312 



KNOWLEDGE 



[Oct. G, 1882. 



relatively very small, an<l provided with minute teeth. The 

 bright, silverj', ribbon shajM-d body is provided with dark 

 spots and stripes, and the dorsal tin is of a mild pink 

 colour. The tirst spines or ossicles are of an uncommon 

 length, and form a fan shaped and exceedingly fragile 

 head ornament, which was not found in a perfect condition 

 in any of the specimens. — ^Scieutijic Americaju 



AXDIAL yACCI^'E. 



DR DRYSDALE, of London, in a paper read before 

 the Sanitary Congress, said that he had previously 

 recommended that the State, " if it made vaccination obli- 

 gatory, should give a choice to all to have recourse to 

 animal vaccine instead of humanised. As time passed, 

 however, it began to be ascertained that animal vaccination 

 had far higher recommendation. It was stated by Martin, 

 '^ 1'^''''. that erysipelas, one of the dangers in arm-to-arra 

 vaccination, was unknown when animal vaccine was used ; 

 and latterly, in l!<80, it had been given in evidence by 

 Dr. Warlomont, of Brussels, Dr. Martin, of Boston, and 

 Dr. Meares, of San Francisco, that animal vaccination 

 was a perfect preservative against small-pox. Of 80,000 

 vaccinations made by Dr. Aleares, not one was taken 

 with small -pox in the epidemics which attacked so 

 many, and proved fatal to so many of those who were 

 supposed to be protected by having been vaccinated with 

 long-humanised lymph. Dr. Drysdale remarked that he 

 himself had witnessed the great dill'erence in the appearance 

 of the scab when humanised and animal lymph were used. 

 In the former case, the crusts fill before the tifteenth day, 

 and the scar was often extremely slight; in the latter, tfie 

 crusts often remained on for four weeks, and the scar 

 was like that described by Jenner in his early cases. 

 Humanised lymph was not now nearly so protective as it 

 was at the commencement of the century. Then it was 

 supposed to protect for life. Now, one-tenth of the vacci- 

 nated when attacked with small-pox died. He concluded 

 that there was no longer any doubt on this question, and 

 that humanised lymph should be entirely abandoned, as it 

 had been in B.-lgium, Holland, and the United States, in 

 favour of calf lymph. The State should as soon as pos- 

 sible have stations in the United Kingdom, and dispense 

 gratuitously animal vaccine, as it now does humanised." 



AUTUMN LEAVES.* 



WE can imagine no more suitable orcharming present, 

 at this season, than the beautiful work before us. 

 It has always seerned to us that if an answer is needed to 

 the gloomy question, "Is life worth living?" which some 

 in these days have thought lit to ask, the answer is to be 

 found in the hky and in the woods. Life is always worth 

 living for those who ha\ e eyes to see and sense to feel the 

 glory of the cl< ar or cloud-drifted sky, the infinitely varied 

 Ijcauties of woodland scenery. No writer of our day has 

 done more than Mr. Heatli to r.pen men's eyes to the grace 

 and charm of forest scenes. Pictorially and poetically, he 

 has brought before us the varied wealth of our woods, our 

 hedgerows, and our pleasant tree-strewn meadows. Ho 



• Aut'imn Leave). By Fbaxci.h Gkosge IIeatiij with twelve 

 coloured x>laU.-i. (Sampjion Low, Karston, Scarle, & Rivington : 



has caught, also, with true poetic feeling, that aspect of 

 the woods in which their beauty is combined with the far- 

 otr splendour of the sunlit sky. Hero, for instance, in 

 the book before us is a passage in which the peculiar love- 

 liness of the blue sky as seen through the foliage of 

 trees is admirably depicted : " Oaks where we stand, 

 growing from either bank, fling their branches 

 from side to side, and meet and interlace midway. 

 But at one spot there is an opening in the leafy 

 shroud, and through the ' vignette ' thus woven by the 

 natural and untrained garlands of oak foliage we see the 

 blue sky, and though it is but a patch of uniform colour, 

 and we cannot now see as we could at night the contrast- 

 ing beauty of the stars -' golden nails ' — as a pretty 

 fancy loves to consider them, ' of the floor of heaven ' — the 

 sunny blue serves to throw out in strong relief the 

 autumnal colouring of the oak leaves." In this work Mr. 

 Heath describes and pictures the tints of autumn foliage, 

 not only as we sec them displayed in great masses in forest 

 scenery, but (with special care) as they are seen in detail. 

 In a former work he has illustrated the leaves of our trees 

 in the summer months. Here he has undertaken the more 

 difficult task of depicting them as they appear when 

 the changes begin to take place on which the exquisite 

 tinting of the trees in autumn depends. He shows us, in 

 fact, the touches by which the great artist Nature produces 

 those charming eflects which our painters love to copy, so 

 far as their less masterly touch permits. It is singular, 

 by-the-way, that with Nature teaching them in our 

 woods the beauty of soft tints and gentle contrasts, our 

 British tastes should be chiefly for glaring contrasts and 

 the primary colours, whereas in America, where the woods 

 in autumn actually glow with lich colours and splendid 

 but ever beautiful contrasts, the prevalent national tastes 

 should be in favour of tertiary tints, and associated rather 

 than contrasted colours. In Australia, on the other hand, 

 where the autumn colours are much brighter than in 

 England, the taste for bright and gaudy colouring is more 

 marked e\en than in this country. 



It has been proved that the tissues of plants contain a 

 number of difl'erent colouring substances, to which the 

 pleasing name c/iro/iio/JiyU has been given, to distinguish 

 these colouring matters considered collectively from rhloro- 

 jiltijU, the substance which, when present in the superficial 

 cells of leaves, causes them to assume, under the action of 

 light, their characteristic green colour. " At night," writes 

 Mr. Heath, " oxygen is largely absorbed by the green parts 

 of leaves. When these are performing healthy functions 

 and are in full vigour, the action of sunlight causes them 

 to part with their oxygen. But as they approach the 

 season for their fall, the active functions of assimilation and 

 exhalation become retarded. The oxygen absorbed at 

 night is not freely given oil' during the daytime, and its 

 retention in the cellular tissues causes, under the sun's 

 rays, tlie exquisite tints of autumn. How much," he 

 adds, " these striking effects may be partly dependent upon 

 chemical substances other than oxygen, absorbed into the 

 tissues of plants from their roots, towards the approach of 

 the season for the fall of the leaf, and how much on the 

 action of light upon all these substances, science has not 

 yet been able to accurately determine." 



Mr. Heath gives us many specimens in this work of the 

 actual colouring of autumn loaves, tho " blossoms of 

 autumn" as they have been poetically called. These pic- 

 tures show with singular accuracy the outlines of form, 

 the characteristic venation, and tho tinting of the leaves. 

 The method by which these beautiful pictures have been 

 obtained is described in the t<;xt, though not, perhaps, 

 quite BO fully as many readers might wish. There are 



