A D I A N T U M A D I P O C I R E. 



are deprived of the epidermis, and brought into 

 contact. 



This tendency is turned to account in the arts, in 

 what is sometimes called a Dutch hedge, a descrip- 

 tion of fence which might be advantageously intro- 

 duced in all places where land is valuable. It consists 

 of twigs rooted in the ground, made to cross each 

 other in lozenges, the surfaces being rubbed where 

 they come in contact, and tied together till the whole 

 unites into one solid piece, occupying only a few 

 inches in breadth, and yet stronger than any hedge- 

 row of detached plants. 



All vegetable growth may be considered as pro- 

 ceeding by a sort of adhesive process, at least all 

 which proceeds by a series of growths with pauses 

 between, as in plants which continue to grow for 

 several successive years, and more especially all which 

 increase by layers on the wood and bark, and elon- 

 gations of the twigs. In these, the part which is 

 once formed, and has rested for one season of inac- 

 tion, does not again increase its volume, either in 

 length or in diameter ; but the new parts are formed 

 external to it, and produced upon it, by different 

 degrees of adhesion, according to the nature of the 

 plant. 



This principle of adhesion, which of course is the 

 only one by means of which plants, which are formed 

 as it were by a succession of cases or deposits, which 

 do not increase after they are once formed, could at 

 all increase in volume, and which is in itself a result 

 of the peculiar mode of action in the species, has 

 been perhaps carried a little too far by those who are 

 determined to know more of nature than nature itself 

 reveals. It has been described, and that too by 

 modern botanists, not only as its otvn cause, but as the 

 cause of that of which it is in truth but the ejfcct, 

 namely, the peculiar habit of the plant, that which 

 makes it one particular species and not another. It 

 has sometimes happened, rather unfortunately for the 

 truth, that those who have attempted to generalise in 

 those matters of natural science where much remains 

 unknown, have been but lame logicians ; and though 

 their confounding of causes and effects, in these 

 matters, can do little or no moral harm, it is a stum- 

 bling block in the way of knowledge. 



It cannot be too plainly or too frequently put, that 

 the' character of a plant or an animal, whether we call 

 it generic, specific, or any thing else, is purely and 

 wholly matter of observation ; and if we venture to add 

 one word more than what that observation will bear 

 out, we must be wrong, inasmuch as there is but one 

 truth, and all else is error. If we find that certain 

 parts of the character are changed by one mode of 

 treatment, and not by another, we are warranted to 

 conclude that so much of the character as has been 

 changed depends upon that mode of treatment ; and 

 if we find a change taking place in nature, precisely 

 similar to that which we effect by artificial treatment, 

 we may conclude that the natural circumstances have 

 been similar to our artificial ones. By thus experi- 

 menting, in as far as we can subject the living sub- 

 ject to experiment, we question nature by the test of 

 art, and regulate future art by the knowledge of 

 nature ; and thus bring to living nature a portion at 

 least of that inductive philosophy which has worked 

 so many wonders for us in the study and use of dead 

 matter ; but if we invert the order of nature, and call 

 the final result, of which we can know nothing more 

 than the simple fact of its having taken place, its 



own antecedent or cause, there is an end of all philo- 

 sophy of all sense and meaning. 



ADIANTUM. A genus of plants belonging to 

 the Acotyledonou$ or cellular order of vegetables; and 

 to the natural family of Filices, the fern tribe. The 

 name is derived from the Greek word aSuwroi, dry, 

 because the plants are of such a nature that they 

 cannot easily be made wet. 



Generic characters : Clusters of capsules, oblong 

 or roundish, with a membranaceous covering arising 

 from distinct portions of the margin of the frond,which 

 is folded back. 



Upwards of sixty or seventy species have been dis- 

 covered in different parts of the world in Europe, 

 North and South America, the West Indies, New 

 Holland, &c. 



Adiantum Capilli Veneris, or Venus's Hair, is an 

 elegant fern, which, with its five green fronds, contri- 

 butes not a little to adorn the dripping rocks and 

 caves in various parts of Europe. It is rare in Britain, 

 but very common in moist shady places in the south 

 of Europe. Dr. Hooker has frequently noticed it 

 lining the inside of wells with a " tapestry of the ten- 

 derest green." It has been found growing at Bagueres 

 in water of the temperature of 105 of Fahrenheit's 

 thermoirteter. Its fronds or leaves are from six to 

 twelve inches in length, and retain their green colour 

 even when dried : hence they have a fine appearance 

 in a herbarium. The plant possesses demulcent and 

 mucilaginous properties. 



Adiantum pedntum, another species, is common in 

 France, and is employed extensively on account of its 

 astringent pectoral qualities. 



Both these species of adiantum, but especially the 

 latter, are used for the preparation of a pectoral syrup, 

 which has received the name of capillaire. The syrup 

 is made with honey and orange-flower water, and is 

 administered as a lenitive in coughs and catarrhs. 



The other species of the genus are not put to any 

 particular use. 



ADIPOCIRE (Fat Wax). A substance, in its 

 external or natural history properties, apparently in- 

 termediate between the two from which the name is 

 formed. 



The chemical properties of adipocire, or the species 

 of chemical action by which it is produced, do not 

 fall within the scope of natural history ; but we may 

 briefly notice the circumstances under which it is 

 formed. If animal matter is left on the surface of the 

 ground, or otherwise freely exposed to the atmo- 

 sphere, no adipocire results; neither is there any 

 formed when the animal matter is in small quantity, 

 and not deep below the surface, in ground which is 

 moderately warm, and not very moist. But when 

 the quantity of animal matter is great, and the depth 

 considerable, it not only forms in the situations that 

 have been mentioned, but, after the lapse of several 

 years, becomes partially transparent, and of a granu- 

 lated texture approaching to crystalline. This was 

 the case in the burial ground at the church of the 

 Innocents in Paris, where the substance was first 

 noticed, in the year 1787, when the matter of that 

 common place of inhumation was removed. Bodies 

 in vast numbers had there been thrown into pits, 

 thirty feet deep, and twenty in each of their other 

 dimensions. Those near the surface tainted the air 

 very much, which was the cause of the removal ; but 

 when they had been heaped to a considerable thick- 

 ness, the middle strata were converted into adipocire 



