,transcriber's ,notes3    #a4 ,footnotes
 have been moved to immediately after   
the associated     paragraph4    #b4    
,obvious typographical errors have been 
silently corrected4    #c4 ,spelling and
 hyphenation has been made consistent   
with the most     common usage4 ,quoted 
text from other works and authors was   
left     unchanged4    #d4 ,characters  
between underscores 8 0 are italicized4 
,,notes ,,upon ,,indigo4                
,,by                              ,,john
 ,l4 ,,hayes1       ,,secretary ,,of    
,,the ,,national ,,association ,,of     
,,wool ,,manufacturers1 ,,fellow        
,,of ,,the ,,american ,,academy1 ,,and  
,,corresponding ,,member ,,of ,,the     
,,academy ,,of ,,natural ,,sciences ,,of
 ,,philadelphia4    ,from 8,the         
,bulletin of the ,national ,association 
of ,wool ,manufacturers40               
,,boston3                       ,,press 
,,of ,,john ,,wilson ,,and ,,son4       
#ahgc4      ,,part ,i4    ,,notes ,,upon
 ,,indigo4    ,,part ,i4    ,a          

publication devoted to the interests of 
the woollen manufacture1  while giving  
due prominence to its first raw         
material1 wool1 cannot  neglect the     
secondary materials which enter into    
finished fabrics4 ,the  attractiveness  
and utility of the largest class of     
these fabrics are  due to the hue given 
them by the dyer2 and of all the        
coloring  materials one of the most     
precious is indigo4 ,in former times1 as
 it  still does at the ,east1 it        
occupied with madder the place of one of
  the two most important of all dyeing  
materials4 ,forced of late years  to    
give way to the marvellous products of  
modern chemistry1 it will  doubtless    
resume its place under the influence of 
a more enlightened  economy and a more  
subdued taste4 ,to contribute to the    
hastening of  this return is one object 
of this essay4 ,the most usual reproach 
against ,american fabrics is the want of
 stability in our dyes1--a  reproach    
without justice1 if applied to ,american

 fabrics alone2 for  the cheapening of  
dyestuffs is practised in all the       
so-called  manufacturing nations1 and is
 contemned alone in the ,east1 from     
which  we have derived our arts1 and by 
the people whom we despise as           
barbarous4 ,to remove this reproach from
 ,american fabrics would be  worthy of  
no little temporary sacrifice on the    
part of our  manufacturers4    ,the     
value of indigo as a dyeing material is 
due to the great stability  of the blue 
color1 and the derivatives from blue1   
which it gives to  fabrics1 especially  
of wool and cotton4 ,it is not          
sufficient that a  dyed fabric should   
preserve its color when submitted to    
violent tests1  as when acted upon by   
vegetable or mineral acids or alkaline  
or soapy  baths3 the only stable dyes   
are those which resist air and light1   
the  two destructive agents of vegetable
 colors4 ,indigo1 from the  remarkable  
manner in which its color becomes fixed 
upon a fabric1 to  be hereafter         

explained1 possesses properties of      
resistance and  stability in a higher   
degree than any blue dye4 ,and when we  
consider  that this blue has not only   
its own hue1 but is the best foundation 
for blacks1 greens1 purples1 and even   
browns1 the importance of these         
properties cannot be over-estimated4    
,says ,m4 de ,kppelin1 a chemist  and   
manufacturer of ,mulhouse1 in one of a  
series of articles furnished  to the    
,annales du gnie ,civil1 #ahfd3 8,so    
high are the properties of  resistance  
and stability which indigo possesses1   
that it is perhaps to  be regretted for 
the art of the dyer and manufacturer of 
printed  calicoes1 that the use of      
indigo becomes more and more rare1 and  
that  the recent discoveries which      
modern science has placed at the service
  of industry are daily eliminating it  
from our factories4 ,i have  observed   
that whenever we have to dye stuffs of a
 high price1 it is  indigo which always 
serves as a base for the foundation of  

all the  blue colors1 or of those which 
are derived from blue4 ,it is the same  
for the fabrication of printed tissues1 
which serve for the poorer  classes1    
whose colors should have great stability
 without much  increase of cost4 ,but of
 late years1 especially1 we find a      
tendency to  employ colors of little    
stability1 and to prefer them1 even in  
the  class of fabrics first referred to1
 to those which are more fast1 on       
account of their vivacity and freshness 
of tone4 ,it is this tendency1  which   
the consumer partakes of even while     
complaining of it1 that the  textile    
manufacturers ought to seek to combat4  
,how often have ,i heard  the greatest  
manufacturers of ,alsace deplore the    
obligation which they  felt that they   
were under of printing their tissues by 
means of colors  so fugacious and so    
little resistant as those composed from 
aniline4  ,we must hope1 then1 in the   
interest of that industry1 that while   
adopting the marvellous discoveries     

which science is every day making1      
there shall be made a less general      
application of them1 and that we  shall 
return to the fabrication of the styles 
which necessitate the  more constant    
employment of coloring materials1--less 
brilliant1 it is  true1 but more        
adherent to the tissues1 and less       
alterable by air and  light4 ,it seems  
to me1 also1 that taste would lose      
nothing2 and that  printed stuffs1      
colored in a manner less brilliant1 but 
more  harmonious1 would be perhaps more 
appreciated1 especially by those who    
use them40    ,the tendency to          
substitute the brilliant for the stable 
dyes prevails  too much in our own      
manufacture4 ,a very considerable cloth 
manufacturer replied to our inquiry as  
to the extent to which he used  indigo3 
8,i hardly use it at all2 the dye of the
 indigo blue is not  bright enough to be
 popular40 ,on the other hand1 we have  
heard our  leading manufacturer of      
carpets1 whose cultivated taste has led 

him to  partake of ,m4 de ,kppelin's    
views1 deplore the introduction of      
aniline  dyes1 as a positive calamity to
 the textile industry4 ,it is the       
influence of the trade1 the immediate   
consumers of fabrics1 rather  than the  
judgment of manufacturers1 which        
promotes the use of the  modern         
fugacious dyes4 ,the dealers desire not 
only to imitate the  fashionable colors 
of ,european goods1 but to secure the   
utmost  cheapness4 ,one of our largest  
manufacturers of woollen goods1 who had 
made a special study of the best        
processes abroad1 and was desirous of   
bringing better dyed goods into more    
general consumption1 urged one of  his  
largest customers1 an extensive dealer1 
to allow him to dye the  waterproof     
cloakings which he was furnishing for   
his house1 in fast  indigo colors1      
assuring him that he would charge simply
 the additional  cost of the indigo1    
without profit4 ,the offer1 which       
involved the cost  of only a few cents a

 yard1 which would have been gladly paid
 by the  last consumer if the difference
 of value had been made known1 was      
declined4 ,it is not improbable that the
 inferior goods which the  manufacturer 
was compelled to furnish were sold to   
the public as fast  dyed4 ,our          
manufacturers1 therefore1 may not have  
been responsible for  the predicament in
 which the most enthusiastic defender of
 our  protective policy found himself1  
as we have it from his own lips4  ,being
 about to make a speech in ,congress in 
defence of ,american  industries1 he put
 on1 for the first time1 a coat declared
 to have  been made of ,american cloth4 
,sitting down1 heated and perspiring    
from  the excitement of his effort1 he  
found that beneath the arms whose       
gestures had enforced his eulogies of   
,american industry1 the pretended  fast 
blue of his coat had become red1        
literally blushing for its  unmerited   
praise4 ,that fast-dyed goods of the    
highest excellence can  be and are      

furnished by ,american manufacturers1 is
 shown by our army  cloths4 ,the        
government specifications1 copies of    
which are published  elsewhere in this  
number1 require that all the blue       
woollen cloth1 cap  cloth1 and flannels 
furnished for the army shall be 8pure   
indigo  dyed40 ,the requisition is      
strictly enforced4 ,the admirable effect
 of  this regulation may be witnessed at
 any dress parade of a battalion of     
,united ,states soldiers4 ,the          
persistency and uniformity of the hue   
under constant wear--the cloth of the   
common soldier in its superior  dye     
often favorably contrasting with the    
finer but fancy dyed cloth of  the      
officer--is one of the circumstances    
which justify the assertion1  that our  
army is the best clothed in the world4  
,the contrast is more  remarkable still 
with the quondam blue cloth1 converted  
by sun and  rain-into every shade of    
shabbiness1 which we purchased in       
,europe for  our soldiers at the        

commencement of our late war4           
,,origin ,,and ,,extraction ,,of        
,,indigo4    ,indigo is a coloring      
material of vegetable origin1 which owes
 its  color and its important           
applications to a direct blue principle1
 known  under the name of indigotine4   
,it has been used as a dyestuff from    
time  immemorial1 by the inhabitants of 
,india2 and it is from the ,east1 the   
cradle of the textile arts1 that ,europe
 has derived it4 ,it was  probably      
received from ,india by the ,greeks1    
among other products first  made known  
to them by the expeditions of ,alexander
 the ,great4  ,dioscorides clearly      
refers to indigo in mentioning the two  
coloring  matters brought from ,india4  
,pliny mentions a coloring material1    
having  an admirable mixture of blue and
 purple1 as coming from ,india1 which   
he calls indicum4 ,that he refers to    
indigo is curiously manifest by  the    
test which he gives1 by which the       
genuine drug might always and  certainly

 be distinguished from the spurious4    
,this is by putting it  on live coals1  
when1 says he1 8the true indicum will   
burn with a  flame of a most beautiful  
purple tint40 ,the purple vapor from    
burning  indigo is still a              
characteristic test4 ,the ,romans1 it is
 apparent1  used indigo only as a       
pigment1 not knowing what is still the  
most  important art connected with its  
use1--how to make it soluble so as to   
be available in dyeing4    ,that indigo 
as a commercial product was first       
obtained from ,india is  not only proved
 by the testimony of ,pliny1 and other  
ancient writers1  but is confirmed by a 
variety of circumstances1 and           
particularly by  its name1 which is     
known to have been nil in the ,hindu    
language1  from the earliest times of   
which there is mention of it4 ,this name
 is  still given by the ,hindoos to the 
color blue1 and to all the plants       
producing indigo4 ,the ,arabs and       
,egyptians1 who obtained a knowledge of 

indigo from ,india1 adopted the ,hindu  
name1 the ,arabs calling it nil  or nir1
 and the ,egyptians nil or niel4 ,the   
,portuguese preserved  the ,indian name1
 with a slight modification1 the        
substance being  called aniliera in     
their language4 ,the coloring substances
  afterwards found in coal-tar having   
been first found in indigo1 modern      
science has adopted for them the name of
 aniline4    ,it has been asserted that 
this substance was not known in ,europe 
until  the time of the discovery of the 
passage to ,india round the ,cape of    
,good ,hope4 ,but ,dr4 ,bancroft has    
shown that indigo was brought by        
merchants from ,india to ,alexandria1   
and thence to ,venice1 when that  city  
was the entrept of ,europe and the      
,east4 ,it doubtless  contributed to the
 excellence which the ,italian states   
first attained  in the wool manufacture4
 ,the drug was called endigo in ,venice1
 and  it is from that city that we have 
derived its name and use4 ,it was       

imperfectly known in ,england under its 
,spanish name in the sixteenth  century1
 for we find in ,hackluyt 8,voyages0 his
 instructions to a  traveller who was   
going to ,turkey to ascertain 8if anile1
 that  coloureth blue1 be a natural     
commodity of those parts1 and if it be  
composed of an herbe40    ,the general  
introduction of indigo into ,europe was 
impeded by  legislative enactments1     
prompted mainly by those employed in    
industries which it threatened to       
displace4 ,these were chiefly the       
producers of and dealers in woad1       
formerly used exclusively for  dyeing   
blue1 and the corporation of woad dyers4
 ,when dyers from ,italy  and ,flanders 
attempted to introduce the superior dyes
 of indigo1 the  woad interests were    
sufficiently powerful to induce the     
,elector of  ,saxony to denounce the use
 of the new dyestuff4 ,it was pronounced
 in  the ,diet of the ,empire as 8a     
corrosive color10 and 8fit food only for
  the devil10 fressende teufels4        

