrument,  connect  the
short wires as represented in the figure.  Connect the flexi-
ble wires  with the cups at the end  of the helix marked P
and N.   Attach the handle to the wire connected with the
234853234848234853485353534848485353530053235323 
OF ELECTRO-MEDICAL INSTRUMENTS.
7
                       Fig. 12.
cup marked P.  Attach the wire connected with the cup
marked N to  the  forceps; this can  be done by drilling a
hole in the handle  of the forceps, and inserting the end of
the wire so as to  make good connection.  The current is
graduated by removing the regulator from the centre of the
helix.   Care  should  be taken to insulate  the gums and
cheek from the forceps, so as to cause the whole current to
go direct to the tooth: a slight  current has been found the
best to produce the desired effect.
Fig. 13 
8
HALL'S CATALOGUE
  No. 13, Represents the best battery for this  purpose,
as it  is a constant battery, always ready for use,  and re-
quires little  care  in  its management, the zinc plates not
requiring any cleaning.   It consists  of amalgamated zinc
and platinum, with sulphuric acid and water;  for a solution,
about one twentieth acid to water.  Care should be taken to
keep the zinc plates well coated with  mercury, as that pre-
vents the acid from acting on the zincs only when in use.
They should be amalgamated  once a month, if used con-
stantly.  To amalgamate the zincs, clean  them well with a
strong solution of sulphuric acid and  water, then rub them
in a dish of quicksilver, rubbing it on Avith an  old tooth
brush.  See that the zincs are Avell coated  with mercury, as
the action of the battery depends a great deal on the amal-
gamation.  Do not let the  platinum plate touch the zincs,
as that would stop the action  of the  battery.  Disconnect
the battery from the instrument when  not in use.
  This battery is peculiarly adapted to dentists' use, as it is
always ready, day and  night, and there is no cleaning of the
zincs, as  in the sulphate of  copper batteries.  It is also the
battery used by dentists for gilding their plates.*
                        Fig. 14.
  No. 14,  Represents a footboard, for  letting the current
on  the forceps  by the  foot  or hand,  a very convenient
     • See Hall's Instructions for Electro-Gilding and Silvering. 
OF  ELECTRO-MEDICAL  INSTRUMENTS.
9
method of operating, as you need  no assistant.   This is
connected by the wire in between the  instrument  and the
handle  Avhich the patient  holds.  By pressing the spring
down it closes the circuit.   By releasing the pressure the
eurrent is  broken.   By this arrangement you can let the
current on at pleasure.
   Dentists' set complete, including battery, helix, footboard,
wires, and  handles.  Price, $12.00.
                        Fig. 15.

  No.  15.   Hall's Improved  Compound Magnetic Instru-
ment, producing a constant current.  For Rheumatic and
Nervous Diseases.*
  In offering this instrument to the public, we would call
their attention to the following  advantages over all others
now in use.
  This instrument is arranged with a Pole Changer, so that
* An application for a patent has been made. 
10
HALL'S  CATALOGUE
you can determine which  is the positive or negative pole,
(the negative pole being the strongest,) which is very essen-
tial to know in applying it for diseases.  The coils revolve
without belt or band,  so  that it cannot get out of order.
Having a magnet at each end of the coils, we  get a very
powerful current, which can be controlled by the U arma-
ture.   Shocks can be obtained by turning the crank either
way.   The changing of the  positive or negative  pole in the
conductors depends upon the direction in which the crank is
turned.   This instrument is thoroughly made, and warranted
to keep in order for years  if carefully used.  Price, $10.00.

  Directions. — Connect  the  conducting wires with the
sockets at the  end of the box, screw the crank on the wheel-
shaft,  and turn slowly, as the  current depends  upon the
velocity with  which  coils  revolve; the greater  the  speed,
the more powerful the shocks Avill be received.   By putting
a piece of wet sponge in the ends  of the conductors, the
shock will be more pleasant, as  the sponge spreads upon a
Fig. 16. 
          OF ELECTRO-MEDICAL INSTRUMENTS.        11

larger surface  of the  skin, and obviates that pricking sen-
sation which is so unpleasant.  In applying it, hold the con-
ductor in one hand, and apply the other to the part affected.
To produce- a  constant current,  pull the lever at the  end
of the box.

   No. 16.   Large size Magneto-Electric Machine, for hos-
pitals and institutions. The advantages that this instrument
possesses over the induction coils is, that there is no battery;
it is always ready;  by turning the crank you produce a cur-
rent.   This is  used very extensively in Europe, but we do
not think it  gives  so  steady a current as  the instruments
worked with the  battery.   Price, $50.00.
                        Fig. 17.

