The St. Johns herald., 1901-07-06
EkyS1ClenCe
 k( S5@@~ 40 s |S:zI1ventiOf1
-o~~~00O~~

| During the recent trlp OI tue OeiSICa
 in the Antarctic more than sixty oD-
 servatiOns of the aurora australls, the
 southern counterpart of our northern
 lights, were made. The appearance or
 the light resembled that presented m
 the Arctic regions. But the maximum frequency did not occur during the
 months of the long polar night, and the
 phenomenon was most intense at the
 time of the equinoxes, when the sun Is
 perpendicular over the equator and
 daylight is simultaneous at both the
 north and the south pole.
 Among North American birds the grebe nests in and near the water. The prairie hen, on the contrary, nests on the ground, being terrestrial bird. Some birds, like the meadow lark, are partly arboreal, nesting near the ground in trees. The indigo bird is neither arboreal nor terrestrial, al- though it nests in the trees. The heron Is striking exception to the theory that habit decides the nesting site. AL though terrestrial bird, 1t places it's nest high in the trees, as does the wood duck, which is an aquatic bird. Wood hawks nest in bOgs, as do the marsh gulls.
 Sir John Murray recently showed how remarkably the Black Sea differs from other seas and oceans. A surface cur rent flows continuously from the Black Sea into the Mediterranean, and an under current from the Mediterranean into the Black Sea. The latter current is salt. and, being heavier than the fresh water above, it remains stagnant at the bottom. Being saturated with sulphuretted hydrogen, this water will not maintain life, and so the Black Sea contains no living inhabitants below the depth of about 100 fathoms. The deeper water when brought to the sur face smells exactly like rotten eggs.
 Dr. c. T. Williams in a recent address before the Life Assurance Medical Off, cers' Association of England gave some interesting details as to the mortality and expectation of life in the various European states. Taking an average of twenty-five recent consecutive years, the deaths per thousand of the popula- tion in the several countries are as fol- lows: Norway, 16S; Sweden, 173; Ire land, 1S.1; Denmark, 1S.S; England, 19.6; Scotland, 20; Belgium, 21; Swftz- erland, PIT; France, 22.6; German em- Q, Cfrio O. Hungary, 35.4. Norway has the low est death rate, 16.S, and Hungary the highest, 354. With regard to the ex- pectation of life at 20 years, the figures for America are 42.19 years, Britain 42.10, Germany 39.6S, and France 41.S3.
 If the mosquito has any friends among mankind, they may rejoice in the assurance given by pr. L. O. How ard, of the Department of Agriculture, that this cosmopolitan pest does not necessarily perish with the oncoming of winter. On the contrary, mOsqui- toes have been observed in the lati tude of Washington to hibernate, adult specimens living from November until the succeeding April or May with all their powers of torment unimpaired, although their activity is suspended in winter. The mosquito needs but little food, and 1t is the female that thirsts for blood, the males contenting themselves with water and vegetable fluids. Dr. Howard ascribes the fact that mosquitoes are often found upon dry prairies, many miles from water, to the longevity of the adults of certain species, which enables them to survive seasons of drought. Railroads have been responsible for the transportation of mosquitoes into regions where they were previously rare. Their power of flight Is not great, and 1t is believed that they are not distributed far through the agency of winds.