5. In like manner add 0.1 c.c. of the contents of capsule II to capsule III; and then 0.1 c.c. of the contents of capsule III to capsule IV. Then 1 c.c. of dilution I contains 0.1 c.c. milk sample. 1 c.c. of dilution II contains 0.001 c.c. milk sample. 1 c.c. of dilution III contains 0.00001 c.c. milk sample. 1 c.c. of dilution IV contains 0.0000001 c.c. milk sample. 6. Melt the gelatine and the agar tubes in boiling water; then transfer to the water-bath and cool them down to 42° C. 7. Number the gelatine tubes consecutively 1 to 12. 8. Inoculate the tubes with varying quantities of the material as follows: To tube No. 1 add 1.0 c.c. of the milk sample. 2 add 0.1 c.c. of the milk sample. { 3 add 1.0 c.c. from capsule I. { 4 add 0.1 c.c. from capsule I. { 5 add 1.0 c.c. from capsule II. { 6 add 0.1 c.c. from capsule II. { 7 add 0.5 c.c. from capsule III. { 8 add 0.3 c.c. from capsule III. { 9 add 0.2 c.c. from capsule III. { 10 add 0.5 c.c. from capsule IV. { 11 add 0.3 c.c. from capsule IV. { 12 add 0.2 c.c. from capsule IV. 9. Pour plates from the gelatine tubes; label, and incubate at 20° C. 10. Liquefy five wort gelatine tubes and to them add 1.0 c.c. of the milk sample and a similar quantity of the diluted milk from capsules I, II, and III and IV respectively. 11. Pour plates from the wort gelatine; label, and incubate at 20° C. 12. Inoculate the liquefied agar tubes as follows: To tube No. 1 add 0.1 c.c. of the milk sample. 2 add 0.1 c.c. from capsule I. 3 add 0.1 c.c. from capsule II. 4 add 0.1 c.c. from capsule III. 5 add 1.0 c.c. from capsule IV. } 6 add 0.1 c.c. from capsule IV. } 13. Pour plates from the agar tubes; label, and incubate at 37° C. 14. After twenty-four hours' incubation "inspect," and after forty-eight hours' incubation, "count" the agar plates and estimate the number of "organisms growing at 37° C." present per cubic centimetre of the sample of milk. 15. After three, four, or five days' incubation, "count" the gelatine plates and estimate therefrom the number of "organisms growing at 20° C." present per cubic centimetre of the sample of milk. 16. After a similar interval "count" the wort gelatine plates and estimate the number of moulds and yeasts present per cubic centimetre of the sample of milk. NOTE.--Many observers prefer to employ gelatine agar (see page 193) for the quantitative examination. In this case gelatine-agar plates should be poured from tubes containing the quantities of material indicated in step 8, incubated at 28° C. to 30° C. and after five days the "total number of organisms developing at 28° C." recorded.