BIGNONIACE^. 



[ 07 ] 



BINOCULAR. 



bigny. B. agglutinans (PI. 23. fig. 50) is an 

 elongate and coarso-slielled variety of B. 

 nodosan'a. Common in many seas, and in 

 the fossil state. 



BiiiL. D'Orbiguy, For. Foss. Vien. 237 ; 

 Carpenter. Litrod. For. lUl. 



BIGNOXIACE.E ( Dicotyledons) .—The 

 wings of the seeds of this family allbrd very 

 beautiful objects. They are either thin 

 membranes composed of a layer of lignified 

 cells ; or, as in the Catalpas, the -sving con- 

 sists of a fringe of hairs. 



BILE. — Three colouring - matters have 

 been obtained from the bile, viz. cholepyr- 

 rhine, biliverdine, and bilifulvine. These 

 Avero formerly regarded as distinct ; but 

 later researches have tended to show that 

 they are modifications of the same pigment. 

 Cholepi/rrhine ovhilirtihine, the colouring- 

 matter in its ordinary state, is characterized 

 by the series of tints through which it 

 passes when treated with nitric acid, 

 especially if this contain nitrous acid; 

 becoming first brownish, then green, bluish, 

 violet, red, and finally yellow. It is some- 

 times found in bile and the liver-cells in the 

 form of yellow semicrystalline gi-ains ; also 

 it enters into the composition of biliary 

 calculi. 



Biliverdine is found in the bile, but not in 

 gall-stones; it is formed from bilu'ubine by 

 oxidation. It is most abundant in the bile 

 of the Herbivora. 



Biliprasine is brown, becoming green with 

 acids ; it occm's in decomposing bile. 



BiUfulvine is also sometimes found in bile 

 which has been retained in the gall-bladder. 

 The bile then appears thick and dark brown, 

 and exhibits small dark grains ; the crystals 

 are found in these grains. They form 

 longish, very fine needles, of a reddish-yel- 

 low colour, either single or severalcombined. 

 AVhen aggregated, they sometimes resemble 

 the crystals of lu'ate of soda, and are often 

 curved and twisted. Caustic potash dis- 

 solves them tolerably readily. Acetic acid 

 produces no change in them. Nitric acid 

 has but little efiect upon them, unless the 

 action is very intense, when they are decom- 

 posed. Yirchow notices the occurrence of 

 these crystals upon the walls of the cysts 

 of Echinococci in the liver, where we have 

 also found them, and in the liquid contents 

 of the cysts. In this instance, tAvo kinds 

 of crystals were met with (PL 13. fig. 15) : 

 some" of these were rhombs (b), others were 

 twsted and elegantly curved bundles of nee- 

 dles («)• ^Vheu first examuied, they were 



yellowish-red ; but after remaining a day or 

 two in the liquid of the cysts, they became 

 almost perfectly yellow. When mounted in 

 balsam, the rhombs remained unaltered, 

 whilst the long filamentous groups of nee- 

 dles lost all colour, leaving a barely dis- 

 tinguishable transparent skeleton. Both 

 kinds were insoluble in acetic acid, but 

 soluble in potash with a yellow colour. 



In morbid bile, crystals of cholesterine, 

 globules of fat, and small bundles of needles 

 of margarine are also occasionally found. 

 See ILematoidine. 



BiBL. Gineliiis Handb. d. Chem. vii. & 

 viii. ; Virchow, An. d. Phartn. 1851 (Chem. 

 Gaz. X.); Karsten, I)e hep. et bile Crustac. 

 et Mollusc. ; Frey, Histol. &c. 187G, p. 551 ; 

 Stiideler, Fogq. Anmd. cxxxii. p. 323. 

 BILHARZIA. See Distoma. 

 BILIFULVINE. See Bile. 

 BILOCULI'NA, D'Orb.— One of the 

 Milioline Foraminifera, in which each suc- 

 cessive segment embraces more or less com- 

 pletely the preceding segments, on alter- 

 nate sides, so that only two chambers of 

 the shell are visible externally. It varies 

 much in form and size ; the Varieties are 

 very common, recent and fossil, and have 

 numerous names : the largest has been found 

 at 650 fathoms in the North Atlantic {Car- 

 penter). B. ringens (PI. 23. fig. 3) is taken 

 as the type. 



BiBL. B'Orbigny, For. Foss. Vien. 261 ; 

 Williamson, Brit. For. 78; Carpenter, 

 Intr. For. 75, 78. 



BIMETJA, T. S. Wright.— A genus of 

 Hydroid Zoophytes, family Atractylidse. 



The body and lower part of the tentacles 

 enveloped by an opaque brown membrane. 

 B. vestita. Attached to zoophytes and 

 sea-weeds. 



BiBL. Ilincks, Ili/droid Zoophutes, p. 103. 

 BINOCULAR MICROSCOPE.— This 

 has been alluded to at p. xiv of the Intro- 

 duction. We have no space for the figures 

 requisite to illustrate descriptions of the 

 three principal forms of binocular micro- 

 scope ; hence we must be satisfied with 

 referring to the works in which they will 

 be foimd. In the examination of new 

 structiu-es, no reliance should be placed upon 

 the appearances presented by objects under 

 binocular vision, unless controlled by the 

 means pointed out in the second part of the 

 Introduction. 



The three principal forms of binocular 

 construction are those of Wenham, Holmes, 

 and Stephenson. 



H 



