Category Archives: CO2 Production

Respiration Apparatus, Ludwig’s, 1887


From Treatise on human physiology by Henry Cadwalader Chapman, Published by Lea Brothers & Co, 1887, page 446.

“A more modern apparatus used by Ludwig and his pupils, differs from that of Regnualt and Reiset just described, not so much in principle as in certain mechanical details. The most noticeable of these is the ingenious contrivance by means of which the oxygen expired passes from g (Fig. 251) into the respiratory tube d, communicating through an air-tight covering with the nostrils of the animal at e, alternately with the passage of the carbonic acid expired into the bulbs f, and which is accomplished through the alternate expansion and contraction of valve c. For with the rarefaction of the air through inspiration the valve c is drawn from the end of the tube b, the effect of which is that the air entering the tube b drives the water out of a, which in turn drives the oxygen out of g into the tube d.  On the other hand, with the condensation of the air through expiration, the valve c is forced back close to the end of tube b, the flow of oxygen from the tube d ceases, the carbonic acid exhaled passing into the bulbs f.”

Respiration Apparatus, Regnault and Reiset, 1887


From Treatise on human physiology by Henry Cadwalader Chapman, Published by Lea Brothers & Co, 1887, page 443.

“Within the tabulated bell-jar A, immersed in the cylinder of water B, is placed a little animal, a dog, for example, the subject of the experiment.  The animal having been introduced from below, and the opening hermetically closed, the large pipettes G G, filled with a solution of potash or soda of known strength and quantity, and communicating with each other by a caoutchouc tube, absorb and measure the CO2 exhaled unto the air of the jar A, the air being drawn alternately into the pipettes G G through their elevation and depression by hand of some simple mechanical arrangement.  According as the oxygen is absorbed by the animal, the gas pressure falls in A, and consequently the oxygen of the balloon N, under the pressure of the calcium chloride solution in P, flows through M, replacing that lost in A.”

Respiraton Apparatus, Valentin and Brunner, 1887


From Treatise on human physiology by Henry Cadwalader Chapman, Published by Lea Brothers & Co, 1887, page 438.

“Let us endeavor to determine the amount of oxygen absorbed, and that of carbonic acid, etc., exhaled in a given time.  This can be done is several ways the simplest of which consists in comparing the composition of the ordinary atmospheric air with that which has been breathed, with the object of determining the amount of oxygen absorbed during one inspiration, and multiplying this by the minutes, hours, etc. in order to obtain, approximately at least, the amount of oxygen absorbed in the twenty-four hours. The apparatus of Valentin and Brunner, as used by the author for this object, consists (Fig. 249) of a Woulff’s bottle A having a capacity of about a liter (61 cubic in.). One of the openings communicates with the mouth-piece B, into which the person expires, the air first passing through pumice-stone and sulphuric acid C so as to dry it. The middle opening communicates with the set of tubes G H I K.  H and I contain phosphorus and baryta for the absorption of the oxygen and carbonic acid of the expired air, G and K pumice stone, etc., that of G for the absorption of watery vapors that may have escaped, the pumice-stone, etc., in C K for retaining that taken up by the dry air passing through the baryta solution, and which, if lost, would cause an error in the estimate of the carbonic acid exhaled, the tubes being weighed before and after the experiment. Through the middle opening of the Woulff’s bottle a funnel (D) provided with a stopcock is introduced, the opening then being hermetically closed.  The funnel is filled with a know quantity of mercury. The manner of using the apparatus is as follows: having breathed for say fifteen minutes through the mouthpiece until the air of the Woulff’s bottle has been entirely displaced by the expired air, the mouth-piece is entirely closed, any external air being further prevented from passing into the Woulff’s bottle by the mercury in E acting as a valve, the air-tightness of the apparatus being assured by the rise of the mercury in the tube F, through the contraction of expired air in A, consequent upon its cooling and the closure of the tube funnel. The stopcock of the funnel being then turned, the mercury passes into the Woulff’s bottle, displacing a know quantity of expired, the latter passing into the set of tubes G H I K, previously adjusted to the middle opening.  The weight of the tubes H and I having been previously determined, their increase in weight will give, respectively, the amount of cabonic acid and oxygen absorbed.”

