Improvements in and connected with Thermo-cauters.
Year: 1890

page_text: Date of Application, 25th Sept., 1890
Complete Specification Left, 27th May, 1891-Accepted, 15th Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in and connected with Thermo-cauters.
I, CLAUDE ANDRÉ PAQUELIN of 12, Place Vendôme, Paris, France, Doctor of
Medicine, do hereby declare the nature of this invention to be as follows:-
The thermo-cauter as now used comprises three principal parts, viz. a hollow
point of metal such as platinum having the property of condensing gases, a
carburetter, and a pneumatic blower.
This invention relates to improvements in each of said parts and also to the
application to the thermo-cauter of a simple form of blow-pipe heater burning a
mixture of air and gas or hydrocarbon vapor.
Reference is to be had to the accompanying drawings, forming part of this
Specification, in which
Figure 1 represents a part sectional view of the entire apparatus, as arranged
for use.
Figure 2 is a cross-section of the carburetter.
Figure 3 is a longitudinal section of the cauter proper.
Figure 4 comprises longitudinal and cross-sections on an enlarged scale, shewing
the passages for the gases.
Figure 5 shews cross and longitudinal sections of a modified arrangement.
Figure 6 is an elevation of the blow-pipe heater.
Figure 7 is a detail section of its burner.
Figure 8 is a detail section of a modified burner.
Figure 9 shews a micrometer adjustment for regulating the mixing cock of the
carburetter.
Figure 10 is a section of the carburetter at right angles to Figure 2.
Figure 11 shews the thermo-cauter applied as a desiccator, and
Figure 12 shews the thermo-cauter as applied for local illumination in dental and
other operations.
Figures 13 and 14 shew two forms of points for the cauter.
Figure 15 shews a form of carburetter for use in workshops.
In this improved cauter the combustion is effected by conducting the combustible
gases through the central tube a to the tube c of platinum or other gas-condensing
metal which conveys them to the end of the cauter point where combustion takes
place, the resulting products passing off through the annular space between the
central tube a and the sleeve e and finally escaping through perforations in the
boss d at the rear end of the handle f The use of the condensing metal is
restricted to the exact dimensions required and the platinum gauze now employed
in large cauters is dispensed with, the instrument being thus reduced to mininium
dimensions.
A current of cold air is blown between the sleeve e and sheath or handle ƒ and
may either circulate freely, or through a coiled tube, as shewn in Figure 1, or
otherwise, and a non-conducting substance such as asbestos may also be interposed
between e, f, either or both these means of preventing the transmission of heat to
the handle being employed. One of the products of combustion of hydrocarbons
is steam which condenses in the perforations g of boss d, in the form of drops.
These condensed vapors may be utilised for cooling purposes, either by allowing
them to leak between the parts & and for by blowing them in by the air current
above mentioned, or the orifices in d may be closed and the accumulated pressure
utilised for carrying the condensed vapors to any point desired.
The reduction of the mass of condensing metal as above mentioned enables the

page_text: instrument to be ignited at the flame of a candle, but, notwithstanding such
reduction, the construction of the thermo-cauter is such that if, when the point is
in complete incandescence, it be dipped in cold water and held there while
continuing to supply the combustible gases, it will regain its incandescence when
withdrawn. and it will pass through animal tissues or liquids without being
extinguished.
By the present improvements there is also a considerable reduction in the field
of combustion with a proportionate diminution of the radiant heat; the edges and
sides of cavities are protected from the contact of the gaseous products of
combustion with consequent greater freedom for operating in cavities; the
concentration of the heat in the handle of the instrument is prevented; the hand
of the operator may be brought close to the field of operation and the instrument
may be handled with greater precision. The instrument may be employed, among
other uses, in dental operations, for desiccating by hot air, and also for illuminating
the parts under treatment.
