54 
THE TROPICAL 
AGRICULTURIST. [Julv 2, 1894. 
ANEW TANNING MATERIAL DESTINED 
TO SUPERSEDE GAMBIER ? 
The General Scarcity op Tanning Material ; 
" Canaigre " as a Substitute fob Barks in 
Tanning. 
The latfst number of the Board oj Trade Journal 
contains information respecting a new tanniDg 
material whioh ia likely to affeot, if not revolu- 
tionize the present trade. A Report on the 
eubject has been made bj an American Consul, 
who writes ; — 
" The first efforts to find out canaigre's value for 
tanning in Germany failed because the tests were 
made from the green plant. Still, so good were 
the results, that a Scotch firm offered to take 10,000 
*ons yearly if it could be sent for 40 dols. per ton. 
Nothing came of the offer. Herr Eitner, director of 
the experimental station for the leather industry at 
Vienna, took up the matter, made original experi- 
ments, and gave the facts to the world iu a small 
pamphlet. He says canaigre is especially suited to 
upper, saddlers', and fancy leathers. He said 
further, that 30 marks, delivered in Vienna, per 100 
kilogrammes (220 lb.), would be a mo ierate price. 
He has only words of praise for the new article. 
So, too, the tanning school at Freiburg ; although 
Director Haenlen stated he would like very much to 
get a large quantity dried, so as to make better 
experiments than he was able to make with what 
was sent him from Liverpool. The value of 
canaigre as a tanning medium is settled ; the only 
question now is to get enough at satisfactory 
prices. 'Ihe plant is native to many parts of 
America. It has long been known in Mexico, both 
for its tanning and medicinal properties. It grows 
well in Mexico, New Meiioo, Tex^s, both Californias, 
Utah, and in the Indian Territory. 
In these places it appears in February, just after 
the rainy season, ripens rapidly, and is ready to har- 
vest at the en\ of May. Sometimes it begin? to grow 
in the fall, continues growing during the winter — of 
coarse, in oountries where the winter is not severe — 
and gives in the spring a very strong p'aut. 
The p'aut has seed and root, but is repro luced from 
the latter, bscause no experiments as yet have suc- 
ceeded in doing much with the seeds. The roots yield 
the most tannic acid. Their growth depends mostly 
on soil and rain. The old roots, hard as wood and 
almost black, are especially rich in tannic acid. The 
stalks, stems, and leaves have tannin material too — 
enough to pay for harvesting. The cell juioe in roots 
and leaves gives a pronounced reaction when touched 
with iron sulphate or double chromic acid-kali. Touch 
a thin cut in the root with either of thess reactionary 
agents and a precipitation takes place as soon as the 
cell juice is met. Age aids to the roots aa excellent 
colouring essence, as well as tanning material. 
Analyses of New Mexicau cansigre gave about the 
same results. The one-year ruot3 yield from 20 to 
25 pfr cent., the older roots 25 to 40 per cent. Fresh; 
the canaigre contains (average) 66 per re^t. of water 
two months old, 58 par cent; one jear old, 32 per 
cent.; dry 8 percent. Thus, 31b. of fresh yield lib. 
of dry — 30 per oent. of tanniu. One centner* of 
dry roots yields 451b of extract with 66 per cent, 
of tannin ; hence, 6 centners of fresh yield 2 ceut- 
ners of dry 66, per cent, of tannin. Furlher, out of 
6 centners of fresh one gets 2 centners of dry or 1 
centner of extract. By taking the extract from roots 
and leaves where it grows much money might be 
saved and losses due to transport spared. The 
refute could be used to burn or as cattle fodder, 
for which purpose it equals wheU straw. In extra ct- 
• 1 centners 112 lb. 
mg the tannin it is best to cut up the roots aod to 
use a defusion method similar to that used in extract- 
ing sugar from cane or beets. It ia necessary to nee 
copper kettles, as the car. a ; gro influences and ia 
influenced by iron. It is good, also, when Hitractiog by 
means of lye and when eteamiug to u>e vaoum pans 
otherwise th? tannic acid runs the risk of going over 
into garlic acid. By steaming uoder small pressure 
there is no loss of tanoio, and one gets ao excellent 
extract of a bright colour, easily soluble in water." 
Then further we read = — 
" The demand for tannin all over the world is lery 
large. In every continent new tannin-containing 
plan's are being sought. A fear has beeo fe't for 
some time that with the constantly increasing de 
mand the present fources of supply mu«t soon 
run out. Most American leathers are tanned 
with oak ard hemlock barks and extracts. The 
supply cannot Inst for ever. It is running down 
fast. Europe buys large quantities of the cak and 
hemlock, the best known barks. Even America, with 
its almost boundless forests of oak and hemloek, im- 
poits tannin in large quantities In 1«91 theri were 
imported 15,000 tons of gambier (300.000 centDers) 
worth 1,500,000 dols. A centner cf caDaigre extract 
equals a centner of gambier besides it has colour- 
ing and finishing qualities, as above indicated, fitting 
it for special needs, 1,800,000 csntnera of canaigre 
could keep out the 300,000 centners of gambier. 
Many practical tanners fay gambier must go, tint 
canaigre is destiued soon to replace it. Large quau- 
titi. s are already finding their way into the world's 
markets and are being warmly weloomed. 
Dr. Von Scliroeder say that canaigre is rich iu 
tirnin that it dissolves aud gives out its acid 
even in cold water: an! that which it does not 
give out can easily be got out by hot water or sfam 
extraction. By gricding the dry ro .ts or plant tne 
getsa very good material to mix with tanning 
barks— cak, hemlock, &c Canaigre gives leather a 
soft, bright colour, often a clear, bright orange 
Tho leather cimrs out full smooth, and with a 
good grain. Dr. Von Schroeder agre>s with the 
Vienna chemist tint canaigre is especially suited to 
uppe r, saddler, and fancy leathers. He snys it ia 
one ot the very best materials for uppers, and that it 
is also well suited to other kinds. He is very en- 
thusiastic about it. Its large nmount of tannin the 
ease with wbich it dissolves in water, the presence 
cf sufficient aoid producing stuff, aod the beautiful 
colour, touch snd grain that it gives commend it 
It it is possible to produce oanaigre i u Americi in 
large quantities at fur prices, it w iU certainly 8 ' II 
not onty here, but all over the world, He savs 
investigations made by himself resulted in showing 
that the centner (112 1b.) inclusive of freights, costs 
the tanner 15 to 16 marks. This, at ao average of 
28 per cent of tannin, gives it to the tanneries at 55 
pfennigs. This is much too high, and prec'u^es 
importation." 
We referred to the Director of our Botanical 
■ T^ ES i 0r informati on respecting this new plant 
and Dr. Tnmen kindly replied as follows : - 
"None of our native tanning barks are of first- 
rate quality though always employed locally. The 
Mangroves (several species) are perhaps the best 
and 1 believe there is a small export of these 
barks tj India where the native tanners employ 
them extensively; but it is a familiar fact that 
all Indian and Ceylon leather is soft and second-rate 
•Canaigre' is a Dock (liunex) a largo herb with 
a thick root, which is the part used. It is a 
native of Texas and New Mexioo." 
If " Canaigre " prove the success that is anticipated 
for it, the Gambier trade of the Straits Settle- 
ments may be greatly affected. There are nearly 
a million cwt. cf Gambier exported every year 
from Singapore and adjacent ports. It is 
evident from what Dr. Trimen says that good 
tanning material is a desideratum in both India 
and Oeylon. 
