Online Encyclopedia

Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.

SLEEPER

Online Encyclopedia
Originally appearing in Volume V25, Page 240 of the 1911 Encyclopedia Britannica.
» Make a correction to this article.
» Add information or comments to this article.
Spread the word: del.icio.us del.icio.us it!

SLEEPER , a See also:

term used with many technical applications for a piece of See also:timber, See also:metal, &c., used as a support; in See also:carpentry it is such a piece of timber laid on See also:low See also:cross walls as a See also:plate to receive ground joists; in See also:shipbuilding, a strengthening timber for the bows and stern See also:frame; the most frequent use of the term is for a timber or See also:steel support on which the chairs are fixed for carrying the rails on a railway; in See also:America these are called" ties " (see See also:RAILWAYS). The See also:common explanation of the origin of the word is to connect it with " See also:sleep," the timbers supposed to be lying at See also:rest. The real source of the word is the Norv,egian sleip, a piece of timber used for dragging things over, a See also:roller, especially used of timbers laid in a See also:row in making a road. This word See also:Skeat (Etymol. See also:Diet., 1898) connects with " slab," a See also:flat piece of See also:stone or See also:wood. The See also:French term dormant is used in carpentry, but as See also:part of the frame of a window or See also:door. SLEEPING-SICKNESS (Trypanosomiasis), a remarkable parasitic disease, See also:familiar among See also:West See also:African natives since the beginning of the 19th See also:century, and characterized by protracted lethargy, See also:fever and wasting. It is attributed to the trypanosoma gambiense, a See also:parasite which was discovered in the See also:frog by Gruby in 1847, and in 188o by See also:Griffith See also:Evans in horses afflicted with the disease called " surra " in See also:India. In 1895 Surgeon-See also:Major (afterwards See also:Sir) D. See also:Bruce found a trypanosoma similar to Evans's in cases of what was known in See also:cattle as " tsetse-See also:fly disease "; and though the trypanosoma had not then actually been found in See also:man, Bruce suggested that this was akin to the human " sleeping-sickness " which had now extended into the See also:Congo See also:Free See also:State, See also:Uganda and elsewhere, and was causing See also:great mortality, many Europeans having died of the disease. In 1903 Castelani found the trypanosoma in the cerebra-See also:spinal fluid of human patients afflicted with the disease. The question of the See also:pathology of " sleeping-sickness " was vigorously taken up, and in See also:June 1907 an See also:international See also:conference was held in See also:London for the purpose of organizing See also:research on the subject.

As was pointed out by See also:

Lord Fitzmaurice (18th of June), in his opening address, it was already accepted that trypanosoma gambiense was the cause of the disease, and it was even then " all but proved " that the parasite was conveyed by at least one See also:species of tsetse fly (glossina palpalis), the See also:distribution of which was limited to the neighbourhood of open See also:water. It had further been ascertained, experimentally in animals, and therapeutically in man, that the infection once acquired could be controlled, to some extent, by various substances—See also:arsenic, certain See also:colours, dyes, in combinations of arsenic and See also:colour dyes, e.g. atoxyland by See also:mercury. It remained a question how far certain unascertained factors were at See also:work in the spread of the disease, and for this purpose the See also:British See also:government invited the co-operation of all the See also:powers interested in tropical See also:Africa in considering certain problems, See also:annual or biennial conferences being suggested, and the formation of a central See also:bureau, in See also:order to organize the research. These problems were: (I) to determine whether the tsetse fly (glossina palpalis) was a See also:direct or indirect conveyor of the parasite; (2) whether the parasite underwent necessary developmental changes in the tsetse fly; (3) if so, whether the See also:developed germs were conveyed by the See also:original fly or its larva when arrived at the imago See also:stage; (4) how See also:long an infected glossina palpalis remained infected; (5) whether other species of glossina were concerned; (6) the See also:geographical distribution and habits of the fly; (7) whether and how far the spread of infection was the work of any of the vertebrate See also:fauna (other than man); (8) to suggest preventive methods for exterminating the glossina, or protecting uninfected districts by segregation or otherwise; (9) to study the See also:therapeutics of the disease. In the See also:history of See also:modern pathology, this organization of research in respect of " sleeping-sickness " must hold an important See also:place as the application of state effort on behalf of the See also:advancement of See also:science.

End of Article: SLEEPER

Additional information and Comments

There are no comments yet for this article.
» Add information or comments to this article.
Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML.
Site content, images, and layout Copyright © 2006 - Net Industries, worldwide.
Do not copy, download, transfer, or otherwise replicate the site content in whole or in part.

Links to articles and home page are always encouraged.

[back]
SLEEP (0. Eng. slcepan; Ger. schlafen; cf. Lat. lab... 		[next]
SLEET (either from Nor. sletta, of the same meaning...

Site © 2006 - Net Industries