ASPHALT 257 



ASHLAR, or ASHLER. "\Vlion stones are -worked in regular beds and joints, 

 and are dressed for facing work, they are called ashlar. The stone used as ashlar is 

 called ashlaring, when in thin slabs, and made to servo merely as a case to the regular 

 body of the wall. 



ASHLERING, in carpentry, are the short upright pieces of timbering or quar- 

 tering fixed, in garrets, to the floor and rafters, to cut off the acute angle which they 

 form. 



ASPARAGINE. Syn. Asparamide, altheine. C 9 H 8 N 2 O s +2Aq. (C 4 H fl W 2 O 3 + 

 H'-O.) A beautifully crystallised substance, firstfound in asparagus juice, by Vauquelin 

 and Robiquet, in 1805. It not only exists in a great number of vegetables, but some 

 which do not contain it naturally may bo made to afford it by being grown in dark 

 damp cellars. Many plants normally containing only small quantities of it may be 

 made to yield more by being allowed to germinate in that manner. Among the 

 vegetables from which it can be directly obtained may be mentioned the following : 

 Althtea officinalis, Asparagus acutifolius, A. off., Atropa belladonna, Convallaria majalis, 

 C, multiflora, Cynodon dactylon, Glycyrrhiza glabra, Lactuca sativa, Ornithoffalum 

 caudatum, Paris quadrifolia, Robinia pseudacacia, Solarium tuberosum, and Symphytum 

 off. The following list contains the names of some plants normally containing no 

 asparagine, but yielding it when allowed to germinate in darkness in damp cellars : 

 Colutca arborescens, Cytisus laburnum, Ervum lens, Genista juncea, Hedysarum 

 onobrychis, Lathyrus odoratus, L. latifolius, Phaseolits mdgaris, Pisum sativum, T-ri- 

 folium pratense, Vicia Faba, and V. saliva. 



Preparation. Perhaps the most convenient and economical mode of procuring 

 asparagine is from the etiolated (blanched) shoots of vetches. When they have- 

 acquired a length of two inches which, under favourable circumstances, will be in 

 about three weeks they are to be crushed, and the juice pressed out. The quantity 

 yielded will be rather less than three-fourths of the weight of the plant. It is then 

 to be boiled for a short time, to coagulate the vegetable albumen, and strained. This 

 clarified fluid is to bo evaporated until almost syrupy, and put aside to crystallise. 

 The product is at first brown, but by washing with cold water, afterwards dissolving 

 in boiling water, and subsequent crystallisation, it may be obtained pure. If, previous 

 to putting the hot fluid aside to crystallise, a little pure animal-charcoal be added, 

 and the whole be digested a short time, and then filtered, the crystals will be obtained 

 brilliantly white at one operation. Some chemists advise the germination to bo 

 allowed to go much further than was mentioned above, so that the shoots may bo as 

 long as 15 inches. The crystals obtained by the process given have the formula 

 C s H* N 2 8 +2 Aq., but the water is expelled at 212. Asparagine possesses the 

 peculiarity of behaving like a base towards strong oxides and like an acid towards 

 bases. The crystals obtained by the method given contain, in the 100 parts, carbon 

 32-00, hydrogen 6-67, nitrogen 18'67, oxygen 42-66. Dried at 212, it has the fol- 

 lowing composition: carbon 36'36, hydrogen 6'06, nitrogen 21 '21, oxygen 36-37. 

 C. G. W. 



ASPARAGOLXTE. A name given to a variety of apatite of the colour of 

 asparagus. 



ASPARAGUS OFFICINALIS. An esculent vegetable belonging to the 

 natural order LUiacetE. The young shoots sent up from the underground stem are the 

 parts used. 



ASPEN. The Populus tremula. A tree native of almost all parts of Europe as 

 far north as Siberia. The wood is white, and is applied to many useful purposes. 

 The charcoal prepared from the aspen is said to be well adapted for gunpowder. See 

 POPLAH THEE. 



ASPHALT, ASPHALTXT1VT, or MINERAL PITCH. (Asphaltc, Fr. ; 

 Asphalt, Sergpech, Ger.) A name applied to the solid varieties of bitumen. In 

 its purest form asphalt presents the appearance of a black or brownish-black 

 solid substance, possessing a bright conchoidal fracture. It fuses at 212 F., burning 

 with a brilliant flame and emitting a bituminous odour. Specific gravity = 1 to 

 1'2. Asphalt is insoluble in alcohol, but soluble in about five times its weight of 

 naphtha. 



The mineral substances included under the rather wide term of asphalt appear to 

 differ considerably in chemical composition. They may generally be resolved proxi- 

 mately into certain oils, resins, and pitch-like solids ; whilst ultimately they yield 

 carbon, hydrogen, and oxygen, associated with a small proportion of nitrogen 

 and mineral matter. The asphalts appear to have been formed by the evaporation, 

 solidification, and consequent partial oxidation of certain liquid hydrocarbons, 

 such as petroleum. Their ultimate origin may no doubt be traced to organic 

 sources. 



Asphalt is found in small quantity in the carboniferous limestone of Perbyshiro, 

 Vol. I. S 



