Category Archives: 1860s

Haemodynamometer used for respiratory pressures, 1863


From “A Treatise on Hygiene with special reference to the military service”, by  William Alexander Hammond (Surgeon-General, U.S. Army.), published 1863, page 48.

“The haemodynamometer enables us to determine both the expiratory and inspiratory power, and is therefore more useful (figure 9).  It consists of a bent tube of glass, attached to a scale graduated for both sides.  An India-rubber tube is attached to one end of the glass tube, to which a suitable mouthpiece is affixed.  Mercury is poured into the glass tube till the zero on both scales is reached.  Upon expiring into the arrangement, the mercury is forced to rise in the opposite portion of the tube, and is correspondingly depressed in the portion to which the elastic tube is attached.  When the act of inspiration is performed, the opposite movements of the mercury takes place.  The same precautions are requisite as in using the cardiometer.

“The height to which the mercury be raised is greater by expiratory than by inspiratory efforts.  A healthy man, five feet eight inches high, can raise the column of mercury about three inches by expiration, and about two inches by inspiration.”

Cardiometer used for respiratory pressure, 1863


From “A Treatise on Hygiene with special reference to the military service”, by  William Alexander Hammond (Surgeon-General, U.S. Army.), published 1863, page 47.

“The respiratory power of an individual may be ascertained by the cardiometer or haemodynamometer.  The former, modified somewhat for its present use, is represented in figure 8.    It consists of an iron bottle, having a hollow arm at one side, communicating both with the cavity of the bottle and with a glass tube, open at both ends, to which a graduated scale is attached.  The mouth of the bottle is closed with a tight-fitting cork, through which a brass tube is passed.  This tube is connected with one piece of India-rubber, having a mouthpiece.  Sufficient mercury is placed in the bottle to reach the zero on the scale, and upon applying the mouth to the end of the tube, and breathing through it, the mercury rises in the glass tube.  Several points must be observed in using this instrument.  The joints must all be air-tight, and, above all, care must be taken to exert only the muscles of the chest, and not those of the mouth and cheeks.  This instrument only measures the expiratory power.”

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.