Quekett journal of Microscopy, 2001, 39, 3- 14 3 Arranged and Type Slides BRIAN DAVIDSON Based on the Club Lecture delivered 7 November 2000 Arra.nged s li des recognized The considerable advance in lens design resulted in marked improvement in optical For the purposes of this paper I use the word performance, and the manufacturers vied with 'arranged' to describe any preparation where the each other to produce higher powers, and a subjects have been placed in such a manner as to greater diversity of objectives, offering enhanced be displayed to best advantage. This is in contrast, resolving power. In order to choose from this for example, to a spread slide of diatoms which increasing array, some objective comparison of have been cleaned but are shown randomly, with performance became a necessity, and could best no attempt at arrangement. be achieved by using uniform test slides. Selected As the manufacture of scientific and technical species of diatoms, scales from insects, hairs, instruments developed during the second half of insect parts, wood and Nobert's Rulings all had the 19'h century, it gave rise to a variety of their advocates. specialized ancillary skills to meet the inc reasing Up to 1850 all diatom slides were strewn potential of the instruments and the requirements mounts. It seems likely that the advent of the of those using them. Slide mounting was just such arranged slide was due equally to commercial a skill fulfilling the demand The earlier bone and expediency and scientific enquiry. As the ability wood sliders which preceded glass slides were was acquired to prepare and manipulate very mounted dry, the object held in place between small objeCts manually or with specially made glass and mica slips secured by brass wire. These "mechanical fingers", the presentation of subject had sufficed for over a century, as the resolution matter entered a new er a. The microscopist was of most microscope optics was limited by the offered more sophisticated and attractive prepara- simple lenses and the variety of aberrations extant tions, even showing the same diatom for instance, before the advent of the achromatic lens from the from more that one aspect. By the 1850s slides of 1820s. individual species were being mounted with a few Lister's development of achromatic objectives, frustules neatly arranged for examination, in and the appearance in this country of Canada addition to the mixed mounts and spreads. balsam as a mounting medium from 1832 [1], transformed microscopy and the preparation of The basic skills of collecting, separating, clean- slides. Balsam greatly increased the mounter's ing, identifying and mounting diatoms were of ability to prepare objects to demonstrate internal necessity developed by those who specialized in as well as external structures, leading to a far this field The significance of the diatoms, both greater range of microscopical objects being uti- Uve and fossil, as markers and indicators became lized for educational, scientific and recreational apparent, leading to a greater variety provided for purposes. study and identification. These improvements in microscopy, especially Improved techniques of gathering and clean- with medium to high powers, and in mounting ing, and the use in mounting of the sable hair media, stimulated the creativity and commercial brush and mechanical finger resulted in an acumen of the makers of slides. They naturally improved level of skill during the 1860s. It sought innovative methods for displaying speci- became possible to mount not only individual mens in novel ways, to gain an advantage. Balsam diatoms in a chosen attitude and alignment, but was an excellent medium for exhibiting fo r exam- also to do the same with butterfly scales, hairs, ple, the great variety and intricacy of the Diato- Foraminifera, seeds, insect parts and eggs, sections maceae. Interest in this class of aquatic Algae was Echinus, spicules, botanical subjects etc. It is not of stimulated by the work of such luminaries as the possible to say who invented the 'mechanical Revd W. Smith His two volumes Synopsis of finger', but such a necessary aid was a logical British Diatomaceae [1 853 - 56, 2] accelerated an development from the single sable hair, with interest, which would grow exponentially. its obvious limitations for those making time- At this time the 'test' slide was becoming more consuming mounts commercially. Moller does
