136 



HARD WICKE'S SCIENCE- GOSSIP. 



Messrs. Spicer, of New Bridge-street, Blackfriars 

 (who also supply white paper for mounting, in sheets 

 nbout 17 in. by 11 in.), but in default of this, thick 

 blotting-paper is said to answer, though I have not 

 tried it. The plants must not be damp when they 

 are put in the press, and if the roots have been 

 washed to clean them, they should be wiped as dry 

 as possible. If for any reason the plants are at all 

 damp, the papers should be changed very frequently 

 at first, even twice a day, until the excess of moisture 

 has been removed. I am frequently asked, "How 

 is it you manage to keep the colours of your flowers 

 so well ? " Mainly by attention to this point — by 

 not allowing the flowers to remain damp. Otherwise 

 they are very apt to change their colour ; as, for 

 example, the Wood Anemone, or Windflower, which 

 .generally turns brown, but which may be kept white 

 with proper care. Heaths and firs are said to require 

 a dip in boiling water before drying, in order to pre- 

 vent the foliage from falling off. The same process 

 prevents succulents, such as the curious flesh-coloured 

 parasitic Toothwort, from growing during or after 

 pressure, by killing them at once. Here, also, the 

 superfluous moisture should be removed by a hand- 

 kerchief before pressing. Do not mix fresh speci- 

 mens with dry ones, but separate them with several 

 sheets of brown paper. Laying -the plants out will 

 often be found a troublesome process, and one which, 

 in order to do it well, will in some cases require time 

 and patience, but it is not of much use to give advice 

 on this head, except to say that the various parts of 

 the flower should be as well exhibited as possible. 

 For instance, where the flower has a coloured calyx 

 and no corolla, as in Marsh Marigold, Clematis, and 

 Wood Anemone, one blossom should be folded up so 

 -as to show the absence of the customary row of green 

 leaves below the coloured ones. Or the same subject 

 may be effected by completely reversing one blossom, 

 so that its face is towards the paper. Where bracts, 

 or small leaflets at the base of the flower-stalks occur, 

 as in orchids, they should be shown. The specimens 

 should be distributed among the sheets of porous 

 paper in such a way that the pressure may be some- 

 what equal in all places ; but those plants, however, 

 are likely to dry more quickly which are nearer the 

 margin of the sheets. Thick stems had better be 

 sliced in half longitudinally, as it prevents their 

 taking up too much room, and also enables them to 

 dry veiy much faster. The same course may be taken 

 with thick roots or root-stocks, as in Primrose and 

 Coltsfoot ; but in such cases care must be taken to 

 leave enough root-fibres adhering to the main axis. 

 Bulbs and corms, and the fleshy tuberous roots of 

 orchids may also be sliced ; some recommend scooping 

 out the inside, but this is apt to make them break and 

 spoil under pressure. Berries and stems that are not 

 thick enough to slice may be repeatedly pricked on 

 their under surface, or slashed with the point of a 

 penknife, to let out the moisture. A very good plan 



with fleshy berries, and thick stems and roots, is to 

 dry them, apart from the rest of the plant, by pressing 

 them between several folds of porous paper, and 

 baking the whole for three-quarters of an hour in an 

 oven. But this does not always answer, and should 

 not be tried with green leaves, as it is apt to turn 

 them brown. In short, the more rapid the drying 

 process the better ; and hence the necessity of having 

 recourse to these contrivances in order that the colours 

 of the blossoms may not be injured through being 

 kept damp by the slow drying of the thicker parts. 



( To be continued. ) 



MICROSCOPY, 



" Cutting it fine." — At the usual conversazione 

 which followed the ordinary meeting of the Quekett 

 Microscopical Club on April 26th, Mr. E. T. Newton 

 exhibited thirty-three sections of the head of one cock- 

 roach ! — Blatla Orientalis. 



Fossil Diatomace^e. — The Diatomaceze in the 

 Cementstein are described and figured (very beauti- 

 fully) by Dr. Heiberg, in his " Kritisoversigt over 

 de Danske Diatomeer." The richest in diatoms is 

 the Cementstein from the island of Mors, situated in 

 the Liimfjord, lat. 56 50' N., long. 8° 40' W. This 

 fjord is the largest in Jutland, and runs from east to 

 west, connecting the North Sea with the Kattegat. 

 The material is also known as "Jutland slate." A 

 similar deposit occurs in Fuur ; it is less affected by 

 acid, and bears considerable resemblance to the de- 

 posit known as "Brown coal." Another deposit is 

 found at Nykjobing, a village on the western side of 

 the island of Mors. This is much more difficult to 

 prepare, neither acid nor alkali making much im- 

 pression upon it. The following forms have been 

 described and figured by Dr. Heiberg in his treatise, 

 and by myself in the "Journal of the Quekett Micro- 

 scopical Club," in the Parts for 1870 and 1871. 

 The following are the most abundant forms in the 

 Mors deposit : — Trinacria regina, Heiberg; T. cx- 

 cavata=.Triccratium solenoceros, Ehr= T. A'ittou- 

 ianum, Greville ; Trinacria Hcibcrgia, Kitton ; Do. 

 var., Kitton; Triceratium maculatum, Kitton; 

 Solium exsculptum, Heiberg ; Corinna elegans, 

 Heiberg ; Stictodiscus angulatus, Grunow ; Stcpha- 

 nogonia Danka, Grunow; Trochoscira mirabilis, 

 Kitton ; T. spinosa, Kitton ; Hemiaulus protcus, 

 I leiberg ; II. host His, Heiberg ; //". februatus, 

 Heiberg; Do. (q. sp. ), Kitton; Coscinodiscus sicl- 

 latus, Roper ; C. radiatus, Ehr ; C. octdus Iridis, 

 Ehr ; Stephanopyxis (qu. sp.) ; Aidacodiscus yut- 

 landkus, Kitton. Triceratia occur in the Barba- 

 does, Californian, and Morsa deposits, as well as in 

 the Virginian "earths." — F. Kitton, Norwich. 



Aquaria for MicROSConc Work. — In answer to 

 W. D. B., I would suggest that I find several small 

 aquaria (none of them holding more than a quart) 



