Micro-organisms oi? Man.k Sap . r >".': 



tubes having ;i reaction of +30 at the end of 4 days. No 

 further change occurred thereafter during the [9 days the tubes 



were held under observation. Similar results were obtained upon 

 the second series, growth being obtained upon 3 out of 5 tub 

 having a reaction of +30. In the third series 4 out of 5 tubes 

 having a reaction of +3° showed growth. The organism was 

 less resistant to acetic than to hydrochloric acid. Feeble growth 

 occurred in 2 out of 5 of the tubes having a reaction of f-20 

 Fuller's scale, and in the weaker solutions of acetic acid the 

 growth was delayed and restricted. 



Toleration- of sodium hydroxid. — For this work 100 cc. por- 

 tions of nutrient bouillon having a reaction of o Fuller's scale 

 were measured out and to each was added the theoretical amount 

 of N/i sodium hydroxid to produce reactions of — 5, — 10, etc., 

 every 5 degrees of Fuller's scale up to — 45. The tubes were 

 inoculated as soon as possible after sterilization under pressure, 

 placed at room temperature, 20 to 24 C, and held under ob- 

 servation. Growth was observed at the end of 24 hours in 

 tubes calculated to have a reaction of — 5, and in one tube cal- 

 culated to have a reaction of — 10. At the end of 4 days growtli 

 was visible in all tubes calculated to have a reaction of — 15, and 

 in 2 out of 4 tubes calculated to have a reaction of — 20. At the 

 end of 7 days growth was observed in all tubes calculated for 

 — 20. At the end of 12 days growth was observed in all tubes 

 calculated to have a reaction of — 25. Thereafter no change oc- 

 curred during the 19 days the tubes were held under observation. 

 Transfers made from tubes which developed no growth after 

 19 days showed them to be sterile. Sterile control tubes of this 

 broth calculated to have a reaction of — 25, — 30 and — 35 were 

 titrated at the end of 20 days and found to have a reaction of 

 from — 19 to — 14. This change in reaction is of course to be 

 attributed to the formation of sodium carbonate from the carbon 

 dioxid of the atmosphere. The results however show that the 

 organism is killed when introduced to beef broth medium con- 

 taining sufficient sodium hydroxid to give a reaction of some- 



