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fuam trahat originem formamque propriam ? Nam vix credibile, quod pollen flofculorum mafculorum plantæ fertilis fuas femellas impregnans, possit alias plantas producere, quam matribus suis fimillimas. Ergo ftatuendum, aut quod pollen ex planta fterili, quandoque fecundet ovaria plantæ fertilis, unde proles a matre diversa ; aut quod pollen plantæ fertilis producere pofsit fætus, in totum forma et destinatione diversos : id quod autem miraculo foret proximum, quia hoc in casu Aosculi masculi plantæ fterilis præter omnem fcopum atque necessitatem a natura fuissent producti. Habentur quidem exempla variarum plantarum fexu et forma diversarum, et tamen ab eodem polline productarum ; fed exemplum · plantæ perfelle et ex nature instituto sterilis, istoque modo gignitæ, nullum, quod fciam, habetur.'

The male plant in this case (by no means perfect, nor probably ex nature instituto sterilis, ' being furnished with the rudiments of the feinale ilowers) appears to be morbidly, though habitually, steril by abortion; a phenomenon observable in almost all the

роlygamous, and many of the dioecious plants. Nor is it unfrequent among plants that at first sight appear to be really hermaphrodite ; such as several of the Sapindi, in which the stamina of the flowers of one stem will increase at the

expense
of the

ovary, -which ceases to grow; while those of the female or fertile plant are found to contain incomplete anthers without any pollen. In the same manner, what appear complete stamina in the male flowers of the fertile plant of Arctopus, may possibly be imperfect, so that the influence of the other plant is requisite in order to effect fecundation.

Coprosma is one of those genera with whose fructification we are but little acquainted, even after the description and figure here given of C. lucida, which, it may be remembered, does not appear to be that described by Forster under this name. fectly agree with Dr Gärtner, that this genus belongs to the Rubiacea, and not to the Umbellifere ; nor, indeed, do we know by whose ingenuity it has been referred to the latter natural order. As Mr Brown of this city has most probably met with several of its species, in his interesting botanical expedition to New Holland, we may expect that this very acute naturalist will soon throw more light upon the history of the genus,

The two following plates (tab. 83.84.) appear to us, more than the rest of this number, in the style and spirit of those of the preceding volumes ; and, indeed, the specimens from which the figures are made (except Hydropityon, on which we shall remark by and by) were so complete as to admit of that copiousness in the descriptions, which constitutes the chief merit of that work. Though several of the plants they represent are far from being uncommon, such as Cyclamen europæum, Soldanella alpina, Illecebrum verticillatum, Coris, Glaux, &c. yet their fruits and seeds were

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by no means so well understood as it might be expected. With regard to Cyclamen, for instance, we are even now uncertain whether its embryo be of one or two cotyledons. Dr Gærtner, the father, in describing Cycl. europæum, makes no mention of these organs, though fig. K. in the plate represents something like a dicotyledonous embryo; upon which his son has made the following remark.

Embryo in hac ftirpe admodum fallax eft ; in plurimis enim exemplis quæ pater defunctus scrutinio subjecit, ad unum omnes invenit totos solidos ; quamvis omnes oculorum intenderit nervos, optimasque adhibuerit lentes. Ex figura autem K, poft descriptionem factam adjecta, elucet, ipfum tandem denique unicum ex centenis reperiiffe embryonem dicotyledoneum, de quo autem in defcriptione ne verbulum quidem fecit. Embryo itaque revera dicotyledoneus eft, cotyledonibus autem, in plurimis exemplis, brevissimis et vix ac nevix quidem discernibilibus.'

But should we not rather suspect, that the solitary observation alluded to was founded in an optical or accidental deception, and that the embryo of Cyclamen is really of one lobe only? The general habit of the genus (though furnished both with calyx and corolla) would appear to be in favour of this supposition.

