An improved method for preparation of feces for bomb calorimetry.

was standardized before no. 1 and between the two no. 10 samples. The time required when the Auto Dilutor was used was: 3 mm to assemble equipment, 2.5 mm to label flasks, 9 mn to dilute standard and samples, and 8 mm to take readings. The on-line system only took 8 mm to run the standards and samples, saving 14.5 mm for the 10 duplicated determinations. No flasks are needed when an on-line dilutor is used. In addition, as shown in Table 2, two of the flasks used with the Auto Dilutor were not rinsed properly, so the results were invalid. Slighter contamination can produce undetected erroneous data. Parts for modifying the pump and the pump itself cost about $1,000, which is justified by savings of personnel time and equipment. In our opinion, the cost is justified by reliability and technician satisfaction alone.