a 
’ 
+ 
4 
q 
a 
4a 
_ ¢ross-hairs are placed in front ofits eye-piece. 
_ turned until the image of these cross-hairs is brought to coincide 
_ of the flames against the wind was noted, and explain 
NATURE 
4 
~ 
215 
December 10.—Professor’ E. C. Pickering exhibited a 
new form of theodolite magnetometer, which may be con- 
structed at small expense from a common surveyor’s transit. 
A mirror and magnet like that of a Thomson’s galvanometer is 
attached ‘o the cap of the telescope, and a right-angled prism and 
The telescope is 
with those already in the eye-piece, when the axis of collima- 
tion will be exactly at right angles to the magnetic meridian. 
The remainder of the evening was devoted to a discussion of 
the great fire of November 9, by which sixty acres of the most 
valuable part of the city of Boston were destroyed. Numerous 
specimens of the effects of the fire were exhibited, among others 
a fused mass originally leather, but converted by the heat into a 
substance resembling resin, A strong wind with a velocity of 
twenty to twenty-five miles per hour was induced by the ascent 
of the heated air, although the velocity before the fire was but 
seven miles. This wind converted a narrow street into a sort 
4 of gigantic blow-pipe, and the flames were thus carried across 
Franklin Street, where it is over 100 ft. in width. The es 
y the 
radiant heat, which was so great that some of the engines were 
unable to get near enough to play on the fire. Buildings to 
windward might thus be set on fire, while those to leeward 
would be comparatively protected by the smoke. The carrying 
power of the air was remarkably great. Flakes of granite were 
carried across the water to South Boston, and fell in quantities 
on the side-walks and roofs, and papers were borne in some 
cases to a distance of over twenty miles. The light was so 
strong that it was easy to read by it in the higher parts of 
Belmont, over fifty miles distant ; and the fire was seen at sea to 
_ adistance of ninety miles. 
Rica. 
Society of Naturalists, March 6 (18 N.s.)—M. Frederking 
communicated a third section of his history of chemistry, in 
which he referred to the development of the electro-chemical 
hypothesis, and the discovery of isomorphism, and to that of the 
vegetable alkaloids. 
April 3 (15 N.s.)—M. L. Taube presented a report on a work 
by M. Fischer, on the disease of bees, colled ‘foul brood,” 
which is ascribed by the author to the dying and subsequent 
putrescence of a portion of the larve. M. Fischer believes that 
the fluid given by the worker-bees to the larve is secreted by 
the salivary glands, and that the mortality amongst the larvz is 
- caused by a deficiency of this secretion brought on by a scarcity 
of food. He considers that this is proved by the fact that 
** foul-broodedness” in a hive is caused by the removal of its 
own workers and the substitution of healthy workers from 
another hive. : 
April 10 (22 N.s.)—M. Schroeder referred to the comet which 
was expected by some people to come in contact with the earth 
in August.—Colonel von Gotschel read a paper on diseases of 
cage-birds, in which he especially recommended prophylactic 
measures. 
April 24 (May 6 N.s.)—M. C. Berg criticised Sir William 
Thomson’s opinion as to the origin of the first organisms from 
germs conyeyed by meteorites.—M. Teich communicated a 
contribution to the Natural History of Cucullia precana. 
May 1 (13 N.S.)--A discussion took place on the means to 
be adopted for the protectioneof small birds, in which MM, 
Gégginger, Nauck, Westermann, and Burchardt, took part. 
May 15 (27 N.s.)—M. Schroeder presented a table of the 
rainfall at various stations during the summer of 1871, and 
called attention to the very small amount recorded at Riga. 
May 22 (June 3 N.s.)—Dr. Nauck communicated some 
observations on the torpidity of JZyoxus nitela.—M. Wester- 
mann exhibited a pane of glass in which a circular hole of two 
inches diameter had been made by a hailstone on May to. 
(22 N.s.) Dr. Nauck exhibited plaster-casts of hailstones from 
the same fall, and proposed a theory of the formation of hail 
by the production of a whirlwind caused by warm, moist winds 
meeting cold winds under angles of 90°, when the aqueous 
vapour is condensed, causing an inflow of air from above and 
below, and consequently an increase of precipitation, during 
which the water, striving to retain its fluid form, may easily 
fall several degrees below its freezing point; and its congelation 
into masses of ice may be accounted for by the fall into it of 
small grains.—M. J. H. Kawall gave an account of the publi- 
tations of the Society of Naturalists of Charkow, including the 
- titles of all the papers. 