To use the thermo-cauter as a desiccator (Figure 11) a nozzle h of straight or
curved tapering form is attached to the instrument by a bayonet or other joint and
air is blown both through the carburetter and desiccator the current circulating
between the sleeve e and handle f becoming heated by contact with the incandescent
condensing metal and escaping through the perforated end of nozzle by which it
is projected upon the parts under treatment.
To apply the instrument for the purposes of illumination (Figure 12) the cap h
(Figure 11) is replaced by an enamelled hood i and wire gauzej or other arrange-
ment giving the same result. The instrument may thus be inserted in the buccal
cavity, for example for lighting it.
It has been stated that the use of platinum gauze as heretofore in large cauters
is no longer indispensable, but an indispensable clement of thermo-cauters generally
is the internal surface of gas condensing metal constituting the focus of combustion
(which in Figure 3 is in the form of a tube c) serving to prevent the extinction of
the thermo-cauter by the loss of a great part of the heat derived from the internal
combustion when the instrument is introduced into animal tissues.
To effect the combustion of the gases or hydrocarbon vapors, 1 may employ the
condensing metal in the form represented in Figure 13 in which the cauter has a
longitudinal partition or in that shewn in Figure 14 in which it is formed of a tube
doubled on itself, neither wire gauze nor a central tube being employed.
The carburetter, for generating the hydrocarbon vapors serving to maintain the
incandescence of the cauter, is specially arranged according to the combustible,
gas or vapors, employed. When employing a gas, such as illuminating gas for
example, the carburetter is provided with a special mixing cock.
When vapors
are used (benzoline vapors for example) it is furnished in addition to the said cock
with a saturator (washer or atomiser). In the former case the gas is supplied to
the carburetter according to the requirements of the consumption, with or without
an automatic governor; in the latter case, hereinafter described, the combustible
is contained in a liquid form in the carburetter itself.
The form of the carburetter may vary. In Figure 1 it is of rectangular section,
concave on one side and convex on the other, for application against the body by
which it is warmed. The carburetter is filled to the proper height by first
completely filling it at orifice n then its concave side being towards the operator
the excess is poured off by tilting it to the left. The orifice n is preferably closed
by a screw cap o made perfectly tight and provided with a strainer p to act as a
filter in filling the vessel.
The regulator mixing cock fitted to the carburetter consists of a rotary plug
provided with an inclined groove 1 (Figure 2) which may either be made of the
form shewn or be formed of several spirals. 2 is a stop to limit the motion of the
plug. The body of the cock extends within the carburetter and has two passages,
of which the one passage 3 leads directly to the plug while the other passage
connects with an obtuse-angled channel leading past the plug, a horizontal branch
4

page_text: channel 5 terminating in a nipple 9 connected with the bellows by a flexible
pipe y, while the inclined branch 6 extends up to the top and connects with another
channel 7 leading to the plug like the passage 3 to which it is diametrically
opposite. Another horizontal nipple », similar and opposite to g, places the valve
in direct communication with the thermo-cauter by a flexible tube.
Figures 1 and 2 shew the saturator, which consists of an atomising injector, or,
by suitably modifying the carburetter, an atomizer operated by air pressure may
be used. Or a saturator of the kind represented in Figure 10 may be used
consisting of a bent pipe perforated at its lower end which dips into the liquid
contained in the vessel. The saturator is branched on to the passage 4, but it may
be independent of said passage and open out on the exterior in which case said
passage 4 need not extend below the pipe connection 7, the air supplied by the
bellows being distributed directly, partly through 9 and partly to the saturator.
In all cases the carburetter is so arranged that it may be overturned without
spilling the liquid. The mixing cock may be attached to the carburetter by a
screw-nut provided with a packing ring so as to enable it to be removed for the
purpose of inspecting the injector and keeping it in working order; the liquid
container may also be provided with glazed openings, if desired.
