LIST OF ILLUSTRATIONS. 
Page. 
Fig. 1. Diagrammatic representation of Ehrlich’s side-chain theory, 
a. Tbe cell with various receptors 13 
b. The toxin molecule 13 
Haptophore group 13 
Toxophore group 13 
c. First stage of antitoxin formation 14 
d. Second stage of antitoxin formation 14 
e. Third stage of antitoxin formation 14 
/. Fourth stage of antitoxin formation 15 
g. Neutralization of toxin by antitoxin in the blood 15 
h. Second order of immunity 16 
Intermediary body 16 
Complement 16 
i Another order of immunity 16 
2. Ehrlich’s spectra 28 
3. A spectrum of a simple poison 30 
4. Illustrating record kept of each lot of bouillon 37 
5. Method of filtering the culture 38 
6. Illustrating record kept of each toxine 41 
7. The apparatus used in evaporating the serum to dryness 51 
8. U -shaped tube used for preserving the standard serum 53 
9. Special pattern mixing flasks for measuring toxine and serum dilu- 
tions 56 
10. Capacity flasks for measuring dilutions of toxine, etc 57 
Ih Graduated pipettes 61 
12. Method of using capacity pipettes 62 
13. Method of using delivery pipettes 64 
14. Showing the three parts of the syringe, viz, the rubber 1>ulb, the glass 
barrel, and the needle 65 
15. A batteiy of 12 syringe barrels ready for use 66 
16. Animal record card 09 
17. Illustration of record used for testing the potency and purity of diph- 
theria antitoxin bought on the open market 75 
( 9 ) 
