The author describes of the relationship between the merits of water and the function of the forests from the Numerical Reports of the Ministry of Agr-iculture and Forestry. He also investigating the policy of the Japanese forests for reconstruction, advocates a radical policy of rebuilding the forests by abolishing the use of charcoal and a great many of wooden fuels. He concludes that without the cooperation among scientists, industrialists and statesmen, the prosperous rebuilding of the industry for the benefit of the country could not be expected.

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Submerged combustion is a method of heating liquid by direct contact of combustion gas immersed below its surface. Experimental equipments have been constructed for the evaporation of liquid, using town gas and producer gas as fuel. The evaporation process of water was carried out in the apparatus and the efficiency of which was 80 -90 percent.
Unneutralized sulphite waste liquor was successfully evaporated by submerged combustion without difficulties generally encountered in case of using the usual tube evaporaters. The product containing 55 % solid matter was obtained at almost the equal thermal efficiency as the evaporation of water. Therefore it was found that the application of the principles of submerged combustion offered a technical solution to the problem of sulphite waste liquor disposal. From the experimental results the producer gas is observed to have an easier ignition and more stable feature of flame than town gas.
As above mentioned, the principles of submerged combustion can be applied to the evaporation process of other liquids advantageously.

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The concentration, temperature and velocity patterns have been obtained in flat diffusion flames formed by town gas and air issuing upward separately from rectangular ports into confined space of the combustion chamber. The experimental data indicate that (1) the rate of combustion is slightly affected by relative port velocity between gas and air, but strongly affected by excess air ratio, (2) in some cases both hydrogen and oxygen are presented in a time-average sample, (3) the upward component of momentum passing through the transverse cross section decreases slightly with an increase of distance from the port.

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(I) On the Catalytic Cracking of Cumene under Reduced Pressure. We have dehydrogenated ethylbenzene with copper-chromite catalyst at 500-700°C under reduced pressure and obtained 50-60% yields of styrene per pass. The same method was applied to the catalytic cracking of cumene. The possible products by the cracking of cumene are benzene, styrene and α-methylstyrene. The analysis of styrene and α-methylstyrene was carried out by the bromide method. Styrene was determined in a form of styrene dibromide and the amount of a-methylstyrene was calculated as a difference between the amounts of styrene, estimated by the amounts of dibromide, and those of vinyl compounds determined by the bromine number of the tar free products.
Although kaolin catalyst is reported to produce mainly styrene, copper-chromite catalyst produced mainly α-methylstyrene, acting as a dehydrogenating catalyst at lower temperature.
The optimum-conditions for the formation of styrene and α-methylstyrene were confirmed to be as the followings:
styrene α-methylstyrene
Temp.(°C) 670-680 ca.650
Press.(mm Hg) 500 500
Ultimate Yield (%) ca.50% 46-48%
The combined yields of styrene and α-methylstyrene were up to 75%.(II) On the Catalytic Cracking of p-Cymene.
The reduced pressure method by the use of copper-chromite catalyst, developed in our laboratory, was successfully applied to the dehydrogenation of ethylbenzene as well as to the preparation of a-methylstyrene and styrene from cumene. This report deals with the application of this method to the catalytic craickng of p-cymene.
The reacting conditions selected in this experiment were temperature: 600-700°C. L.S.V.: 0.3-1.6, pressure: 500mm Hg.
The possible products from the cracking of p-cymene are α-p-dimethylstyrene and p-methylstyrene. The composition of the reaction product has been determined by the bromine number of the reaction product and the analytical method according to Elliot. Elliot method is based on the difference in the rate of hydrolysis of HCl add-ition compounds of α-p-dimethylstyrene and p-methylstyrene.
The products obtained by the cracking of p-cymene were first distilled under a reduced pressure of about 10mm Hg to remove volatile matters, such as benzene, toluene and xylene, and also tarry products. The distillates obtained were then
subjected to bromine number determination and Elliot analysis.
The yield of α-p-dimethylstyrene was maximum at a lower temperature of 600°C and a higher rate of 0.9, whereas that of p-methylstyrene was increased with the rise in the temperature and with the decrease in the flow rate of p-cymene.
The optimum conditions for the formation of α-p-dimethylstyrene and p-methy- lstyrene are as the followings:
α-p-dimethylstyrene
p-methylstyrene
Temp.(°C) 600 670
L.S.V. 0.9 0.3
Maximum yield (%) 72 29
Copper-chromite catalysts acted as a superior dehydrogenation' catalyst for the cracking of cumene and p-cymene in producing a-methylstyrene and α-p-dimethylst-yrene respectively. The formation of hydrogen was active at a lower temperature, but with a rise in the temperature, hydrogen was gradually replaced by methane, this is being coincided with the fact that the formation of α-p-dimethylstyrene is predominant at a lower temperature, whereas that of p-methylstyrene at a higher temperature.
The comparison of our results with those of Kobe [Ind. End. Chem., 43, 1755.(1955)] is given hereunder:
Yield of α-p-climethyscyrene (%)
L.S.V. Kobe (Cr-Al2O2 Cat.) Authors (Cu-Cr2O4Cat.)
1.0 65 74
0.7 50 67
0.5 38 63

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