  No. 17.   Medium  size  Magneto-Electric  Machine, in
box, suitable for a physician's office.  Price, $35.00. 
12                HALL'S  CATALOGUE
                       Fig.18.

  No. 18.  Magneto-Electric Machine, without box, neat-
ly mounted on rosewood base.   Price, $25.00.
  No. 19.  Magneto-Electric Machine, Avith Single Magnet.
This is intended for institutions.  Price, $30.00.
  No.  20.   Largest Size,  run  with Clockwork, with four
coils, producing quantity and intensity at the  same time.
Double  Compound Magnets.   "Well  made  and finished-
Price, $100.00.
                        Fig. 21.

  No. 21.  A Series of Twelve Grove's Battery, in box.
"We consider this battery the best for  the electro-chemical
baths.   It consists  of amalgamated  zinc  and platinum, 
          OF  ELECTRO-MEDICAL  INSTRUMENTS.        13

excited with sulphuric and nitric acid.  It is a very intense
battery.   From twelve to fifteen cups is the best number to
each tub.   Price, per cup, $2.00.
   Directions. — Fill the glass jars with water within one
and a half inches of the top; then add one  half ounce of
sulphuric acid; stir it up well with a stick; set the zinc in
the jar, and the earthen or  porous cup in the zinc; fill the
porous cup with nitric acid within one half an inch of the
top ;  place each platinum strip in the nitric acid, or porous
cup,  as shown  in the cut above;  connect wires with each
end of the battery, then touch the  ends of the  wires to-
gether, — if there is a spark, the battery is in good order.
   Care  should be taken to  keep the zincs Avell coated with
mercury, as that prevents the acid acting  on  the  zinc  only
when in  use.   They should be amalgamated once a week
if used constantly.  To amalgamate the zincs, you  clean
them  well  with a  strong solution  of sulphuric acid and
water, then rub them in a dish of quicksilver, — put it on
with  a brush.  See that the  zincs  are  well  covered  with
mercury, as  the action of the battery depends a great deal
on the amalgamation.
   This battery will work from eight  to  ten  hours with  a
constant  current.   It is best to  soak the porous  cups in
 water after using, as it frees them from the old acid.
   No. 22.  A  Series  of Twelve  Smee's  Batteries, in box.
 Consisting of amalgamated  zinc and platinum, excited Avith
sulphuric acid.  This is applied directly to the patient by
 means of directors.  Price,  $24.00.
   No. 23.   Hall's  Improved Constant Battery, composed
of copper and  zinc, excited by sulphate of copper.   The
 zinc  is placed  in the  centre  of a  porous cup, filled  with
 water. The porous cup is placed within a cylinder of sheet
 copper, surrounded Avith crystals of sulphate of copper, set
 within a  glass jar.   Fitted in boxes of ten cups each. 
14
hall's  catalogue
Fig. 23.
  The advantage of this battery as a medical agent is very
great, as it will remain in constant action from nine months
to a year without replacing, except Avith water, to  replace
that which has evaporated.   Price, per cup, $1.25.
                       Fig. 24.
  No. 24.  Manipulator.   This is a very ingenious instru-
ment, contrived by Dr. William F. Channing, for bringing
any number of batteries into circuit at pleasure from one
to one hundred  cups.   It is arranged with a pole-changer,
break-piece, key, and clock-work electrotome.  This is a very 
          OF ELECTRO-MEDICAL INSTRUMENTS.        15

desirable instrument, when the constant current is used, as
it  places  the battery in  perfect control  of  the  operator.
Price, 100 cups, $50.00;  50 cups, $40.00; 30 cups, $30.00;
20 cups, $15.00; 15 cups, $10.00.
   No. 25.  Improved Electro-Surgical Instrument.  Loop
Ligature.  This is arranged so as  to let the  current on by
merely pushing the knob, after placing the loop in the right
Fig. 25. 
16                BALL'S CATALOG^

