MADDER 171 



was at the same time charred, so as to prevent it from attracting and binding any 

 of the colouring-matter. This explanation is not entirely correct, since it is not 

 necessary to carry the action so far as actually to carbonise any of the constituents 

 of the root, and it is also doubtful whether the woody fibre ever attracts the useful 

 colouring-matters in any considerable degree. The account above given of the 

 chemical constitution of madder, may easily lead us to the conclusion, that, during 

 the action of the acid, the following processes take place: 1. The bitter principle or 

 colour-producing body of the root is decomposed, yielding, among other product*, a 

 quantity of alizarine which did not previously exist 2. The red colouring-matters 

 are rendered by the acid insoluble in water, and thus it becomes possible to wash out 

 the extractive matter, sugar, &c., without the madder losing any of its tinctorial power. 

 3. The lime, magnesia, and other bases which are combined in the root with colouring 

 matter, or would combine with it during the dyeing process, are removed by the acid, 

 and thus prevented from exerting any injurious action. The subsequent addition of 

 a suitable quantity of lime, soda, or other base, serves to neutralise the effect of the 

 excessive amount of poetic acid and resinous colouring matters, which were sot free by 

 the action of the mineral acid. 



The method of manufacturing garancine, as practised at the present day, may be 

 shortly described as follows: The ground madder is mixed with water, and the 

 mixture is left to stand for some hours. During this time it is probable that the 

 rubian is decomposed by the ferment of the root, otherwise a great loss woidd be 

 experienced. More water is now added, in order to remove all the soluble matters, 

 and is then run off. The liquid contains sugar, and is employed on the Continent for 

 the preparation of a kind of spirit, which on account of its peculiar smell and flavour 

 cannot be consumed as a beverage, but is used in the arts for the preparation of 

 varnishes and other purposes. A sufficient quantity of alcoholic spirit is thus obtained 

 to pay for the whole cost of the process. The residue left after washing the madder 

 may be employed for dyeing without any further preparation, and is then called fleur 

 de garance. In order to convert it into garancine, it is mixed with sulphuric acid, and 

 the mixture is heated and left to itself for some time. Water is then added in suc- 

 cessive portions until the excess of acid is removed. The pectic acid of the root 

 always retains a portion of the sulphuric acid in chemical combination ; and the 

 compound being but little soluble in water would require for its removal a very long 

 washing. The addition of a small quantity of carbonate of soda, by neutralising this 

 double acid, serves to abridge the time of washing very considerably. The residue is 

 then filtered on strainers, pressed, dried, and lastly ground into a fine powder. This 

 powder has a dark reddish-brown colour, and a peculiar odour, different from that of 

 madder, but no taste. It communicates hardly any colour to cold water. Dyeing 

 with garancine is attended with the following advantages: 1. The whole tinctorial 

 power of the madder is exerted at once, and garancine is therefore capable of dyeing 

 more than the material from which it is made. 2. The colours produced by its 

 means are much brighter than those dyed with madder, and the parts of the fabric 

 destined to remain white attract hardly any colour, so that very little treatment is 

 required after dyeing. 3. Much less attention is required in regard to the temperature 

 of the dye-bath and its gradual elevation than with madder, and a continued ebullition 

 produces no injurious effects, but only serves to exhaust the material of all its colour- 

 ing-matter. On the other hand, garancine colours are not so fast as madder colours, 

 they do not resist so well the action of soap and acids, and hence garancine cannot be 

 employed for the production of the more permanent colours, such as pink and fine 

 purple. By the use of a product which was patented by Pincoffs and Schunck several 

 years ago, and which is obtained by exposing garancine to the action of steam of high 

 pressure it is indeed possible to dye as beautiful and as permanent a purple as with 

 madder, and its use is attended by a considerable saving of fime as well as of dyeing 

 material and soap, but it is not so well adapted for dyeing pink. As yet therefore we 

 have not succeeded in obtaining a preparation which shall serve as a perfect substitute 

 for madder, and the latter consequently continues to bo employed for some purposes. 



The residue left after dyeing with madder as well as the dyeing liquor still contain 

 some colouring-matter in a state of combination, as mentioned above. By acting on 

 it with sulphuric acid it affords a product similar to garancine. which is called 

 gamnceux. This prodxict is, however, adapted only for dyeing red and black, as it 

 does not afford a good purple. (See CALICO-PBINTING.) Numerous other methods of 

 treating madder for the use of the dyer have been invented and patented of late years, 

 but they are not sufficiently important to merit description within the limife of the 

 present article. E. S. 



The following notes of a journey to the madder-growing districts of France, (October 

 1866), by James Higgin, who contributed the important article on CALICO-PRINTING, 

 will be found to have considerable interest : ' The part of the Comtat d 1 Avignon 



