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Talc and Soapstone.
Aug., 1924.1
U.
S. BUREAU THE
ACTIVE
OF CHE~~ISTRY
ACIDITY
By Edgar
NOTES.
253
OF SOILS.
T. Wherry.
[ABSTRACT.]
ACTIVE acidity and alkalinity are important in connection with They may be the growth of plants, both directly and indirectly. directly toxic in high concentrations and indirectly toxic through They also exert a affecting the solubility of iron and aluminum. marked influence on the activities of various soil organisms, both beneficial and injurious. In the writer’s opinion, no soil survey can be regarded as complete without including determinations of Both electrothe reaction in terms of active acidity or alkalinity. metric and color-comparative methods of determining active acidity have inherent defects, but when care is taken to avoid errors of manipulation, the two methods give accordant results. The second of these is the simpler, and a convenient apparatus for applying it in the field is now available. of the strength of pure Data on Structural Material .-Values metals and their alloys, and of wood are given in the revised edition of the Bureau of Standards circular on the physical properties of materials. The data include the strength in tension, compression, and shear, the resistance to fatigue, and many other properties which an engineer must know in order to design a structure that will safely carry its intended load. The effect of high temperatures on the strengths of different metals is shown by tables and by graphs, and the physical properties such as specific gravity, melting point, and coefficient of expansion are given. The information given is compiled from various sources, including The data on wood are taken tests made at the Bureau of Standards. from Bulletin 556 of the United States Forest Service, Department of Agriculture. The data are given in Circular 101 of the Bureau of Standards, entitled “ Physical Properties of Materials.” Copies may be obtained from the Superintendent of Documents, Washington, D. C. Talc and Soapstone.-The Department of the Interior reports that the total quantity of talc and soapstone produced in the United The output represents States in 1923 was nearly 170,000 Short tons. a decrease of about I per cent. as compared with 1922, but prices were higher. Unlike the supply of Fuller’s earth, which is mostly from the southern states, talc and soapstone are mined in the northern regions. H. L. ‘Published in /. Wash.
Acnd.
Sci.,
pi
(May
19. 1024) : 207.
U.
S. BUREAU THE
ACTIVE
OF CHE~~ISTRY
ACIDITY
By Edgar
NOTES.
253
OF SOILS.
T. Wherry.
[ABSTRACT.]
ACTIVE acidity and alkalinity are important in connection with They may be the growth of plants, both directly and indirectly. directly toxic in high concentrations and indirectly toxic through They also exert a affecting the solubility of iron and aluminum. marked influence on the activities of various soil organisms, both beneficial and injurious. In the writer’s opinion, no soil survey can be regarded as complete without including determinations of Both electrothe reaction in terms of active acidity or alkalinity. metric and color-comparative methods of determining active acidity have inherent defects, but when care is taken to avoid errors of manipulation, the two methods give accordant results. The second of these is the simpler, and a convenient apparatus for applying it in the field is now available. of the strength of pure Data on Structural Material .-Values metals and their alloys, and of wood are given in the revised edition of the Bureau of Standards circular on the physical properties of materials. The data include the strength in tension, compression, and shear, the resistance to fatigue, and many other properties which an engineer must know in order to design a structure that will safely carry its intended load. The effect of high temperatures on the strengths of different metals is shown by tables and by graphs, and the physical properties such as specific gravity, melting point, and coefficient of expansion are given. The information given is compiled from various sources, including The data on wood are taken tests made at the Bureau of Standards. from Bulletin 556 of the United States Forest Service, Department of Agriculture. The data are given in Circular 101 of the Bureau of Standards, entitled “ Physical Properties of Materials.” Copies may be obtained from the Superintendent of Documents, Washington, D. C. Talc and Soapstone.-The Department of the Interior reports that the total quantity of talc and soapstone produced in the United The output represents States in 1923 was nearly 170,000 Short tons. a decrease of about I per cent. as compared with 1922, but prices were higher. Unlike the supply of Fuller’s earth, which is mostly from the southern states, talc and soapstone are mined in the northern regions. H. L. ‘Published in /. Wash.
Acnd.
Sci.,
pi
(May
19. 1024) : 207.