Improvements in Apparatus for Administering Nitrous Oxide Gas, or a Mixture of Nitrous Oxide Gas and Ether.
Year: 1887

page_text: Date of Application, 5th Aug., 1887
Complete Left, 5th May, 1888
Complete Accepted, 8th June, 1888
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Administering Nitrous Oxide Gas,
or a Mixture of Nitrous Oxide Gas and Ether.
We, SAMUEL MITCHELL, of 21 Bradford Road Dewsbury, Yorkshire, Dental
Surgeon, and THOMAS ROBERTSHAW 35 Horton Street, Halifax, Yorkshire Dental
Surgeon, do hereby declare the nature of this invention to be as follows:-
Our invention has reference to a certain class of apparatus employed by surgeons
for administering gas to patients whilst undergoing painful operations, and the object
of our invention is:-
Firstly. To reconstruct the valve arrangements of such apparatus so that when
required the gases inhaled and exhaled by the patient may-instead of being sent into
the atmosphere be diverted and sent back again into the main supply pipe, or supply
vessel, so that the gases so used may be re-used again by the patient instead of being
allowed to escape into the atmosphere: and
Secondly. In the application to such forms of apparatus of an additional piece of
mechanism containing an absorbent substance supplied with ether, the gases or vapour
arising therefrom when required being conducted in communication with the nitrous
oxide gas to the face piece of the apparatus to be inhaled by the patient.
In carrying out the first part of our invention we use an ordinary face piece, to
which is attached a short horizontal tube, in which tube we fix a three-way cock, one
of the openings or ports of which cock can be in direct communication with the
atinosphere, but a second opening can be placed in communication with the gas
admission pipe or valve, whilst another or third opening in the said cock can be, placed
in communication with an exhaust valve, therefore when the cock is in communication
with the gas inlet pipe and exhaust pipe, the patient can be freely supplied with nitrous
oxide gas, whilst the air exhaled from the lungs can freely escape from the exhaust

page_text: valve; when the patient, however, has exhaled the nitrogen from the lungs, the stop-
cock can be operated in such manner as to close the valves, but at the same time opening
another part, which is in direct communication with the gas supply pipe, which enables
the patient to inhale the nitrous oxide gas, and as his lungs will now contain nothing,
but such said gas, he inhales and exhales into the gas supply pipe, so that from this
time, instead of the gases exhaled from his lungs being sent into the atmosphere, it is
returned to the supply pipe, and is used and re-used by the patient.
In carrying out the second part of our invention we employ another cock, having a
suitably shaped chamber therein, which we fix in connection with the gas supply pipe.
This chamber wo fill with an absorbent substance saturated with ether, so that when
required, the patient can be made to inhale by the same form of apparatus nitrous
oxide gas alone or a mixed gas comprising nitrous oxide gas in combination with
ether.
By this means a simple and effective apparatus is provided, whereby nitrous oxide
gas may be administered alone or in combination with ether.
TASKER & CROSSLEY,
Halifax, Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Administering Nitrous Oxide Gas,
or a Mixture of Nitrous Oxide Gas and Ether.
We, SAMUEL MITCHELL, of 21 Bradford Road, Dewsbury, Yorkshire, Dental
Surgeon, and THOMAS ROBERTSHAW, of 35 Horton Street, Halifax, Dental Surgeon,
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:
Our invention has reference to a certain class of apparatus employed by surgeons
for administering gas to patients whilst undergoing painful operations, and the object
of our invention is:-
Firstly. To reconstruct the valve arrangements of such apparatus, so that when
required the gases inhaled and exhaled by the patient may instead of being sent
into the atmosphere, be diverted and sent back again into the main supply pipe or
supply vessel, so that the gases so used may be re-used again by the patient instead of
being allowed to escape into the atmosphere.
In order that this part of our invention may be better understood, we will now make
reference to the accompanying sheets of Drawings wherein Fig. 1 is elevation of an
instrument or apparatus for administering nitrous oxide or other gases, having our
improvements applied thereto, and Fig. 2 is section of the same." a represents the
ordinary face-piece, which by means of horizontal pipes and opening c is in direct
communication with the gas admission pipe d. The vertical pipe e is provided with
an inlet valve f, which is composed of a flat piece of indiarubber or other suitable
material, secured at one part by a small screw g, whilst a similar valve in the after part
of the vertical pipe e is shewn at h; therefore, when the patient is receiving nitrous oxide
gas, and draws in his breath, the inlet valve will be raised, allowing gases to enter
therein to be inhaled by the patient, but when the patient expels the air from his lungs,
the inlet valve will be closed and the outlet valve opened, thereby permitting the air
and gas from the lungs to escape into the atmosphere. Thus far, the apparatus is of
ordinary construction. When, however, a patient has expelled the nitrogen from his
lungs, the valve or stop cock is turned partially around (see Fig. 3), so as to place
the openings cand c¹ away from the inlet and outlet valves and present to such valves a
blank part of the stop cock, thus preventing the passage of gases therethrough. The
turning of the stop cock i, however, to close the openings c and e', presents a third
opening J in communication with the branch pipe k; if, therefore, the patient continues
to respirate, his lungs, having been freed from nitrogen, will now contain nothing but
the nitrous oxide gas; consequently the gas he inhales and exhales will be received
from, and made to return to the supply pipe e; consequently instead of the gases being
sent into the atmosphere through the exhaust valve h, as was hitherto the case, the
nitrous oxide gas is not wasted, but re-used by the patient.
Secondly, our invention consists in the application to this form of instrument or

