326 



THE GARDENERS' CHRONICLE. 



[September 22, 1888. 



lished at Geneva his Physico-Chemical Memoirs " On 

 the Influence of Solar Light in the Three Kingdoms 

 of Nature, especially the Vegetable." In this he showed 

 that carbonic acid was essential to the production of 

 oxygen by sunlight. He also gave results of the 

 examination of the action of different rays on ger- 

 minating plants, and said he found that the size and 

 extent to which the leaves grew was proportional to 

 the intensity of illumination ; that red rays had 

 more effect than violet or blue ; and that the green 

 of leaves depended on the quality of the ray. Two 

 years later he gave the results obtained by having 

 separated out the green colouring matter of leaves 

 (chlorophyll — x^P". green ; <pi\\ov, leaf) by solu- 

 tion in spirits of wine, and examined the action of 

 light on this tincture. He examined it also in ether 

 and essential oils. He further examined the action 

 of light on the coloration of fruit and flowers. Here 

 was a new line of research opened up, which, how- 

 ever, lay dormant for about forty years, though when 

 resumed it led to important results, and is now actively 

 pursued with the aid of delicate apparatus of recent 

 construction. 



De Saussuke. 



Following the more strictly chemical side of Senc- 

 bier's work, Nicolas de Saussure~(son of the famous 

 "alpine" H. B. de Saussure) took up, among his 

 many investigations, the question of quantities of 

 oxygen, carbonic acid, &c, involved in such changes 

 as Senebier had demonstrated. He introduced new 

 methods * for determining the amount of oxygen 

 present in gaseous mixtures. He clearly proved that 

 plants put to grow in an atmosphere freed from car- 

 bonic acid do not increase the amount of their 

 carbon. He found they cannot decompose carbonic 

 oxide. Here was established clearly the fact that 

 the source of carbon in plants is the carbonic acid of 

 the atmosphere. How they obtain it, the conditions 

 under which they obtain it, and what particular 

 parts of the plants are concerned in the process, 

 remained for investigation at a future period. 



The actual composition of plants, roots, seeds, 

 fruits, juices, and of vegetable products used as foods, 

 drugs, and in arts and manufactures, was being 

 actively prosecuted, and this was being done by many 

 chemists in many lands. 



Meanwhile the explanation of chemical changes, 

 and of the constitution of compounds that chemists 

 obtained from many sources and examined, was re- 

 ceiving attention from deeply-thinking minds. The 

 composition of an immensely greater number of 

 compounds than De Morveau and Lavoisier were 

 acquainted with when their " system " and " nomen- 

 clature " (mentioned above) was devised, had become 

 known. Their proposed definition, for example, of 

 an "acid" was found to be too narrow. To the 

 word " radical," which combines with an "acid "to 

 form a " salt," it was found needful to extend a 

 wider meaning, as there were found so many " com- 

 pound radicals." t 



One most important piece of work, celebrated from 

 the discussions it raised, especially with Berzelius, 

 was that by Liebig and Wohler on the radical of 

 benzoic acid. They showed that it contained a 

 radical (C, H s O) common also to oil of bittter 

 Almonds and other compounds.} To this they gave 

 the name Benzo-yl. Here was introduced into 



* He used sulphide of potassium and phosphorus as agents 

 in analysis. 



f Much of the work that Lavoisier and his friends did in 

 classification and nomenclature cannot even now be overlooked 

 without the chance of missing the meaning of words we still 

 use, such as '* acid," "salt," "base or radical." For the son 

 of a cultivator, on the modern side of his school, here is a holi- 

 day amusement. " Le mot acide sera lc nom generique; 

 chaque acide sera ensuite differencie dans la language comme 

 il est dans la nature par le nom de sa, base o.i de son radical."' 

 This is on p. 58 of vol. i. of the four volume edition mentioned. 

 The context will supply the explanations. A sister or cousin 

 who carried off a French prize last half may perhaps help. How 

 plants obtain their carbon was worked out. while carbon dioxide 

 ■was still known by Lavoisier's name " l'acide carbonique," and 

 oxygen was called "l'air eminement respirable," " l'air pur," 

 or "l'air vital." So, historically, the question of nomenclature 

 is not altogether unimportant. 