The mixing cock is operated in the following manner :-(1) Supposing the
stop 2 to be at the right hand end of its course; in this position the two passages qr
are in direct communication by means of the groove in the plug and the
passages 76 and 3 are completely closed. The air from the bellows consequently
passes, first, both to the carburetter and also to the outlet passager but as the
return passage 3 is closed, immediately the carburetter becomes filled with air, the
whole of the air supplied by the bellows will pass directly from one to the other
pipe connection 9, r, so that in this position of the cock it may be said that hardly
any but pure air passes from one to the other. (2) Supposing the cock be turned
to the left; during the whole of this movement, the passage which places the pipe
connections in communication becomes gradually reduced at same time that the
return passage for the carburetted air is opened and gradually increased to a
corresponding extent. Thus the further the plug is turned to the left, the more
will the quantity of air passing from one pipe connection to the other be reduced,
and the more will that which enters the carburetter be increased, whereby the air
will become more highly carburetted. Thus when the stop 2 is vertical that is to
say in the intermediate position indicated by the notch 8 in the head of the plug
(Figure 2) one half of the air supplied by the bellows will pass to the carburetter
and half to the left hand pipe connection r. (3) Supposing the stop 2 to be turned
to the left to the full extent; in this position the passage 6, 7, which puts the
right hand pipe connection in communication with the groove in the plug is closed
but as the passage 3 is in direct communication with said groove all the air from
the bellows will consequently pass through the carburetter. The cock serves thus
both for proportioning and mixing, which enables the operator to produce,
according to the action desired to be obtained, a series of gaseous mixtures of
exactly determined composition and more or less rich in carburetted hydrogen.
The cock may be operated by a micrometer screw (see Figure 9) whereby much
greater precision may be obtained in its operation and consequently in the
distribution of the air. The regulating action of this cock is indispensable for
ensuring the proper working of the thermo-cauter. By its aid the operator can
both regulate at will the degree of incandescence of the instrument, and also
compensate for any irregularities due to the varying conditions either of the
surroundings or of that existing in the interior of the carburetter, owing to the
exhaustion of the supply of liquid, or its vaporization, etc.
The blow-pipe, to be employed in combination with the thermo-cauter, which I
will now proceed to describe, is intimately connected in its action with the mixing
cock. It is of special construction and consists, as shewn in Figure 6, of a single
tube like a jeweller's blow-pipe but differs therefrom in the form of the burner

page_text: which emits two kinds of flame viz. a central tongue or flame around which at its
base is a circle of small flames serving to prime and feed the former. The blow
pipe tubes terminates at one end in a nipple t and at the other in a burner u upon
which is fitted a short tube or sheath y as shewn in Figure 7 in which v is the
central orifice of the burner and a the lateral orifices inclined at an angle of
about 45°. In the slightly modified arrangement shewn in Figure 8, the orifices
are formed horizontally in a groove formed at about mid-height of the burner.
The metal tube, which may be of variable height, surrounding the burner while
permitting of free communication between the central and lateral jets, ensures the
combustion of the generating current, by ensuring the convergence of the lateral
jets. The central tube s is enclosed in a handle which may be protected from
the heat in the manner before described for the thermo-cauter.
With a blow-pipe constructed as described all the necessary variation in the
form, dimensions, color, and intensity of the flame may be obtained by varying the
relation between the areas of the central tube and of the central and radial orifices
of the burner for each particular case. The same remarks apply with regard to
the dimensions form and construction of the burner and other parts of the blow-
pipe. For a burner of the kind represented in Figure 7 the following dimensions
of the orifices have given good results :-
Diameter of central orifice of burner
وو
"
22
"
outlet orifice
millimetres.
