From the relativity principle and the conservation of energy in particle collisions we deduce the form of the energy function, and the conservation of inertial mass and three-momentum. We show that the arguments are parallel under Einsteinian and Galilean kinematics

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The nitrate deposits of Chile are in the northern part of that country, in the region lying between about 190 and 260 south latitude, and mostly in the provinces of Tarapaca and Antofagasta. Some more or less isolated deposits have been found both north and south of these limits, but, as yet, have not proved of very great extent.' The Tarapaca region has been worked for a longer time, and at present supplies more nitrate than the Antofagasta region, but the latter is an important producer and has great future possibilities. I Many changes have occurred in the last thirty years in the boundaries separatingChile, Peru, and Bolivia; and even provinces which bear the same names now as they did then may have different boundaries, so that different accounts of this region written at different times necessarily conflict in statements of boundaries and names. The data in the present paper are based on the boundaries of states and provinces as they now exist.

SThe exact age of the iron and manganese deposits here referred to is, in some cases, a little uncertain. Some may be Cambrian, others Silurian, but the exact determination of the age of the horizon is not a part of the present discussion. The matter has been discussed by the writer in Geological Survey of Arkansas, 189o,

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