I Cntersiichungen Tiber das radikal der Bcnzolnsuure. Ann. 

 Pharm, vol. iii., 1832, p. 219. 



chemical nomenclature the termination yl, now so 

 much employed. At the top of p. 202 they say they 

 take the termination from 'vXtj — matter. [The Ger- 

 mans equally use their own word "storF," our" stuff," 

 as in wasserstoff (hydrogen), &c, but not for radicals.] 

 Following this kind of nomenclature we have hydr- 

 ox-yl (HO), Meth-yl, Eth-yl, &c * 



The recognition of organic radicals was a very im- 

 portant step. While it gradually led to a chaoge in 

 nomenclature to the puzzle of those who did not closely 

 follow chemical work, it opened up fresh subjects 

 for enquiry. For a long time it was debated whether 

 organic compounds obey the same laws as inorganic. 

 No one now doubts that they do, but it is fully 

 recognised they are far more complicated, W. 8. M. 

 (To be continued.) 



Orchid Notes and Gleanings. 



CYCNOCHES CHLOROCHILON. 

 A figure of this Orchid appeared in the last 

 volume of the Gardeners' Chronicle, at p. 145, show- 

 ing a plant with an erect spike of two flowers, this 

 being, so far as I have seen, about the usual number. 

 A plant is now flowering at Kew which shows the 

 variable character of the species — a character, how- 

 ever, common to the whole genus. It bears two 

 pendent spikes of flowers, one with eleven and the 

 other with eight ; the flowers are much smaller than 

 those in the above quoted figure. The sepals and 

 petals are yellowish-green ; the lip is creamy-white, 

 with a dark olive-green blotch in the centre ; and the 

 column is about 1 inch long, with an inflated apex, 

 where the pollen masses are inserted. The stem- 

 like pseudobulbs are 12 inches high, with lanceolate, 

 plaited leaves from 6 to 12 inches long. W. B. 



BDXBOPHYLLUJI UMBELLATtJM. 



As none of the popular works on Orchids make 

 any mention of this species, it is probably but little 

 known under cultivation. It is figured in the 

 Botanical Magazine, where it is said to have flowered 

 at Kew in 1846 ; it has now appeared again, and 

 proves to be an extremely pretty little Orchid — cer- 

 tainly not to be beaten by any other Bulbophyllum. 

 The flowers are produced in a verticil at the top of 

 a slender scape 6 inches high, each flower being 

 about three-quarters of an inch across. The lower 

 sepals are pale yellow, spotted with reddish-purple, 

 and have the margins recurved ; the upper sepal and 

 the two petals (which are about one-third the size) 

 are of a brighter yellow, thickly dotted with crimson 

 spots. The purple lip is small, and is articulated in the 

 manner characteristic of the genus. The species is 

 a native of Northern India, and therefore requires 

 cool-house treatment. It thrives well potted in 

 peat-fibre and sphagnum. 



Catasetum Rxjssellianum. 

 No doubt the time will arrive when Catasetums 

 will be amongst the most popular of Orchids, for 

 the interest of Orchid cultivators is happily no longer 

 restricted to those subjects which have merely bright 

 colour to commend them. Certainly no genus of 

 Orchids shows the marvellous structure and arrange- 

 ments to secure fertilisation by insect agency in a 

 clearer or better fashion than do Catasetums. The 

 power certain kinds have of swiftly ejecting the 

 pollen masses, when either of the horns attached to 

 the column are touched, is in itself one of the most 

 interesting phenomena in the floral world. Neither 

 are they destitute of beauty; few Orchids, indeed, 



* In floriculture "fancy names" are used which have no 

 meaning. It may. le well to mention that names used by 

 chemists have a definite meaning which refers to the composi- 

 tion of the compound named. 



