I876.J 
Electricity . 
z 43 
oil. and put between the two horizontal plates of the apparatus. The metallic 
points are brought opposite each other, and the outer ends of the rods put in 
connection with an e’eCtric machine or induCtion-coil. 
Professor W. L. Brown, of the University of Georgia, calls attention to a 
remarkable instance of the formation of impressions upon the human body by 
a lightning stroke. On the 12th of July, 1875, at about 4 p.m., a stroke of 
lightning fell upon a house in Americus, Ga., rendering insensible for a time four 
persons who were seated in one of the rooms. The two outer sides of this 
room, which was at a corner of the house, §had each one window, and nearly 
opposite these on the two other sides were the chimney and the door 
respectively. Outside, a tree stood in front of each of the windows, and about 
12 feet from the house. A third tree, a locust, stood opposite the outer corner 
of the room and about the same distance from the house as the others. This 
tree was severed by the lightning, but the other two were not affeCted. A 
young child was sitting near the centre of the room, while the mother and a 
lady were seated not far from the chimney, near which, and close to the wall, 
was another child. All these persons were rendered insensible for a time by 
the stroke which severed the tree, and on their recovery there were found im- 
pressed upon the bodies of them all more or less distinCl images of this tree. 
The child near the centre of the room was impressed upon its back 
and exactly opposite upon its stomach. The entire tree was plain, and 
perfect in toto\ every limb, branch, and leaf, and even the severed part, 
was plainly perceptible. It impressed the young lady upon the left hip 
and right leg, the mark being quite as perfect as that upon the body of 
the child. The mother and other child also bore less distinCt impressions 
upon the leg. The marks are not permanent, for on August 7, the im- 
pressions were no longer distinCt. It is possible to produce similar figures 
artificially with an electrical machine, such as the Holtz machine, capable of 
giving electricity of very high potential. When the poles of the latter are 
strongly charged and are separated to the distance of a few inches, the dis- 
charge, instead of producing a spark or brush, sometimes consists of a very small 
jet upon the negative, and a sort of phosphorescent glow upon the positive. 
The space between them, though not luminous, is the seat of a discharging 
action which appears to take place along definite lines, like a stream or cur- 
rent, and is sometimes called the dark discharge. An objeCt placed between 
the poles, and in the path of the discharge, interrupts this, and destroys the 
glow upon the positive pole in points corresponding to the lines thus broken ; 
and in this way there is produced an image or shadow of the interposed objeCt, 
which is often strikingly distinCt and perfect. In the case above described the 
phenomena are readily accounted for, if we suppose the thunder-cloud to have 
been negatively charged, and the tree to have stood in the path of the dark 
discharge which preceded or accompanied the lightning stroke, the aCtion 
having been sufficiently intense, and the quantity of electricity great enough, 
to produce a visible impression upon the delicate tissues of the skin. 
The Oestereichische Landwirthschaftliche W ochenblatter states that Dr. 
Virson, Superintendent of the Italian Experimental Silk-Farm at Padua, has 
discovered that the hatching of silk-worm eggs, of suitable age, may be 
accelerated by a period of ten or twelve days, and a yield of at least 40 per 
cent of silk-worm caterpillars secured, by exposing the eggs to a current of 
negative electricity from a Holtz machine for the space of eight or ten minutes. 
It is suggested that the same method might perhaps prove useful in hastening 
the germination of various seeds. 
In a recent number of Les Mondes the Abbe Moigno direCts attention to 
hygienic application of electricity. From his remarks it would appear that 
Dr. Poggioli has advised a system of “ electrical gymnastics.” The exaCt 
nature of these “ gymnastics” is not stated, but it is mentioned that recent 
trials, in the presence of a committee appointed by the Prefect of the Seine, 
upon twenty-one school children of known physical weakness and mental 
debility, resulted in improved respiration and appetite, as well as in improved 
mental conceptions and an increase in height, weight, and chest-measurement. 
These beneficial effects are said to have remained three months after the 
