1906.] Action on Bacteria of Electrical Discharges. 



75 



Solution. 



W eight of potassium 

 nitrite in 1 c.c. 



Equivalent weight 

 of nitrous acid 

 in 1 c.c. 



W eight of nitric acid 

 in 1 c.c. 





gramme. 



gramme. 



gramme. 





-00074 



-00041 



0-0005 



b 



-00148 



-00082 



o-ooi 





-00222 



-00123 



-0015 



d 



-00296 



-00164 



0-002 





0-0037 



-00205 



-0025 



Assuming that all the available nitrous acid is liberated by the nitric acid 

 added, the composition of each solution at the time of carrying out the 

 experiment would be — 



Solution. 



Weight of nitrous 

 acid in 1 c.c. 



Weight of nitric 

 acid in 1 c.c. 



Weight of potassium 

 nitrate in 1 c.c. 





gramme. 



gramme. 



gramme. 





-00041 



0-00009 



-00088 



b 



-00082 



-00018 



-00176 





-00123 



-00027 



-00264 



d 



-00164 



-00036 



-00352 





-00205 



-00045 



-0044 



But whatever the interaction between the nitrite and the nitric acid may 

 be, one may assume that the acidity of the respective solutions was - 05, 01, 

 - 15, 0'2 and - 25 per cent, respectively, calculated as nitric acid. 



Nitrous acid being unstable, and decomposing readily at ordinary 

 temperatures into nitric acid, nitric oxide, and water, we carried out two 

 sets of experiments, one at a temperature of 0° C, the other at a temperature 

 of 15° C. 



Immediately after they had been prepared the respective solutions were 

 inoculated with two loopfuls of the several bateria tested : loopfuls of the 

 acid emulsion were taken immediately after the bacteria had been introduced 

 (" momentary " exposure), after an interval of 15 minutes, and after an 

 interval of 30 minutes nutrient agar tubes were inoculated with the 

 loopfuls and incubated side by side with control tubes. 



The results of the experiments are given in Table IV. 



