A manual of practical hygiene for students, physicians, and health officers / By Charles Harrington.

  • Harrington, Charles, 1856-1908.
Date:
1914
Catalogue details

Licence: Public Domain Mark

Credit: A manual of practical hygiene for students, physicians, and health officers / By Charles Harrington. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    880/992 (page 828)
    them that they were obliged to cover themselves to get any sleep. After fumigation of the forecastle, the dead mosquitoes could be scooped up in the band. Howard relates that mosquitoes were intro- duced into the Hawaiian Islands by sailing vessels from the United States, and deems it probable that they bred more or less continuously in the water barrels during the voyage. Mosquitoes may be blown along by the wind through long distances, but ordinarily they take shelter on the leeward side of any object as soon as the wind begins to be strong. Howard cites an instance of mosquitoes crossing a strip of water a mile wide, aided by gentle and continuous wind, and another in which a migratory cloud of the insects, extending three miles in width, traversed 60 miles; and Dr. Kallock, of the Gulf Quarantine Station, reports (August 2, 1901) that the cap- tain of the ship America stated that mosquitoes came aboard the vessel when she was at least 10 miles from land. But Anopheles are not likely to fly far from their birthplaces. They are not such strong fliers as Culices. Stephens and Christophers' believe that Anopheles in Sierra Leone may fly a quarter of a mile or farther, but in Freetown they found them scarce at a distance of 200 yards from their breeding-places. As stated above, there are many places in this country and elsewhere where Anopheles are common and malaria unknown, although formerly the disease may have raged most extensively. In England, for ex- ample, where malaria was once one of the great national scourges and is now seen only rarely, NuttalP and his associates found, in 1900, specimens either of the imago or of the larvte in no less than 173 dif- ferent places. In some of these places, malaria, so far as known, has never existed ; in others, it once had raged extensively. In France, Ser- gent' has found A. maculipennis and A. bifureatus in great abundance where malaria was formerly common, but now is, and for twenty years has been, unknown ; and in Germany, Pfeift'er* has found them in great numbers in formerly malarious districts, but none of tiiem showed the presence of the parasite. In Italy, too, where Grassi has held that the geographical distribution of Anopheles is identical with that of malaria, Celli'' has found the insects in situations where malaria has never been known. To what the disappearance of malaria in England, Scotland, parts of the United States, France, Germany, and other countries, is due, is not easily explained. To a very lai'ge extent, it is doubtless due to drain- age of the land and general sanitary improvement, the drying of the soil diminishing the opportunity for puddle-breeding mosquitoes to multiply. But this explanation will not apply generally, for in many places now free from malaria the same conditions of soil, wetness, and mosquitoes are found to-day as existed when the disease was endemic. It is interesting to note that, in England, the Anopheles, although fairly ' Loco citato. ^Journal of Hygiene, January, 1901, p. 4. ' Annales de I'lnstitut P.isteur, XV., Oct. 25, 1901. * Correspondenzblatt des allgemeinen iirztlicben Vereins von Thiiringen, 1901, No. 7. 'Centralblatt fiir Bakteiiologie, etc., XXVIII., p. 534.