,similar propositions were made in      
,england and ,france1 in which latter   
the free use of indigo was not          
permitted until #agcg4    ,although     
indigo as known in the arts is a product
 of vegetable origin1  we must not omit 
to notice that one source of its        
production is the  human body4 ,it was  
discovered some years since that the    
blue color  sometimes found in diseased 
urines1 and in certain suppurations1 is 
due to indigo4 ,dr4 ,schunck1 in some   
papers read before the ,royal  ,society1
 has shown that it is a frequent        
constituent of urine secreted  by       
persons in a healthy state1 and that1 in
 fact1 it is produced  generally when   
persons do not take sufficient exercise2
 and he has  several times succeeded in 
producing it by taking in his food a    
rather  large excess of sugar4 ,he has  
found this substance also in the urine  
of beef cattle4 ,it must also be        
observed that the chemical actions of   
indigotine with oxidizing agents1       

showing indigo to have a very close     
relation to aniline and carbolic acid1  
both products derived from  coal-tar1   
have produced in the minds of chemists  
the conviction that  indigotine1 like   
alizarine1 the coloring principle of    
madder1 will one  day be artificially   
produced from coal-tar4    ,the plants  
which are known to furnish indigo are   
quite numerous1 being  not less than    
sixty2 they do not all belong to the    
same family1 and  none of them contain  
the coloring principle already formed4  
,the most  important belong to the      
leguminous family1 from which most of   
the  vegetable dyes are derived1 and to 
the genus indigofera4 ,the species      
cultivated and most esteemed are        
,indigofera tinctoria1 ,i4  disperma1   
,i4 anil1 ,i4 argentea4                 
,illustration3 ,drawing of the          
,indigofera tinctoria plant    ,the     
principal source of the indigo of       
commerce is the ,indigofera  tinctoria4 
,the accompanying figure is a correct   

representation of the  plant1 and we may
 dispense with a description of its     
botanical  characters1 observing only   
that the plant has a half woody stem1   
and  rises to the height of from three  
to five feet4 ,the plants exhale a      
strong odor towards evening in the      
fields where they are cultivated4  ,the 
leaves have a disagreeable taste1 and   
rapidly putrefy in water4  ,the plant   
originated in ,campaja1 or ,guzerat1 but
 is cultivated in  ,hindostan1 ,china1  
,java1 and in the ,east ,indies         
generally4 ,it was  carried by the      
,spaniards to ,south ,america and the   
,west ,indies1 and it  can be acclimated
 in all hot countries4 ,the ,indigofera 
argentea1 or  indigo plant of ,egypt1   
furnishes the indigo produced in that   
country  and ,arabia4    ,the culture of
 the plant and the production of        
commercial indigo is  carried on a vast 
scale in ,lower ,bengal4 ,we have before
 us a large  map1 placed at our disposal
 by an ,india merchant of ,boston1      

showing  the location of each of the    
hundreds of factories of that important 
centre of production4 ,these factories  
have been developed by ,british         
enterprise2 and ,india thus receives    
some slight compensation for the  ruin  
of her cotton manufacture by the same   
influence4    ,the propagation of the   
indigo plant in that country is made by 
sowing  in a thoroughly tilled          
silico-argillaceous soil4 ,the seed of  
the plant  is sowed annually in the     
spring or autumn1 according to the      
variety  used1 some germinating more    
slowly1 and requiring to remain in the  
ground longer than others4 ,the time of 
putting in the seed is also  governed by
 the nature of the soil and its position
 in respect to  neighboring rivers4 ,in 
the lowlands subject to inundations1 the
 indigo  ought to be all cut at the     
period of the rains and inundations1    
which  would destroy the crop in a brief
 time4 ,besides1 during the rainy       
period the planter has at his disposal  

sufficient water to commence  his       
operations of fabricating the indigo1   
which is the suitable time  for         
beginning the cutting of the plant4 ,the
 time of cutting the  indigo plants is  
therefore regulated by the elevation of 
the land and  danger from floods4 ,the  
high lands are always sowed several     
weeks  after those subject to           
inundations4    ,the ,chinese prick out 
the young plants in parallel rows1      
always  preserving the land quite clear 
of weeds4 ,by taking away the blossoms  
of the plant before their development1  
they increase the growth of the  leaves1
 and1 consequently1 the return of       
indigo2 for it is in the  leaves        
principally that the coloring material  
is found4    ,in certain localities the 
planters break off the leaves which have
  acquired a bluish green tint4 ,but    
more frequently the whole plant is  cut 
down close to the ground in the months  
of ,june or ,july1 when the  flowers    
begin to open4 ,the portion of the plant

 which remains pushes  up quite rapidly1
 and furnishes a second1 and even third1
 and  sometimes1 though rarely1 a fourth
 cutting4 ,the quality of the product   
diminishes according to the number of   
the cuttings4    ,the plant called nil1 
cut down to the root and gathered up in 
packages1 is worked up the same evening4
 ,the package is formed from  the       
product of a space of land embraced by a
 chain about three yards  long4 ,the    
value of the first material changes with
 the value of the  soil4 ,thus1 one soil
 produces a plant which has many stems  
and few  leaves1 while another gives    
many leaves and few stems4 ,the richness
 in  coloring material depends upon the 
quantity of leaves1 but varies also     
with an equal weight of leaves with     
atmospheric influences4 ,thus  regular  
dealers in the article observe a marked 
difference in the  quality of indigo in 
different seasons4    ,m4 ,a4 ,koechlin 
,schwartz has recently published some   
interesting notes  upon the preparation 

of indigo in ,lower ,bengal4 ,in that   
country1 which  furnishes excellent     
indigo1 the factory includes1 besides   
filters1  presses1 a steam-engine1      
drying apparatus1 and reservoir of      
water1 two  lines of vats1 arranged one 
above the other1 from fifteen to twenty 
in  each line4 ,these vats are built up 
with bricks1 and covered with a  strong 
coat of solid and well made stucco4     
,they are square1 about six  yards on a 
side1 and about a yard deep4 ,the back  
row is about a yard  above the front    
one4 ,the plant is fermented in the vats
 of the upper  row2 when the operation  
of fermentation is terminated1 a faucet 
is  opened1 and the liquid is run into  
the lower vat4 ,the water of the        
,ganges1 which is relatively pure1 and  
thus well suited for this work1  is     
brought into basins of deposition1 where
 it becomes clarified1 and  is          
distributed by a common canal to the    
vats of the upper row4 ,the  plants1 cut
 in the morning and bound up into       

packages1 come to the  factory after    
midday1 and are thrown into the vat in  
the evening4 ,a  vat contains one       
hundred packages carefully arranged1 one
 beside the  other2 heavy timbers are   
placed upon the plants1 which are       
pressed  down by means of large wedges4 
,it is necessary that the plants should 
be pressed together very compactly1 as  
without this the fermentation  does not 
take place to advantage4 ,at nightfall  
the water is introduced  into the vats1 
and fills them so as completely to      
submerge the plants4  ,the fermentation 
is more or less prolonged according to  
the  temperature4 ,its duration varies  
from nine to fourteen hours4 ,the       
workmen judge as to the procedure of the
 operation by withdrawing a  little of  
the liquid in the lower vat4 ,if it is  
of a clear pale yellow  when withdrawn1 
it will furnish a product less abundant 
but more pure  than if of a deep gold   
color4    ,at the moment of its issue   
from the fermenting vat the liquid is of

 a  yellow color1 more or less deep4    
,the liquid is allowed to remain        
undisturbed for a brief period1 when    
twelve naked men1 armed with long       
bamboos1 enter the vat to beat the water
 while it is still warm4  ,during this  
time the upper vat is emptied and       
cleaned out for the  succeeding         
operation4 ,one vat requires seventeen  
workpeople 7twelve  men and five women74
 ,they thrash the water for two or three
 hours4 ,the  liquid passes by little   
and little to a pale green1 and the     
indigo is  found on suspension in the   
form of small floccules4 ,the liquor is 
suffered to remain undisturbed for half 
an hour2 it is then gradually  decanted 
by opening1 one after the other1 the    
discharging holes placed  at different  
heights4 ,the water returns to the      
river1 and the  precipitate1 under the  
form of a thin bouille1 is turned into a
  reservoir4 ,this bouille is pumped up 
into a vessel1 and made to boil  for a  
moment to prevent a second fermentation1

 which would injure the  quality of the 
product1 by turning it black4 ,it is    
suffered to rest  about twenty hours1   
and the next morning it is again        
subjected to  boiling1 the ebullition   
being kept up three or four hours4 ,the 
boiling  deposit is then turned off upon
 a large filter1 through which the      
water drips4 ,this filter is composed of
 a vat constructed of masonry1  covered 
with stucco1 about eighteen feet long by
 six feet wide and  three feet deep4    
,this is covered with bamboos1 upon     
which is a grating  of smaller reeds1   
and above by a stout strained cloth4    
,there remains  upon the cloth a thick  
paste1 of a deep blue and nearly black  
color4  ,the water which is run into the
 vat deposits some indigo which has     
pressed through the filter4 ,this is    
decanted after being allowed to  rest1  
and the turbid liquid is boiled the next
 day with the fresh  indigo4    ,the    
paste of the filter is introduced into  
some small boxes of wood1  pierced with 

holes1 and provided above and below with
 a strong cotton  cloth4 ,the whole is  
again covered with a piece of stuff1 and
 then with  a covering of wood1 pierced 
with small holes1 and it is placed under
 a  press1 the force being gradually    
applied1 so as to cause the water to    
run out as much as possible4 ,there is  
withdrawn from the box a cake of  the   
size of a cake of ,marseilles soap4 ,the
 water squeezed out flows  back into the
 filtering vat1 to be boiled again with 
the fresh indigo4  ,the drying of the   
cakes ought to be done very slowly4     
,the dry-house is a large building of   
masonry1 quite high1 and pierced  with  
many openings1 provided with narrow     
blinds1 to prevent the direct  light of 
the sun from penetrating into the       
interior4 ,care is taken  also to       
surround the dry-house with large       
shade-trees4 ,the cakes take  from three
 to four days to dry1 after which they  
are packed in small  boxes and carried  
to ,calcutta1 the great market of       

