- Email: [email protected]
Acid sulphates
.\ug.. 101
1
CURREST
TOPICS.
275
noted the information furnished for the protection of blast-furnace worker5 against gas, methods of ferreting out lesions caused by the injection of substances in order to simulate injuries, moving pictures taken for the study of industrial fatigue, data on building material, studies on helicopters and methods of drying good. It i> much to be hoped that this very useful Bureau will receive .supl)ort to a much greater extent from the French government as soon as the financial condition of the countq- G-ill permit it. G. 1;. s. Dr. Edward Bennett Rosa, chief physicist of the Bureau of Standards, died at his work on May 27, 1921. The son of a Methodist minister, he \vas somewhat older than most students ~vhen he was graduated from \I’esleyan University, and his pobvers nere so matured that during his first year at Johns Hopkins he undertook the determination of the ratio’ existing between the two s;vstems of electrical units and carried it to a successful conclusion. \iIiie he was at a later time professor of physics at \Vesleyan, he contributed largely to the design and satisfactory operation of the food calorimeter. In I()IO he was appointed physicist in the Bureau of Standards, ant1 nine years later became chief physicist. His researches deal \\-ith the determination of the coulomb and with methods of standardization and measurement, but along with this side of his scientific usefulness went a no less valuable ability to organize and to bring This quality has been of the highest value in the Bureau. to pass. Those who were fortunate enough to know him well will treasure the memory of the high-minded, cleeply religious man even more than that of the leader in physical research. G. F. s. Acid Sulphates.-J A~VESKENDALL and ~IRTIIUR IjT. I)AVIDSOS. ,oi Columbia Univ,ersity (Jow. AWL Chew. Sm., 1921, xliii, 979990), find that barium, calcium, and magnesium form acid sulphates in which one molecule of the neutral sulphate is combined with three molecules of sulphuric acid. Mercurous mercury forms an acid suiphate by union of one molecule of the neutral sulphate with one molecule of sulphuric acid. Silver forms two acid sulphates, in which one molecule of the neutral sulphate is combined w-ith one molecule and two molecules, respectively, of sulphuric acid. Acid sulphates of zinc and ferrous iron exist, but their composition has not been determined. Isolable acid sulphates could not be obtained from the neutral sulpbates of aluminum, nickel, lead, ferric iron, copper, and mercuric mercury. The acid sulphates of the alkali metals are more stable and more complex than those just enumerated. Arranging the metals in the order of the electromotive series, formation of acid sulphates is found to be dependent upon the position of a given metal with respect to hydrogen. Extensive for-
CURRENT TOPICS.
276
[J. F. I.
mation of acid salts is a characteristic of metals which are much above hydrogen like lithium and potassium, or much below hydrogen like silver. As the zero point is approached from either side, the complex compounds decrease in stability, and finally such compounds cannot be isolated. Solubility relationships follow a similar course. The sulphates of the alkali metals and silver sulpha,te are extremely soluble in sulphuric acid; those of the metals, which are less pronouncedly positive or negative, are much less soluble; those of the metals, which have electrode potentials near to the zero point, are practically insoluble, J. S. H. Photographic (Harrington’s recently appeared an advertisement of the sale of an estate, in which features of the property are admirably shown by two aerial photographs taken by the Aerophoto Company. According to the London Times, this is the first occasion on which photographs taken from the air have been employed for such a purpose, and emphasis is very properly laid upon the advantages which they possess. The aerial method is able to achieve with certainty, and under any topographical conditions, which has been occasionally possible when a distant view-point on ground at a higher level has permitted. But the cases in which an estate is so situated at the bottom of a basin, on the sides of which the telephotographer may erect his camera at any point of the co’mpass, are few and far between, and even under the most favorable of such conditions one can never expect to show the plan and surroundings of a country mansion in so satisfactory a manner as that which is illustrated in the two aerial photographs to which we are referring. One has only to compare these latter with the eight photographs taken on the ground, which are reproduced on the same page of the Times, in order to perceive at a glance the superiority of the aerial method. While that superiority is marked particularly by the showing of the relation of the house to the immediate surrounding country, the architectural design of the building receives at least as adequate a representation as it would in a photograph taken from a relatively near standpoint on the level.