3
-
2.50
"
"
cach of the three radial orifices 1.90
The blow-pipe when combined with the thermo-cauter serves (1) to prime or
start the cauter (2) to clean it (3) to test previous to each operation, the qualities
of the combustible liquid (4) to establish, by means of the mixing cock, previous
to each operation, the desired composition of the gaseous mixture. To prime the
cauter it is simply necessary to connect the blow-pipe with the carburetter, turn
the plug of the cock so as to bring the notch 8 on the head downwards, and work
the bellows, and then light and regulate the flame of the blow pipe so that it
presents hardly any trace of white flame, then heat the cauter to a white heat and
quickly substitute it for the blow-pipe. The incandescence of the cauter is now
regulated by the cock on the carburetter. In order to clean the cauter the same
operation is repeated as in priming, after which the blowing action is increased,
and the condensing metal maintained at a white heat for a few moments. By the
employment of the low pipe, the spirit-lamp and two kinds of combustible liquids
hitherto required are dispensed with while the operator is also enabled to clean his
own instrument. To verify the qualities of the combustible liquid, the precise
moment when the liquid will fail is known when, previous to an operation, whatever
may be the position of the cock, the blow-pipe no longer produces a flame largely
tinted white. Any kind of bellows may be used, but it is preferred to employ a
Richardson bulb perated either by the hand, foot, or pedal. I have shewn, in
Figure 1, an improvement consisting in the application of a thick flange y of india-
rubber between the regulating bulb z and the tube to which it is connected, in
order to prevent throttling by the netted covering when the bulb is fully expanded.
Without this adjunct the tube leading from the regulating bulb is liable to become
imprisoned between the bulb and its netting and flattened so as to suddenly cut off
all circulation of air.
L
Dated this 25th day of Santember 1890
C. A. PAQUELIN.
By A. M. & Wm. Clark,
53, Chancery Lane, London, l'atent Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in and connected with Thermo-cauters.
I, CLAUDE ANDRÉ PAQUELIN of 12, Place Vendôme, Paris, France, Doctor of
Medicine, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
The thermo-cauter as now used comprises three principal parts, viz. a hollow
point of metal such as platinum having the property of condensing gases, a
carburetter, and a pneumatic blower.
This invention relates to improvements in each of said parts and also to the
application to the thermo-cauter of a simple form of blow-pipe heater burning a
mixture of air and gas or hydrocarbon vapor.
Reference is to be had to the drawings accompanying my Provisional
Specification, in which
Figure 1 represents a part sectional view of the entire apparatus, as arranged
for use.
Figure 2 is a cross-section of the carburetter.
Figure 3 is a longitudinal section of the cauter proper.
Figure 4 comprises longitudinal and cross-sections on an enlarged scale, shewing
the passages for the gases.
Figure 5 shews cross and longitudinal sections of a modified arrangement.
Figure 6 is an elevation of the blow-pipe heater.
Figure 7 is a detail section of its burner.
Figure 8 is a detail section of a modified burner.
Figure 9 shews a micrometer adjustment for regulating the mixing cock of the
carburetter.
Figure 10 is a section of the carburetter at right angles to Figure 2.
Figure 11 shews the thermo-cauter applied as a desiccator, and
Figure 12 shews the thermo-cauter as applied for local illumination in dental and
other operations.
Figures 13 and 14 shew two forms of points for the cauter.
Figure 15 shews a form of carburetter for use in workshops.
In this improved cauter the combustion is effected by conducting the combustible
gases through the central tube a to the tube c of platinum or other gas-condensing
metal which conveys them to the end of the cauter point 6 where combustion takes
place, the resulting products passing off through the annular space between the
central tube a and the sleeve e and finally escaping through perforations g in the
boss at the rear end of the handle f. The use of the condensing metal is restricted
to the exact dimensions required and the platinum gauze now employed in large
cauters is dispensed with, the instrument being thus reduced to minimum
limensions.
A current of cold air is blown between the sleeve e and sheath or handle and
may either circulate freely, or through a coiled tube, as shewn in Figure 1, or
otherwise, and a non-conducting substance such as asbestos may also be interposed
between e, f, either or both these means of preventing the transmission of heat to
the handle being employed. One of the products of combustion of hydrocarbons is
steam which condenses in the perforations g of boss d, in the form of drops. These
condensed vapors may be utilised for cooling purposes either by allowing them to
eak between the parts e and for by blowing them in by the air current above
mentioned, or the orifices in d may be closed and the accumulated pressure utilised
for carrying the condensed vapors to any point desired.
