Licence: In copyright
Credit: The prevention of malaria. Source: Wellcome Collection.
Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.
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![The owner, or when required by the local authority, the occupier of every lot of land situate in a town or village district shall effectually drain the lot, and for that purpose shall (r) make such dams and drains on the lot as may be necessary for effectually draining the lot; (2) fill up all irregularities on the surface of the lot, and adjust the surface thereof, and if necessary raise the level of the surface thereof, in such a manner (a) that the water received on the lot may flow into the drains without obstruction, (b) that no water can remain on any portion of the surface of the lot other than the drains, and (<:) that the surface of the lot does not remain swampy. Provided that where the swampy state of any lot in any such district is occasioned by the main drains into which the drains of the lot discharge not having a sufficient outfall or a sufficient capacity to carry off all the water discharged into them, the owner or occupier of the lot shall not be liable under this section to raise the level of the surface of the lot if the level of such surface is as high as the average height of the level of the land surrounding such a lot for a distance of 20 roods (? 20 rods = 110 yards. A rood is a square measure); and provided that any owner may, with the consent of the local authority of the district in which the lot is situated, have a pond on the lot. George- town, British Guiana. All vats, tanks, or other vessels shall be screened with mosquito- proof wire-netting or other suitable material, so as to prevent the entrance into or exit of mosquitos from such vats or tanks or other vessels. British Guiana. Such regulations should, if possible, be included in the general Health Act, and not be left to the bye-laws of local bodies, which are often very incompetent. In my opinion British administration is generally much wanting in discipline, and tends to neglect the health and lives of the people for the sake of antiquated notions about the liberty of the subject. 65. Notes.—I will conclude this book with some miscellaneous notes on points of interest which have been studied while it was in the press. (1). The thick-film process.—For ordinary microscopic preparations, 1 c.mm. of blood is spread out thinly over, say, 4 sq. cms. of area, and then examined either fresh or stained — at the cost of much time (section 18 (9)). Consequently I proposed the following method [1903]. A quantity of blood, say 1 c.mm., is spread over only about 1/4 sq. cm. of area, and allowed to dry. The haemoglobin is then washed out with water, and the residue, consisting of parasites, leukids, micrids and the stromata of the haematids, is stained by any appro- priate method. We can thus search 1 c.mm. of blood in about 1/16](https://iiif.wellcomecollection.org/image/b21351600_0726.jp2/full/800%2C/0/default.jpg)
