A Note on the Relation between Toxicity, Resistance, and Time of Survival

I An interpretation of curves obtained in disinfection, hemolysis, and similar experiments was given in a previous paper. A general equation was offered which made the calculation of the time of survival possible if certain simple assumptions were made concerning the relation between toxicity and concentration. One of the assumptions made was that the toxicity is proportional to the concentration. This assumption led to an equation which agreed with the experimental data in a narrow range only. There were also difficulties concerning the possible limits of integration in this case. The concentration can obviously be raised to any value before the time becomes 0. But in order that this may be possible according to the equation it had to be assumed that the resistance can possess negative values. The meaning of the resistance became thus rather vague if not absurd. It is now realized that the general equation t ffi-a ln(k-r)-{-k (1) (t = time, k = toxicity, r = resistance, a and k are constants) given previously, is incompatible with the assumption that k = f (c) N c, because if r is constant t becomes negative when c approaches infinity. According to Equation 1, k must approach a finite value as c approaches infinity lira he-+. ffi lim f(c)o-oo-const.