62 



HARDWICKE'S SCIENCE-GOSSIP. 



spermaceti, adding any watery liquor and a little 

 syrup to form an emulsion ; two parts of the root, 

 two of gum, and one of spermaceti. In this form, 

 he has given the fresh root from ten grains to up- 

 wards of a scruple three or four times a day. It 

 generally occasioned a sensation of slight warmth, 

 first about the stomach, and afterwards in the 

 remoter parts ; it manifestly promoted perspiration, 

 and frequently produced a plentiful sweat. Several 

 obstinate rheumatic pains were removed by this 

 medium, which he therefore recommends to further 

 trial. Chewed in the mouth it has been known to 

 restore the speech in paralytic cases, and made into 

 a conserve it is efficacious in scurvy and rheumatism. 

 It likewise increases the urinary secretion, and is 

 good in the gravel. But in whatever form it is used 

 the root should be fresh, for it loses the greater part 

 of its efficacy in drying, and becomes insipid." 



In these more enlightened days it may possibly be 

 difficult to find persons with sufficient faith to try for 

 themselves the truth of the above remedies. Certainly, 

 for my own part, I should prefer, if suffering from 

 rheumatism, a course of our own thermal waters. I 

 need hardly say that this plant has ceased to be used 

 in medical practice. It is no easy task to procure the 

 ■corms of A. maculatum. Again and again failure 

 marks the attempt to dig them up. I use a fern 

 trowel, but frequently do not go deep enough, 

 with the result that up come the leaf stalks, leaving 

 the corm deep in the earth. The arum loves, too, a 

 soil somewhat stony, and when the plant is met 

 with in such ground, it is well to leave it alone. 

 Anyone who tries to dig up the corm will soon 

 discover the difficulty. 



The petioles are sheathed at their base. 

 The structure and arrangement of the cellular and 

 fibro-vascular tissues is fairly representative of the 

 monocotyledons. Here again as in the corm, we 

 find starch in the cells, though not in such large 

 quantities. Here, too, for the first time, are to be 

 noticed with distinction, large numbers of raphides. 

 These occur in the corm also, but are not so easily 

 distinguished, owing to the dense mass of starch 

 grains. In a longitudinal section, through a petiole, 

 we get a view of the fibro-vascular bundles, and of 

 the cellular tissue with cells containing starch and 

 raphides. The raphides are very minute, and a \ is 

 required to see them at all well. The epidermis of 

 the petiole consists of elongated cells with some few 

 stomata as in Fig. 53. 



The external appearance of the leaf varies. Its 

 vernation is convolute. The most general and 

 marked form of the leaf is hastate-cordate. (Fig. 54.) 

 Sometimes the lamina are spotted black, though the 

 spots are more frequently absent. On examining one 

 of the spots, a mass of cells filled with chromule will 

 be observed. Other examples of a like nature will 

 readily occur to the mind of the reader. In the 

 epidermal cells of the lamina stomata occur, but 



only in very small quantities, and widely scattered. 

 In structure, the cells of the leaf are of the ordinary 

 type and arrangement, (a) The empty thick-walled 

 cells of the epidermis. (l>) Oblong, closely packed 

 cells containing chlorophyll, (c) Loosely packed 

 cells containing chlorophyll, and so arranged as to 

 have air spaces. It must, I should think, strike the 

 most casual observer that the leaves of the arum 

 show signs of being singularly unhealthy. There are 

 several causes for this. Even early in the season, 

 many leaves exhibit a sickly yellow waxy appearance, 

 very different from the healthy green of some of their 

 relatives. On making sections it will be found that 

 the vivid green of the chlorophyll bodies is in these 

 changed to a golden hue and less in quantity. In 

 several cases I have noted, in sections through the 

 thickness of the lamina, an increase in the quantity of 

 raphidian bundles and a surprising increase in size of 

 the same. 



{To be continued.') 



CIVILISATION AND EYESIGHT. 



AVERY important point and one which, in these 

 times when health questions in general occupy 

 so prominent a position, ought to engage the serious 

 attention of school authorities, is the question of the 

 eyesight of boys and girls, and the injury which may 

 be done by working under bad conditions of light. 

 The matter is not ended by seeing that a large school- 

 room is as a whole well lighted, because the evil effects 

 will probably be found where the pupils sit at some 

 distance from the light, near the walls or corners of 

 the room, reading, it may be, small print, or working 

 by artificial light on greasy slates on which the marks 

 are at no time very easy to see, and with here the 

 added difficulty, that the desk at which they are 

 working perhaps slopes so that the light makes but a 

 small angle with the plane of the slate. There can 

 be little doubt that this state of things, where it 

 prevails, is one cause not only of rounded backs, and 

 undeveloped chests, but of injured eyesight and the 

 need for spectacles among school-boys. Surely it is 

 bad economy to stint light. In a paper on the 

 "Influence of Civilisation on Eyesight," by Mr. 

 Brudenell Carter, read at a recent meeting of the 

 Society of Arts, the author gives very interesting 

 details as to the prevalence of defects of vision. 

 " An enormously large proportion of the whole 

 German nation is composed of the wearers of 

 spectacles, and there is abundant evidence that the 

 need for such assistance dated from a comparatively 

 recent period." In an investigation of a London 

 Board School, made last year by Mr. Adams Frost, 

 it was found that rather more than one-fourth of the 

 children had defective or subnormal vision. Mr. 

 Carter thinks that ignorance of what the normal 