We shall now say a word or two of some of the rarer plants contained in these two plates, and begin with Hydropityon zeylanicum. Its description is deficient with regard to the interior structure of the fruit and the seeds. From the generic character, however, and the figure, we are enabled to say, that the subjoined synonyms, of which the leading one is Tsiunda-Tsiero Hort. Malab. 12. t. 36, are all completely wrong. It cannot be doubted that the plant just mentioned of the Hortus Malabaricus, is the lettonia indi-, ca L., and that both, again, are the same with Gratila trifida ; an observation also made by the late Professor Vahl in his • Enumeratio Plantarum.' Though Gartner could not know this, it is still surprising that a botanist of his accuracy should not have found out the dissimilarity between his plant and that of Rhede's work, especially as the latter is described as having only two stamina, and a corolla entirely different from that of Hydropityon. To enable our readers to judge for themselves, we copy Gärtner's generic character.

• HYDROPITYON.-Cal. in feriis, pentaphyllus ; foliolis ovatis concavis magnis incumbentibus. Cor. pentapetala calyce paulo brevior : petalis ovato-rotundatis concavis. Stam. 10: filamentis craffis brevibus, apice dorso antherarum et basi receptaculo genitalium carnoso et molliter longeque villoso insertus : antheris obefis cordatis bilocularibus. Ovar. superum oblongum definens in Jylum Amplicem, ftimate orbiculato præpilatum. Capf. monosperma, aut femen nudum compreffum (ulcatum.

Both the figure and description of Doræna japonica, Thunb.

are

own,

are very instructive. The dry berry (angidium coriaceum) of this plant has the peculiarity of being crowned at the top with five squamæ clinging closely to the stile, and conveying the idea of a calyx superus. Were it not that this fruit has been communicated, as are almost all the rest here described and figured) by Professor Thunberg himself, we should have doubted its being the plant taken up under that name in the Flora Japonica, where we looked in vain for the description of the scales now mentioned ; though, according to Gærtner, they constitute almost exclusively the essential character of the genus ! Another genus of the Flora Japonica is Deuzia, whose place in the natural series appears to be problematical. We are inclined to believe, in opposition both to Thunberg and Gartner, that the calyx in this genus is really adherent; and, indeed, Kæmpfer speaks of it as a

Caliculus globosus carnosus, fructus futuri, ut apparet, rudimentum.' In the figure of Torenia asiatica, the fruit is well enough represented ; but the corolla, professedly drawn from fancy, is objectionable both in regard to size and shape.

The last of those five plates, which we consider as the late Dr Gärtner's throws light on some fruits which were not well known before, such as Halleria lucida, Ourisia of Commerson, and Disandra Prostrata. But with regard to Sarcodactylis, containod in the same plate, our author labours under a strange mistake, Those who have opportunities of seeing Chinese drawings of vegetables, must have often met in them with a large, strange looking yellow fruit, fantastically grown out at its widened top into fleshy appendages, which bear a distant resemblance to fingers, especially if they are only five in number, which is often the case. This is nothing else than the fruit of a species of Citrus, and probably a monstrosity ; it contains no seeds, but is generally furnished with some irregular loculaments. The figure here given is undoubtedly that of such a lemon, of the smaller sort; but Dr Gaertner mistakes it for the fruit of the famous hand-bearing plant, the Macpalcochi-quahuitl of the Mexicans, figured in Hernandez's work, from whence it is erroneously quoted by Linnæus as a synonym of his Helicteres apetala. To reconcile the dissimilarity subsisting between his figure and that of Hernandez, the author calls the latter miserrima ;' an epithet which, however applicable it may be to most of the figures of that insignificant work, is less so in this case. It gives a tolerably good idea of what it is intended to represent.

The five last plates present us with the first results of the younger Dr Gærtner's carpological tour and subsequent labcurs.' They are seven genera, four of them entirely new, namely, Shorea, Roxb. MSS. ; Dryobalanops, Dipterocarpus, and Lophira, Banks's

MSS.

