ANCHOR 157 



of metal. This has the effect of removing the bland oil known in commerce as almond- 

 oil. Tho residue, when powdered, forms almond-meal. To obtain amygdalin from- 

 tho meal, the latter is extracted with boiling alcohol of 90 or 95 per cent. The 

 tincture is to be passed through a cloth and the residue pressed, to obtain the fluid 

 mechanically adherent to it. The liquids will be milky, owing to the presence of 

 some of the oil. On keeping the fluid for a few hours, it may be separated by pouring 

 off, or by means of a funnel, and so obtained clear. The alcohol is now to be removed 

 by distillation, the latter being continued until five-sixths have come over. The fluid 

 in the retort, when cold, is to have the amygdalin precipitated from it by the addition 

 of half its volume of ether. The crystals are to be pressed between folds of filtering 

 paper, and recrystallised from concentrated boiling alcohol. As thus prepared, it 

 forms pearly scales, very soluble in hot alcohol, but sparingly when cold ; it is 

 insoluble in ether, but water dissolves it readily and in large quantity. The crystals 

 contain six atoms of water of crystallisation. Most persons engaged in chemical 

 operations have noticed, when using almond-meal for the purpose of luting, that, 

 before being moistened with water, it has little odour, and what it has is of an oily 

 kind ; but, after moistening, it soon acquires the powerful and pleasant perfume of 

 bitter-almond oil. This arises from a singular reaction taking place between the 

 amygdalin and the vegetable albumen dr emulsin. The latter merely acts as a 

 ferment, and its elements in no way enter into the products formed. The decomposi- 

 tion, in fact, takes place between one atom of amygdalin and four atoms of water ; 

 the product being one atom of bitter-almond oil, two atoms of grape-sugar, and one of 

 prussic acid. 



In preparing amygdalin, some chemists add water to the residue of the distillation 

 of the tincture, and then yeast, in order to remove the sugar present, by fermentation, 

 previous to precipitating with ether : the process thus becomes much more complex, 

 because it is necessary to filter the fermented liquid, and concentrate it again by 

 evaporation, before precipitating the amygdalin. 



The proof that the decomposition which is experienced by the bitter-almond cake, 

 when digested with water, is owing to the presence of the two principles mentioned, 

 rests upon the following considerations. If the marc, or pressed residue of the bitter 

 almond, be treated with boiling water, the emulsin or vegetable albumen will 

 become coagulated, and incapable of inducing the decomposition of the amygdalin. 

 It is only the bitter almond which contains amygdalin ; the sweet variety is, there- 

 fore, incapable of yielding the essence by fermentation. But sweet almonds resemble 

 the bitter in containing emulsin ; and it is exceedingly interesting as illustrating 

 the truth of the explanation given above that if a little amygdalin be added to an 

 emulsion of sweet almonds, the bitter-almond essence is immediately formed. A, 

 temperature of 100 is the most favourable for the digestion. C. G. W. 



AMYLENE. This hydrocarbon, C' H' (C s H 10 ), is produced by the dehydra- 

 tion of amylic alcohol by sulphuric acid ; also by the dry distillation of amyl-sulphate 

 of calcium. It is a colourless thin liquid, with a faint offensive odour. It has been 

 tried as a substitute for chloroform without success. 



AltXYXilRVI IKAWDXOCJE. Mandioca or Cassava starch. See CASSAVA and 

 MANDIOCA. 



ANACARDItTIVI WTtJT. Dr. Bottyer, in the 'Bayerisches Industrie- und 

 Gewerbe-Blatt,' states that the juice of the Anacardium nut, Anacardium Orien- 

 tale, contains an oily matter, which, by exposure to the air, assumes a fine black 

 colour, which is quite permanent against the influences of acids or alkalies, chlorine or 

 cyanide of potassium. It is recommended for use as a marking ink ; and if the linen 

 be moistened with a little ammonia, the black is very intense and quite permanent. 



ANALYSIS. In chemistry, a term which is employed to signify the art of re- 

 solving a compound substance into its constituent parts. Every manufacturer should 

 so study this art, in the proper treatises and schools of chemistry, as to enable him 

 properly to understand and regulate his business. See Watts's ' Dictionary of Chem- 

 istry.' See also SPECTRUM ANALYSIS. 



ANATASE. An oxide of titanium, of the same composition as Brookite and 

 Eutile. It occurs in Dauphiny with felspar and ilmenite, in Devonshire in chlorite, 

 and in North Wales with Brookite. It is said to be found in the slags from the iron 

 furnaces of Orange County, United States. 



ANCHOR. (Ancre, Fr. ; Anker, Ger.) An iron hook, of peculiar construction 

 and of considerable weight and strength, for enabling a ship to lay hold of the 

 ground, and fix itself in a certain situation by means of a rope" called the cable. The 

 necessity for securing boats, canoes, or ships in a certain position, has led to the adop- 

 tion of anchors, of some description, amongst every nation dwelling upon the shores of 

 seas, lakes, or rivers. They were often of the rudest description. We are informed 

 that the Greeks at first used stone anchors, but that they subsequently employed in- 



