A gas chromatographic equilibration method to determine quantitatively organic solvents dissolved in blood was described. The method is characterized by the fact that when a quantity of organic solvent dissolved in a blood sample is equilibrated with a volume of overlying air, the amount of solvent vapor dissolved in the blood will be calculated from the concentration in the gas phase. In the experiment, one ml of standard material prepared akin to the sample was injected into a vial or syringe, and was equilibrated at 37°C in a thermo-regulated bath. After the equilibration had been established, one ml of overlying air was submitted to gas chromatographic analysis. As a result of investigations of various factors which influence the gas-blood partition coefficient, the method was proved to be able to separate and determine 0.02μg/ml of benzene, 0.04μg/ml of toluene, and 0.1μg/ml of m-xylene, the values corresponding to 1 cm of peak height on the chromatogram. The availability of the method was verified by an experiment in which five men were exposed for two hours to 25 ppm of benzene, 100 ppm of toluene, and 150 ppm of m-xylene.

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The influence of intermittent interception of visual information during the task of target aiming was observed on eight healthy adults. The target aiming task was performed on the apparatus used to measure the function of concentration maintenance. The target aiming task was practiced for one minute before the beginning of the experiment in order to remove the low performance level of the function at the beginning of the task. The experimental period was then divided into three segments, that is, the pre-experimental phase, the experimental phase or the intermittently intercepted phase and the post-experimental phase. The pre and post phases were of sixty seconds duration and visual information was received with no interruption. During the experimental phase the visual information was interrupted periodically by an automatic shutter which was fitted to the front of the telescope. The duration of interception of visual information was called "OFF-time". The duration of visual information was called "ON-time". OFF-time was varied with ON-time held constant and then ON-time was varied with the other variable held constant. The duration of experimental phase, therefore, was varied from 51.0 to 64.5 seconds. The mean of the task performance (L) and the reliability of control of task (D/L) for each experimental condition was measured from the work curve. The results are as follows. 1) The difference in performance level between pre and post and the experimental phase was plotted. It was observed that with ON-time held constant, the performance level of the intermittently intercepted phase decreased as the OFF-time became increased. When the OFF-time became shorter the difference between the pre and experimental phase compared to the post and experimental phase was insignificant. In spite of the insignificant difference of performance level between the experimental and the pre phase, it was always observed that the difference of the performance level between the experimental and the post phase was significant. 2) When the ON- and OFF-time were varied at the same time it was noted that under certain conditions, the performance levels of the pre and experimental phases were the same, but the performance level of the post experimental phase was significantly different. The ON-OFF times were seen to be as follows. A) ON 7 seconds OFF 3 seconds B) ON 3 seconds OFF 2 seconds C) ON 1 second OFF 1 second These conditions are termed the Critical Conditions. 3) The critical condition was dependent not only on the total duration or ratio of OFF-time but also on the combination of ON-OFF time. 4) The factor analysis was conducted for performance level in the critical condition, time of duration of task under the continuous interception of visual information, and time required for reversion to the performance level in the pre phase at the re-insertion of visual information. It was suggested that even in the critical condition, there was difference in meaning between the condition of OFF 3 seconds and that of OFF 2 or 1 second. 5) The systematic influence of the experimental phase on the difference of task performance level between the pre and post experimental phase was not observed. 6) The influence of the experimental phase on the relative reliability of feedback control was also not systematic.

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In order to establish the normal regions of several hematological measurements in healthy workers, specific gravity of whole blood, red cell count, white cell count, hemoglobin content, hematocrit value and red cell sedimentation rate were examined on 4967 healthy men and 4980 healthy women working in an electronic company in the fall of 1967. 1) Frequency distributions of specific gravity of whole blood, red cell count, hemoglobin content and hematocrit value were found to be close to normal, while these of the logarithmic values of white cell count and red cell sedimentation rate were found to be close to normal in both men and women, although many of the distributions were slightly asymmetric. It was also noticed that the type of the distribution of red cell sedimentation rate found in men was slightly different from that in women. Means and standard deviations of the hematological measurements were calculated by age and by sex (Tab. 2). The age and sex differences of the mean were statistically significant in most of them (Tab. 3), though the value of difference of the mean, relative to the value of the means, by age was small in all hematological measurements. Based on the above findings about the distribution of the hematological measurements, criterions of screening for mass blood examination of workers was proposed (Tab. 9). 2) Means of specific gravities of whole blood, red cell counts, white cell counts, hemoglobin contents and hematocrit values found in this investigation were slightly lower than the so-called normal values hitherto reported. These lower means are supposedly caused by the use of cubital venous blood as blood specimen and by the use of new test method blood and apparatus such as an automatic cell counter and cyanmetohemoglobin. 3) Relatively large positive correlation coefficients were found between four blood measurements-specific gravities of whole blood, red cell counts, hemoglobin contents, hematocrit values-in both men and women. Moreover, the factor pattern for eight variables concerning hematological measurements and body size obtained by principal component analysis and varimax rotation showed in all age and sex groups that about 80% of total communality was to be attributed to four common factors and that all coefficients of the first factor for the above four hematological measurements were large. So, it will be reasonable to presume that any one of the above four hematological measurements can be representative of all the other three hematological measurements to certain extent, although of course each measurement, specific gravity of whole blood, red cell count, hemoglobin content and hematocrit value, has the hematological meaning in its own right.

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