54 REPOHT — 1873. 



words, thus summing up the special objects of these reports: — "In the opinion of 

 all, Liebig may be considered a benefactor to his species for the interesting dis- 

 coveries iu agriculture published by him in the hist part of this report. And 

 liaving in that pointed out means by which the food of the human race may be 

 increased, in the work now before us he follows up the chain in its continuation, 

 and shows how that food may best be adapted to the nutrition of man. Surely 

 there are no two subjects more fitted than these for the contemplation of the phi- 

 losopher ; and by the consummate sagacity with which Liebig has applied to their 

 elucidation the powers of his mind, we are compelled to admit that there is no 

 living philosopher to whom the Chemical Section could have more appropriately 

 entrusted their investigation." 



At the Meeting at (jlasgow in 1855 Liebig was also present; but he then only 

 communicated to this Section a short paper on fulmiuuric acid, and some remarks 

 on the use of lime-water in the manufacture of bread. 



Such, I believe, is the history of the direct relationship which has existed 

 between Liebig and this Association. Indirectly we can hardly recogTiize how 

 3niich we owe to him. Interested as he ever was iu the work of this Association, I 

 could not but to-day record the instances of direct aid and support which this 

 Section has received from him. 



I pass on now to the special subject to which I wish to ask your attention. It 

 is the histoi-y of the vegetable colouring-matter found in madder : it has been in 

 use from time inimemoiial, and is still one of the commonest and most important of 

 (lyes; it is obtained from a plant largely cultivated iu many parts of the world for 

 the sake of the colour it yields ; and the special interest which now attaches to it is 

 that the chemist has lately sliown how this natural colouring-matter can be made 

 in the laboratory as well as iu the fields — how by using a bj'-product which for- 

 merly was without value, thousands of acres can be liberated for the cultivation of 

 other crops, and the colouring-matter which they formerly produced be cheaper 

 and better prepared iu tlie laboratory or in the manufactory. That a certain 

 colouring-matter could be obtained from the roots of the Rtibia tinctorum and other 

 species of tlie same plant has been so long known that apparently no record of its 

 discovery remains. Pliny and Dioscorides evidently allude to it. The former, re- 

 ferring to its value as a dyeing material, says :— " It is a plant little known, except 

 to the sordid and avaricious — and this because of the large profits obtained from 

 it, owing to its employment in dyeing wool and leather." He further saj's : — " The 

 madder of Italy is the most esteemed, and especially that grown iu the neighbour- 

 liood of liome, where and in other places it is produced iu great abundance." He 

 fiirther describes it as being grown among the olive-trees, or in fields devoted 

 especially to its growth. Tlie madder of Ravenna, according to Dioscorides, was 

 the most esteemed. Its cultivation in Italy has been continued tiU the present 

 time ; and in ISOo the Neapolitan provinces alone exported it to the value of ni'ire 

 than a quarter of a million sterling. At the present daj' we are all very familiar 

 with this colouriug-matter as the commonest that is applied to calicoes ; it is 

 capable of yielding many colours, such as red, pink, purple, chocolate, and black. 

 The plant which is the source of this colouring-matter is nearly allied, botanically 

 and in appearance, to the ordinary Galiums or Bedstraws. It is a native pro- 

 bably of Southern Europe as well as Asia. It is a perennial, with herbaceous 

 stem, which dies down every j'ear; its square-jointed stalk creeps along the ground 

 to a considerable distance ; and the stem and leaves are rough, with sharp prickles. 

 The root, which is cylindrical, fleshy, and of a pale yellow colour, extends down- 

 wards to a considerable depth ; it is from this root (which, when dried, is known as 

 madder) that the colom-ing-matter is obtained. The ])lant is propagated from 

 suckers or shoots ; these require some two or three years to come to full maturity 

 and yield the finest colours, although in France the crop is often gathered after 

 only eighteen months' growth. From its taking so long to develop, it is evidently 

 a crop not adapted to any ordinary series of rotation of crops. The plant thrives 

 best in a warm climate, but has been grown in this country and in the north of 

 Europe. 



In India it has been grown from the earliest times, and, as before stated, has 

 been abundantly cultivated in Italy certainly since the time of Pliny ; he also 