Spirometer, Palmer, 1934, Knipping Type Closed Circuit Respiration Apparatus


From Palmer, C. F. 1934. Palmer Research and Students’ Apparatus for Physiology, Pharmacology, Psychology, Bacteriology, Phonetics, Botany, etc.: Manufactured by C. F. Palmer (London) Ltd., Myographic Works, 63a, Effra Road, Brixton, London, S.W. 2. England, page 87.

“With this instrument working on the principle used by Prof. Knipping, it is possible to show on the same record, in addition to the volume of oxygen consumed, the volume of C.O2 produced.

“Also by using a rotary air pump to ventilate the apparatus, no valves are necessary.

“Dimensions and features of the spirometer itself and the recording cylinder are identical to those given for No. E150.

“The air circulating pump is substantially made and fitted with a water jacket for cooling; this should be connected to the nearest water supply. Lubricating points in the pump are conveniently placed, and should receive occasional attention.

“The electric motor is quiet running, and has ample power. Two model of this spirometer are made. In one, No. E165, the recording cylinder is driven by a clockwork movement making one revolution in 20 minutes.  In the other, No. E166, the recording cylinder is driven from the motor, this enables a two-speed gear to be used, so the the cylinder can be run at a faster rate (1 revolution in 2 minutes) in addition to the normal speed of one revolution in 20 minutes.”

Spirometer, Palmer, 1934, Knipping Type Closed Circuit Respiration Apparatus, Diagram


From Palmer, C. F. 1934. Palmer Research and Students’ Apparatus for Physiology, Pharmacology, Psychology, Bacteriology, Phonetics, Botany, etc.: Manufactured by C. F. Palmer (London) Ltd., Myographic Works, 63a, Effra Road, Brixton, London, S.W. 2. England, page 88.

“The several parts of the assembly as shown in the outline drawing herewith, consist of the following: —

“1. The Spirometer A, the float of which is carefully balanced by a chain comensated counterpoise.

“2. The rotary air pump P, works on the centrifugal principle, and is driven by the electric motor M.

“3. The glas flask F contains the K.O.H. solution in the bottom, depending into this is a tube with a perforated bulb at one end, so that air from the pump is forced through the solution and to the outlet in the side. At the top of the flask is a container for the H2SO4, which is released through the cock C, when it is desired to ascertain the C.O2 produced.

“4. The three-way cock T.C. is used to connect the subject at the mouthpiece H, to the apparatus, or to the outside air O.

“5. The “U” tube S.V. containing water, acts as a safety valve in the circuit.

“6. The recording cylinder D carries the calibrated record charts W being the ink writing pen.

“Very briefly the circulation system is as follows: Gas is from from the Spirometer A, which has previously been charged with oxygen, into the Pump P, and foced from there down the centre tube of the flask F, and through the K.O.H. where the C.O2 produced is absorbed, and so to the three-way cock T.C, and the mouthpiece H, from thence it returns through the safety valve S.V. to the Spirometer A.  The reduction in volume due to the amount of oxygen consumed, is registered by the ink pen W, on the calibrated chart affixed to the recording cylinder D.

“On order to ascertain the amount of C.O2 produced, the subject at the mouthpiece H should be disconnected from the apparatus by the three-way cock TC, the air should continue to be circulated in the apparatus until the pen W records a horizontal line. The H2SO4 is then run slowly into the K.O.H in the flask F, through the cock C.  Cooling is effected by the water in a cylindrical tank around the outside of the flask.

“The action of the H2SO4 on the K.O.H. causes the C.O2 absorbed to be given off, and so the float of the Spirometer rises, the amount being recorded by the ink pen W.

“The foregoing is only a very simple description of the method of using the apparatus; before actual records are taken with subjects, further information should be obtained from a competent authority.”

Basal Metabolism apparatus, 1866


From “Untersuchungen uber den Stoffverbrauch des normalen menschen” by Max von Pettenkofer and Carl Voit, published 1866, labeled page 246.

The illustration shows a mouthpiece attached to a pair of Muller valves. Exhaled air was directed through a chamber containing caustic soda (potassium hydroxide) which absorbed the exhaled carbon dioxide and from there to a precision gas meter.  The CO2 absorbant was weighed after each experiment to determine how much carbon dioxide was absorbed.  The gas meter allowed the CO2 output per minute to be determined.