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 and posse 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 of indigo, might yet be discovered. The cheap- 
est object for this research 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, R. I., when he visited those works a few years 
ago. 
If then aniline is used by the pound where madder is 
used by the ton, 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 cpiestion. 
“ Every dog has its day,” and in the day of aniline 
