LIME. 



[ 470 ] 



LIMNIAS. 



in the urine, are closely imitated by those 

 formed in urinelo which chloride of calcium 

 has been added, and which has been subse- 

 quently kept for some time. 



Lactate of lime may be obtained by acting 

 upon carbonate of lime with lactic acid. It 

 is soluble in water and alcohol. The mi- 

 croscopic crystals consist of tufts of delicate 

 radiating needles (PL 11. fig. 19). 



Oxalate of lime. This salt exists in solu- 

 tion in the contents of many vegetable cells 

 combined with a proteine compound ; it is 

 also probably a normal constituent of the 

 human blood in small quantity, combined 

 and dissolved as in vegetables. 



In the cells of plants it is very frequently 

 deposited hi a crystalline form, constituting 

 RAPHIDES. From human blood it has been 

 obtained in crystals by treating the alcoholic 

 extract with acetic acid. It is very commonly 

 met with in the crystalline form in various 

 secretions 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 octahedron (PI. 13. fig. 9) ; but it 

 also occurs in the form of the square prism 

 terminated by quadrilateral pyramids, of fine 

 needles, and in that of a flattened body with 

 an ellipsoidal outline, frequently constricted 

 so as to resemble a dumbbell, or variously 

 excavated at parts of the surface (PL 13. 

 figs. 11 & 12). It may be obtained artificially 

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

 dissolving artificial oxalate of lime in dilute 

 nitric acid and evaporating ; 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 13. fig. 14), al- 

 though sometimes the regular octahedra 

 are obtained. 



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 10. 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 aminouio- 

 phosphate of magnesia, from which they 

 may be distinguished by the addition of 

 dilute sulphuric acid, which causes the for- 

 mation 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 10. 

 fig. 16) j when more slowly formed, these 

 are larger and mixed with rhombic plates. 



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 EAPHIDES and URINARY DEPOSITS. 



BIBL. That of CHEMISTRY, ANIMAL. 



LIMNAC'TIS, Ktz. A genus of Rivu- 

 lariacese, Confervoid Algae. 



Char. Filaments pseudo-ramose, subfas- 

 ciculate, sheath more or less distinct. L. 

 panmla ; Lincolnshire. 



BIBL. Rabenh. Fl. Alg. ii. 210. 



LIMNADEL'LA, Girard. A bivalve 

 Phyllopodous Entomostracon, near Es- 

 theria. 



BIBL. Girard, Proc. Phil. Ac. i. 184, & 

 vii. 34 ; Grube, Wiegm. Arch. 1865, 73. 



LIMNADIA, Brongn. An aquatic bi- 

 valved Phyllopod, with thin oval valves, 

 enclosing an elongated body, having a short 

 and a natatory pair of antennae, oral appa- 

 ratus, twenty-two or more pairs of branchial 

 lamellae, and a bifid tail. 



BIBL. Brongniart, Mem. Mus. Hist. Nat. 

 vi. pi. 13 ; Desinarest, Crust. 378 ; Milne- 

 Edwards, Hist. Nat. Crust, pi. 35. f. 7; 

 Baird, Zool Proc. 1849, 86, pi. 11. f. 1 ; 

 Grube, Wiegm. Arch. 1865, 61, pi. 8 ; Lere- 

 boullet, Ann. Sc. Nat. Zool. 5, v. 283, pi. 12. 



LIMNE'TIS, Lov^n. An aquatic bi- 

 valved Phyllopod, related to Limnadia and 

 Estheria. 



BIBL. LovSn, K. V. Ak. Handl. 1845, 

 203; Baird, Zool. Proc. 1862; Grube, 

 Wiegm. Arch. 1865, 71. 



LIMNIAS, Schrank. A genus of Rota- 

 toria, of the family Floscularieea. 



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



