IN DRYOPS. 



price in China is on* hundred time* greater than that of the common 

 .mmphor of commerce. (M'CuUooh. ' Com. Diet.') In the same work 

 it i* mentioned that camphor-oil being nearly as cheap aa spirit* of 

 turpentine, might perhaps be profitably imported into England as a 

 substitute for that article, or for medicinal use. 



Camphor, which in many respects resembles the essential oils, haa 

 been shown by Duma* to be an oxide of hydrocarbon, indeutical in 

 composition with pure oil of turpentine : hence the term Carnphene 

 ha* been applied to it But Dr. Thomson informs us that its camphor- 

 oil differs in some respects from oamnhene, as he was not able to 

 produce camphor with the same facility or in equal quantity by 

 driving a stream of oxygen gas through highly -rectified oil of turpen- 

 tine, which Dumas regards aa pure camphene. 



I'KYOPS, the name given by Olivier to a genus of Pentamerous 

 Coleopterous Inaorls of the family Ctaricornc*. The type is the 

 DmmtHm ouriruialia of Geoffrey, a little obloog gray sluggish beetle, 

 not uncommon in Europe in the neighbourhood of watery places. Fa- 

 bricius chanced the name of this genus into Parnut. It includes 14 

 snnri**, of which 7 are American and 7 European. The name Dryopt 

 wa* applied by Fabricius to another genus of Coleoptera, of which the 

 It'Htmrra femoraJit, a Swiss insect, was the type. Changes of this 

 kind are highly censurable, inc.easing as they do the confusion arising 

 from a complicated synonymy. 



DKY ROT, a well-known disease affecting timber, and particularly 

 the oak employed for naval purposes. When dry rot is produced by 

 the attacks of fungi, the first sign of it consista in the appearance of 

 small white points, from which a filamentous substance radiates 

 parallel with the surface of the timber. This is the first stage of 

 growth of the spores of the fungus, and the filamentous matter is 

 their thallus or spawn. As the thallus gathers strength it insinuates 

 it* filament* into any crevice of the wood, and they, being of exces- 

 sive fineness, readily pas* down and between the tubes from which 

 th* wood is organised, forcing them asunder, aud completely destroy- 

 ing the cohesion of the tissue. When the thalli of many fungi inter- 

 lace, the r*Ktif*'T*r. appearance can no longer be remarked ; but a thick 

 tough leslhsij white stratum U formed wherever there is room for 

 Ha development, and from this a fresh supply of the destructive 

 filamentous thallus is emitted with such constantly increasing rapidity 

 and force, that the total ruin of timber speedily ensues where circum- 

 stances are favourable for the growth of the fungi 



It is generally Hated that dry rot consists of the thallus of Merulitu 

 Utrfmami, or /'u/y/wnu detractor, two highly-organised fungi, whose 

 fructification is sometime* found upon rotten timber. But it is a 

 great mistake to suppose that dry rot belongs exclusively to those 

 two specie*, or that they are even the common origin of it : on the 

 contrary, there is reason to believe that any of the fungi that are 

 commonly found upon decaying trees in woods are capable of pro- 

 ducing dry rot, and it is quite certain that one of the most rapidly- 

 spreading and dangerous kinds is caused by the ravages of different 

 ' of Sftntrick*m. The latter throw up from their tlialhui 



whole f ousts of microscopic branches loaded with reproductive spores, 

 of such excessive smallness that they may insinuate themselves into 

 th* moat minute crevices or flaws even in the sides of the tubes of 

 which timber consists, and they are infinitely more dangerous than 

 MenUii or Patypori, which seldom fructify. 



The eircnmstances that are moat favourable to the development of 

 the dry rot fungi are damp, unventilated situations, and a subacid 

 tate of the wood. The latter condition, especially in oak, is easily 

 (nxliieed by a slight fermentation of the sap which remains in the 

 timber, especially if the latter has not been well-seasoned before 

 bates; employed. It has been proved experimentally that fluids 

 which, in their ordinary state, will not produce fungi, generate them 

 abundantly if ever so slightly acidulated. Dutrochet found that dis- 

 Ulled water holding in solution a small quantity of white of egg will 

 not generate fungi in a twelvemonth, but upon the addition of the 

 minutes* quantity of nitric, sulphuric, nmrintir, phosphoric, oxalic, 

 or acetic acid, it generated them in eight days' time in abundance. 

