12 BULLETIN 989, U. S. DEPARTMENT OF AGRICULTURE. 
immediately after making, at the end of a month, and in from 12 to 
13 months. In these tests Armour’s peptone was substituted for 
Witte peptone, which was difficult to obtain and not of uniform 
quality. The same lot of peptone was used throughout, but the meat 
extract used in the broth was from two different batches, the one 
employed at the end of the experiments being much darker than the 
other. The tests were made by two operators using the same ma- 
terials. 
When freshly made, these six samples gave coefficients varying 
from 3.42 to 4.34. At the end of a month the same samples gave 
coefficients ranging from 3.31 to 4.19, and at the end of 12 months 
they gave coefficients ranging from 3.14 to 4.23. The greatest single 
variation obtained was a drop from 3.85 when freshly made to 3.14 
at the end of a year. The average of the coefficients obtained on these 
six freshly made preparations was 3.88. At the end of the month the 
average was 3.74, and at the end of 12 months the average was 3.66. 
This would seem to indicate a deterioration of less than 10 per cent 
in one year. Taking into consideration the limitations of the test, 
however, it is evident that this apparent deterioration is practically 
negligible. ; 
With respect to dilutions, none of the samples examined were un1- 
form in killing B. typhosus in 45 dilution in 15 minutes, and two 
failed to kill in 34, dilution in this length of time. While it is 
probably true that a =, dilution would have killed if allowed to 
remain in contact with the organism for an indefinite time, yet, con- 
sidering the difficulties of practical disinfection as compared to the 
artificial test, it is evident that a 34, dilution is too high to recom- 
mend even for B. typhosus. Under the circumstances it would be 
much safer to recommend a dilution of not over 1 in 100 when used in 
cases of typhoid fever. 
In testing the efficiency of the product against Micrococcus aureus, 
several strains of this organism were employed, as it varies markedly 
in its resistance to pine-oil preparations. In all, four strains were ~ 
tested. These were given laboratory numbers 200, 202, 2038, and 204. 
No. 200, a stock strain over five years old, formerly used for class 
demonstrations, at that time gave typical lesions in the rabbit. At 
present it is practically nonpathogenic. Nos. 202 and 203 were 
freshly isolated by the writer from infections in the finger and neck. 
No. 202 caused abscess formation in the rabbit. No. 203 was non- 
pathogenic for this animal. No. 204 was a freshly isolated strain ob- 
tained from the United States Navy medical school through the 
- courtesy of Dr. Pryor. It killed the rabbit, when injected intra- 
venously in dosage of 2 cc. broth culture, in from one to two days. 
The lesions produced were those of septicemia. All the strains pro- 
duced pigment on potato, and microscopically and culturally seemed 
Sees 
