zero, the copper became niolteii in about 3 minutes, and the pressure bccame constant in 8 to 10 minutes. RESULTS AND DISCUSSION
Table I shows the variation of the results n i t h sample neight. The results indicate that the method is almost independent of sample weight. The slight deviation of the results w h m samples less than 2.5 grams were used is possiiil,~due to error in reading the nianonieter as the readings are ion, or to a different temperature gradient existing in the systeni nhen low pressures of gas are present, as the correction factor for the expansion of the gas may not be the samc a t all prcssures. The appxratus n a s calibrated a t gas prcwurcs equivalent to those n hich nould lie obtained from the saniplrs to be analyzed. Thc data contained in the first and third columns of Table I n prc’ fittcd by the method of least squares, assuming a rnoclcl of the form I’ = a bx, nhere Y is thc iiiicrogranie of oxygen recovered and z is the sample neight in grams. The brst estimates of the constants
+
Table
I. Variation of Results with
Table II.
Sample Weight
Sample Wt., Grams 0.76
Pressure, l l n i.
1.10
2.59 3.11 3 49 5 61
5 1
16 19 2.‘ :34
Oxygen,
‘;C
Sample
0.055 0.057
1 2
0 061 0 063 0.062
1
0.061
3
5 6
7 8
and 650, respectively, with 95% confidence intervals of -155
