LIME. 



[ 396 ] 



LIMNOCHARES. 



extract with acetic acid. It is very commonly 

 met with in the crystalline form in various se- 

 cretions of animals, as the urine, the mucus of 

 the gall-bladder, that of the surface of the 

 pregnant uterus, the liquid of the allantois, 

 the contents of the Malpighian vessels, and 

 the so-called true renal vessels of insects, 

 cysts, &c. 



Its most characteristic form is the square 

 flattened octohedron (PL 9. fig. 9) ; but it 

 also occurs in the form of the square prism 

 terminated by quadrilateral facets, fine 

 needles, in that of a flattened body with an 

 ellipsoidal outline, frequently constricted so 

 as to resemble a dumb-bell, or variously ex- 

 cavated at parts of the surface (PL 9. figs. 

 11 & 12). It may be obtained artificially 

 in most of these forms (PL 9. fig. 13), by 

 dissolving artificial oxalate of lime in dilute 

 nitric acid and evaporation; some of the 

 forms thus obtained resemble those of car- 

 bonate of lime. When obtained by mixing 

 oxalate of ammonia with soluble salts of 

 lime, as chloride of calcium, &c., the crystals 

 are generally peculiar (PL 9. fig. 14), although 

 sometimes the regular octohedra are ob- 

 tained. 



It is insoluble in hot and cold water, 

 acetic acid and ammonia, but is soluble in 

 dilute mineral acids without effervescence. 



Phosphate of lime. This salt is most fre- 

 quently deposited from animal liquids in 

 an amorphous or granular state. It may be 

 obtained in the crystalline form by mixing a 

 solution of phosphate of soda with chloride 

 of calcium. The crystals are mostly thin 

 rhombic plates (PL 6. fig. 17). 



They are soluble in acetic and dilute 

 mineral acids without effervescence, but not 

 in potash or water. Some of the compound 

 crystals resemble those of the ammonio- 

 phosphate of magnesia, from which they may 

 be distinguished by the addition of dilute 

 sulphuric acid, which cause the formation of 

 needles of sulphate of lime. 



Sulphate of lime. Well known as form- 

 ing gypsum, alabaster, selenite, &c. It 

 rarely or never occurs in the crystalline form 

 in animal or vegetable products. When 

 rapidly formed in chemical testing, the 

 crystals consist of minute needles or prisms 

 (PL 6. fig. 16); when more slowly formed, 

 these are larger andmixed with rhombicplates. 



The crystals are but little soluble in water, 

 and not in acetic or the dilute mineral acids. 

 They are sometimes found in bottles con- 

 taining spirit in which marine animals have 

 been preserved. 



Medicinal precipitated sulphur is very 

 commonly adulterated with sulphate of lime. 

 The microscope at once enables the crystals 

 of the salt to be recognized. 



Urate of lime. See Urates. 



See Raphides and Urinary Deposits. 



BiBL. That of Chemistry, animal. 



LIMNIAS, Schrank.— A genus of Rota- 

 toria, of the family Flosculariaea. 



Char. Eyes (when young) two, red; ur- 

 ceoli or sheaths single ; rotatory organ with 

 two lobes. Teeth forming a row in each jaw. 



L. ceratophylli (PL 34. fig. 45). Urceolus 

 at first whitish, subsequently becoming 

 brown or blackish, smooth, or in consequence 

 of its viscidity covered with foreign bodies. 

 Aquatic; length 1-24 to 1-18". 



BiBL. Ehrenberg, Infus. p. 401. 



LIMNOCHARES, Latr. — A genus of 

 Arachnida, of the order Acarina and family 

 Hydrachnea. 



Char. Palpi small and short, with the 

 fifth joint small and forming a claw ; man- 

 dibles with the last joint subulate ; rostrum 

 cylincb'ical, elongate; eyes four, approximate; 

 coxae concealed beneath the skin, the ante- 

 rior larger than the posterior ; legs ambula- 

 tory. 



L. aquatica (holosericea) (PL 2. fig. 27). 

 The only species. It differs from all other 

 water-spiders by its walking instead of swim- 



mmg. 



Body very soft and often spontaneously 

 variable in form ; epidermis covered with 

 little conical granules (?) ; no hairs upon the 

 body, and but few u]5on the legs ; eyes at- 

 tached to a lanceolate scaly piece {d), and 

 surrounded by hairs; rostrum partly con- 

 cealed beneath the skin, the anterior ex- 

 serted half {b) cylindrical and accompanied 

 by the palps, the last joint of which is very 

 slender and obtuse ; by pressure the broader 

 base of the rostrum is made to protrude (/) ; 

 tarsi (c) thickened at the end, with large 

 claws ; coxse of four posterior pairs of legs 

 longer than the others, which is contrary to 

 what occurs in Hydrachna, Atax, &c.; coxae 

 of the anterior two pairs of legs closely 

 approximate, as are also those of the two 

 posterior pairs (e), but the two groups are 

 widely separated. 



The larvae have six legs, a large head-like 

 rostrum, with two large palps and two black 

 latero-anterior eyes, and fix themselves upon 

 or near the head oiGerris lucustris; they sub- 

 sequently detach themselves from this insect, 

 fall into the water, and pass their nymph- 

 stage under submersed stones, the perfect 