The reduction of the mass of condensing metal as above mentioned enables the
nstrument to be ignited at the flame of a candle, but, notwithstanding such
reduction, the construction of the thermo-cauter is such that if, when the point is in

page_text: complete incandescence. it be dipped in cold water and held there while continuing
to supply the combustible gases, it will regain its incandescence when withdrawn
and it will pass through animal tissues or liquids without being extinguished.
By the present improvements there is also a considerable reduction in the field
of combustion with a proportionate diminution of the radiant heat; the edges and
sides of cavities are protected from the contact of the gascous products of com-
bustion with consequent greater freedom for operating in cavities; the concentration
of the heat in the handle of the instrument is prevented; the hand of the operator
may be brought close to the field of operation and the instrument may be handled
with greater precision. The instrument may be employed, among other uses, in
dental operations, for desiccating by hot air, and also for illuminating the parts
under treatment.
To use the thermo-cauter as a desiccator (Figure 11) a nozzle h of straight or
curved tapering form is attached to the instrument by a bayonet or other joint and
air is blown both through the carburetter and desiccator, the current circulating
between the sleeve e and handle becoming heated by contact with the incandescent
condensing metal and escaping through the perforated end of nozzle / by which it
is projected upon the parts under treatment.
To apply the instrument for the purposes of illumination (Figure 12) the cap h
(Figure 11) is replaced by an enamelled hood i and wire gauze or other arrange-
ment giving the same result. The instrument may thus be inserted in the buccal
cavity, for example for lighting it.
It has been stated that the use of platinum gauze as heretofore in large cauters is
no longer indispensable, but an essential element of thermo-cauters generally is the
internal surface of gas condensing metal constituting the focus of combustion
(which in Figure 3 is in the form of a tube c) serving to prevent the extinction of
the thermo-cauter by the loss of a great part of the heat derived from the internal
combustion when the instrument is introduced into animal tissues.
To effect the combustion of the gases or hydrocarbon vapors, I may employ the
condensing metal in the form represented in Figure 13 in which the cauter has a
longitudinal partition or in that shewn in Figure 14 in which it is formed of a tube
doubled on itself, neither wire gauze nor a central tube being employed.
The carburetter, for generating the hydrocarbon vapors serving to maintain the
incandescence of the cauter is specially arranged according to the combustible, gas
or vapors, employed. When employing a gas, such as illuminating gas for example,
the carburetter is provided with a special mixing cock. When vapors are used
(benzoline vapors for example) it is furnished in addition to the said cock with a
saturator (washer or atomiser). In the former case the gas is supplied to the
carburetter according to the requirements of the consumption, with or without an
automatic governor; in the latter case, hereinafter described, the combustible is
contained in a liquid form in the carburetter itself.
The form of the carburetter may vary. In Figure 1 it is of rectangular section,
concave on one side and convex on the other, for application against the body by
which it is warmed. The carburetter is filled to the proper height by first
completely filling it at orifice n then its concave side being towards the operator the
excess is poured off by tilting it to the left. The orifice n is preferably closed by a
screw cap o made perfectly tight and provided with a strainer p to act as a filter in
filling the vessel. In Figure 15 the carburetter A is of pyramidal form for use in
workshops and is provided with a cock B from which extend two branch pipes a, b,
connected respectively with the bellows and blow-pipe.
The regulator mixing cock fitted to the carburetter consists of a rotary plug
provided with an inclined groove (Figure 2) which may either be made of the
form shewn or be formed of several spirals. 2 is a stop to limit the motion of
the plug. The body of the cock extends within the carburetter and has two
passages, of which the one passage 3 leads directly to the plug while the other
passage 4 connects with an obtuse-angled channel leading past the plug, a hori-
zontal branch channel 5 terminating in a nipple 9 connected with the bellows by a

page_text: flexible pipe y, while the inclined branch 6 extends up to the top and connects with
another channel 7 leading to the plug like the passage 3 to which it is diametrically
opposite. Another horizontal nipple r, similar and opposite to g, places the valve
in direct communication with the thermo-cauter by a flexible tube.