,bengal4    ,the details above given    
apply to the factories managed by       
,european  planters4 ,the natives       
operate in nearly the same manner1 but  
with less  care1 and consequently their 
products are inferior4 ,the average     
product of indigo in ,lower ,bengal is  
stated at #d1jjj1jjj kilograms1 or      
#h1hdj1jjj pounds per year4 ,the most   
remarkable fact to be noticed in  these 
operations is1 that the blue principle  
is developed by chemical  action from   
certain absolutely colorless principles 
existing in the  plant4 ,the theory of  
the change effected is still somewhat in
 doubt1  because no chemist has studied 
the fresh plant1 and observed upon the  
spot the phases of the operation of the 
production of indigo on a  large scale4 
,but the most accepted theory is that   
derived from the  researches of ,dr4    
,schunck1 upon the isatis or woad-plant1
 which  produces indigotine in a much   
less degree than the true indigo plants2
  viz41 that the indigo exists in the   

plants combined with sugar1  forming a  
glucoside1 to which he gives the name   
indican4 ,this  compound1 under the     
influence of fermentation in the        
manufacturing  process1 is supposed to  
be unfolded into indigo and sugar4      
,without dwelling upon this question1   
which is beyond our province1 we        
observe that the plants of the genus    
indigofera are used for the  production 
of commercial indigo1 on account of the 
greater richness in  the coloring       
principle4 ,other plants1 which furnish 
the same coloring  principle1           
indigotine1 are more frequently used    
directly in dyeing to  furnish the blue 
principle than they are for the         
production of indigo4    ,the most      
important of these plants1 although     
there are others1 such as  the          
,polygonum tinctorium and the ,nerium   
tinctorium1 is the ,isatis  tinctoria1  
which produces pastel1 or woad4 ,this1  
plant belongs to the  family of         
crucifer1 and is a biennial4 ,it is     

represented in the  accompanying figure4
    ,illustration3 ,drawing of the      
,isatis tinctoria plant    ,the leaves  
which surround the stem are collected in
 ,may or ,june of the  second year1 when
 they begin to turn yellow4 ,the wasted 
and dried  leaves are sometimes used    
directly for dyeing1 but more generally 
the  leaves1 after being cut and dried1 
are carried to a mill1 and then  ground 
to a paste1 after which it is formed    
into a mass or heap1 and  being covered 
to protect it from rain1 is left to     
undergo a partial  fermentation for     
about a fortnight4 ,the heap is then    
well mixed and  formed into balls1 which
 are exposed to the sun and wind to dry1
 and  thereby prevent the putrefaction  
which would otherwise take place4       
,being afterwards collected in heaps1   
these balls again ferment1 become  hot1 
and emit the odor of ammonia1 which     
,hume tells us1 in the ,history  of     
,england1 gave such offence to ,queen   
,elizabeth that she issued an  edict to 

prohibit the cultivation of this plant4 
,after the heat has  continued for some 
time1 these balls fall into a dry       
powder1 in which  form the woad is      
usually sold to the dyer4 ,the best     
,french woad comes  from ,provence1     
,languedoc1 and ,normandy4 ,in ,germany1
 the pastel of  ,thuringia is used      
almost exclusively2 the packages have   
the trade-mark  of three towers1 with   
the numbers #d1 #e4 ,in this country1   
owing  probably to the prejudices of    
practical dyers1 who have generally come
  from ,england1 the ,lancashire woad is
 almost exclusively used4 ,the very     
little imported of late years1 ranging  
from two thousand to twelve  thousand   
dollars annually in value1 is used for  
mixing with indigo in  the so-called    
woad vat1 to be hereafter described4    
,,commercial ,,indigoes4    ,the        
following description of the indigoes of
 commerce is taken  principally from    
,schutzenberger's excellent treatise on 
coloring  materials4 ,it coincides very 

nearly with that given by ,napier from  
,dumas and ,chevrueil4 ,indigoes are    
classed1 according to their origin1     
into three groups4    #a4 ,indigoes of  
,asia 7from ,bengal1 ,oude or           
,coromandel1 ,manilla1 ,madras1  and    
,java74    #b4 ,indigoes of ,africa     
7,egypt1 ,island of ,france1 ,senegal74 
#c4 ,indigoes of ,america 7,guatemala1  
,caraccas1 ,mexico1 ,brazil1 and the    
,west ,indies74    ,the three varieties 
in most esteem are those of ,bengal1    
,java1 and  ,guatemala4    ,indigoes of 
,java4--,these are distinguished by the 
great purity of  their coloring         
material4 ,they contain the minimum of  
extractive  organic matter4 ,if1 in     
spite of this1 they do not give a high  
yield of  indigotine2 this is owing to a
 mixture of silicious mineral substances
  with their paste4 ,the paste is soft4 
,it adheres strongly to the  tongue1 and
 its density is feeble4 ,they are       
generally of a pure blue1  light or ash 
colored in the kinds which are less     

rich1 and of a  magnificent violet blue 
in the superior qualities4 ,the last    
take a  beautiful copper color when     
scratched by the nail4 ,they are placed 
in  the very first rank among all       
indigoes in respect to fineness and     
beauty1 if not in richness in the blue  
coloring principle4 ,their  purity1     
complete absence from carbonate of lime1
 and the small  quantity of foreign     
organic materials which they contain1   
cause them  to be much sought for1 for  
the preparation of carmine of indigo4   
,the  consumption of the ,javan indigoes
 in this country is so small as not  to 
be appreciated4    ,bengal              
,indigoes4--,these are the indigoes par 
excellence1 for in  them are found the  
most varied qualities1 from the most    
beautiful and  rich to the most         
ordinary4 ,the superior qualities are of
 a deep violet  blue1 with a fine and   
uniform paste2 they adhere to the       
tongue1 are  easily pulverized1 and take
 a beautiful coppery tint when scratched

 by  the nail4 ,the fresh fracture shows
 a magnificent purplish blue            
reflection4 ,their yield in indigotine  
does not surpass seventy-two per  cent4 
,after these come the reddish-violet    
indigoes with a purplish hue1 and  a    
fracture more uniform and shiny4 ,they  
are also more dense and hard  than the  
superior qualities4 ,the reddish hue    
does not proceed from the  greater or   
less amount of coloring material        
contained1 but from the  presence of a  
greater quantity of brown and red       
extractive matter4  ,these qualities are
 not to be despised1 for the kinds which
 give the  best results in the dyeing   
vat are found in these indigoes4 ,it    
would  seem1 in fact1 says the author   
whom we are following1 8that the browns 
and reds of indigo play an important    
part in vat dyeing1 that they are  able 
to become dissolved and to fix          
themselves upon the tissues at the  same
 time as the indigotine1 and thus       
operate to reinforce the hue4  ,the fact

 is1 that dyers generally prefer the    
reddish indigoes to the  other          
varieties40 ,among the ,bengal indigoes 
there is found a clear  blue variety1   
less rich in coloring matter1 but also  
more exempt from  organic substances4   
,the impurity is constituted by mineral 
matters4 ,it  is less dense1 adheres    
strongly to the tongue1 and does not    
take a  coppery hue1 like the other     
varieties1 when scratched by the nail4  
,the worst qualities of the ,bengal     
indigoes1 as in all the species1 are    
the clear blues1 shading on to gray or  
green4 ,this coloration denotes  a great
 quantity of extractive matter different
 from the indigo brown  which           
characterizes the red varieties1 and    
completely inert4 ,these  indigoes are  
hard1 dense1 adhere little or none to   
the tongue1 and do  not show coppery    
reflections when scratched4    ,the most
 skilful connoisseurs distinguish       
forty-three varieties of  ,bengal       
indigo4 ,the most important are the     

following3--    #a4 ,superfine blue1    
light or floating4--,color bright blue2 
light1  friable1 and spongy2 adherent to
 the tongue1 soft to the touch1  showing
 coppery reflections when rubbed by the 
nail2 paste uniform and  pure4    #b4   
,fine blue4--,like the preceding1 but   
the color a little less vivid4    #c4   
,violet blue4--,a little less light and 
friable4 ,has a violet blue4    #d4     
,superfine violet4    #e4 ,superfine    
purple4    #f4 ,fine violet4    #g4     
,good violet4    #h4 ,red violet4    #i4
 ,ordinary violet4    #aj4 ,good soft   
red4    #aa4 ,good red4    #ab4 ,the    
indigoes1 fine coppery1 good coppery1   
ordinary coppery1 and  low coppery4     
,the ,indigoes of ,oude and             
,coromandel4--,these are made in the    
interior  of ,hindostan4 ,those of the  
best quality correspond to the middling 
,bengal indigoes1 and are met with in   
square masses1 having an even  fracture1
 but are more difficult to break2 the   
inferior qualities are  heavy1 of a     

sandy feel1 having a blue color1        
bordering on green or  gray1 or even    
black2 often in large squares1 and      
covered with a slight  crust or rind of 
a greenish color4 ,they are the most    
difficult to  break of all the indigoes 
of commerce4    ,madras                 
,indigoes4--,they have a grained        
fracture1 and are of a cubical  figure4 
,the superior qualities have no rind4   
,the qualities are fine  blue1 mixed    
violet blue1 and ordinary4 ,they are all
 lighter1 and less  rich in coloring    
matter than the ,bengal indigoes4       
,manilla ,indigoes4--,these occur in    
cubical blocks1 flat squares1 or in     
irregular pieces4 ,they are light1 with 
a fine paste1 and of a clear  blue4     
,they effervesce with acids1 showing the
 presence of carbonate of  lime         
incorporated in their paste4 ,they are  
consequently poor in  coloring material1
 and are hence almost exclusively used  
as a bluing  material in washing        
fabrics4    ,american ,indigoes4        

