448 PHYSIOLOGICAL KEGULATIONS 



for what is primary to an organism. Actually each adjustment is 

 part of several or many equilibrations, even as rate of water ex- 

 change was found to vary in relation to loads of heat, glucose, and 

 chloride as well as of water. All exchanges that occur are equally 

 parts of the study of physiological constitutions. 



On the whole, large numbers of loads and rates are continually 

 compatible among themselves. Evidently one recovery does not 

 ordinarily proceed in disregard of others. That is a description 

 of observed phenomena, whatever implications of fitness be sus- 

 pected in the plain statement of it. 



§ 162. Signs and tests 



An equilibration diagram is an orderly description of regula- 

 tion in some component, of a completeness that has so far been 

 attained for few components. Yet if their relation to the whole 

 diagram is understood, much can be inferred from a few signs and 

 tests. What is the relation of signs and tests to the diagram as a 

 whole? 



In clinical use a sign (of disease) is but poorly distinguished 

 from a symptom ; often the two words are synonymous. In terms 

 of the definitions formulated in this investigation, a sign is a load ; 

 a content of some component observably different (qualitatively 

 or quantitatively) from that in control individuals or states. 



No clinician regards "seriously" those signs or symptoms that 

 also occur physiologically and from which recovery is rapid. 

 Rapid is here defined according to the rate at which each compo- 

 nent recovers in usual individuals. Every clinician has a rough 

 idea of the mean rate of recovery from each such displacement, 

 even though in most instances those rates and their variations have 

 not been accurately recorded. In the present terminology, he im- 

 plicitly estimates loads or states, and rates of recovery from them. 

 No one worries about an increment of rectal temperature in man 

 after muscular effort or exposure to hot atmospheres that has a 

 half -life of less than 1.0 hour ; nor about an arterial blood pressure 

 double the usual that lasts for 0.1 hour after a mountain climb. 

 The persistence of a sign indicates that ordinary recovery is de- 

 layed or inoperative, though eventually unloading may occur. 

 Meanwhile an excess (load) of heart frequency may be borne for 

 years, but a deficit (load) of oxygen may be instantly fatal. 



