4. Place a square wire basket of about 50 tubes capacity close to the left of the test-tube rack, for the reception of the inoculated tubes. 5. Take a sterile 1 c.c. pipette from the case, pick up a sterile rubber washer with forceps and push the point of the pipette into the central hole. 6. Put down the forceps on the bench with the sterile points projecting over the edge. Without taking the tube from the rack remove the cotton-wool plug from tube A, and lower the pipette, with the rubber washer affixed, on to the open mouth of the tube; with the help of the forceps to steady the washer, push the pipette on through the hole until the point of the pipette has reached to within a few millimetres of the bottom of the tube (see fig. 219). 7. Adjust in the same way a pipette and a washer in the mouth of each of the other tubes, B, C, D and E. 8. Set the electric signal clock to ring for the commencement of the experiment and at subsequent intervals of 2-1/2, 5, 25 and 30 minutes. 9. Take up 0.5 c.c. of B. coli emulsion in sterile pipette graduated in tenths of a cubic centimetre and stand by. 10. As soon as the bell rings lift the pipette from tube A with the left hand and from the charged pipette held in the right hand deliver 0.1 c.c. of B. coli emulsion into the 1:100 solution. Then replace the pipette and washer. [Illustration: FIG. 219.--Test-tube rack.] 11. Raise the tube with the left hand and shake it to mix germ and germicide, whilst returning the delivery pipette in the right hand. 12. Repeat the process with tubes B, C, D and E; then drop the infected delivery pipette in the lysol jar. The inoculation of the five tubes can be carried out very expeditiously, but a period of 10 seconds must be allowed for each tube. 13. When the bell rings at 2-1/2 minutes blow through the pipette in tube A (this agitates the germ + germicide mixture and ensures the collection of a fair sample); allow the mixture to enter the pipette, and as the column of fluid extends well above the terminal graduation, the right forefinger adjusted over the butt-end of the pipette before it is lifted will retain more than 0.1 c.c. of the mixture within the bore when the point of the pipette is clear of the fluid in the tube. Touch the point of the pipette on the inner wall of the tube, and allow any excess of fluid to escape, only retaining 0.1 c.c. in the pipette. 14. At the same time, with the left hand remove Bile Salt Tube No. 1 from the upper tier of the rack, take out the cotton-wool plug with the hand already holding the pipette (the relative positions of pipette, plug and culture tubes being practically the same as those of platinum loop, plug and culture tube shown in Fig. 68, page 74). 15. Insert the point of the pipette into the subculture tube, and blow out the mixture into the medium--replug the tube and drop it into the wire basket. Replace the washer-pipette in tube A.