SEPTEMBER 8, 1899. ] 
The pamphlet also contains a paper by Profes- 
‘sor Ch. Richet on the physiological schedule, 
and reprints from this JourNAL Dr. H. H. 
Field’s article on the catalogue. 
~ PRoFEsSOR ROWLAND’s table of solar spec- 
trum wave-lengths originally printed in the 
Astrophysical Journal has been reprinted in a 
single volume containing 225 pages, and is of- 
fered for sale by the Press Division of the Uni- 
versity of Chicago. The table gives the wave- 
lengths of nearly 20,000 lines measured from 
photographs made with the concaye grating of 
the Johns Hopkins University. 
BOOKS RECEIVED. 
Descriptive General Chemistry. S. E. TILLMAN. New 
York, John Wiley & Sons; London, Chapman & 
Hall, Ltd. 1899. Pp. x + 429. 
Elementary Studies in Chemistry. JOSEPH TORREY, 
Jr. New York, Henry Holt & Co. 1899. Pp. 
viii + 487. 
Insects ; Their Structure and Life: A Primer of Ento- 
mology. London, J. M. Dent & Co. Pp. xi 494. 
SCIENTIFIC JOURNALS AND ARTICLES. 
THE American Naturalist for August opens 
with an article by Vernon L. Kellog on ‘The 
Hopkins Seaside Laboratory,’ calculated to 
make Eastern naturalists envious of the advan- 
tages enjoyed by their friends on the Pacific 
coast. J. A. Allen discusses ‘The North 
American Arboreal Squirrels,’ in view of Mr. 
E. W. Nelson’s recent revision of the Southern 
species of the group. William Trelease gives a 
brief biographical sketch of ‘Alvin Went- 
worth Chapman,’ and Thomas H. Montgomery, 
Jr., continues the ‘Synopsis of North American 
Invertebrates,’ with a short account of, and key 
to, the Gordiaceee. An interesting account of 
‘An Abnormal Wave in Lake Erie’ is given by 
Howard S. Reed. There is an unusually large 
number of reviews of zoological publications, 
and in the correspondence Dr. Alex Hrdlicka 
considers ‘The Needs of American Anthropol- 
ogists,’ the greatest of which he believes to be 
the establishment of an Anthropological Insti- 
tute to form a common, independent center. 
The American Journal of Science for Septem- 
tember contains the following articles: 
Gas Thermometer at High Temperatures, by L. 
Holborn and A. L. Day. 
SCIENCE. 
(Sy) 
(ey) 
“A 
Flicker Photometer, by O. N. Rood. 
Quantitative Investigation of the Coherer, by A. 
Trowbridge. | 
Double Ammonium Phosphates of Beryllium, Zine, 
and Cadmium in Analysis, by M. Austin. 
Separation of Iron from Chromium, Zircomium 
and Beryllium by the Action of Gaseous Hydro- 
chlorie Acid on the Oxides, by F. S. Havens and A. 
F. Way. 
Albertite-like Asphalt in the Choctaw Nation, In- 
dian Territory, by J. A. Taff. 
Notice of a New Meteorite from Murphy, Cherokee 
Co., N. C., hy H. L. Ward. 
Separation of Alumina from Molten Magmas, and 
the Formation of Corundum, by J. H. Pratt. 
Ir will be remembered that a department of 
agriculture for the British West Indian Islands 
was created last year with Dr. Morris, of Kew 
Gardens, as Director. We also called attention 
at the time to the agricultural conference held 
at Barbados in January. A further step in ad- 
vance has now been taken by the establishment 
of a West Indian Bulletin, containing a number 
of articles on the agricultural problems of the 
islands. Like our agricultural bulletins, it is 
sent without charge to residents. 
DISCUSSION AND CORRESPONDENCE. 
DARK LIGHTNING. 
To THE Epiror or ScrENCcE: I have been 
greatly interested by some photographs show- 
ing the rare phenomena of dark lightning, 
which have recently been sent to me. So far 
as I know, the only explanation that has ever 
been offered to account for them is photographic 
reversal, due to extreme brilliancy. This ap- 
pears to me to be wholly out of the question for 
two reasons. In the first place, a dark line on 
the picture, resulting from over-exposure of a 
very brilliant line, would be surrounded by 
bright edges, due to the lesser photographic 
action in the halation region. This is never 
present, so far asI know, the dark flashes being 
minute dark lines ramifying from, or in the 
neighborhood ofthe main discharge. Secondly, 
from what evidence I can gather, the dark parts 
of the flash are not those which appear most 
brilliant to the observer. Mr. Jennings, of 
Philadelphia, who in 1890 secured a remarkable 
picture, reproduced in Photographic Times An- 
nual for 1891, showing a very brilliant flash with 
