A Stem Bright oe Field and Garden Peas 
29 
tliese were transferred to tubes of nutrient broth. There was con¬ 
siderable irregularity in the way these grew after different periods 
of drying, due presunmbly to the unevenness of the suspension. Up 
to 13 days drying, growth was fairly uniform!, but none occurred 
again until the i8th day and then not until 21 days. No growth 
took place with the films dried for 22 days, but as none was dried 
longer than this, we can only say that 21 days dessication, under 
experimental conditions, was not sufficient to kill the organismi. 
13. PERCENT killed by FREEZING. — (Salt and crushed ice.) 
The organism is relatively sensitive to freezing. From a 100 c.c. 
bouillon culture, 24 hours old, 10 c.c. were placed in each of four 
tubes of uniform diameter. These were packed in crushed ice and 
salt, frozen solid and kept frozen for 15, 30, 45, and 60 minutes 
respectively. 
As soon as the specified time was up, each tube was thawed 
at once by placing it in cool water (four to five minutes required) 
and when entirely liquefied, dilution plates were made in +10 
nutrient agar. Before freezing, dilution plates were made from 
the original culture as a check. Plates were kept at 20° C. and 
colonies counted after four days. 
The original culture contained 19,800,000 bacteria per c.c. 
Eighty-five and 85/100 percent (8.85%) were killed by 15 min¬ 
utes freezing; 93.03% by 30 minutes; 95-75% by 45 minutes, and 
95.73% by 60 minutes. The number present after freezing 45 
and 60 minutes is practically the same, althofhe figures are slightly 
larger for the 60-minute tube; this is probably nothing more than 
an error due to dilution. The detailed results are given in 
Table IV. 
TABLE IV 
Sensitiveness to Freezing 
Length of expos¬ 
ure to freezing 
temperature 
Dilution 
No. bacteria 
per c.c. after 
freezing 
No. bacteria 
killed per 
c.c. 
Percent 
killed 
Check not frozen. 
1 -100,000 
19,800,000 
0 
0 
15 minutes 
1 -100,000 
2,800,000 
17,000,000 
85.859 
30 minutes 
1 -10,000 
1,380,000 
18,420,000 
93.03 
45 minutes 
1 -10,000 
840,000 
18,960,000 
95.758 
60 minutes 
1 -10,000 
845,000 
18,955,000 
95.732 
14. SUNLIGHT.— The organism is rather sensitive to the 
germicidal action of sunshine. 
' Flamed cover-glasses were spread thinly with a suspension of 
a 24-hour agar culture in distilled water and dried in the air. They 
were then exposed, germ side up, in covered petri-dishes to the 
bright sunshine. At the end of 15, 30, 45 minutes, i, 1.5, 2, 