Figures 1 and 2 shew the saturator, which consists of an atomising injector, or,
by suitably modifying the carburetter, an atomizer operated by air pressure may be
used. Or a saturator of the kind represented in Figure 10 may be used consisting
of a bent pipe perforated at its lower end which dips into the liquid contained in
the vessel. The saturator is branched on to the passage 4, but it may be independent
of said passage and open out on the exterior in which case said passage 4 need not
extend below the pipe connection, the air supplied by the bellows being distributed
directly, partly through and partly to the saturator. In all cases the carburetter
is so arranged that it may be overturned without spilling the liquid. The mixing
cock may be attached to the carburetter by a screw-nut provided with a packing
ring so as to enable it to be removed for the purpose of inspecting the injector and
keeping it in working order; the liquid container may also be provided with glazed
openings, if desired.
The mixing cock is operated in the following manner:-(1) Supposing the stop 2
to be at the right hand end of its course; in this position the two passages q r are
in direct communication by means of the groove 1 in the plug and the passages 7 6,
and passage 3 is completely closed. The air from the bellows consequently passes,
first, both to the carburetter and also to the outlet passage r, but as the return
passage 3 is closed, immediately the carburetter becomes filled with air, the whole
of the air supplied by the bellows will pass directly from one to the other pipe
connection 7, r, so that in this position of the cock it may be said that hardly any
but pure air passes from one to the other. (2) Supposing the cock be turned to
the left; during the whole of this movement, the passage which places the pipe
connections in communication becomes gradually reduced at same time that the
return passage for the carburetted air is opened and gradually increased to a
corresponding extent. Thus the further the plug is turned to the left, the more
will the quantity of air passing from one pipe connection to the other be reduced
and the more will that which enters the carburetter be increased, whereby the air
will become more highly carburetted. Thus when the stop 2 is vertical that is to
in the intermediate position indicated by the notch 8 in the head of the plug
(Figure 2) one half of the air supplied by the bellows will pass to the carburetter
and half to the left hand pipe connection r. (3) Supposing the stop 2 to be turned
to the left to the full extent; in this position the passage 6, 7, which puts the right
hand pipe connection in communication with the groove in the plug is closed, but
as the passage 3 is in direct communication with said groove, all the air from the
bellows will consequently pass through the carburetter. The cock serves thus both
for proportioning and mixing, which enables the operator to produce, according to
the action desired to be obtained, a series of gaseous mixtures of exactly determined
composition and more or less rich in carburetted hydrogen.
say
The cock may be operated by a micrometer screw (see Figure 9) whereby much
greater precision may be obtained in its operation and consequently in the
distribution of the air. The regulating action of this cock is indispensable for
ensuring the proper working of the thermo-cauter. By its aid the operator can
both regulate at will the degree of incandescence of the instrument and also
compensate for any irregularities due to the varying conditions either of the
surroundings or of that existing in the interior of the carburetter, owing to the
exhaustion of the supply of liquid, or its vaporization, etc.
The blow-pipe, to be employed in combination with the thermo-cauter, which I
will now proceed to describe, is intimately connected in its action with the mixing
cock. It is of special construction and consists, as shewn in Figure 6, of a single
tube like a jeweller's blow-pipe but differs therefrom in the form of the burner,
which emits two kinds of flame, viz. a central tongue or flame around which at its
base is a circle of small flames serving to prime and feed the former. The blow

page_text: pipe tube s terminates at one end in a nipple t and at the other in a burner u upon
which is fitted a short tube or sheath y, as shewn in Figure 7 in which v is the
outlet orifice of the burner and the lateral orifices inclined at an angle of
about 45°. In the slightly modified arrangement shewn in Figure 8, the orifices.
are formed horizontally in a groove formed at about mid-height of the burner. The
metal tube y, which may be of variable height, surrounding the burner, while
permitting of free communication between the central and lateral jets, ensures the
combustion of the generating current, by ensuring the convergence of the lateral
jets. The central tube s is enclosed in a handle which may be protected from the
heat in the manner before described for the thermo-cauter.
