Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

present the closest analogy to the galvanic battery. Their dele- terious effects are formidable in exact proportion with the quan- tity of saline or organic matter contained in the waters ; and observation proves that diseases developed by the influence of marshy emanations are, at first, of a nervous nature ; hence one of the methods which will be most efficient in preventing inter- mittent fever and neuroses, must be the electrical isolation of chairs, beds, and tables from the earth by glass supporters. Electric Changes the Cause of Epidemic Diseases. In 1849, M. Andraud made daily observations and experi- ments in and about Paris during the cholera there, which show a striking coincidence between the amount of atmospheric elec- tricity and the virulence of the epidemic. In a letter to the President of the French Academy, dated June 10, 1849, he says, — The machine I have used for my daily observations is rather powerful. In ordinary weather it gives, after two or three turns of the wheel, brilliant sparks of five or six centimetres. I have noticed that since the invasion of the epidemic I have not been able to produce on any one occasion the same effect. During the months of April and May, the sparks, obtained with great trouble, have never exceeded two or three centimetres, and their variations accorded very nearly with the statistic variations of the cholera. This was already for me a strong presumption that I was on the trace of the important fact I was endeavoring to find. Nevertheless, I was not yet convinced, because one might attribute the fact to the moisture of the air, or to the irregularities of the electric machine. Thus I waited with im- patience the arrival of fine weather with heat, to continue my observations with more certainty. At last fine weather came, and to my astonishment, the machine, though often consulted, was far from showing, as it ought, an augmentation of electricity, but gave signs less and less sensible to such a degree, that dur- ing the days of the 4th, 5th, and 6th of June, it was impossible to obtain any thing but slight cracklings without sparks. On 5*