MSS. Their appearance is fingularly beautiful, from the lucinia of the calyx growing out, after the flowering is over, into long wings, covering the pericarp, and of different shape in the different genera. The construction of the embryo of the three former is remarkably complicated, but pretty well explained both by the descriptions and figures. With regard to his Dryobalanops, we notice two errors: first, this excellent timber-tree is not, as here stated, a native of Ceylon, but of Sumatra ; and, fecondly, it does not yield cinnamon, but camphor, known by the name of the Sumatra camphor, and mentioned by Kæmpfer, and also by Mr Marsden in his account of that island. Besides these, we have Vateria indica, Genipa americana, and Tocoyena of Aublet. The first of these genera being referred by Retzius and his followers to Eleocarpus, affords another proof how little attention botanists pay to the fruit ; for even Rhede's figure shews how little it has to do with that genus.

We cannot dismiss this work without expressing our wishes that no obstacles may arise to its uninterrupted continuation ; and, at the same time, exhorting its author not to sacrifice to expedition the proper selection of his materials, or the accuracy of his delineations and engravings. Dr Gärtner cannot fail to know what anxious diligence his father bestowed upon the latter, and that he was even in the habit of sending proofs to London, for the inspection of an eminent botanical artist then residing in that city.

ART. V. On an Artificial Substance which pofelles the principal

Characteristic properties of Tannin. By Charles Hatchett, Efq F. R. S.

Additional Experiments and Remarks on an Artificial Substance

which poftelses the principal - Characteristic properties of Tannin.

By the fame Author. From Phil. Trans. for 1805. Part II. W!

E have generally contented ourselves with selecting from

the memoirs of academies the papers most interesting, either for novelty or merit, and have passed over the rest, without attempting to give any account of their contents. In pursuance of this plan, we are now to direct the attention of our readers towards some of the most curious and important fpeculations that are to be found in the late volumes of the Royal Society's Transactions. Much as Mr Hatchett has contributed to the advancement of chemical science on former occasions, we think the services which these recent inquiries render to that

branch cesa

1

branch of knowledge, are of a different and a higher cast. As they are contained in two papers, we have thought it right to take them together, and consider them as parts of the same investigation.

Before Mr Hatchett entered upon this course of experiments, it had never been supposed that tannin could be produced artificially. Mr Chenevix had indeed found, that a decoction of cof. fee berries had not the quality of precipitating gelatine, unless they were previously roasted ; and hence it might be concluded that the process of burning produced tannin. But this was only an indistinct and imperfect inference, and we were still left to regard tannin as exclusively prepared by nature. The inquiries of Mr Hatchett, however, place this matter in a new light, and warrant the conclusion, that if not tannin itself, at least a body resembling it in its chief characteristic properties, of precipitating gelatine, and rendering skins of animals insoluble in water and imputrescible, may be obtained by a simple process, both from vegetable, mineral, and animal matter.

When nitrous acid is digested upon asphaltum, jet, or other bitumens, containing a portion of uncombined carbonaceous matter, a yellow viscid substance is separated, perfectly fimilar to that which we obtain by the same process with resins; but the remainder of the solution is a dark brown colour, and has different properties. The former consists of the effential portion of the bitumen; the latter of the uncombined carbonaceous

A fimilar product is obtained from the various kinds of mineral coal; but those which contain no bitumen, yield none of the yellow solution. Having by this process of digestion with nitrous acid, obtained the dark brown folutions from bitumens, coals, and charcoal, they were evaporated to dryness, and the refidua examined. They reddened vegetable infusions, werehighly astringent, and separated glue or ifinglass from their folution in water, forming a precipitate quite insoluble, either in hot or cold water. A similar product was obtained from digesting isinglass itself in nitric acid; and the solution of isinglass in water being added to the substance procured from the digestion of isinglafs with acid, the isinglass was precipitated from the water in an insoluble form : uncharred wood, or even bovey coal, which had the appearance of being only half charm red, yielded none of this substance by treatment with nitrous acid ; but when charred, the same bodies gave it in great abund

matter.

ance.

Our author having been engaged in an interesting course of experiments upon the production of coals in the humid way, he found, that by uniting the results of this inquiry with the pro.

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