 flllilnnant lifusinns possess the same property. This observer states 

 that the only poisons which will prevent the appearance of fungi are 

 UM oxid* or salta of mercury. A solution of fish-glue yields fungi 

 rapidly and in great abundance ; but a small quantity of red precipi- 

 tate or corrosive sublimate destroys this power entirely. It is more- 

 over an important feet that no other mineral preparation has any 

 such prutWUsa. Dutrochet ascertained that other metallic oxides 

 acted diflartntly. Oxides of lead and tin hastened the development 

 of fungi ; thost of iron, antimony, and sine, were inert ; and oxides of 

 copper, nickel. Mid cobalt, although they retarded the appearance of 

 fank yet did not prsvent their growth in th* end. These facts are 

 aunlrmed by UM experience of the use of Ryan's process for preparing 

 timber, which consist* in submitting the wood to the action of corro- 

 sive sublimate. Immersing the wood in chloride of one also prevenU 

 the attack of fungi, and also submitting it to the action of the vapour 



Dry rot also occurs In animals. Specimens of hymenopterous 

 famed* resembling wasps have been brought from UM West Indira, 

 with a fungus allied to jMbtria mUilaru (rowing from between th-ir 

 ' ir cox. and it is positively awn-tod by traveller* that the 

 fly about while burdened with UM plant. Upon owning the 



DUCKS. si 



bodies of the wasps they are found filled with the thallus of Uie fungus 

 up to the orbits of the eyes and the points of the tarsi ; the whole of 

 i!i.' intestines being obliterated. In nucli canes it is to be supposed 

 that the thallus of tin- .''/ Jutria first kills the wimp l>_v ..impressing 

 and drying up the body, aud then, continuing to grow, occupies the 

 whole of the cavity of the shell of the insect. A more common 

 instance of animal dry rot is the disease in silkworms called La 

 Muscadine. Silkworms of all ages are occasionally liable to become 

 sickly and to die, soon after death becoming stiff, and acquiring such 

 a degree of firmness as to be readily broken. They then throw out 

 from their surface a sort of white efflorescence, which is the fructifi- 

 cation of the fungus called liutrylu Batriana, their inside being filled 

 by the thallus of the same plant If some healthy caterpillars are 

 placed beneath a bell-glass, along with a small portion of worm killed 

 by the Bolrylii, they soon catch the disease, exhibit the same symp- 

 toms as those already mentioned, and eventually perish ; having, no 

 doubt, been infected either by rubbing themselves against the dead 

 worm, or, which is more probable, having received upon their skins 

 the infinitely minute seeds dispersed by the liotryiit. If healthy 

 crysalids are inoculated by the introduction below their shell of a 

 little of the Eatrytu matter upon the point of a needle, they also 

 . and die. 



In theae cases effects arc produced upon insects similar to those 

 upon timber ; that is to say, vitality in the one case and cohesion in 

 the other is destroyed by the growth of the thallua of certain fungi, 

 which spread with great and irresistible rapidity, aud fructify where 

 occasion offers. 



For other instances of the agency of fungi in producing the 

 destruction of vegetable and animal tissues, see KUNOI. 



USIIIKKKTKl (XUctelei). Cuvier writes the word I^iyguelai, 

 and Buffon Ikigithai, the native name for the Equa Jlrmiuniu of 

 Pallas, AHUM Jfemionut of Gray. [Kyuiujj.] 



DUCK-HI I,L. [ORNITHORHYNCHUS.] 



1'1'i'KS, Duck Family, Anatida, a family of Birds belonging to 

 the order ffatalura, Antera, or Palmipede*. They are all Aquatic 

 limls, and have webbed feet. 



Willughby distinguishes the whole-footed birds with shorter legs 

 into such aa want the back toe, and such as have it ; these latter into 

 such as have all four toes webbed together, and such aa have the 

 back toe loose or separate from the rest ; these latter again he sub- 

 divides " into narrow-billed and broad-billed ; the narrow-billed have 

 their bills either hooked at the end, or Btraighter and sharp-pointed. 

 The hook-billed have their bills either eveu or toothed on the sides. 

 Those that have straighter and sharp-pointed bills are either short- 

 winged and divers, called Douckers and Loons, or long-winged and 

 much upon the wing, called Gulls. The broad-billed are divided into 

 the Goose kind and the Duck kind. The Duck kind are either Sea- 

 Ducks or Pond-Ducks." He afterwards, in his section on the Broad- 

 Billed Birds of the Duck kind, thus treats (chap, i.) of the Duck 

 in general : " The Duck kind have shorter necks and larger feet in 

 proportion to their bodies than Geese : lesser bodies. Howbeit, the 

 biggest in this kind do equal if not exceed the least in that. They 

 have shorter legs than Geese, and situate more backward, so that 

 they go waddling ; a broader aud Hatter back, and so a more OOBt- 

 pressed body ; and lastly, a broader and flatter bill Their tongue is 

 pectinated or toothed on each side, which is common to them with 

 i: 



" These are of two sorts, either wild or tame. The wild again are 

 of two sorts 1. Sea-Ducks, which feed mostwhat in salt water, dive 

 much in feeding, have a broader bill (especially the upper part) and 

 Iwnding upwards (to work in the sletn), a large hind toe, and thin 

 (likely for a rudder), a long train, not sharp-pointed. 2. Pond-Ducks, 

 which haunt plashes, have a straight anil narrower bill, a very little 

 hind toe, a sharp-pointed train, white belly, speckled feathers, black 

 with glittering green in the ini<!.l!i> wing, with a white transverse 

 line on either side. For this distinction of Sea-Ducks and I'.m.l- 

 Ducks we are beholden to Mr. Johnson." 



Ray divides his 'Pamipedes latirostra miuores, seu Auatinum 

 genus' into Anala marina: and A.jtvriatiiei, aqwu duleet pracipui 

 frequrnlanlai, A. exotica Branliennct, and A. domatinr. Itrisson's 

 24th order, consisting of birds with four toes, the three anterior 

 Iwing joined together by membranes, the posterior separated, and 

 with a dentilated bill, includes the genera Harle, Oie, and Canard 

 (Goosanders, Geese, and Ducks). This order is placed between that 

 order of birds the arrangement and connection of whose toes is 

 similar to the modifications of those parts in the 24th order, but 

 which have a bill without denotations (Puffins, Petrels, Gulls, Terns, 

 Ac.), and the 25th order, which is distinguished by the birds arranged 

 under it having all the toes joined by membrane* (the Darters, 

 Boobiea, Pelicans, Ac.). 



Liumcus, under his third class of birds, Anteni, included the 

 general not, Mtrgiu, A lea, ProceUaria, Diomedca, POecamu, Plotiu, 

 Pkaeta*, tUymow, Larut, Sterna, and Rynchop* ; in short, all those 

 birds which possess a rather blunt bill, covered with an epidermis 

 gibbous at the base, dilated at the apex, ami with dentieiiluW bumf, 

 a fleshy tongue, and palmatod natatorial feet. The class stands between 

 the Pica and the Orallit. The genus A not comprehends the Swans, 

 the Geese, and all the Ducks in the general ncn-ptnti.in <>l (! 



