Raphides, sphaeraphides, and crystal prisms / by Professor Gulliver.

  • Gulliver, George, 1804-1882.
Date:
[1873]
Catalogue details

Licence: Public Domain Mark

Credit: Raphides, sphaeraphides, and crystal prisms / by Professor Gulliver. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    100 HARDWICKE’S SCIENCE-GOSSIP. parts, such as bulb-scalcs of the Shallot and fronds o( Lemuel trisulcu, may be examined very easily without any such preparation. Fig. 6l. p, Crystal Prism from ovary-coat of Centaurea nigra ; q, different forms, one in its cell, from the same part of Centaurea scabiosa; r. Crystalline Cross, and three single crystals, from bulb-scale of Shallot. All highly magnified. 4. Microscopic Interest of the Crystals.—Of all the objects in the plant-tissues, there are none more beautiful and more likely to interest the tyro in micrographic botany than these crystals. While under examination the glassy raphides roll about in various directions, like a loose bundle of sewing- needles thrown on a table. The sphaeraphides are commonly contained in distinct cells, and the crystal prisms are scattered and fixed in the direction of the fibres of the plant, but sometimes, as in the Shallot, lie across the tissue-cells. The prisms are well adapted for experiments on the polarization of light, as Colonel Horsley has often shown at the Canter- bury meetings of the East Kent Natural History Society. Any of the crystals may be easily pre- served, either simply dried, or in balsam or dammar, or in glycerine and other wet mediums. And when numerous slides have been collected and correctly labelled, their taxonomic interest will become -evident, and thenceforth go on increasing with the increase of the collection, which may become an important one for reference as to the value of the crystals as characters in systematic botany. Thus this might well be an elegant and useful occupation, in which ladies could engage, for pleasing and instruc- tive “ half-hours with the microscope ”; and which in this single subject would afford an extensive and valuable cabinet of beautiful microscopic objects, and rational researches that are not likely to be exhausted after many half-years have been thus employed. The inquiry might be extended to the ■ development of the raphides, from the ovule and seed-leaves, to the different parts of the mature and growing plants, to their decline, death, and rotten- ness. Eor experiments of this kind the common Onagraceae of our gardens, fields, and lanes, and the different species of Ornithogalum, would answer; and they might be grown for the purpose in little pots of various _sods, and thus give perpetual pleasure and profit to any one with the mind and means to use the microscope thus rationally. 5. Nature and Use of the Crystals.—The crystals are by no means, as maintained by eminent observers, diseased or irregular products in plants, like calculi’ in animals, but are so truly part and parcel of the essential nature of the plant in which they occur, that it cannot be well grown without producing them, and this from the birth to the grave of the species. Numberless examples of this truth may be found in the plants of our common pools and fields; and I have often proved it experimentally in various members of the dicotyledonous orders Balsaminace®, Galiacem, and Onagracese, and in some Monoco- tyledons. The crystals are mostly oxalate of lime, with a small proportion of other earthy salts. Though this, according to Professor Douglas Maclagan, is the case with raphides, some of them appear to be phosphate of lime, according to examinations made, at my request, by the late John Davy, of these crystals in Upilohium, Galium, and Smilax {Ann. Nat. Hist., June, 1864). And this leads us to a notice of the use of such crystals. The Sarza of the Pharmacopoeia is a Smilax very rich in raphides and starch; and hence, probably, the well-known efficacy of this drug in those diseases, especially of the bones, in which there is a deficiency of the earthy phosphate. In like manner the Duck- weeds abound in raphides and starch, and on these plants young mammalia, water-birds, and lower- animals feed greedily; and no doubt this is the very pabulum best adapted for the nourishment and growth of the bones and other parts. Many animals are ever feeding on seeds in which microscopic crystals abound. Thus we come to understand some of the manifold ways in which Nature has provided for the wants of her creatures. We have seen that science too can turn these crystals to good taxonomic purpose; and it may be added that they are often the best tests of the genuineness of many vegetable drugs; such as Orris, Quillaja, Guaiacum, and Rhubarb. The false or American Sarza, being an Aralia, is at once plainly distinguishable by its sphaeraphides from the genuine Sarza. Again, as manure, the calcareous salts which compose the crystals must be of great value; nature storing a superabundance of them in the living plant, to be restored in the dead leaves and other parts to fertilize the earth. Accordingly, we see good reason why the gardener so carefully husbands his leaf-mould; and that such plants as the Duckweeds, Puchsias, and Willowherbs, should, from their profusion of raphides, in this respect best serve his purpose. In fine, as poor Charlotte Smith, who loved our wild flowers so well and truly, sung of them “ All are for use, for health, for pleasure given, All speak in various ways the bounteous hand of heaven.M Canterbury, March 6,1873.