page_text: apparatus of an additional piece of mechanism or chamber for containing an absorbent
substance such as sponge or other suitable material saturated with ether, the gases or
vapour arising therefrom, when required, can be conducted to, and placed in commu-
nication with the nitrous oxide gas to the face piece of the instrument so that the
compound gases can be inhaled by the patient.
This part of our invention is illustrated in the accompanying Drawings, where is a
chamber in which works a second stop cock m containing a sponge n, saturated with
ether. This stop cock is made with two casings o and p, the inner one containing the
sponge. These two casings are connected together top and bottom and have a direct
way through in one direction, so that if the patient is to receive the compound gases
the second stop cock is operated to be in the position shewn in Fig. 3 and plan Fig. 5,
where it will be seen that the nitrous oxide gas will be drawn up the pipes e, k, and
through the sponge (as shewn by arrows) and if the sponge is saturated with ether the
patient inhales the compound gases; if, however, the ether is not required, the stop
cock is operated so as to place the openings and s away from the horizontal pipe 6,
in doing which the openings t and in the outer casing are presented opposite the
pipes b, by which means the nitrous oxide gas cannot get to the sponge, but passes
around the annular space w, between the two casings (see section Fig. 4 and plan Fig. 5).
The modus operandi is as follows:-When the instrument is first applied to the
patient, the parts occupy the position shewn in Fig. 2, where the gas passes up the
pipe e and through pipe b, where it is inhaled by the patient, whilst the air and gases
expelled by the patient pass out of opening c¹ and escape out of the exhaust valve h.
When the patient's lungs are free from nitrogen the stop cock i is operated, closing
the inlet and outlet valves fand h, as shewn in Fig. 3, whereupon the gases from the
service pipe e will pass up the branch pipe to be inhaled by the patient, and the
gases exhaled are returned by the same route, and if an admixture of ether is required
to be given the second stop cock m is operated, and placed as shewn in Fig. 4, whereby
the compound or mixture is administered.
It must be understood that whilst we have shewn in the Drawings and described in
the Specification the use and construction of the chamber and sponge for administering
ether in conjunction with the nitrous oxide gas, that the apparatus for administering
nitrous oxide gas can be used, as shewn in Fig. 6, without the chamber and its
sponge, as in many cases the ether will not be required.
It will therefore be seen that a simple and effective apparatus is provided whereby
nitrous oxide gas may be administered alone without any waste; or it may be
administered in combination with ether.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is
Firstly. In an instrument or apparatus for administering nitrous oxide or other
gases, the arrangement of pipes and openings, whereby the said gases can be exhaled
into the atmosphere or conducted back to the supply pipe, substantially as described,
and shown in Fig. 6 of the accompanying Drawings.
Secondly. In an instrument or apparatus for administering nitrous oxide or other
gases, the combination therewith of a device or appliance whereby nitrous oxide gas
and ether can be administered in combination, in manner substantially as herein shewn
and described.