60 INJURY, RECOVERY, AND DEATH 



the instant of transfer the following values : Aq = 2700, 

 ^0=90, ^1=0.018, and ^2=0.540. As no more of A is 

 produced A^ diminishes and at the end of time T has the 



jr f 



value At'^A^ During exposure to NaCl a cer- 



tain amount of M is formed from A. Some of this dis- 

 appears during exposure. The amount which remains 

 at the time T may be called M ^. At the time T the 

 amount of M^ which disappears in unit time is M^K^. 

 At this time the amount of M produced in unit time is 



TT T 



The change in M^, occurring in unit time, which we may 

 call -p~,^^ equal to the difference between the amount 

 formed and the amount decomposed, or 



The solution of this equation is of the form 



By substitution it is found that a = -^ ^ 



Aa — Ai 



Since M^= o when T = o, b= ^1 



"^ -{K,-Kr) 



Thus M^=Aoi-^^) (e-^'^-e-^''^) 



A2 — Ai 



or Mr = 2700*^^^) (e-^^^-e""^^^) 



A2 — Ai 



TVe must also consider that at the beginning of the 

 exposure to NaCl 0.52 M there was present a certain 