,guatemala4--,these indigoes are        
produced now  altogether in ,hunduras1  
although they still retain in commerce  
the  name of ,guatemalan4 ,they are     
generally found in small pieces1        
irregular in form and size1 and come in 
envelopes of skin containing  about half
 as much as the ,bengal chests4 ,putting
 aside the difference  in exterior form1
 these indigoes approach very closely to
 those of  ,bengal4 ,the same qualities 
are found1 only they are more frequently
  mixed4 ,the clear blue is more rare1  
and1 when it is found1 it is  poorer in 
coloring matter4 ,in purchasing these   
indigoes it is  necessary to beware of  
the reds1 which often contain a strong  
proportion of the brown extractive      
matter4 ,it is not rare to find  among  
the ,guatemalan indigoes beautiful      
specimens of the blue violet1  equal to 
the richest ,bengal variety4            
,unfortunately1 this superior  variety  
is generally mixed with inferior kinds1 
as to have less value4  ,the ,american  

indigoes are classified as follows3--   
,guatemala floro4--,bright blue1 paste  
uniform1 soft and light4 ,this  variety1
 in ,bancroft's time1 was the most      
esteemed of all indigoes4    ,guatemala 
sobresaliente4--,less light1 the paste  
firmer and the blue  less beautiful4    
,guatemala corte1 or                    
copper-colored4--,paste less firm and   
heavier1  coppery red4                  
,caraccas4--,these resemble very much   
the ,guatemala varieties4 ,the          
qualities are designated by analogous   
names1 but they are1 in general1  less  
esteemed than the preceding4            
,mexican4--,they hold an intermediary   
rank between the ,caraccas and          
,mexican4    ,brazil4--,these indigoes  
are in small rectangular parallele-piped
  masses1 or in irregular lumps of a    
greenish gray color externally1 and     
having a smooth fracture1 a firm        
consistency1 and a copper-colored  tint 
of greater or less brilliancy4    ,the  
indigoes of ,africa and ,egypt4--,these 

have only been manufactured  within the 
last twenty years2 they are in flat     
squares4 ,the paste is  fine and quite  
light1 and the color pure blue or       
bordering on violet4  ,the varieties are
 distinguished as fine blue and good    
violet and red4    ,indigoes of the     
,isle of ,france and ,senegal4 ,rare in 
commerce1 but  of good quality4    ,the 
indigoes of the inferior qualities1     
characterized by a salt-like  color1    
bordering more or less upon green2 by a 
coarse1 uneven1 and  very dense paste2  
by not adhering to the tongue1 and by   
not showing a  coppery color when       
scratched1--can never be employed to    
advantage1  notwithstanding their low   
price4 ,the purchaser of these qualities
 must  be guided solely by the results  
of analysis2 for an article is found  in
 commerce whose richness in indigotine  
does not exceed twelve to  fourteen per 
cent4 ,the presence of so high a        
proportion of foreign  matter prevents  
the chemical change which the indigo    

ought to undergo  in the dyeing vat2 and
 this foreign matter1 added to the      
deposits of  the dyeing vats1 causes    
great loss of the coloring matter4      
,these  indigoes should be used as      
little as possible1 especially in the   
cold  vats used for dyeing cotton and   
linen4 ,the middle varieties of the     
,bengal and ,guatemala indigoes1 and1   
above all1 the red varieties1  produce  
in the cold vats the most advantageous  
results4 ,the lower  qualities above    
spoken of present less inconvenience in 
the hot vats  used for dyeing wool2 and 
it is for this purpose that they are    
generally used4 ,in considering the     
previous observations1 the wool         
manufacturer may arrive at this         
conclusion3 that while he can1 with     
less loss than the maker of cotton      
fabrics1 make use of the lowest         
qualities of indigo1 he will obtain the 
best results from the middle  qualities 
of the reddish ,bengal indigoes4    ,the
 skilled dealers in indigo recognize not

 only the above  distinctions1 founded  
upon the country of production1 color1  
and  physical qualities1 but they       
observe whether the article has any of  
the following defects1 which are        
designated by certain well-understood   
terms3 such as whether the indigo is    
sandy1--when brilliant points  are      
observed in the interior1 which are in  
reality particles of sand2  spotted1    
that is to say1 of unequal tint1 and    
marked by small  blackish points2       
ribboned1 marked by transversal bands of
 a paler1  and sometimes red color2     
burnt1 the pieces having a scorched     
appearance1 due to rapid drying1 and    
separating into small black  fragments  
under the pressure of the hand2 crumbly1
 when in pieces of  irregular figure1   
proceeding from fractures of the        
squares2 cold1  when the indigo does not
 adhere to the tongue4 ,the above       
classification is presented with a full 
knowledge that these  distinctions are  
by no means recognized in the ordinary  

commerce in  this article4 ,it is not1  
however1 without interest as an         
illustration  of the minute attention   
given to this subject in ,europe1 where 
a  higher manufacture requires a nicer  
investigation of the qualities of       
materials employed4      ,,determination
 ,,of ,,the ,,richness ,,and ,,purity   
,,of ,,indigoes4    ,it is evident that 
the commercial form and the high price  
of this drug  favor fraud1 and the      
desire to illicitly introduce foreign   
substances  into the paste4 ,it is      
important1 therefore1 that the purchaser
 should  carefully ascertain the actual 
value of the article which he is to     
use4 ,he should know not only the       
proportion of indigotine contained1     
which varies in the commercial indigoes 
from twelve to seventy-five  per cent1  
but the hardness and density4 ,a good   
indigo ought to have  qualities which   
can be recognized by the eye and touch  
alone4 ,the  first and the only         
examination ordinarily made by          

purchasers is in  respect to the        
physical qualities of the article4      
,different pieces are  selected1 and    
their fresh fracture is attentively     
observed4 ,the  purchaser observes      
whether the squares are like each other1
 and if the  parts of the same piece    
present the same tint4 ,he determines   
the  porosity by the simple means of    
applying his tongue to the fresh        
fracture4 ,the more rapid the adherence 
of the tongue1 the more porous  the     
indigo4 ,by scratching the piece with   
his finger-nail1 he  determines the     
extent of the coppery reflection1--an   
important test4    ,from all these      
characters1 taken together1 the         
purchaser can form  quite a correct idea
 of the value of indigoes in general2   
and the  greater number of dyers1 both  
in ,europe and this country1 are        
satisfied to make their purchases with  
only this physical examination4  ,the   
most experienced dealers in this country
 make no other examination  than the    

physical one4 ,an eminent indigo broker 
in ,boston has  permitted me to copy the
 following memoranda for the physical   
examination of indigo from his notebook4
    ,the chief signs of good indigo are 
its lightness1 feeling dry when         
touched1 and1 when broken1 appearing of 
a beautiful violet blue4 ,good  indigo  
swims in water2 if thrown upon burning  
coals it emits a  violet-colored smoke1 
and leaves but little ashes4    ,in     
selecting indigo the large regularly    
formed cakes should be                  
preferred1--those of a fine1 rich blue  
color1 extremely free from the  white   
adhesive mould#a1 and of a clean1 neat  
shape4 ,when broken1 it  should be of a 
bright purple cast1 of a close and      
compact texture1  free from specks or   
sand1 and when rubbed with the nail     
should have a  beautiful shiny coppery  
appearance2 when burnt in a candle it   
should  fly like dust2 that which is    
heavy and dull colored should be        
rejected4 ,indigo is estimated and      

classed in commercial language1 as      
follows3 fine blue1 ordinary blue1 fine 
purple1 inferior purple1 and  violet1   
strong copper1 and ordinary copper4 ,it 
is purchased by the  factory maund 7#gd 
lbs4 ,the ,bazaar maund is #hb lbs471   
packed in  cases containing on an       
average #b cwt41 dammered 7pitched7 and 
covered  with gunny bagging4            
----------------------------------------
---------------------    #a ,many       
experienced purchasers in this country  
pay no regard to    this mould1 as it   
weighs scarcely any thing4--,ed4        
----------------------------------------
---------------------    ,still1 in     
making large purchases1 as a measure of 
wise precaution the  chemical test      
should be added4 ,this is used to       
ascertain the  proportion per cent of   
indigotine which a given indigo has4    
,the  determination of the quality of   
indigotine contained is not alone       
sufficient to fix the value of an       
indigo4 ,with an equal yield of         

indigotine1 the indigoes are always to  
be preferred which have a light  and    
soft paste2 and for the preparation of  
the indigo vat the  preference should be
 always given to the violet red rather  
than to the  clear blue indigoes4       
,the chemical works which treat of this 
subject give elaborate details  of a    
great number of processes for           
determining by chemical tests the       
amount of indigotine1 or the coloring   
material in indigoes4 ,to give  these   
numerous processes would only confuse   
the reader4 ,in our own  confusion upon 
this subject we submitted the           
descriptions of these  various processes
 to one of the most eminent and         
practical of ,american  chemists1 ,dr4  
,charles ,t4 ,jackson1 an official      
,state ,assayer for the  ,state of      
,massachusetts1 who has had much        
experience in testing indigo1  with a   
request that he would describe the      
process which he approves  and          
practises4 ,he has obliged us by the    

following communication3--              
,boston1 ,nov4 #ba1 #ahgb4              
,no4 #dg ,court ,street1 ,room #d4      
,john ,l4 ,hayes1 ,esq4    ,dear        
,sir1--,in reply to your inquiry as to  
the simplest method of  analyzing       
indigo1 ,i would say that ,i first      
ascertain the amount per  cent of earthy
 matters and metallic oxides1 in the    
samples brought to  me1 by burning a    
weighed quantity in a counterpoised     
platinum  crucible1 until all organic   
matters are removed or consumed1 and    
then  weighing the ashes obtained4 ,the 
ash is then subjected to analysis in    
the usual way1 and lime1 alumina1       
peroxide of iron1 and some other  earthy
 impurities are separated4    ,then1 to 
determine the amount of coloring matter1
 or indigotine1 ,i  make use of a       
standard sample of pure reduced indigo1 
which is  dissolved in the most         
concentrated sulphuric acid1 and diluted
 with  water after solution4 ,then ,i   
ascertain how much bleaching powder     

7chloride of lime7 is required to       
dissolve the solution4 ,this is the     
quantity required for absolutely pure   
indigo4    ,now1 the indigo of commerce 
does not contain more than say from     
forty  or fifty per cent of pure        
indigotine1 and of course will require a
  smaller quantity of bleaching powder  
to decolor it2 or the quantity of       
bleaching powder to decolor a given     
weight of pure indigo may be  weighed   
out1 and the sample to be compared      
having been dissolved in  strong        
sulphuric acid1 and diluted with water1 
is to be poured in and  stirred or      
shaken well until the point of          
decoloration is ascertained4  ,in this  
case it is best to weigh out at least   
twice as much of the  sample to be      
tested as was used of pure indigo1 and  
to measure the  solution in a graduated 
glass vessel1--an alkalimeter1 for      
example1--so  that by measure we may    
know exactly how much of the sample we  
add to  the solution of bleaching       

powder4 ,thus the relative coloring     
values of  the samples may be readily   
ascertained4    ,if you have no purified
 indigo on hand1 you can make a good    
comparative trial of your samples       
against a perfectly good sample of      
,bengal indigo1 which may be kept for a 
standard of comparison4 ,very  useful   
practical results may thus be obtained4 
,it is well1 however1 to keep on hand a 
standard sample of pure indigo1         
prepared from reduced or white indigo1  
as directed by ,berzelius 7vol4  vi4    
page #c1 ,french ed41 #ahcb71 and in    
,muspratt's ,chemistry applied to  the  
,arts 7,dyeing1 ,indigo74    ,in the    
analysis by reduction of indigo1 the    
process is simply as  follows3 ,reduce  
the indigo to fine powder1 and weigh it2
 weigh out an  equal quantity of pure   
quicklime 7made from pure white marble74
  ,measure in a graduated vessel a      
certain volume of water4 ,slack the     
lime with a portion of this water4 ,the 
rest of this water is to be  used in    

