62 



SCIENCE. 



locality changed readily. The block, as seen in the 

 figure, has a bead on each edge ; these beads are 

 grooved to admit the label, which is of stiff parch- 

 ment paper. The upper groove is deepest, so that 

 the upper edge of the label may be pressed into it 

 sufficiently to allow the lower edge to drop into the 

 lower groove. It will be seen that we then have a 

 label free to move, the entire periphery giving the 

 utmost freedom for exhibiting every aspect of the 

 specimen. Of course these blocks may be made 

 with upright sides. Though the labels are more ex- 

 pensive for the bevelled ones, the latter have a more 

 pleasing appearance. 



COMPETITION BETWEEN THE ANILINE AND 

 MADDER DYES. 



BY A. S. MACRAE. 



As these dyes are globularly used to the extent of 

 some one hundred million dollars per annum ; as they 

 are as well known to the manufacturers of New Eng- 

 land as to the horse-hide colorers of Japan, it may be 

 interesting to inquire what effects, in esse a.nd/>c?sse the 

 one is having upon the other in commercial value. 

 And as the market price invariably depends upon sup- 

 ply and demand, the source of the former must be ex- 

 amined into that the estimate of the latter may lead 

 to judicious deductions. 



Previous to the modern use of the above, indigo, 

 cochineal, and the vegetable or wood dyes were alto- 

 gether in vogue, and the inestimable appreciation of 

 the indigo was primarily the cause which led to the 

 discovery of aniline. The coloring matter of indigo 

 has long been technically known as anil, and the man- 

 ner in which it gave the name to aniline, has perhaps 

 never been published before this present article. The 

 botanist had ever been puzzled to know whence came 

 the coloring matter of the indigo plant. Where it was 

 indigenous the dyeing matter was inherent; but al- 

 though the plant flourished almost anywhere in tropi- 

 cal climates, it invariably lost its color yielding power 

 on this transportation ! How was this? The botanist 

 had to appeal to the chemist for explanation. Inves- 

 tigation demonstrated that the anil or coloring matter 

 was solely due to the subsoil over which the indigo 

 plant fructified, and that apart from this metaliferous 

 or possibly bituminous earth, the coloring idiosyncrasy 

 was lost. It will thus be seen that the article cannot 

 be produced at will, but only where it and the soils are 

 indigenous. However much this certainty baffled the 

 botanist, it only set the chemist a-thinking. His an- 

 alysis and synthesis showed beyond cavil, that anil, 

 pure and simple, was neither more nor less than a hy- 

 dro-carbonic compound, and that amongst some of these 

 artificially produced compounds, anil, otherwise than 

 the anil ol indigo, mighl yel be discovered. The cheap- 

 est object fortius rescue h naturally suggested itself, 

 and common coal tar the refuse of gas works — 



presented itself as the most economic basis of naphtha, 

 and the matrix of an abundant hydro-carbon. It 

 would be irrelevant here to trace the success which 

 crowned the chemists' efforts to produce anil, or as it 

 was now called, aniline, from this once — but now no 

 longer so — rejected filth. But one portion of the dis- 

 covery must be referred to, not only in demonstrating 

 the discoverers' wonderful patience, but as proof of 

 the capricious supply of this marvellous product. Coal 

 tar, then, yields naphtha ; naphtha, benzole ; ben- 

 zole, nitro-benzole ; nitro-benzole, aniline. When 

 the naphtha was first distilled from coal tar, no 

 benzole was discovered in it, or, if it was dis- 

 covered, in such small quantities as to defy remu- 

 nerative production. But the trace was there, and 

 as most auriferous deposits are discovered by traces, 

 these said traces were pursued until the golden goal 

 was scientifically and successfully attained. When 

 the naptha was distilled by different temperatures, 

 it was found that benzole was produced at one tem- 

 perature that was smothered at another, and that by 

 grading the distillations actual benzole could be elimi- 

 nated in paying quantities ! From this moment com- 

 mon coal-tar became the matrix of those valuable 

 aniline dyes, which under the names of roseine, ani- 

 line reds and crimsons, Nicholson's blues, Humbolts, 

 mauves, magentas, Bismark browns, oranges, iodine 

 greens, purples, magdalas, violets, greens, phosphines, 

 etc., have astonished the world for the last twenty 

 years. Nearly all the dazzling colors worn now-a-days, 

 that dim the sun and flaunt the eyes, are derived from 

 the very cheapest of bases named, yet have arrived at 

 such a value in the manipulation, that prices run from 

 $2 to $30 a pound and in some cases even $6 an 

 ounce. 



At the period of these discoveries, madder had 

 largely superceded indigo, cochineal and other dyes, 

 and at its producable price was certainly the most 

 economic dyeing product extant. Madder is neither 

 more nor less than the ordinary madder root ground, 

 a root capable of cultivation to an unlimited extent. 

 Turkey in Asia, Italy, France, Spain, Holland, and 

 Naples produced it in enormous quantities and British 

 India soon followed suit. The importations into 

 Great Britain at one time amounted to 50,000 tons, 

 and at least a similar quantity was consumed in the 

 countries of production. Unknown as madder may 

 be by that nomenclature, every housewife knows it 

 under the appellation of the " Turkey Red," the 

 name manufacturers gave to their prints dyed by this 

 article. Some idea of its consumption even in Amer- 

 ica may be given, when it is stated that the writer of 

 this article saw some 500 tons of this madder in the 

 manufactory of A. & W. Sprague & Co., of Prov- 

 idence, K. I., when he visited those works a few years 

 ago. 



If then aniline is used by the pound where madder is 

 used by the Aw, it may well be asked by merchants, 

 manufacturers and dyers, what will be the effect of 

 the competition between them? the one the limited 

 production of human manipulation, the other the un- 

 limited production of cultivated nature. We will ex- 

 amine the question. 



" Every dog has its day," and in the day of aniline 



