498 



NKGKETTI AND ZAMBRA, HOLBOEN VIADUCT, E.G., 



FIG. 3088. 



Fm. 3089. 



MEDICAL, SURGICAL AND PHARMACEUTICAL INSTRUMENTS 

 AND APPLIANCES. 



Each. Each. 



s. d. s. d. 



3088 Hutchinson's Spirometer, for measuring the Yital 



Capacity of the Lungs (fig. 3088) . 440 



3089 Ditto ditto improved, with Dial Indicator, &c. 



(3089) . . .' 660 880 



3090 Measuring and Weighing Machine, for use with the 



Spirometer 660 880 



The object of this instrument is to measure that volume of breath expired from 

 the lungs which is made by the deepest expiration immediately following the 

 deepest inspiration. It has been determined by actual experiment upon 4,400 

 males, that this volume (or vital capacity) increases with the stature, quite 

 irrespective of any other measurement upon the human frame. The law is For 

 every inch of stature from 5 ft. to 6 ft., eight additional cubic inches of air, at 60 

 Fahrenheit, is (in the erect position) exhaled from the healthy lungs. In 

 Consumption this volume is diminished 33 per cent, in the first stage, and 53 per 

 cent, in the second stage of that complaint. 



As a man at 5 ft. 8 in. in health breathes 230 cubic inches, and a man in the 

 first stage of Consumption breathes 154 cubic inches, so the healthy condition of the 

 lungs differs from the pthisical lung. All diseases of the Chest dimmish the 

 healthy volume of expired air. For particulars see Medico- Chirurgical Trans., 

 vol. xxix., p. 137, and Cyclopaedia of Anatomy and Physiology, Art. THORAX. 



