DECEMBER 29, 1899. ] 
Paucker went to the college at Mitau, 
Struve obtained the degree of doctor of 
philosophy there and was soon made ‘ Ob- 
servator’ at Dorpat, where he remained 
a quarter of a century as professor. During 
his professorship at Dorpat he prepared lec- 
tures on the transit instrument, which were 
translated into French by a pupil, Lieut. 
Schyanoff, and are still an admirable text- 
book. Struve’s ability attracted the atten- 
tion of Tsar Nicholas I., and in obedience to 
his orders, Struve built and furnished the 
great central observatory at Pulkova, a 
suburban village near St. Petersburg. For 
the instruments he consulted the best mech- 
anicians in Hurope, especially the firm of 
Repsold of Hamburg. The observations at 
Pulkova were of the highest possible ac- 
curacy and were continued till Struve him- 
self had retired from active service and had 
been succeeded by his son, Otto Struve, one 
of his most faithful students and an admir- 
able observer. He died in 1864, and left 
the reputation of a scientific man, who had 
accomplished great results for the geography 
of his adopted country, and was one of the 
most practical astronomers of the present 
century. 
George Biddell Airy, born in 1801, and 
surviving till 1892, was chiefly remarkable 
for the business-like routine which he intro- 
duced into the royal observatory at Green- 
wich, and for the example which was then 
set to less able astronomers of the manner 
in which they might conduct extensive 
operations connected with the vast study of 
the universe. 
The writer considers himself not mis- 
taken in assigning the position of astronom- 
ical science during the first half of the nine- 
teenth century to the four philosophers 
mentioned in this brief paper, viz.: Gauss, 
Bessel, W. Struve and Airy. 
TRUMAN HENRY SAFFORD. 
WILLIAMS COLLEGE. 
_ SCLENCE, 963 
THE ELECTRIC FISH OF THE NILE.* 
Tue lecture dealt almost exclusively with 
the formidable fish found in the rivers of 
North and West Africa, Malapterurus electri- 
cus. 
Photographs were shown of the drawings 
upon the interior of the tomb of Ti, show- 
ing that the fish was recognized as remark- 
able by the Egyptians five thousand years 
before the Christian era. Living specimens 
of the fish were also displayed, these having 
been given to the lecturer, for the purpose 
of illustrating the lecture, by the authori- 
ties of the Liverpool Corporation Museum. 
The structure of the electrical organ was 
then described. It is situated in the skin 
enclosing the whole body of the fish, and 
has a beautiful and characteristic appear- 
ance when seen in microscopic sections. 
Each organ consists of rows of compart- 
ments, and each compartment has slung 
athwart it a peculiar protoplasmic dise 
shaped like a peltate leaf, with a projecting 
stalk on its caudal side. Nerves enter each 
compartment, and end, according to the re- 
cent work of Ballowitz, in the stalk of each 
disc. By these nerves nervous impulses can 
reach the organ; the arrival of such im- 
pulses at the nerve terminations evokes a 
state of activity which is associated with 
the development of electromotive charges 
of considerable intensity constituting the 
organ shock. The shock is an intense cur- 
rent traversing the whole organ from head 
to tail and returning through the surround- 
ings; it stuns small fish in the neighborhood 
and can be felt by man when the hand is 
placed near the fish, as a smart shock reach- 
ing up the arms to the shoulders. 
Recent investigations made by the lec- 
turer at Oxford in conjunction with Mr. G. 
J. Burch were next described. These com- 
prised a large series of photographic records 
of the displacement of the mercury of a 
* Abstract of a lecture before the Royal Institution 
of Great Britain. 
