716 
matter in this latter condition is explosive. The 
tests have been made on thin fuse wires sealed into 
long glass tubes through which the wire passes. 
The wires were sealed in by means of hard sealing 
wax. A discharge from a battery of Leyden jars 
was passed through the wires. The disintegration 
of the wires is much greatest at the positive end. 
The sealing wax, wire and glass tube in almost 
every case, break down at that end. The lead is 
dispersed in a fine powder or dust. 
Professor Nipher remarked that he had just 
found in the London Phil. Mag., Vol. 46, of 1815, 
pp. 161 and 259, an account of the work of De 
Nelis and Singer, who passed a positive discharge 
through a lead wire of 0.01 inch diameter con- 
tained in an iron tube. The wall of the tube was 
usually about 0.14 inch in thickness. In one case 
the tube was one inch in external diameter, with a 
small bore admitting a steel needle with wax in- 
sulation and terminating in the short lead wire 
resting on the bottom. The lead wire was sur- 
rounded by oil. Such tubes were burst by re- 
peated explosions of the lead wire, which required 
to be replaced at each discharge. The discharge 
was from a battery of Leyden jars having an area 
of from 75 to 100 square feet. The needle and 
part of the liquid were thrown out at each explo- 
sion. In some eases the liquid was thrown to a 
height of 40 feet. The experimenters do not seem 
to have used the negative discharge. They at- 
tributed the effects to the expansive power of the 
electric fluid. 
What they were doing was to suddenly drain 
that lead wire of the negative fluid. The atoms of 
lead then repel each other. Some of the effect is 
of course a heat effect. The question arises, how- 
ever, will the negative discharge produce a like or 
an equal effect? Is it not possible that such 
molecular repulsion is primarily concerned in the 
formation of disruptive channels in air and result- 
ing in spark discharges and lightning? 
GEORGE T. Moore, 
Corresponding Secretary 
THE BOTANICAL SOCIETY OF WASHINGTON 
THE 79th regular meeting of the society was 
held at the Shoreham Hotel, Tuesday, March 5, 
1912, at 8 o’clock P.M. President W. A. Orton 
presided. This being the annual open meeting the 
program was devoted to an address on ‘‘The 
Present Status of the Genetics Problem,’’ by the 
retiring president, Professor W. J. Spillman. The 
address will appear in SCIENCE. 
SCIENCE 
[N.S. Vou. XXXV. No. 905 
THE 80th regular meeting was held at the 
Cosmos Club, Tuesday, April 2, 1912, at 8 o’clock 
P.M. President W. A. Orton presided. Highteen 
members were present. Dr. Errett Wallace and 
Messrs. L. H. Evans, 8. M. MeMurran and 8. C. 
Stuntz were admitted to membership. 
The following papers were read: 
Studies on European Herbaria with Special Refer- 
ence to Preservation of Type Specimens: WaAu- 
TER T. SWINGLE. 
The speaker on recent visits to the principal 
European herbaria was impressed by their lack of 
the geographic limitations, so common in American 
herbaria. However, the management is much the 
same as it was a century ago. There is no ade- 
quate correlation of the seed and fruit collections 
with the plants in the herbaria. Alcoholic speci- 
mens scarcely exist, and such as are found are 
neither well indexed nor referred to on the speci- 
men sheets. ; 
The method generally followed at present of 
leaving types along with the other specimens is 
certain to lead to their rapid deterioration and 
ultimate loss. Provision should be made for saving 
fragments which may drop from the specimen and 
to this end it was suggested that a sheet of trans- 
parent paper be pasted to the back of the her- 
barium sheet, bending over it, thereby protecting 
the specimen. Smaller types and fragments of 
types can be preserved in pasteboard boxes with 
a glass top, the specimens being pressed against 
the glass by layers of cotton batting. 
It is important to recognize that in plants type 
specimens can often be indefinitely multiplied by 
cutting branches from the same plant, or by se- 
curing flowers or fruits from the same plant during 
successive years. These types which are secured 
from the same plant individual are termed mero- 
types. 
The Celebration of the One Hundredth Anniver- 
sary of the Academy of Natural Sciences of 
Philadelphia: W. E. SAFFORD. 
Mr. Safford, the delegate of the Botanical So- 
ciety at the academy’s centenary celebration, gave 
a graphic and comprehensive report of the meet- 
ings and made special mention of the papers of 
botanical interest there presented. The speaker 
also gave an account of the development and 
resources of the academy’s herbarium. 
W. W. STOCKBERGER, 
Corresponding Secretary 
