PHYSIOLOGICAL EEGULATIONS 



449 



Signs may be considered in general as either qualitative, or else 

 quantitative abbreviations (portions) of the relations shown in the 

 equilibration diagram. The total data of equilibration can rarely 

 be measured at one sitting ; on that account if on no other, simpli- 

 fied and conventional observations are substituted. The fact that 

 the substitution was made without formal comprehension of the 

 multiple and quantitative interrelations, is an illustration of the 

 usual manner in which science proceeds. Almost never does a 

 well-rounded description spring full-formed to light. 



Tests are sequelae of disturbances artificially introduced. Not 

 being satisfied with measurement of whatever loads and rates occur 

 spontaneously, the physiologist or physician prods the organism to 

 see how certain loads and rates are modified. 



TABLE 46 



Some signs and tests commonly used in appraisal of certain regulated 

 components of man 



The general form of tests is the tolerance curve (A, fig. 180). 

 By some one type of procedure or agent, a measurable load is im- 

 posed and the subsequent changes are followed with respect to 

 time. Occasionally the observer differentiates with respect to 

 time, obtaining a net exchange curve (B). Rarely indeed are the 

 complete rates of total gain and the complete rates of total loss (C) 

 recorded. Of course, in many components it is quite sufficient for 

 most purposes to observe merely the maximal load, or to demon- 

 strate that recovery is sensibly complete within 0.1 hour, or the 

 like. I note no exception to the guess that every sign and every 

 test can be represented as a point in a diagram or a curve of the 

 forms shown in figures 110 and 180. 



In physiological as in clinical appraisal of an individual, each 

 sign and test partially represents the regulation of a particular set 



