LABORATORIES AND PROBLEMS 



one find a really elaborate piece of apparatus. This 

 exceptional mechanism consists essentially of a cab- 

 inet large enough to give comfortable lodgment to a 

 human subject a cabinet with walls of peculiar struct- 

 ure, partly of glass, and connected by various pipes 

 with sundry mysterious-seeming retorts. This single 

 apparatus, however, is susceptible of being employed 

 for the investigation of an almost endless variety of 

 questions pertaining to the functionings of the human 

 body considered as a working mechanism. 



Thus, for example, a human subject to be experi- 

 mented upon may remain for an indefinite period within 

 this cabinet, occupied in various ways, taking physical 

 exercise, reading, engaged in creative mental labor, or 

 sleeping. Meantime, air is supplied for respiration in 

 measured quantities, and of a precisely determined 

 composition, as regards chemical impurities, moisture, 

 and temperature. The air after passing through the 

 chamber being again analyzed, the exact constituents 

 added to it as waste products of the human machine in 

 action under varying conditions are determined. It 

 will readily be seen that by indefinitely varying the 

 conditions of such experiments a great variety of data 

 may be secured as to the exact physiological accom- 

 paniments of various bodily and mental activities. 

 Such data are of manifest importance to the physiolo- 

 gist and pathologist on the one hand, while at the same 

 time having a direct bearing on such eminently prac- 

 tical topics as the construction of shops, auditoriums, 

 and dwellings in reference to light, heat, and ventila- 

 tion. It remains only for practical architecture to 

 take advantage of the unequivocal data thus placed at 



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