position.   The battery current is produced by four cups of
Bunsen's  battery,  composed of zinc and  carbon, giving a
powerful quantity current.  It is  let on to the instrument
by means of large flexible wires.   Price, $8.00.
Fig. 27. 
OF ELECTRO-MEDICAL INSTRUMENTS.
17
  No. 26.  Directors for Destroying the Nerves of Teeth,
by means of red hot platina wire.   Price, $3.00.
  No.  27.   The  same as No.  25, with the exception of
lancet instead loop.  Price, $8.00.
Fig. 28.                       Fig. 29.
  No. 28.  Small Sulphate Copper Battery.  Price, $2.00.
  No. 29.  Showing a  section of Fig. 28.   C C copper,
Z  zinc, the solution as composed of sulphate of copper,
about one ounce to a pint of water.
                       Fig. 30.
  No.  30.   Medium  Size  Sulphate  Copper Battery.
Price,  $5.00.
           2* 
18
hall's  catalogue
                        Fig. 31.
  No. 31.   Daniels's Protected Battery.   The difference
betAveen this and Fig. 30 is, that the  zinc cylinder is  pro-
tected by a porous  cup.  By this  arrangement the battery
is more constant, and will remain in action for-several days,
but is not so powerful.   Price, $2.00.
  No. 32.  Large Size ditto.  Price, $4.00.
                        Fig. 33.
  No. 33.   Smee's Constant Battery.   This is  composed
of zinc and platinized silver, sulphuric acid and  water, for
solution.  It is very constant, and will remain in  action for 
OF  ELECTRO-MEDICAL  INSTRUMENTS.       19
several months.   This for an office battery is decidedly pref-
erable over all others, as it is less expensive to work, and
less trouble.  Price, 1 quart jars, $2.50; 3 quart jars, $3.50.
j]____I
   Figs. 34.     35.         36.        37.
  No. 34.   Directors for the Hand.  German silver, with
insulated handle.  Price, per pair, $2.00.
  No. 35.   German Silver Handle.  Per pair, $1.25.
  No. 36.   Silver Plated Surface Director, with insulated
handle.   Per pair, $2.00.
  No. 37.   Sponge Director, with glass handle.  75 cents.
Figs. 38.   39.
40. 
20
hall's  catalogue
No. 38.  Ear Director, silver plated, with insulated han-
dles.  Price, 75 cents.
  No. 39.   Rectum ditto.  75 cents.
  No. 40.   Tongue ditto.  75 cents.
  No. 41.   Scalp ditto.  $1.25.
Figs. 42.        43.    44.    45.   46.
  No. 42.   Flat Sponge Director, Avith long insulated han-
dle.  This is very convenient, as you can apply it without
disrobing the patient.   Price, $1.25.
  No. 43.   "Womb Director, with insulated handle.  Price,
$1.25.
  No. 44.   Ditto, with glass handle.  $1.25.
  No. 45.   Vagina Director^silver plated-  Price, $1.25,
and $1.50. 
       OF  ELECTRO-MEDICAL INSTRUMENTS.       21

No. 46.   Dr. Channing's Eye Glass.  75 cents.
                      Fig. 48.
  No. 48.  Hall's  Hard  Rubber  Sponge Cup.   This is
used by placing the hemisphere in the palm of the hand, 
22                HALL'S  CATALOGUE

and letting  the  knob project through the  fingers.   Tl:
sponge is fastened in the cup by a spring.  By this arrange
men" the  sponge can be taken out of the cup and washe
which is very desirable.   Price, without sponge, 75 cent:
with sponge, $1.37.
 
OF ELECTRO-MEDICAL INSTRUMENTS.       23
  No. 49.  Hall's Universal Handle, embracing the Tongue,
Ear, Eye, Rectum, Sponge, Womb, and Vagina  Directors.
Silver  plated.  By this arrangement, all the directors are
fitted to one handle.   They can be fitted in the draw of the
instrument,  and take up but little  room.  Price, $5.00.
Neatly fitted in box,  $6.00.
  The above directors should be covered with cotton flannel,
moistened with Avater, when in  use,  as  this will prevent
that burning sensation so disagreeable to patients.
Fig. 50.
  No. 50.  Tie  Connecting Cups, for joining  two wires.
Price, 25 cents.
     ggmnL

      pi'"

       Fig. 51.                  Fig. 52.
No. 51.  Screw Connecting Cups.  Price, 17 cents.
 
24               hall's catalogue.

  No. 52.  Screw Cups.   Price, 17 cents.
                       Fig. 53.

  No. 53.  Galvanometers,  for  testing various  galvanic
currents.  Price, $10.00 to  $35.00.
  No. 54.  Vertical  Calvanometer, in case, for office use.
Price, $15.00. 
           OF  electro-medical instruments.       25


                   MISCELLANEOUS.

