io 4 THOMPSON YATES LABORATORIES REPORT 
the surface of the medium many organisms will remain entangled in the wool, and in 
the subsequent broth culture they will either not grow or be overgrown by other 
organisms to which broth is a more suitable medium. 
It has been noted in many cases that a far larger number of colonies, 
particularly of the xerosis bacillus, has been produced by the use of the loop than by 
the use of the swab. 
Solidified horse-serum was used throughout for the primary inoculations ; in 
previous investigations it was observed that some of the organisms, notably the 
xerosis bacillus, present in the sac grew with great difficulty in primary culture on 
agar-agar, gelatine, etc. 
After inoculation the tubes were generally kept in the incubator for forty- 
eight hours before examination ; at the end of twenty-four hours it was often im- 
possible to detect any growth with the naked eye, whilst at forty-eight hours an 
abundant growth was revealed. Even those organisms which from other situations 
presented a good growth at twenty-four hours here produced a very inconsiderable 
growth. 
The loopful of fluid was smeared well over the surface of the serum and the 
resulting colonies were so perfectly discrete that pure cultures of the different 
organisms could easily be obtained. 
The following table shows the source of the material and the percentage of 
sterile sacs in the different groups of individuals. 
TABLE I 
No. 
Source 
No. of Sacs 
examined 
Sterile Tubes 
Method 
Percentage 
Sterile 
I 
Workers in 
Laboratory 
I 2 
8 
Platinum loop 
66-6 
2 
Liverpool Parish 
Infirmary 
(Children) 
+° 
1 1 
Platinum loop 
and 
Diphtheria swab 
2 7'5 
3 
Liverpool Royal 
Infirmary 
(a) Children and 
Adults 
(b) Adults 
146 
I 2 
25 
3 
Platinum loop 
Diphtheria swab 
17-1 
25*0 
Total 
2IO 
47 
