SIRS,--I do not wish t o enter into a controversy with Mr. W. Raymond Philipson on the theoretical side of t h e above subject, which, it is agreed, needs much more observation in the field. If Mr. Philipson intends t o continue t h e work and would find m y notes of any use, I shall be very pleased t o send a copy on receipt of his address.SIRS,--In reply t o Mr. Burkitt's letter in the August iss...

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