With a low-pipe constructed as described, all the necessary variation in the
form, dimensions, color, and intensity of the flame may be obtained by varying
the relation between the areas of the central tube and of the central and radial
orifices of the burner for each particular case. The same remarks apply with
regard to the dimensions, form and construction of the burner and other parts of
the blow-pipe. For a burner of the kind represented in Figure 8 the following
dimensions of the orifices have given good results :-
Diameter of central orifice of burner
"
"
outlet orifice
"
"
each of the three radial orifices
3 millimetres.
2.50
1.90
"
وو
The blow-pipe when combined with the thermo-cauter serves (1) to prime or
start the cauter (2) to clean it (3) to test, previous to each operation, the qualities
of the combustible liquid (4) to establish, by means of the mixing cock, previous to
cach operation, the desired composition of the gaseous mixture. To prime the
cauter it is simply necessary to connect the blow-pipe with the carburetter, turn
the plug of the cock so as to bring the notch 8 on the head downwards, and work
the bellows, and then light and regulate the flame of the blow pipe so that it
presents hardly any trace of white flame, then heat the cauter to a white heat and
quickly substitute it for the blow-pipe. The incandescence of the cauter is now
regulated by the cock on the carburetter. In order to clean the cauter the same
operation is repeated as in priming after which the blowing action is increased, and
the condensing metal maintained at a white heat for a few moments. By the
employment of the blow pipe, the spirit-lamp and two kinds of combustible liquids
hitherto required are dispensed with, while the operator is also enabled to clean his
own instrument. To verify the qualities of the combustible liquid, the precise
moment when the liquid will fail is known when, previous to an operation, whatever
may be the position of the cock, the blow-pipe no longer produces a flame largely
tinted white. Any kind of bellows may be used, but it is preferred to employ
Richardson bulb operated either by the hand, foot, or pedal. I have shewn, in
Figure 1, an improvement consisting in the application of a thick flange y of india
rubber between the regulating bulb z and the tube to which it is connected, in order
to prevent throttling by the netted covering when the bulb is fully expanded.
Without this adjunct the tube leading from the regulating bulb is liable to become
imprisoned between the bulb and its netting and flattened so as to suddenly cut off
all circulation of air.
a
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is;
1st. The improved thermo-cauter consisting in the combination of the cauter
proper with a carburetter having a dosing and mixing cock, a pneumatic bulb, and
blow-pipe, as hereinbefore described and represented in Figures 1 to 10.
2nd. A thermo-cauter having a tube c of gas-condensing metal, an outlet at the
end d of the handle for the escape of the gases of combustion, a circulation of cold
air and of the products of condensation for the purpose of cooling the handle, as
hereinbefore described and illustrated in the drawings.

page_text: 3rd. The application of the herein described thermo-cauter as a hot-air desiccator,
by the application, to the incandescent point, of the nozzle h, as represented in
Figure 11.
4th. A thermo-cauter arranged as an apparatus for illuminating internal cavities
of the body, by the application, to the incandescent point, of a hood or cap i, as
represented in Figure 12.
5th. The employment, at the incandescent point, of a thermo-cauter, of a
partitioned tube or a tube folded on itself, as represented in Figures 13 and 14.
6th. The arrangement of blow-pipe serving to ignite and clean the cauter and
test the gaseous mixture, consisting in the combination of a burner or head having
central and lateral orifices, as described and represented in Figures 6, 7, and 8.
7th. The arrangement of dosing and mixing cock for controlling the admission of
air to the carburetter and cauter, as described with reference to Figures 1, 2,
and 10.
8th. The combination, with the pneumatic bulb, of the enlargement y between
the air tube and the regulating bulb z, as shewn in Figure 1 for the purpose
specified.
Dated this 27th day of May 1
C. A. PAQUELIN.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.