rubbing up the indigo in a mortar4 ,then
 the slacked lime is to  be mixed with  
the indigo1 rubbing the substances well 
together4  ,introduce the whole into a  
large flask2 #a to #b litres 7about #c  
to #d  pints7 of water is required for  
#a gramme 7or about #ae grains of       
indigo74 ,the flask and contents are    
then to be exposed to a heat of  from   
#agf to #aij ,f4 for some hours4 ,this  
is best effected in a water  bath4 ,by  
this digestion the lime is made to      
combine with the indigo  brown1 and the 
coloring matter is set at liberty4      
,dissolve in the  liquor a little       
protosulphate of iron1 exempt from      
copper1 and reduced  to a fine powder4  
,the flask is to be corked and well     
shaken1 and  allowed to cool4 ,when the 
sediment is settled1 decant the clear   
solution by means of a syphon into a    
graduated glass4 ,the coloring  matter  
oxidizes by exposure to the air2 and to 
favor this oxidation  and to keep the   
lime in solution1 add muriatic acid to  

the liquor4  ,when the liquor has become
 clear1 filter and collect the          
precipitate  on a weighed filter1 which 
wash with hot water1 and dry at a       
temperature of #bab ,f4 ,thus we can    
learn1 by weighing the filter  again1   
how much indigotine is contained in the 
sample4    ,if we make use of #bjj      
measures of water1 and have drawn off   
#ej  measures of the solution to        
oxidate1 and this #ej measures has      
produced  #aj grains of indigo1 the     
whole sample evidently contained #dj    
grains of  indigo blue4    ,this method 
serves both for an assay of the sample  
and the production  of a standard sample
 of pure indigotine4 ,the operation may 
be carried  on upon a larger scale for  
the manufacture of a standard sample4   
,yours truly1    ,c4 ,t4 ,jackson4      
,dr4 ,jackson adds the following note3--
    ,in the processes given ,i have not 
referred to the qualitative analysis  or
 testing for all the kinds of           
adulterations1 but have given only      

valuation of the coloring power of      
indigo4    ,i have had occasion to      
search indigo for ,prussian blue1 an    
occasional  adulterant4 ,this is        
ascertained by caustic potash1 which    
becomes in  part an oxide if ,prussian  
blue is present4 ,this acidulates with  
muriatic acid1 and1 tested with sulphate
 of iron1 proves1 by formation  of      
,prussian blue1 the presence of the     
ferrocyanide of potash in the  solution1
 and hence ,prussian blue in the indigo4
 ,lime and clay are the  usual          
adulterants1 and oxide of iron is often 
present accidentally or  from the clay  
adulterants4 ,starch and flour are      
rarely used1 as they  add little to the 
weight4    ,c4 ,t4 ,j4      ,,commerce  
,,in ,,indigo4    ,before proceeding to 
a consideration of the practical        
applications of  indigo in              
manufacturing1 we must pause to make    
some general  observations upon the     
commerce in indigo4    ,the first       
,european impulse given to this commerce

 was made by the  ,spanish and          
,portuguese4 ,they not only imported    
indigo from the ,indies1  but           
established its fabrication in their    
colonies4 ,to them we owe its           
production in ,guatemala1 ,caraccas1 and
 ,brazil4 ,the ,french exported  from   
the ,island of ,san ,domingo1 only1 in  
#aggd1 #b1cej1jjj pounds weight  of this
 commodity4 ,british influence was      
exerted in favor of the  development of 
this article in the ,american colonies1 
and1 in #aggc1 in  the space of twelve  
months1 over a million pounds of indigo 
were  exported from ,south ,carolina4   
,the production in ,india was at that   
time  of little importance4 ,it was not 
until #aghc that the attention of the   
,english was directed to the culture of 
indigo in ,india for ,european          
consumption1 that produced by the       
natives being all consumed in their  own
 manufactures4 ,in the hands of the     
,english this product rapidly  rose to  
be the most important of ,india1 in a   

commercial view1 except  that of rice4  
,the small cost of a factory1 and the   
comparatively small  capital required   
for this production1 caused the indigo  
culture to be  preferred to sugar       
planting4 ,the importation and sale of  
this  commodity at the ,east ,india     
,house1 in #agib1 amounted to #eha1hbg  
lbs41  while the importation into ,great
 ,britain from other parts of the world 
amounted to #a1bhe1ibg lbs4 ,in #ahjf   
the importation from the ,east  ,indies1
 and sales at the ,east ,india ,house1  
amounted to #d1haa1gjj lbs41  and       
produced in sterling money #a1fhe1bge4  
,in the year #ahfb-fc1 the  export from 
,india1 and the destination of supplies1
 were as follows3--      ,destination4  
,quantity4         ,value4              
----------------------------------------
------------    ,united ,kingdom        
#h1ecg1acc lbs4  #a1fbg1jce    ,america 
#acd1jfd           #bf1idi    ,arabian  
and ,persian ,gulfs   #cdc1jcg          
#cc1che    ,france                      

#a1ibb1abj          #cga1cif    ,germany
                      #he1fhj           
#ae1ejd    ,suez                        
#bie1bfi           #ea1gcj    ,other    
places                  #i1egg          
#hae                                    
----------------------------------------
------------    ,total                  
#aa1cbf1hhj lbs4  #b1abf1had    ,the    
value of exports in #ahff was           
#a1hfa1eja4 ,in the same year the       
imports of indigo from the whole of     
,central ,america1 including  ,honduras1
 was #fgb1dhj lbs4 ,the consumption of  
indigo in ,great ,britain  did not      
increase during the ten years ending    
with #ahfg4 ,this  stationary demand1   
notwithstanding the fall in the price of
 the drug  and increase of population1  
is attributed by ,mc,culloch principally
 to  the decreasing use of blue cloth4  
,it is more probably due to the         
substitution of cheaper dyes4 ,the      
average home consumption in ,great      
,britain for seven years ending in      

#ahfg1 was #a1fge1jgb lbs4 per year4    
,the importation into this country for  
the twenty years last past is  shown by 
the following table1 kindly prepared at 
our request by the  chief of the ,bureau
 of ,statistics3--    ,statement of     
,imports of ,indigo into the ,united    
,states during the  ,fiscal ,years ended
 ,june #cj1 #ahec-ahgb4                 
,,indigo4    ,fiscal    ,year    ended  
,june #cj   ,,free ,,of ,,duty4         
,,dutiable4                             
----------------------------------------
----------            ,pounds4          
,dollars4    ,pounds4    ,dollars4      
#ahec                         #a1chg1hdg
    #idg1cfg    #ahed                   
#a1ife1ghi  #a1bhb1cfg    #ahee         
#b1jig1cig  #a1aea1eaf    #ahef         
#a1gcb1bij  #a1jfc1gdc    #aheg         
#a1ecc1jcg  #a1jaj1eji    #aheh         
#a1fdg1gfg    #ide1jhc    #ahei         
#a1ggc1hfh  #a1dda1dbi    #ahfj         
#a1gjg1aaf  #a1dac1gij    #ahfa         
#ahe1jci    #afj1ach     #gai1efc       

#eje1gff    #ahfb  #b1eja1jeb           
#c1bha1dda    #ahfc    #hhe1hcd         
#a1jjh1ahg     #agh1cfd    #bai1afi     
#ahfd    #fhd1hac    #fbc1djf           
#hig1hba    #fga1hii    #ahfe           
#gda1dch    #fja1bhc     #dae1ege       
#cbd1bjg    #ahff    #gih1hee           
#fji1afj      #dd1ffj     #da1bfh       
#ahfg  #a1jfi1ejf    #haf1igd    #ahfh  
#hgj1afd    #gge1gea    #ahfi           
#a1egd1ddi  #a1fdi1eej    #ahgj         
#a1bgj1egi  #a1bjc1ffd    #ahga         
#a1iid1agb  #b1jeb1bbb    #ahgb         
#a1ebf1hfi  #a1dhd1gdd      ,,edward    
,,young1 ,chief of ,bureau4    ,bureau  
of ,statistics1 ,nov4 #af1 #ahgb4       
,the extraordinary quantity imported in 
#ahfb1 we hardly need remark1  was due  
to the demand for consumption in army   
cloths4 ,indigo imported  directly1 was 
made free of duty in #ahfa4 ,the duty   
which appears by the  above table to    
have been charged since that period1 was
 upon indigo1  the product of ,india1   
imported by way of ,england1 which was  

subject to  an extra duty of ten per    
cent4    ,the indigo consumed in the    
,united ,states is generally supplied by
 the  ,boston and ,new ,york ,calcutta  
houses1 who have either an ,american    
partner resident in ,calcutta1 or who   
employ a resident ,american as  agent4  
,indigo1 like other ,calcutta goods1 is 
sold through the agency  of brokers1 who
 receive on this article a commission of
 one per cent4  ,the value of the       
article is known almost daily in these  
cities by  telegrams1 giving exact      
information of the state of the trade1  
transmitted from ,calcutta as often as  
every five days4 ,some of the  brokers  
publish monthly circulars1 showing the  
stock of indigo with  other ,calcutta   
goods on hand in our market4 ,the       
regular trade reports  issued by the    
,india merchants show that ,the higher  
qualities of indigo  do not come to our 
market4 ,the following is an extract    
from a report  of ,whitney1 ,brother1   
,co41 of #ahga3--      ,indigo for      