    Sulphate of Copper, per pound, 15 cents.
    Mercury,               "      70 cents.
    Sulphuric Acid,         "
    Nitric Acid,            "
    Silk Conducting Wires, per pair, 37 cents.
    Cotton   "       "       "     25 cents.
    India Rubber«   «       "     $1.50.
    Golding Bird's Electro-Moxa plates, 75 cents.
    Insulated Conducting Wires of every description.
    Zincs for various kinds of batteries.
    Connecting  Cups of various kinds.
    Platinum Wire and Foil.
    Porous Cells.
    Amalgamating Brushes.
    Galvanic Soles.
    Dr. Garret's Spine Directors.
    Galvanic Tubs for Foot Baths.
    Batteries and Apparatus for Electro-Chemical Baths.
    Improved Instruments and Batteries  for  Dentists' use.
 Price, $12.00.
    Dr. W. F. Channing's Work on Medical Electricity, fifth
 edition, enlarged, with seventy original illustrations.   $1.00.
    Golding Bird's Lectures on Medical Electricity.   $1.00.
    Hand-Book  of Anatomy, with Charts.  $5.00.
    Davis's Manual of Magnetism.

    English, French, and  German Scientific Works  and
 Instruments, imported to order.
               3

) 
26
hall's catalogue
INDEX.
No.  1.  Single Coil, in black walnut box.....................$ 20.00
No.  2.  Double Coil Graduated Battery.....................   25.00
No.  3.  Silver Plated Instrument, single  coil................   25.00
No.  4.  Double  Coil, silver plated...........................   30.00
No.  5.  Dr. Page's Portable Instruments....................   12.00
No.  6.  Family Instruments................................   10.00
No.  7.  Mounted on Rosewood Base.....................8, 10, 12.00
No.  8.  Small Coil, in box..................................    8.00
No.  9.  Compound Electrotome............................   20.00
No. 10.  Horizontal Compound Electrotome..................   29.00
No. 11.  Coil  in box, with Constant Battery.................   14.00
Nos. 12, 13, and  14.  Instruments used in the application to
    Teeth..................................................   12.00
No. 15.  Hall's Improved Magnetic Machine.................   10.00
No. 16.  Large size Magnetic  Machine.......................   50.00
No. 17.  Medium size Magneto-Electric Machine.............   35.00
No. 18.  Magneto-Electric Machine, without box..............   25.00
No. 19.  Magneto-Electric Machine, with Single Magnet......   30.00
No. 20.  Largest size, with clockwork........................  100.09
No. 21.  Grove's Battery, in box.............................   24.00
No. 22.  Smee's  Battery, in box.............................   24.00
No. 23.  Hall's Improved Constant Battery, per cup..........    1.25
No. 24.  Dr. Channing's Manipulator, per 100  cups...........  50.00
          "     "           <<          50  "  ...........  40.00
          "     "           «          30  "  ...........  30.00
          "     "           "          15  "  ...........  20.00
          "     "           "          10  "  ...........   15.00
No. 25. Electro-Surgical Loop..............................   8.00
No. 26. Director for Destroying the Nerves of Teeth..........   3.00
No. 27.  Electro-Surgical Lancet............................   8.09
No. 28.  Small Sulphate Copper Battery.....................   2.00
No. 30. Medium Size Sulphate Copper Battery...............   5.00
No. 31.  Daniels's Protected  Battery........................   2.00
No. 32.     «        "        «     large size..............   4.0(' 
OF electro-medical instruments.        27
 No. 33.  One Quart Battery.................................    2.50
          Two   "      "    ................................    3.50
 No. 34.  German Silver Directors for the Hand, per pair......    2.00
 No. 35.     "       "     "     ««  <<   «<    <<   <<.......    125
 No. 36.  Silver Plated Surface Handle,........ "   «.......    2.00
 No. 37.  Sponge Director..................... «   «.......    1.50
 No. 38.  Silver Plated Ear Directors, each....................75
 No.39.    "     "   Rectum"     "  ....................75
 No.40.    "     "   Tongue  "     "  ....................75
 No. 41.    "     "   Scalp    "     "  ...................    1.25
 No.42.  Flat  Sponge Handle...............................    1.25
 No. 43.  Womb Director....................................    1.25
 No. 44.     "       "   glass...............................    1.25
 No. 45.  Vagina Director, silver plated.....................1.25, 1.50
 No. 46.  Dr. Channing's Eye Glass...........................75
 No. 47.  Metallic Slippers, per  pair..........................    1.25
 No. 48.  Hard Rubber Sponge  Cup...........................75
 No.49.  Universal  Handle..................................    5.00
          In Box............................................    6.00
 No. 50.  Tie Connecting Cups................................25
  No.51.  Screw  "       " ................................17
 No. .32.  Screw Cups........................................     .17
 No. 53.  Galvanometers................................10, 15, 35.00

  Every description of Magnetic and Galvanic Instruments manufactured
to  order, for professors, physicians, teachers, experimenters, and manu-
facturers.  Illustrated catalogue of Electro-Medical Instruments, Philo-
sophical Instruments, and Telegraphic Instruments.