I.ND 



INF 



not produce a clear dye. It may be 

 puritied by adding the solution to a 

 considerable amount of builing wa- 

 ter, and putting into it wool to mace- 

 rate in the cold for 24 hours. The 

 wool becomes deep blue, and should 

 remain until the liquor is greenish 

 blue ; it is then to be taken out, 

 drained, and washed in a stream of 

 pure water until the fluid ceases to 

 be coloured or acid. The washed 

 wool is next to be placed in a copper 

 full of water, containing two percent, 

 of pearlash, or carbonate of soda (or 

 three times the weight of indigo), and 

 kept boilmg a quarter of an hour ; 

 The pure blue (sulphate and hypo- 

 sulphite of indigo) colours the wa- 

 ter, the woo] remaining dyed a dirty 

 brown (indigo red) : the solution may 

 be used as a dye, yielding a bright, 

 good colour, called distilled or soluble 

 blue. I 



Wools and other textures are first 

 boiled in alum before bemg perma- 1 

 nentjy dyed in the soluble blue, the 

 depth of tone being increased by sev- 

 eral applications of alum and immer- 

 sions in the solution ; it also serves 

 to make olives, greens, and other 

 mixed colours. 



Other means of dyeing are exten- 

 sively used, founded on the property 

 of indigo to become soluble in alka- 

 line solutions, or limewater, and col- 

 ourless when brought in contact with 

 a deoxydizing substance, as green 

 vitriol, and recovermg its hue on sub- 

 sequent exposure to air. The indigo 

 (indigogene) may be thrown down 

 from solution by acids as a white 

 body, of which blue indigo is suppo- 

 sed to be the oxide. The most com- 

 mon means of dyeing is the cold or 

 copperas tat ; this is made as follows : 

 The indigo is well rubbed into a fine 

 paste with water or lye ; it is then 

 stirred into a vat of hot water, and 

 newly slacked lime added ; a solution 

 of green vitriol is then stirred into 

 the preparation. The quantities em- 

 ployed are one pound of indigo, four 

 pounds of lime, and three pounds of 

 copperas. The dyeing vat is sep- 

 arate, and furnished with the result- 

 ing solution, which contauis deoxy- 



dized indigo of a reddish yellow col- 

 our. There is a precipitate left in 

 the preparing vat of sulphate of lime, 

 lime mixed with indigo, brown, and 

 some blue, and peroxide of iron. 



In using this cold vat, cotton and 

 linen are to be first boiled in a weak 

 alkaline lye, and the cloth, whether 

 cotton, wool, or silk, is to be merely 

 dipped without starring, and allowed 

 to remain from eight to ten minutes ; 

 they are hung to drain over the vat ; 

 they are then to be exposed to the 

 I air to acquire a blue colour, and dip- 

 ped until the proper tint is obtained. 

 When suitably coloured, they must 

 be plunged into a sour bath of very 

 dilute sulphuric or muriatic acid to 

 remove the lime, and finally rinsed 

 in running water. 



Boussingault is of opinion that the 

 dye-stuff might be prepared in the 

 beginnmg from the mash-vat by this 

 process with great advantage. Nu- 

 merous products obtained by the ac- 

 tion of re-agents on indigo are known 

 in chemistry, but are of little impor- 

 tance to us. 



irsDUCTION. The process of ar- 

 riving at generalizations, or laws, by 

 a judicious investigation of numerous 

 facts. In electricity, it is the influ- 

 ence one electrified body exerts on 

 another, whereby its nearest surface 

 is made to exhibit a kind of electri- 

 city differing from that of the excited 

 substance. 



INDUMEXTL'M. The coating of 

 feathers on birds. 



INDUSLE. The cases of certain 

 water insects ; they are silicious, 

 calcareous, or ferruginous. 



INDUSIUM. The thin membrane 

 covering the fruit of some ferns. 



INDUVLE. Organized remains ; 

 the withered leaves of monocotyle- 

 donous trees, &c. 



INERMIS. Unarmed; without 

 spines or prickles. 



INERT VEGETABLE MATTER. 

 Peat, tan, <kc., which does not readi- 

 ly ferment ; mixture with dung, lime, 

 or ashes reduces it. 



INERTIA. The indifference of 

 matter to rest or motion 

 INEIELD. Under improved tillage 



419 