July 20 (August 1 N.s.)—The society assembled in the court 
of the Polytechnicum to hear an address in honour of Dr,G, 
Schweinfurth on his return from his African travels, 
August 21 (September 2 N.s.)—Dr. Schweinfurth described 
several types of the inhabitants of Central Africa, belonging to 
the Ujam-Ujam, Bongo, Djur, Dinka, Mittu, and Akka 
branches of the Negro, noticing especially their modes of 
adorning themselves, and a few peculiar habits.—Baron F. 
Hoejningen-Huene communicated a continuation of his Pheno- 
logical observations, containing notes on weather and other 
oe phenomena during the months of July and August, 
1871. 
PHILADELPHIA 
Academy of Natural Sciences, July 2.—‘‘On a new 
Genus of Extinct Turtles.” Prof.Leidy stated that he had deter- 
mined that the fossil-turtle he had named Bena undata be- 
longed to a different genus. Besides other well-marked distinc- 
tive characters, like the genus P/atemys, it possessed an additional 
pair of plates to the usual number found in the sternum of the 
emydoids. These plates are iritercalated between the hyo- and 
hypo-sternals. In Platemys Bullockis they are quadrate. Inthe 
new genus they are triangular, and the sutures defining them cross 
the plastron like a prostrated letter X, from which character 
it was proposed to name the genus Christernon. 
July 9.—Prof. Leidy directed attention to a bottle containing 
numerous specimens of a minute crustacean from Salt Lake, 
Utah, caught on the 22nd of June by Mr. C. Carrington, a mem- 
ber of Prof. Hayden’s exploring party now in the field. They 
were received from Prof. Hayden with the remark ‘‘ that Salt 
Lake has been supposed, like the Dead Sea, to be devoid of life, 
but its saltest water contains the most of these little creatures.” 
The crustacean is the Artemia salina, which has long been 
known in Europe, and has been previously found in other locali- 
ties of this country. The animal has always been viewed with 
especial interest, in its order, from the fact that it lives and 
thrives best in a concentrated solution of salt, which would destroy 
most marine anitnals. It has not, I believe, been noticed in the 
ocean, but is found in salt Jaf&es, and salt vats, in which, by eva- 
poration, the brine has become more concentrated than sea water. 
Artemia is furnished with eleven pairs of limbs, which serve 
both for progression and respiration. The limbs are four-jointed, 
and the joints have leaf-like expansions fringed with long feather- 
like bristles. The narrow abdomen, or tail-like prolongation of 
the body is six-jointed, and traversed by the intestine. The last 
joint ends in a pair of processes, furnished each with a bunch of 
bristles like those of the limbs. The head exhibits a median, 
quadrate, black eye-spot, and in addition is provided with a pair 
of pedunculate, globular compound eyes. A short narrow pair 
of inarticulate antennz project in advance of the eyes. The 
head of the male is furnished with a pair of singular organs 
for seizing the female. These claspers are large double-jointed 
hooks. In the female they are replaced by a pair of compara- 
tively small horn-like processes. The first abdominal segment 
bears the ovarian sac in the female, and two cylindroid appen- ~ 
dages in the male. The female of the Salt Lake Artemia ranges 
from four to seven lines in length ; the male from three to four 
lines in length. The colour is translucent-white and ochreous- 
yellow, with three black eye-spots, anda longitudinal line varying in 
hue with the contents of the intestine. The ovarian sac appears 
orange-coloured from the eggs within. The antennz end in three 
or four minute setee, and are considerably longer in the male 
than the female. The first joint of the claspers is provided on 
its inner side just below the middle with a spheroidal knob. The 
last joint forms a rectangular hook, the angle having an elbow- 
like prominence. When the clasper is thrown forward, the outer 
border of the hook is convex ; the anterior border straight, 
slightly or deeply concave, and the inner or posterior border is 
sigmoid. The antennz are longer than in the female, and longer 
than the first joint of the claspers ; and in the female are longer 
than their homologues. The ovarian sac is inverted flask-shaped, 
and has a pair oi lateral conical or mamillary, finely tuberculated 
processes. The caudal setz are longer than in the male, and are 
eight to each process. This description is taken from alcoholic 
specimens. They exhibit considerable variation in size, and to 
some extent in detail. Prof, Verrill has described what he views 
as two species of Artemia distinct from the well-known 1. sa/inc. 
One he names 4. gracilis, from near Newhaven, Conn. ; the 
othe: A. Monico, from Lake Mono, Cal. That from Salt Lake 
differs from either of them as much as they do from 4, salina, 
and with the same propriety may be regarded as a distinct species. 