,continent      fine             #cej to
 #cfb rupees4                           
good             #ccj   #cde            
middling         #caj   #cbe            
,american consuming        fine         
#bhj   #cjj                             
good             #bej   #bge            
middling         #bjj   #bdj            
low and ordinary #aej   #agj       ,at  
the present moment there is great       
depression in the trade in this         
article4 ,the last telegrams show a     
decline of price in the ,indian  trade  
in this article of from fifty to        
seventy-five per cent from the  prices  
of last year2 and the apprehension is   
even entertained that  indigo is going  
out of use1 the dreaded competitors     
being the aniline  dyes1 and            
particularly the ,nicholson blue4 ,we   
maybe presumptuous in  giving our       
opinion on the question1 but we hazard  
the prediction that1  notwithstanding   
the temporary popularity of the cheap   
substitutes1 a  reaction will take place

 in favor of that 8wonderful and most   
valuable  production10 whose importance 
as a dye has been held in ,india for    
thousands of years and ,europe for two  
centuries1 8greatly to exceed  any      
other40#b                               
----------------------------------------
---------------------    #b ,the        
8,dictionnaire ,universel du ,commerce10
 c41 published in    #ahfa1 contains an 
exhaustive article on the commerce in   
indigo1    by ,m4 ,s4 ,beekrode4 ,from  
the statements of this writer1 it       
appears    that the consumption of      
indigo was estimated1 in #ahce1 as      
follows3--        ,great ,britain       
#a1bad1chj kilograms 7#b1fhc1ggi7 lbs4  
,france                     #iab1iae    
7#b1jag1edb7        ,united ,states     
#acj1jjj            7#bgg1cjj7          
,other countries          #b1dce1dgc    
7#e1chb1cie7                            
---------           -----------         
,total                    #d1fib1gfh    
kilograms 7#aj1cfb1jaf7 lbs4      ,the  

approximate consumption in #ahei is     
stated as follows3--        ,great      
,britain              #hjj1jjj kilograms
 7#a1gfh1jjj7 lbs4      ,france         
#hjj1jjj          7#a1gfh1jjj7          
,united ,states              #djj1jjj   
7  #hhd1jjj7        ,russia             
#hfj1jjj          7#a1ijj1fjj7          
,the ,zollverein           #a1bej1jjj   
7#b1gfb1ejj7        ,switzerland        
#aej1jjj          7  #cca1ejj7          
,austria                    #djj1jjj    
7  #hhd1jjj7        ,other countries    
#cjj1jjj          7  #ffc1jjj7          
---------           -----------         
,total                    #d1ifj1jjj    
kilograms7#aj1ifa1fjj7 lbs4      ,the   
average production in #ahei is estimated
 as follows3--        ,bengal1 ,madras1 
c4      #c1ejj1jjj kilograms            
7#g1gce1jjj7 lbs4      ,java            
#eej1jjj          7#a1bae1ejj7          
,central ,america            #cjj1jjj   
7  #ffc1jjj7        ,other sources      
#ajj1jjj          7  #bba1jjj7          

---------           -----------         
,total                    #d1dej1jjj    
kilograms 7#i1hcd1ejj7 lbs4      ,as the
 maximum annual consumption in #ahei is 
set down at    #e1jjj1jjj kilograms1 the
 author concludes that the average      
production at that time did not surpass 
the requirements of the    dyers of the 
whole world4                            
----------------------------------------
---------------------      ,,former     
,,production ,,in ,,the ,,carolinas4    
,as pertinent to the commercial branch  
of our subject1 we must briefly  notice 
the remarkable facts of the sudden      
growth and equally sudden  and          
extraordinary extinction of the         
production of indigo in the  ,carolinas4
 ,indigo was for many years the second  
great staple of ,south  ,carolina4 ,so  
highly was this staple estimated that   
the historian of  the ,state declares   
that 8it proved more really beneficial  
to ,carolina  than the mines of ,mexico 
or ,peru are or ever have been to ,old  

or ,new  ,spain40 ,its introduction was 
the happy result of a woman's culture   
and  energy4 ,in the early part of the  
last century1 the indigo plant had  been
 extensively cultivated in the ,west    
,india ,islands1 which then  furnished  
the chief supply of ,europe4 ,the       
governor of ,antigua1 ,george  ,lucas1  
whose home plantation was at ,wappoo in 
,carolina1 having  observed the fondness
 of his daughter1 ,miss ,eliza ,lucas1  
afterwards  the mother of ,general      
,charles ,cotesworth ,pinckney1 for the 
culture of  plants1 was in the habit of 
sending to her tropical seeds to be     
sowed  on his plantation at ,wappoo4    
,among others1 he sent her some seeds of
  the indigo plant cultivated in the    
,west ,indies4 ,she planted them for    
two years2 but the seeds failed to      
germinate1 or were killed by the  frost4
 ,on the third year's trial1 in #agda or
 #agdb1 she was successful4  ,governor  
,lucas1 on hearing that the plants had  
ripened and produced  seed1 sent from   

,montserrat a person skilled in making  
indigo4 ,vats  were built on ,wappoo    
,creek1 and there the first ,american   
indigo was  manufactured4 ,the attempts 
of the expert to conceal his processes  
were  defeated by the vigilance of ,miss
 ,lucas4 ,the process of manufacture    
was made known4 ,seeds from the ,wappoo 
plantation were freely  distributed and 
successfully planted2 and the culture of
 indigo became  common4 ,in #agdg1 a    
considerable quantity of indigo was sent
 to  ,england1 which induced the        
merchants trading with ,carolina to     
petition  parliament for a bounty on    
,carolina indigo4 ,in #agdh1 an act of  
parliament was passed granting a bounty 
of sixpence per pound on  indigo raised 
on ,british-,american plantations and   
imported directly to  ,britain from its 
place of growth4 ,this act stimulated   
the planters of  ,carolina to double    
vigor in the production of this new     
material for  export4 8,many of them10  
says ,dr4 ,ramsay1 8doubled their       

capital every  three or four years by   
planting indigo40 ,in the year #aged1   
the export  of indigo from the province 
amounted to #baf1ibd lbs41 and in the   
years  #aggb and #aggc the export had   
risen to #a1ajg1ffa lbs4 ,the production
  was greatly checked by the war of the 
,revolution4 ,near the close of  the    
century the large importations from     
,india lowered the price1 so as  to make
 the planting unprofitable4 ,in the mean
 time1 the culture of  cotton had sprung
 up under the protective tariff of      
#aghi4 ,the grounds  suitable for indigo
 planting were equally fitted for       
cotton1 and were  for the most planted  
with the new staple4 ,it is curious to  
observe how  the former was displaced by
 the latter staple4 ,the export of      
indigo  from ,charleston in #agig was   
#if1aba lbs43 in #ahjj1 it fell to      
#c1djj  lbs4 ,during the same years1 the
 exports of cotton rose from one        
million to six and a half million       
pounds4 ,the production of ,american    

indigo appears to have revived from time
 to time up to #ahbi4 ,a writer  of that
 period in ,silliman's ,journal of      
,science estimates--although it  would  
seem on doubtful authority--the         
production of indigo in the  ,united    
,states at #bj1jjj lbs4 ,the price of   
the ,american article had  fallen1 owing
 to the great quantity of extractive    
which it contained1  to fifty cents per 
pound1 while the ,bengal indigo was     
worth #a4ae per  pound4 ,we have no data
 as to its production at the present    
time1 but  infer1 from the fact that no 
reference has been made to this product 
in the ,government ,agricultural        
,reports for many years past1 that the  
production1 if any1 is too unimportant  
to be noticed4      ,,industrial        
,,application ,,of ,,indigo4    ,all the
 applications of indigo require that the
 material should first  be reduced to an
 impalpable powder4 ,it is better to    
grind it with  water1 to prevent the    
loss of material in the form of powder1 

although  the dry pulverization is      
necessary when the indigo is to be used 
for  the manufacture of the sulphate4   
,to facilitate the grinding the         
material into a paste1 it should be     
previously soaked in hot water  from one
 to three hours4 ,the grinding on a     
small scale may be done by  a very      
simple apparatus4 ,this is a            
hemispherical vessel of copper or       
cast-iron1 eighteen inches in diameter1 
furnished at the edge with two  handles4
 ,the workman1 sitting astride a bench1 
places the vessel  before him1 in which 
he places three heavy cast-iron balls1  
the indigo  which has been softened1 and
 a sufficient quantity of water4        
,holding  the basin by the handles1 he  
gives it a circular oscillatory         
movement1  in such a manner that the    
balls1 following this movement1 crush   
the  indigo which surrounds them2 after 
which the contents are poured into      
another vessel1 water is added1 and the 
material is stirred4 ,the  portions     

incompletely ground are made to reunite 
themselves at the  bottom by means of   
regular blows with a hammer on the rim  
of the  vessel4 ,the upper liquid is    
decanted1 and the deposit is submitted  
to  a new manipulation in the basin4    
,in large establishments the grinding is
 done by machinery4 ,an  apparatus      
highly recommended1 consists of two     
circular plates of  cast-iron1 arranged 
horizontally and slightly separated1 one
 from the  other1 which are rapidly     
rotated by power1 in inverse1           
directions4 ,the  interior surfaces of  
these disks are provided with deep      
grooves  radiating in a curved line from
 the centre to the circumference1 and   
diminishing in depth in the same        
direction4 ,the indigo which has been   
previously softened enters between the  
two plates by an opening in the  centre 
of the upper one1 and escapes in a thin 
paste by the  circumference4    ,the    
application of indigo to the coloring of
 textile fabrics requires  the complete 

dissolving of the substance1 for which  
the mechanical  division is only a      
preliminary4 ,there are only two known  
means of  dissolving this substance3 #a4
 ,by reduction2 #b4 ,by the action of   
concentrated sulphuric acid4 ,the first 
means allows indigotine to be           
regenerated2 and1 when the dyeing is    
completed1 it is pure indigotine  which 
adheres to the colored fibre4 ,by the   
second means1 or dissolving  by         
sulphuric acid1 the coloring material   
enters into a new  combination1 from    
which it can never be separated3 it     
becomes a new  substance1 endowed with  
new and special properties4    ,the     
fixing of ,indigotine by means of       
,reduction4--,in this method the        
operator avails himself of one of the   
most remarkable qualities of            
indigotine3 this is the facility with   
which this body takes up  hydrogen1 and 
becomes transformed into a colorless    
substance1 which is  soluble in favor of
 alkaline or alkaline-earthy bases1 and 

is  susceptible of reproducing          
indigotine by simple oxidation in       
contact  with air4 ,this hydrogenized   
substance is called white indigo4 ,blue 
indigo1 or indigotine1 is insoluble     
except by concentrated sulphuric  acid2 
and this insolubility gives it its      
superiority to all other blue  dyes4    
,not being soluble1 it cannot1 as blue  
indigo1 attach itself to  the material  
to be dyed2 but in the soluble form of  
white indigo it  can perfectly penetrate
 the fibre4 ,if by any means of         
oxidation we can  transform the white   
indigo into blue indigotine1 the latter 
becomes  insoluble1 and is imprisoned in
 the pores of the fibre4 ,this is1      
briefly1 the whole theory of the use of 
indigo in dyeing or printing1  although 
the reaction may be applied in different
 ways to the coloring  of fibres1 such  
as--    #a4 ,the indigo is dissolved by 
means of an alkaline reduction in a vat1
  and the fibre is immersed in the bath4
 ,this is the common blue vat4    #b4   

,the solution prepared beforehand is    
painted by a hair pencil and  printed by
 a stamp or roller upon only certain    
parts of the tissues4  ,this is the     
pencil blue4    #c4 ,the white indigo is
 precipitated under the form of a paste1
 in  combination with a metallic oxide  
having strong reducing power1 such  as  
hydrated protoxide of tin1 which        
prevents the too rapid reoxidation  of  
the indigotine4 ,the thickened paste is 
printed1 and the tissue is  placed in an
 alkaline bath 7lime or soda71 which1   
displacing the oxide  of tin1 forms a   
soluble combination of white indigo4    
,the latter can  then penetrate the     
fibre1 and afterwards become fixed by   
reoxidation4  ,this is the printer's    
solid blue4    #d4 ,the finely ground1  
but not dissolved indigo1 is placed upon
 the  tissue in such conditions that it 
can be dissolved and reduced in  place4 
,this done1 the fixing of the indigotine
 is effected by  oxidation4 ,this is the
 method for ,china blue or bleu faence4 