4 BR I AN DAV IDSON mounters including Thomas Comber[6] were not disclose what method he used, but his ar ranged and type slides made from the late producing slides with selected diatoms placed in 1860s onwards, could have been made with the groups. Nelson claimed at a RMS meeting on use of a mechanical finge r. By the 1880s these April 16th 1890 [7] that Comber was the first to devices were described in leading journals [3] and pr oduce diatoms arranged in "regular rows" or various reference works [ 4 ]. groups, in the late 1850s. Certainly C. M. Topping was arranging dia- There were of course those who came later, but were of a traditional bent such as distinguished toms in loose geometric groups of various forms Club member A Morley J ones, who would not and single and groups of a selected spec ies , as well use a mechanical device and relied solely on the as attractive ar ranged groups of different butterfly steadiness of his own hand. As this method of scales during the 1860s [see Fig. 1]. His catalogues placing the diatom depended on the minute move- did not however specifically offer these as ment caused by the heartbeat, a lack of stress 'ar ranged'. Although the manipulation of indivi- would have been a necessity when mounting! dual diatoms was initially perceived as easier than Club member Strauss Durckhem abstained from insect scales, which were offered as spreads on test coffee at breakfast in order to maintain a steady slides, it was not long before the commercial potential for the artistic arrangeme nt of scales hand. mo unt ed dry was realized, leading eventually to It is difficult to find a definitive date for the the wo nd erful 'scale picture' of preparers such as appearance of arranged slides, The first mention H arold Dalton. of selected diatoms mounted using a "sable pencil" was by Shadbolt in a paper in the Trans- Duri ng the next two decades most of the larger actions of the Microscopical Society of London firms with printed catalogues, and also certain on November 14 1849 [SJ. The early catalogues of individual mounters, offered arranged slides and "salon circles". The most commo n objects treated preparers such as Topping, West and Pritchard do not offer slides mounted in a manner which could in this manner were diatoms, Foraminifera, and be described as arranged. It is probable that some butterfly scales. They were described on slide preparers began to mount attractive arrangements labels as Salon -s lides, Salon circles, Rosettes, at about the same time, and by 1860 a number of Fan -rosettes, Exhibition slides, Artistic groups, - , • • • • • • , • I - - • ' • FIG . 1. A butterfly scale arrangement by Topping, c. 1860.
Arranged and Type Slides 5 F1 c. 2. Vase of flowers by Dalton. Arranged groups, G roup s, and Butt erfly scales in microscopy is ao example. Th e proliieration of arranged. after-dinner diversions in genteel households is documented by social commentators of the period. Carpenter's Microcosm in Regent Street The expanding and relatively affluent market for things microscopical in the developing 19 <h was a successful ente rprise from 1827 [8] onwards, century fueled the spin-off from practical neces- and clearly indicated the fascination with the sity to commercial possibility. Th e microscope as natur al wor ld, including images of minute organ· entertainment for those not necessarily interested 1sm s.
6 BRIAN DA VIDSON Ft G. 3. A Dal£on 'cornucop ia of flowers'. FtG . 4. An arran ge me nt of diatoms, sponge s pi c ul cs and sca les by Thum.
Arranged and Type Slides 7 FIG. S. An arrangement of diatoms, and bunerfly scales by Thum . FIG . 6. A presentation arrangement of butterfly sca le s by Klaus Kemp.
8 BRIAK DAVIDSON F IG. 7. A salon circle of diatoms by Klaus Kemp . small number of species placed together, later followed by all manner of varied and pleasing 'artistic' arrangementS. The majority of these arranged slides were relatively simple patterns, such as the circles sold in significant numbers by Watson. Fir st class mounters such as J. T. Norman, whose output covered a considerable range of subjects, also made complex arranged slides using butterfly scales. His son kept the details of each one in a little note book, recording details of 117 such slides [9]. A bouquet and vase of flowers containing 959 pieces which he mounted in Feb- ruary 1883, took 13 hours and 35 minutes. In March of the following year he mount ed the same subject with 1050 pieces in a tin1e of 14 hours and 25 minutes. Frc . 8. 'Choir boys' in diatoms by Klaus Kemp. Perhaps the name which first comes to mind when co nsidering arranged butterfly scale pictures Once the techniques bad been mastered the is that of Harold Dalton. His bright green labeled intricacy of the mount was only limited by space slides are distinctive, and the quality of work is and commercial time strictures. After mounting very fine indeed. I have a number of scale pictures individual diatoms for identification, it is likely which do not have Dalton's usual printed label, that the first attractive arrangements would have but have labels with his name and description been a few frustules of an identified species or a written in his own hand.
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