30 
free poison {toxhi) to kill one guinea pig. Therefore, the next 100 
segments of this spectrum will consist of toxin. 
If we now add one two-hundredths more of antitoxin the mixture 
will fail to kill. Thus, 
immunity unit=will not kill acutel}^, but causes paraly- 
sis {toxones). 
immunity unit = will not kill acutely, but causes paral}"- 
sis {toxones). 
immunity unit = will not kill acutel}", but causes paralj^- 
sis {toxones). 
immunit}^ unit = complete neutralization. 
The last 50 segments of the spectrum would, therefore, be made up 
of toxone. 
The spectrum of this poison Avould, therefore, be expressed as fol- 
io avs : 
Fig. 3. — A spectrum of a simple poison. Redrawn from Madsen, La Constitution du poison diphthe- 
rique. Ann. de I’lnstitut Pasteur. A’'ol. XIII, 1899, p. 576. 
this graphic representation of the results of the studies of toxine- 
antitoxin mixtures it is possible to tell at a glance the proportional 
amounts of toxin., toxoid., or toxone contained in a giA^en poison. 
The folloAAung instructive instance is taken from Ehrlich’s poison 
No. 5:« 
L" dose of this toxine No. 5 Avas 0.125 cc. 
L+ dose of this toxine No. 5 Avas 0.25 cc. 
MLl) dose of this toxine No. 5 Avas 0.0025 cc. 
It will, therefore, be seen that the dose of this particular toxine 
contained exactly" 50xMLD, and the L-J- dose contained lOOxMLD. 
The gradual ciianges which this poison under Avent, as shown b}" the 
spectra, may be explained as follows: 
In A (tig. 2) pure heniitoxin is shoAAm. By this is meant that the 
addition of each one two-hundredths of the immunity unit to the L'* 
« Ehrlich: Ueber die constitution des diphtheriegiftes. Dent. med. Avoch., J^eip- 
zig, V. 24 (38), 1898, pp. 597-600. 
Ehrlich: Ueber die giftcomponenten des diphtherietoxins. Berl. klin. woch., 
1903, nos. 35-37. 
. i 
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