Aero-Photographs
Jou~nul, January
of
I,
Estates
1921) .-There
1
CURREST
TOPICS.
275
noted the information furnished for the protection of blast-furnace worker5 against gas, methods of ferreting out lesions caused by the injection of substances in order to simulate injuries, moving pictures taken for the study of industrial fatigue, data on building material, studies on helicopters and methods of drying good. It i> much to be hoped that this very useful Bureau will receive .supl)ort to a much greater extent from the French government as soon as the financial condition of the countq- G-ill permit it. G. 1;. s. Dr. Edward Bennett Rosa, chief physicist of the Bureau of Standards, died at his work on May 27, 1921. The son of a Methodist minister, he \vas somewhat older than most students ~vhen he was graduated from \I’esleyan University, and his pobvers nere so matured that during his first year at Johns Hopkins he undertook the determination of the ratio’ existing between the two s;vstems of electrical units and carried it to a successful conclusion. \iIiie he was at a later time professor of physics at \Vesleyan, he contributed largely to the design and satisfactory operation of the food calorimeter. In I()IO he was appointed physicist in the Bureau of Standards, ant1 nine years later became chief physicist. His researches deal \\-ith the determination of the coulomb and with methods of standardization and measurement, but along with this side of his scientific usefulness went a no less valuable ability to organize and to bring This quality has been of the highest value in the Bureau. to pass. Those who were fortunate enough to know him well will treasure the memory of the high-minded, cleeply religious man even more than that of the leader in physical research. G. F. s. Acid Sulphates.-J A~VESKENDALL and ~IRTIIUR IjT. I)AVIDSOS. ,oi Columbia Univ,ersity (Jow. AWL Chew. Sm., 1921, xliii, 979990), find that barium, calcium, and magnesium form acid sulphates in which one molecule of the neutral sulphate is combined with three molecules of sulphuric acid. Mercurous mercury forms an acid suiphate by union of one molecule of the neutral sulphate with one molecule of sulphuric acid. Silver forms two acid sulphates, in which one molecule of the neutral sulphate is combined w-ith one molecule and two molecules, respectively, of sulphuric acid. Acid sulphates of zinc and ferrous iron exist, but their composition has not been determined. Isolable acid sulphates could not be obtained from the neutral sulpbates of aluminum, nickel, lead, ferric iron, copper, and mercuric mercury. The acid sulphates of the alkali metals are more stable and more complex than those just enumerated. Arranging the metals in the order of the electromotive series, formation of acid sulphates is found to be dependent upon the position of a given metal with respect to hydrogen. Extensive for-
CURRENT TOPICS.
276
[J. F. I.
mation of acid salts is a characteristic of metals which are much above hydrogen like lithium and potassium, or much below hydrogen like silver. As the zero point is approached from either side, the complex compounds decrease in stability, and finally such compounds cannot be isolated. Solubility relationships follow a similar course. The sulphates of the alkali metals and silver sulpha,te are extremely soluble in sulphuric acid; those of the metals, which are less pronouncedly positive or negative, are much less soluble; those of the metals, which have electrode potentials near to the zero point, are practically insoluble, J. S. H. Photographic (Harrington’s recently appeared an advertisement of the sale of an estate, in which features of the property are admirably shown by two aerial photographs taken by the Aerophoto Company. According to the London Times, this is the first occasion on which photographs taken from the air have been employed for such a purpose, and emphasis is very properly laid upon the advantages which they possess. The aerial method is able to achieve with certainty, and under any topographical conditions, which has been occasionally possible when a distant view-point on ground at a higher level has permitted. But the cases in which an estate is so situated at the bottom of a basin, on the sides of which the telephotographer may erect his camera at any point of the co’mpass, are few and far between, and even under the most favorable of such conditions one can never expect to show the plan and surroundings of a country mansion in so satisfactory a manner as that which is illustrated in the two aerial photographs to which we are referring. One has only to compare these latter with the eight photographs taken on the ground, which are reproduced on the same page of the Times, in order to perceive at a glance the superiority of the aerial method. While that superiority is marked particularly by the showing of the relation of the house to the immediate surrounding country, the architectural design of the building receives at least as adequate a representation as it would in a photograph taken from a relatively near standpoint on the level.
Aero-Photographs
Jou~nul, January
of
I,
Estates
1921) .-There