286 Action of Chemicals on Spirochaetes 
Comparative summary , etc. (continued). 
Reagent 
Spirochaeta 
Effect on Spirochaete 
Observer 
17. 
White of egg 
S. balbianii 
Die very quickly 
Perrin. 
Die very quickly 
Fantham. 
18. 
Pepsin+ HC1 
S. buccalis, etc. 
Some swell up, some are practically 
Siebert. 
dissolved, others remain unaltered 
S. pallida 
Contents of periplast apparently dissolved 
Prowazek. 
Swollen appearance and partial paling 
Siebert. 
19. 
Sodium tauro¬ 
S. buccalis, etc. 
Dissolve instantly 
Neufeld and Pro¬ 
cholate 
S. marchouxi 
wazek. 
Neufeld and Pro¬ 
Dissolve instantly 
wazek. 
S. pallida 
Dissolve in 10 % solution ... 
Prowazek. 
Dissolve 
Neufeld and Pro¬ 
wazek. 
In 10 °/ 0 solution first swell, then gradu¬ 
ally dissolve 
Siebert. 
S. recurrentis 
Dissolve 
Neufeld and Pro¬ 
wazek. 
S. schaudinni (Spiro- 
chaete of Ulcus tro- 
picum ) 
Dissolve 
Prowazek. 
20. Sapotoxin 
S. buccalis, etc. 
Become immobile and die ... 
Neufeld and Pro¬ 
wazek. 
S. marchouxi 
Become immobile and die ... 
Neufeld and Pro¬ 
wazek. 
21 
Saponin 
S. pallida 
In 10 °/ 0 solution become swollen and 
Siebert. 
show partial paling 
Conclusions. 
The general consensus of opinion goes to show (1) that spirochaetes 
are dissolved in solutions of caustic potash (5 to 25 °/ 0 ) and of sodium 
taurocholate (10 °/ 0 ), and possibly to a slight extent in acids; (2) that 
they are not plasmolyzable in the strict sense, and that plasmotypsis is 
rare ; and (3) that certain reagents, such as glycerine, may alter the 
form, by flattening the curves, or by causing contraction. 
I am greatly obliged to Professor Nuttall for his suggestions in 
connection with these observations. The work was done during my 
tenure of a research grant from the Carnegie Trust for the Scottish 
Universities. 
