992 
remain, even though chemical activity be 
absent, so also the peculiar molecular consti- 
tution, characteristic of life may remain even 
though life—i. e., active life—be absent. As 
chemism may be completely destroyed by cold 
and revived by heat, if the necessary condition, 
viz., a certain equivalent composition, remains : 
so life may be completely destroyed by cold, 
and again revived by heat if so be the neces- 
sary condition—a certain molecular constitu- 
tion remains. 
Again, Mr. Brown, in the article referred to, 
says that Spencer’s definition of life, viz., ‘a 
continuous adjustment of internal to external 
conditions’ must be revised, since it applies 
only to active life and not to suspended life. I 
think not. Life in the true sense, i. e., actual life 
must be active —the essential nature of life, as 
of all energy, is activity; but there is a neces- 
sary underlying condition, 7. e., a peculiar mo- 
lecular constitution, which may be called poten- 
tial life. As equivalent composition is potential 
chemism, which may under certain conditions 
become actual chemism, so a peculiar molecu- 
lar constitution of protoplasm is potential life, 
which may under certain conditions become 
actual life. Deathis not merely an extinction of 
life, 7. e., actual life, but also the destruction of 
the necessary condition of life, 7. e., the char- 
acteristic molecular structure of protoplasm. 
Extinction of life, therefore, is not necessarily 
death. There are therefore three conditions 
of protoplasm, viz.: (1) living, a condition in 
which life is actual; (2) potentially living, in 
which the necessary molecular constitution or 
vital constitution is present; and (8) dead, in 
which the vital constitution also is wanting.* 
JOSEPH LE CONTE. 
BERKELEY, CAut., May 24, 1901. 
A ‘SAND-BOW’—AN UNUSUAL OPTICAL 
PHENOMENON. 
THE following description, based on personal 
observation, is presented without discussion of 
the optical principles involved. 
* Similar views on the molecular constitution of liv- 
ing protoplasms were brought out by me, in January, 
1892 in a lecture before the Philosophical Society of 
Washington. Bulletin, Vol. XII., p. 29, 1892. 
SCIENCE. 
[N.S. Vou. XIII. No. 338. 
On the evening of May 16, the writer was 
crossing the main ridge of Antelope Island— 
the largest land body within the area of the 
Great Salt Lake. As he began the descent on 
the eastern slope, there appeared between the 
island and the mainland what seemed at first 
glance to be segment of a brilliant rainbow of 
unusual width. It was evident, however, that 
no rain was falling in that direction. Clouds 
were gathering in the south and west, but the 
sun was yet unobscured. A wind setting toward 
the mainland had lifted from the dry flats large 
quantities of the ‘oolitic sand,’ with which the 
lake bottom and the recently dried patches on 
this side of the island are covered to a depth 
varying from a few inches to several feet. This 
so-called ‘sand’ consists of calcareous spher- 
ules, fairly uniform in size between the limits 
of No. 8 and No. 10 shot. The oolitic bodies 
are polished and exhibit a pearly luster. 
It would seem that the outer spherical sur- 
faces reflected the light in such a manner as to 
produce the bow. The colored column ap- 
peared almost to touch the lake bed, and its 
ends subtended with the observer an angle of 
about 40°. The prismatic colors were distinct, 
the red being outside, 7. e., away from the sun. 
In apparent width the column was fully double 
that of the ordinary rainbow. A fainter sec- 
ondary bow was plainly visible beyond the pri- 
mary, with the colors in reverse order. The 
phenomenon was so brilliant as to attract the 
attention of all members of the party, and 
it remained visible for over five minutes, 
then, as the sun sank lower, it rapidly died 
away. 
The production of a color bow by reflection 
from the outer surfaces of opaque spherules is 
a new phenomenon to the writer. It is inex~ 
plicable on the principle of refraction and total 
reflection from the interior of transparent 
spheroids, according to which the rainbow is 
generally explained. 
If phenomena similar or analogous to the 
foregoing have been observed, reports of the 
same would doubtless be of instructive in- 
terest. 
JAMES HE, TALMAGE. 
UNIVERSITY OF UTAH, 
SALT LAKE City, May 20, 1901. 