Lothar Mayer has said, "chemical symbols and formula 

 which a few years ago received such prominence, are now 

 regarded with indifference, since what was formerly expressed 

 symbolically and indistinctly, or even without proof or clear- 

 ness, by their aid can now be expressed iu clear words with 

 fixed meaning." But query? Do all chemists conform to this 

 fsed meaning? 



produce a finer effect than C. Bungerothii, a recent 

 introduction with large beautiful white flowers. It has 

 been well figured and frequently mentioned in these 

 columns. C. Russellianum is one of the older but 

 still desirable species, having been introduced from 

 Guatemala in 1838. It has pendent spikes of from 

 twelve to eighteen flowers, produced from the base 

 of the ovate pseudobulbs. The flowers are 3 inches 

 across the sepals, these and the petals being pale 

 green marked with lines of a deeper shade ; the lip 

 is similar in colour, and is slipper-shaped and some- 

 what inflated ; at the sides and front the margin 

 projects forward and is fringed. A plant with thirteen 

 flowers is blooming now at Kew. Like the other 

 species it enjoys abundance of warmth, moisture 

 and especially light during the growiDg period, and 

 a prolonged period of rest afterwards. W. B. 



Cattleya Loddigesii, Lindl. 

 This, the first Cattleya ever introduced into 

 European gardens, is a fine autumn flowering plant, 

 and may just now be seen in perfection in various 

 collections. It was originally received from Rio de 

 Janeiro by the Messrs. Loddiges, of Hackney, early 

 in the present century, and may be found figured in 

 their Botanical Cabinet, t. 337, under the name of 

 Epideadrum violaceum. Lindley founded the genus 

 Cattleya, on C labiata, about the year 1822, at which 

 time he added Epidendrum violaceum as a second 

 species, under the name Cattleya Loddigesii. It is 

 a rather widely diffused plant, and, according to the 

 Messrs. Veitch, is spread over Southern Brazil from 

 the Organ Mountains to the Rio de la Plata, from 

 the Atlantic Ocean almost to the River Uruguay, 

 growing in a great variety of situations, sometimes 

 on trees, sometimes on bare rocks, both in shade and 

 in full exposure to all weathers — circumstances which 

 more or less influence the habit of the plant, and the 

 size and colour of the flowers. No special treatment 

 is required for its successful cultivation beyond that 

 necessary for other ordinary species of the genus. 

 R. A. S. 



Cattleya aubea maemobata. 



There is now in the gardens of Lord Roths- 

 child at Tring Park a most remarkable and 

 exquisitely beautiful Cattleya of the C Dow- 

 iaua aurea class, which came in an importa- 

 tion received by Messrs. Shuttleworth, Carder 

 & Co., Park Road, Clapham. It appears to be a 

 natural hybrid between C. aurea and O gigas, and 

 those who know the superb O Hardyana can picture 

 this fine form by imagining a flower intermediate 

 between it and C. aurea. The variety mar- 

 morata has large flowers, the ground colour 

 of the sepals being yellow, the sepals slightly, 

 and the beautifully crimped petals heavily, 

 marbled with dark rose colour. The finely-expanded 

 labellum is violet-crimson on the front portion, and 

 golden-yellow veined with purple on the basal half. 

 The whole lip has a purple margin. In point of 

 beauty and fragrance it is equal to the best Cattleya ; 

 and Mr. Hill is hopeful that similar forms will ap- 

 pear among the other plants received from the same 

 importer. Cattleyas are well grown by Mr. Hill, 

 and these newcomers could not get into better hands. 

 When in an article on large-flowered Cattleyas in 

 the Gardeners' Chronicle, p. 404, September 29, 1883, 

 I predicted the coming of these intermediate forms 

 between O aurea and O gigas, the present magni- 

 ficent variety is just the plant I had in my mind. 

 James O'Brien. 



Cypripedium Miteauanuh, Zindenia, t. 146. 

 Leaves oblong, green, with dark spots, peduncles 

 rufous, hairy ; flowers 4J inches across, upper sepal 

 broadly ovate, acute, white, with numerous purple 

 stripes ; petals linear oblong, red-violet, with tufts 

 of dark hairs on the edge ; lip reddish-brown, 

 shining. 



Fruit and Vegetable Exhibition at Bar- 

 net. — An exhibition of the above on a large scale 

 is being organised by Mr. John Munro, formerly of 

 Potter's Bar, to take place at New Barnet at the end 

 of September or the beginning of October. A great 

 deal of local support is being promised, and a 

 schedule of prizes will shortly be issued. 



