Microfilming

Abstract: ANY REVIEW on blood platelets is likely to start with a historical paragraph mentioning Bizzoeero, Hayem and Eberth and Schimmelbusch, or if the author wishes to display greater erudition, and has read the excellent note by Tocantins (1948), he may add the names of Donnt, Zimmermann and Osler, but it is extremely unlikely that he will tell us who these people were, and why the platelets were first recognized about the middle of the nineteenth century, when the erythrocytes had been known from the seventeenth century and the leucocytes in the eighteenth century. Everyone is aware that Antony von Leeuwenhoek, the Dutch linen draper, gave the first clear account of the erythrocyte, observed protozoa, bacteria and many other minute objects, all with a simple microscope of which he had ground the lenses himself, and which gavc magnifications of the order of 300, but what is not so well understood is that effective microscopy of greater magnitude than this was not achieved until the beginning of the nineteenth century; this time the advance was due to a wine merchant, Joseph Lister (the father of Lord Lister), and, when the limit in optical visibility had been reached, it was a hatter, J. E. Barnard, who enhanced resolution by devising ultraviolet microscopy. It is true that Robert Hooke greatly improved the compound microscope and was the first to observe the walls of a cell, but his instrument had a magnification of only about 30 diameters, for the lenses were single and non-achromatic; the field was far from flat, only sharp at the centre and any attempt to use high magnifications led to indistinct colour-fringed images. The scientists to a large extent abandoned the compound microscope, leaving it as a plaything for the amateur philosophers of nature, who demanded elegant instruments to look at a bee's wing or a plant seed; Madame de Pompadour had a charming little instrument in a green gilded leather case lined with velvet, while George Adams made a fantastic silver microscope for George I11 surrounded by urns and figurines so that it looks more like an epergne for the desert table. In 1773, William Hewson, often called the first of the haematologists, gave an admirable appraisal of microscopy as it then was: 'Some have gone so far as to assert that no credit can be given to microscopes; that they deceive us, by representing objects different from what they really are. These assertions, though not entirely without foundation, when we speak of one sort of microscope, are very unjustly applied to them all. In compound microscopes, when the object is viewed through two or more glasses, if these glasses be not well adapted to the focus of each other, the figure of the object may be distorted; but no such circumstances takes place when we view an object through a single lens. All who use spectacles agree that the figures of objects appear the same through them, as they do to the naked eye. And as the singlc microscope has, like the spectacles, but one lens between the eye and the object, there is no reason to suppose the one can deceive us more than the other. The compound having a

Abstract: Preserving and providing access to records and archives are some of the major reasons for the existence of archives. The need to preserve records and archives arises from their format, the environment in which they are stored, and frequent handling and use. While archivists are aware of the preservation challenges they face in the management of records, their major dilemma lies in choosing an appropriate preservation method. A variety of products available in the market claim to provide preservation solutions as well as guaranteed continued access to archives. However, microfilming and digitisation are the two widely used reformatting products. The choice of the reformatting strategies has a profound impact on how archival institutions manage and deliver information. The issues at stake are: Can digitisation be used as a tool for the preservation of archives in Sub-Saharan Africa? Will microfilm become obsolete? It is evident that until feasible solutions to preserving long-term access to digital documents are developed, microfilming will remain the most appropriate preservation strategy for archivists, especially, in the developing countries. These expensive digitisation projects are often impeded by scarce resources and scant research in digital preservation. Presently, digital conversion seems to be attractive only in terms of enhancing access to documents. (African Journal of Library, Archives and Information Science: 2002 12 (2): 117-132)

Abstract: Completely revised from the first edition this is a a basic yet comprehensive overview of the state of preservation in libraries and archives. For those unfamiliar with the issue of preservation, this is an excellent introduction, sketching the background of the problem and touching on the simplest and most effective methods of prevention-such as housekeeping practices, staff training, preservation microfilming, and the creation of a disaster plan. For the experienced, the author provides an enormous bibliography, citing writings by many of the leading authorities in the field