,without dwelling upon the details of   
these methods1 we hasten to a           
consideration of the most important of  
all the applications of indigo3--       
,,dyeing ,,by ,,the ,,indigo ,,vat4     
,the ,copperas ,vat4--,for dyeing       
cotton1 the method of reduction found   
by experience to be the most convenient 
and practical is founded upon  the      
action of the hydrate of the protoxide  
of iron in the presence of  lime4 ,the  
hydrated protoxide of iron is obtained  
from sulphate of iron  7green vitriol1  
or copperas7 with freshly burned lime4  
,certain  precautions should be observed
 in the use of these materials4 ,the    
copperas used for the preparation of    
these vats should be free from  sulphate
 of copper1 because the oxide of copper 
which would be formed  in the vats      
rapidly oxidizes the reduced indigo1 and
 causes its  precipitation in the bath4 
,the copperas ought not to contain red  
oxide  of iron1 nor sulphate of alumina4
 ,the coppery or oxidized vitriol may   

be purified by boiling the solution with
 pieces of iron1 which  precipitates the
 iron and neutralizes the oxide4 ,the   
lime ought to be  pure1 containing no   
magnesia2 when slacked lime has been    
exposed to  the air1 even for a short   
time1 it absorbs carbonic acid1 and     
becomes  converted into chalk4 ,the     
lime1 therefore1 should always be newly 
slacked4 ,the ingredients1 then1 of a   
copperas vat are water1 pure or         
purified green vitriol1 indigo ground   
into a homogeneous impalpable  paste1   
and pure and freshly slacked lime4 ,the 
proportions used in  different          
establishments are exceedingly variable4
 ,those which answer  for a laboratory  
vat1 or a small vat used for            
precipitating the white  indigo         
immediately for printing1 are3 indigo1  
one part2 sulphate of  iron1 two parts2 
slacked lime1 three parts4 ,these       
proportions are not  enough for the     
large vats used in dyeing pieces4 ,in   
them it is  necessary to make the       

quantities of lime and sulphate of iron 
larger  than the theory of the vat      
requires4 ,the excess of lime and       
hydrate of  iron serve the purpose1     
whenever the vat is stirred1 to repair  
the  losses of indigo caused by its     
oxidation from contact with the air4    
,schutzenberger gives the proportions   
generally used by the dyers of  ,france1
 as follows3--      ,indigo             
#a part4    ,crystallized sulphate of   
iron                  #c     ,freshly   
slacked lime                            
#c     ,others1 he says1 use more lime  
than copperas1 as in the following      
proportion3--      ,indigo              
#b parts4    ,sulphate of iron          
#e4e     ,quicklime                     
#f4e     ,m4 de ,kppelin1 who is        
especially familiar with the cotton     
dyeing in  ,mulhouse1 describes the     
ordinary vats for cotton dyeing as bound
 with  iron1 and placed on the level of 
the ground4 ,they hold from #c1jjj to   
#d1jjj litres 7#a1jee gallons7 of       

liquid4 ,in preparing them the dyer     
fills them about three-quarters full of 
water1 and pours in a milk of  lime1    
prepared with #de kilograms 7#ajj lbs47 
of freshly slacked lime2 a  fine liquid 
paste having been previously made from  
#ae kilograms 7#cc  lbs47 ground in     
water4 ,this is added to the lime in the
 vat by  portions1 the liquid in the vat
 being stirred up by a rake after each  
portion of the indigo paste has been    
added4 ,the indigo becomes  dissolved in
 about twenty-four hours1 when the vat  
can be used4 ,after  describing the     
manner in which the frame1 or           
champignon1 containing  the goods to be 
dyed is arranged and immersed in the    
vat1 this author  continues3 8,it will  
be understood that the vat is composed  
according  to the degree of intensity of
 the color which is sought to be        
obtained1 and that hues more or less    
deep may be obtained by means of  more  
or fewer repeated immersions of the     
fabric to be dyed4 ,after each          

immersion the champignon is lifted out  
of the vat1 and the fabrics  are left to
 ungreen themselves by contact with the 
air4 7,it must be  observed that1       
although soluble indigo is called white1
 because it is  without color when      
carefully prepared in the laboratory1   
the goods1  when first taken from the   
ordinary vat1 are of a green color47    
,exposed  to the air1 the soluble indigo
 is precipitated in the state of blue   
indigo upon the fibres of the tissue4   
,this oxidation1 or  dehydryzation1 may 
be hastened by plunging the tissue into 
a vat  containing a solution1 very much 
diluted with water1 chloride of lime1   
bichromate of potash1 or sulphuric acid4
 ,the first two act as  oxidizing       
agents2 the last facilitates the        
restoring of the blue  indigo by        
depriving it of the lime which is in    
excess in the solution  of indigo which 
the tissue has imbibed from the vat40   
,he adds further3 8,to facilitate the   
formation of blue indigo in the         

interior of the fabrics1 the stuff to be
 dyed may be previously  impregnated by 
a saline solution1 which has the        
property of  precipitating the white    
indigo from the alkaline solution1 and  
of  fixing itself more rapidly upon the 
tissue4 ,oxide of copper and oxide  of  
manganese possess these properties in a 
high degree1 and are used  in many      
establishments to hasten the dyeing     
process1 and produce an  economy in raw 
materials4 ,the pieces of cloth are     
placed in a solution  of sulphate of    
copper1 in the proportion of #ae to #bj 
grams to the  litre 7#b4aa pints71 and  
lightly thickened with starch4 ,the     
fabrics1  thus impregnated by a kind of 
mordant1 before receiving the blue dye  
are first passed through a weak bath of 
milk of lime1 which fixes the  oxide of 
copper upon the tissue4 ,the blues thus 
obtained are more  intense1 and have a  
peculiar lustre4 ,this process is used  
in ,austria  and ,germany1 where cotton 
fabrics are printed on both sides of the

  tissue40    ,coming to the ,english   
authorities1 ,dr4 ,grace ,calvert1 in   
his recent  lectures before the ,society
 of ,arts1 speaking of the cold vat for 
dyeing cotton1 says3 8,the oldest1 and  
still most generally employed  method of
 preparing cold vats1 consists of       
putting into a vat  containing about    
#bjjj gallons of water #fj lbs4 of      
indigo1 very finely  powdered1 #ahj lbs4
 of slacked lime1 and #abj lbs4 of      
sulphate of  protoxide of iron1 or green
 vitriol 7free from any trace of copper 
salt71 the two latter substances being  
added from time to time4 ,the  greater  
part of the lime used unites with the   
sulphuric acid of the  iron salt1 to    
produce sulphate of lime or gypsum2 and 
the liberated  protoxide of iron removes
 the oxygen from the indigo1 becoming   
converted into saline oxide1 whilst the 
reduced indigo dissolves in  the excess 
of lime employed40    ,he adds the      
following facts1 which may be of        
practical value3--    8,messrs4 ,r4     

,schloesser  ,co41 of ,manchester1 have 
introduced within  the last year or two 
a marked improvement1 in the preparation
 of cold  vats1 which removes the great 
objections of the bulky precipitate of  
sulphate of lime1 the formation of an   
oxide of iron1 and the loss of  indigo  
by its combination with the oxide of    
iron4 ,the bath remaining  much more    
fluid1 the pieces are less apt to be    
spotted1 and a better  class of work is 
produced4 ,to carry out their process1  
they add to the  ordinary #b1jjj gallon 
vat #bj lbs4 of ground indigo1 #cj lbs4 
of iron  borings1 #cj lbs4 of their     
remarkable powdered zinc1 and #ce lbs4  
of  quicklime2 the whole is stirred up  
from time to time1 for twenty-four      
hours1 when it is ready for use4 ,if the
 bath is not considered  sufficiently   
strong1 a little more lime and zinc are 
introduced4 ,the  chemical theory of the
 process is1 that the zinc1 under the   
influence  of the lime1 decomposes the  
water1 combining with its oxygen1 and   

the  hydrogen thus liberated removes    
oxygen from the indigo which then       
dissolves in the lime40    ,an excellent
 description of the processes employed  
at ,manchester1  ,england1 in preparing 
and working the copperas1 or cold vat1  
is given  in ,ure's 8,dictionary of     
,manufactures40 8,the ingredients       
necessary for  setting the vat are      
copperas1 newly slacked quicklime1 and  
water4  ,various proportions of these   
ingredients are employed1 as1 for       
instance3 #a part by weight of indigo   
7dry71 #c parts of copperas1 and #d  of 
lime2 or1 #a of indigo1 #b of copperas1 
and #c of lime2 or1 #h of  indigo1 #ad  
of copperas1 and #bj of lime2 or1 #a of 
indigo1  of  copperas1 and #bj of lime2 
or #a of indigo1 #d of copperas1 and #a 
of  lime4 ,the sulphate of iron should  
be as free as possible1 from red  oxide 
of iron1 as well as sulphate of copper1 
which reoxidize the  reduced            
indigo-blue4 ,the vat1 having been      
filled with water to near  the top1 the 

materials are introduced1 and the whole1
 after being well  stirred several      
times1 is left to stand for about twelve
 hours4 ,the  chemical action which     
takes place is very simple4 ,the        
protoxide of  iron1 which is set at     
liberty by the lime1 reduces the        
indigo-blue2  and the indigo1 which is  
then dissolved by the excess of lime1   
forming  a solution1 which1 on being    
examined in a glass1 appears perfectly  
transparent and of a pure yellow color1 
and becomes covered1 whenever  it comes 
in contact with the air1 with a         
copper-colored pellicle of  regenerated 
indigo-blue4 ,the sediment at the bottom
 of the vat  consists of sulphate of    
lime1 peroxide of iron1 and the         
insoluble  impurities of the indigo1    
such as indigo-brown in combination with
  lime1 as well as sand1 clay1 c4 ,if an
 excess of lime is present1 a  little   
reduced indigo-blue will also be found  
in the sediment in  combination with    
lime4 ,the dyeing process itself is very

 simple4  ,the vat having been allowed  
to settle1 the goods are plunged into   
the  clear liquor1 and1 after being     
moved about in it for some time1 are    
taken out1 allowed to drain1 and exposed
 to the action of the  atmosphere4      
,while in the liquid1 the fabric        
attracts a portion of the  reduced      
indigo-blue4 ,on now removing it from   
the liquid1 it appears  green1 but soon 
becomes blue on exposure to the air1 in 
consequence of  the oxidation of the    
reduced indigo-blue4 ,on again plunging 
it into  the vat1 the deoxidizing action
 of the vat does not again remove the   
indigo-blue which has been deposited    
within and around the vegetable  or     
animal fibre1 but1 on the contrary1 a   
fresh portion of the reduced            
indigo-blue is attracted1 which1 on     
removal from the liquid1 is again       
oxidized like the first1 and the color  
thus becomes a shade darker4 ,by        
repeating this process several times the
 requisite depth of color is  attained4 

