fuam trahat originem formamque propriam ? Nam vix credibile, quod pollen flofculorum mafculorum plantæ fertilis fuas femellas impregnans, poffit alias plantas producere, quam matribus fuis fimillimas. Ergo ftatuendum, aut quod pollen ex planta fterili, quandoque fecundet ovaria plantæ fertilis, unde proles a matre diverfa; aut quod pollen plantæ fertilis producere poffit fœtus, in totum forma et deftinatione diverfos : id quod autem miraculo foret proximum, quia hoc in cafu flofculi masculi plantæ fterilis præter omnem fcopum atque neceffitatem a natura fuiffent producti. Habentur quidem exempla variarum plantarum fexu et forma diverfarum, et tamen ab eodem polline productarum; fed exemplum plantæ perfecte et ex naturæ inftituto fterilis, iftoque modo gignitæ, nullum, quod fciam, habetur.

་

The male plant in this case (by no means perfect, nor probably ex naturæ instituto sterilis,' being furnished with the rudiments of the female flowers) appears to be morbidly, though habitually, steril by abortion; a phenomenon observable in almost all the polygamous, and many of the dioecious plants. Nor is it unfre quent 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. We perfectly agree with Dr Gertner, that this genus belongs to the Rubiacea, and not to the Umbellifera; 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

by

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 fubjecit, ad unum omnes invenit totos folidos; quamvis omnes oculorum intenderit nervos, optimafque adhibuerit lentes. Ex figura autem K, poft defcriptionem 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, breviffimis 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-Tsiera Hort. Malab. 12. t. 36, are all completely wrong. It cannot be doubted that the plant just mentioned of the Hortus Malabaricus, is the Hottonia indica L., and that both, again, are the same with Gratiola 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 Gartner's generic character.

• HYDROPITYON.-Cal. inferus, pentaphyllus; foliolis ovatis concavis magnis incumbentibus. Cor. pentapetala calyce paulo brevior: petalis ovato-rotundatis concavis. Stam. 10: filamentis craffis brevibus, apice dorfo antherarum et bafi receptaculo genitalium carnofo et molliter longeque villofo infertus: antheris obefis cordatis bilocularibus. Ovar. fuperum oblongum definens in Aylum fimplicem, ftigmate orbiculato præpilatum. Capf. monofperma, aut femen nudum compreffum fulcatum.'

Both the figure and description of Dorana japonica, Thunb.

E 4

are

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 Gærtner's own, 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, contained 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 Gærtner mistakes it for the fruit of the famous hand-bearing plant, the Macpalxochi-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 labours. 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 defcriptions 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 alfo by Mr Marsden in his account of that island. Befides thefe, we have Vateria indica, Genipa americana, and Tocoyena of Aublet. The first of these genera being referred by Retzius and his followers to Elaocarpus, affords another proof how little attention botanists pay to the fruit; for even Rhede's figure fhews how little it has to do with that genus.

We cannot difmifs this work without expreffing our wishes that no obftacles may arife to its uninterrupted continuation; and, at the fame time, exhorting its author not to facrifice to expedition the proper selection of his materials, or the accuracy of his delineations and engravings. Dr Gærtner 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 infpection of an eminent botanical artist then refiding in that city.

ART. V. On an Artificial Subftance which poffeffes the principal Characteristic properties of Tannin. By Charles Hatchett, Efq

F. R. S.

Additional Experiments and Remarks on an Artificial Subftance which poffeffes the principal Characteristic properties of Tannin. By the fame Author. From Phil. Tranf. for 1805. Part II.

W E have generally contented ourfelves with felecting from the memoirs of academies the papers most interesting, either for novelty or merit, and have paffed over the rest, without attempting to give any account of their contents. In purfuance of this plan, we are now to direct the attention of our readers towards fome of the moft curious and important fpeculations that are to be found in the late volumes of the Royal Society's Tranfactions. Much as Mr Hatchett has contributed to the advancement of chemical fcience on former occafions, we think the services which these recent inquiries render to that branch

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

Before Mr Hatchett entered upon this courfe of experiments, it had never been fuppofed that tannin could be produced artificially. Mr Chenevix had indeed found, that a decoction of coffee berries had not the quality of precipitating gelatine, unless they were previously roafted; and hence it might be concluded that the procefs of burning produced tannin. But this was only an indiftinct and imperfect inference, and we were ftill left to regard tannin as exclufively prepared by nature. The inquiries of Mr Hatchett, however, place this matter in a new light, and warrant the conclufion, that if not tannin itself, at least a body resembling it in its chief characteristic properties, of precipitating gelatine, and rendering fkins of animals infoluble in water and imputrefcible, may be obtained by a fimple process, both from vegetable, mineral, and animal matter.

When nitrous acid is digefted upon afphaltum, jet, or other bitumens, containing a portion of uncombined carbonaceous matter, a yellow vifcid fubftance is feparated, perfectly fimilar to that which we obtain by the fame procefs with refins; but the remainder of the folution is a dark brown colour, and has different properties. The former confifts of the effential portion of the bitumen; the latter of the uncombined carbonaceous matter. A fimilar product is obtained from the various kinds of mineral coal; but thofe which contain no bitumen, yield none of the yellow folution. Having by this process of digestion with nitrous acid, obtained the dark brown folutions from bitumens, coals, and charcoal, they were evaporated to drynefs, and the refidua examined. They reddened vegetable infufions, werehighly aftringent, and feparated glue or ifinglafs from their folution in water, forming a precipitate quite infoluble, either in hot or cold water. A fimilar product was obtained from digefting ifinglafs itself in nitric acid; and the folution of ifinglafs in water being added to the fubftance procured from the digeftion of ifinglafs with acid, the ifinglafs was precipitated from the water in an infoluble form: uncharred wood, or even bovey coal, which had the appearance of being only half char red, yielded none of this fubftance by treatment with nitrous acid; but when charred, the fame bodies gave it in great abund

ance.

Our author having been engaged in an interefting courfe of experiments upon the production of coals in the humid way, he found, that by uniting the refults of this inquiry with the pro

cefe