Letter to the Editor

Thank you for reviewing my book Inductance in Man in the issue 44 of the Newsletter. You make an important point in your review by querying whether blood could oxygenate tissue as well if it were stable, so that its circulation must have some other purpose. Harvey concluded that that could only be for the purpose of cooling the heart, likely to be overheated by the amount of blood passing through the body, but the tri and bi cuspid valves seem to preclude that. The differences in induced current between anaemic and non-anaemic people could only be tested clinically. As to the importance of the differences in the induced currents of maximum and minimum fields, we can only guess at these from archaeological researches, which suggest that at certain times they may have been of very great strength and importance. Very little research has been done on any of these questions. Records of the earth’s field have been kept only since the eighteen thirties, and changes in the past may have been related to climate changes. Some amateur observations which I took many years ago on the deflection of a magnetic needle in the earth’s field suggested this may be true; there was at least a very great change in the angle of deflection in times of snow.

I am unfortunately too old now and my eyes are failing, so that I can do no more scientific work. However, the accompanying explanation of Harvey’s ideas, elaborated in the light of Faraday’s discoveries, may be of interest to readers.

Jean Edmiston