,this effect cannot1 in any case1 be    
produced by one  immersion in the vat1  
however strong it may be4 ,the beauty of
 the  color is increased by finally     
passing the goods through diluted       
sulphuric or muriatic acid1 which       
removes the adhering lime and oxide  of 
iron4 ,after being used for some time1  
the vat should be refreshed  or fed with
 copperas and lime1 upon which occasion 
the sediment must  first be stirred up1 
and then allowed to settle again1 so as 
to leave  the liquor clear4 ,the        
indigo-blue1 however1 is in course of   
time  gradually removed1 and by degrees 
the vat becomes capable of dyeing  only 
pale shades of blue4 ,when the color    
produced by it is only very  faint1 it  
is no longer worth while using it1 and  
the contents are then  thrown away4 ,in 
dyeing cotton with indigo1 it seems to  
be essential  that the reduced          
indigo-blue should be in contact with   
lime4 ,if potash  or soda are used in   
its place1 it is impossible to obtain   

dark shades  of blue40      ,,fermenting
 ,,vats ,,for ,,wool ,,dyeing4    ,the  
application of indigo-blue to wool and  
woollen tissues is always  made by means
 of vats1 which have special names2 as1 
the pastel or  woad vat1 the urine vat1 
,german vat1 molasses vat1 c4 ,the      
reduction  or hydrogenation of the      
indigo-blue is the result of a peculiar 
fermentation1 which is developed within 
an alkaline liquor by means of          
nitrogenized substances and bodies rich 
in sugar or hydrocarbonized  substances4
 ,it is known that in these conditions1 
especially where the  temperature is    
slightly raised1 the sugar is converted 
into butyric  acid1 and at the same time
 carbonic acid and hydrogen are set     
free4 ,we  find here the source of the  
nascent hydrogen which fixes itself upon
  the indigo-blue1 and transforms it    
into white indigo1 which is soluble  in 
the alkalies of the vat4 ,it has        
recently been observed that the  butyric
 fermentation proceeds from the         

development of minute  infusoria4 ,these
 animalcul live without any supply of   
oxygen1 and1 in  fact1 are killed in its
 presence4 ,they therefore live at their
 ease in  the vat of reduced indigo1    
where no oxygen is permitted to enter4  
,the ingredients most usually employed  
for furnishing the  hydrocarbonaceous   
substances for fermentation are bran and
 ground  madder1 although molasses is   
sometimes used4 ,the nitrogenized       
material  is found in the woad or       
pastel1 which is often added in very    
large  proportions to the fermenting    
vats4 ,it is observed by the chemists   
who  have studied this subject most     
carefully1 that the preparation of      
vats1 founded upon the principle of     
fermentation1 does not repose upon      
principles so sure and constant as those
 of the copperas vat1 and that  many    
unforeseen accidents interpose to       
disturb the work of an  inexperienced   
dyer4 ,the phenomena in fermentations   
are often complex4  ,it is admitted that

 in these phenomena theory has not said 
its last  word1 and that empiricism is  
often more fortunate than science4 ,in  
conducting the operations of the warm   
fermenting vat1 the conceit of  the     
practical dyer1 so often remarked upon1 
is not without foundation4  ,by         
practical experience and the traditions 
of his art he has acquired  a knowledge 
of the almost insensible modification in
 conditions which  can change or arrest 
the chemical reaction4 ,it is the       
knowledge of the  workman1 a knowledge  
almost instinctive1 which can never be  
communicated to the books1 and which is 
most respected by those most  profoundly
 informed in theory4    ,the ,woad or   
,pastel ,vat4--,in former times woad1   
already referred to1  was the only      
material known to the dyers of ,europe  
for producing the  blue color of indigo4
 ,for dyeing wool1 the use of woad1 now 
abandoned  wholly in cotton dyeing1 has 
been retained to the present day1       
generally for the purpose of exciting   

fermentation1 and without regard  to its
 effect in imparting color to the       
material to be dyed2 for the  woad grown
 in ,england1 and used in the dye-houses
 of that country1  contains no trace of 
coloring matter4 ,the woad1 or pastel1  
grown in  the warmer districts of       
,france contains about two per cent of  
indigotine1 which is regarded in that   
country as an important addition  to the
 coloring material1 especially for      
improving the tone of the  color4       
,various substitutes1 such as rhubarb   
leaves1 turnip and carrot  tops1 and    
weld1 have been tried1 but without      
advantage1 with the  exception1 perhaps1
 of weld1 which is still used by some   
dyers4 ,some  chemists regard the use of
 woad as the remnant of a prejudice2 but
 the  better opinion is1 that this      
material possesses peculiar             
fermentiscible qualities1 whose exact   
action science has yet to resolve4      
,according to ,schutzenberger1 the most 
recent and highest ,french  authority1  

the dimensions of the pastel vat are    
about #f feet in  diameter1 by #i in    
depth4 #ajj kilograms 7#bba lbs47 of    
pastel1 in balls1  is placed in the vat1
 which is then filled with boiling      
water4 ,to this  is added #aj kilograms 
7#bb lbs47 of madder1 #c to #d kilograms
 7about #f  to #h lbs47 of bran1 and #d 
kilograms of quicklime1 which has been  
slacked1 and in the form of a bouilli4  
,sometimes weld is also added4  ,after  
three hours of rest1 the vat is well    
raked1 and the operation is  repeated   
every three hours4 ,there is gradually  
developed a  characteristic ammoniacal  
vapor1 and a blue scum1 with veins of   
deeper  blue1 forms on the surface2 and 
the liquid1 when agitated in the air1   
rapidly becomes blue4 ,these symptoms   
indicate the dissolution of the         
indigotine of the woad2 then there is   
added #aj kilograms 7#bb lbs47 of       
indigo which has been previously ground 
in water1 and the vat is  stirred4 ,if  
the fermentation appears to be          

proceeding too actively1  which is      
recognized by the disengagement of      
gases1 it is checked by  the addition of
 a proper dose of lime4 ,on the other   
hand1 the  fermentation is made more    
active by increasing the dose of bran4  
,the  first dyes are not so good as     
those subsequently obtained1 as the woad
  absorbs from the bath certain brown or
 yellow materials1 kept in  solution1   
and furnished as well by the pastel and 
madder as by the  indigo itself4 #ajj   
kilograms of wool require from #h to #ab
 kilograms of  indigo4 ,the vat is kept 
up by successive additions of indigo and
 lime1  made in the evening4    ,another
 kind of pastel vat1 prepared much like 
the last1 receives an  addition of a    
dose of potash4 ,m4 de ,kppelin         
describes it as the one  at present in  
general use in ,france4 ,into a vat     
containing from #c1jjj  to #d1jjj litres
 7#gia to #a1jee gallons7 there is      
placed #ge kilograms  7#aff lbs47 of    
pastel in loaves1 or which has undergone

 a kind of  fermentation2 or1 what is   
preferable1 #hj to #ajj kilograms 7#agf 
to #bba  lbs47 of pastel or woad        
gathered without fermentation1 and #aj  
kilograms 7#bb lbs47 of indigo1 ground  
to a paste with water4 ,this  mixture is
 well stirred1 and there is added #d    
kilograms 7about #i lbs47  of ,avignon  
madder1 and the same quantity of        
carbonate of potash4 ,after  the vat has
 been well raked there is added #b      
kilograms 7#d lbs47 of  slacked lime1   
and some pails of bran4 ,the vat is well
 covered1 either  with a wooden lid1 or 
woollen cloths4 ,the fermentation is    
allowed to  proceed1 and after five or  
six hours the vat is uncovered and raked
  with much care for half an hour4 ,this
 operation is repeated every  three     
hours1 until it is recognized that the  
indigo is well dissolved4  ,in this case
 the bath ought to be of a beautiful    
yellow color1 and be  covered with a    
light blue irised film1 veined with     
yellow at the least  movement given to  

the liquid4 ,if the fermentation        
proceeds too  rapidly1 a little lime is 
added to moderate it4    ,for keeping up
 a vat like this1 and to obviate the    
different  inconveniences to which it is
 subject1 the dyer sometimes adds lime1 
or sugar1 and carbonate of ammonia1     
sometimes madder1 or bran1 or even      
tartar-lees4 ,these last additions are  
made to saturate the excess of  lime    
which the vat contains4 ,in this case   
the yellow veins and the  beautiful blue
 scum which cover the surface disappear1
 or become pale2  a piquant odor is     
disengaged1 and the liquor becomes      
blackish4 ,when  lime or sugar are      
added1 it is for the purpose of         
retarding the  fermentation of the woad4
 ,sugar might even entirely take the    
place of  pastel for effecting the      
reduction of the indigo1 and many       
establishments in ,france are commencing
 to use it for this purpose4 ,a  good   
vat1 well supplied with successive      
additions of indigo1 pastel1  bran1 and 

madder1 in proportions necessary to     
effect and prolong the  fermentation    
necessary for the dissolution of the    
indigo1 may be kept  up many years4     
,schutzenberger observes that the vats  
of fermentation are subject to  certain 
maladies1 the two most frequent of which
 are due1 one to an  excess1 and the    
other to an insufficient quantity of    
lime4 8,in the  first case1 the liquid  
takes a tint more and more free of      
color1 loses  its fleure 7surface scum7 
and odor2 the fermentation is then      
arrested by the precipitation of the    
active matters4 ,this  inconvenience is 
remedied1 if seen in time1 by adding    
sulphate of  iron1 which eliminates the 
too great excess of lime4 ,in the       
second1  the fermentation becomes too   
active1 passes into a putrid            
fermentation1 and the liquid assumes a  
reddish tint2 a fabric dyed  with indigo
 in this state becomes very soon        
discolored4 ,the sole means  of safety  
is to heat the bath up to #ij and to add

 lime4 ,if this does  not accomplish the
 purpose of arresting the putrefaction  
the vat is  lost40    ,the following    
account of the method of dyeing woollen 
goods with  indigo by means of the woad 
vat is given by ,dr4 ,ure1 as that      
carried  on in ,yorkshire1 the great    
centre of the woollen manufacture of    
,england4    8,the dye-vats employed are
 circular1 having a diameter of six feet
 six  inches1 and depth of seven feet1  
and are made of cast-iron  five-eighths 
of an inch in thickness4 ,they are      
surrounded by  brickwork1 a space of    
three inches in width being left between
 the  brickwork and the iron1 for the   
purpose of admitting steam1 by means  of
 which the vats are heated4 ,the        
interior surface of the brickwork is    
well cemented4 ,in setting a vat the    
following materials are used3 #e  cwt4  
of woad1 #cj lbs4 of indigo1 #ef lbs4 of
 bran1 #g lbs4 of madder1 #aj  quarts of
 lime4 ,the woad supplied to the        
,yorkshire dyers is grown and  prepared 

in ,lincolnshire4 ,it is in the form of 
a thick1 brownish  yellow paste1 having 
a strong ammoniacal smell4 ,the indigo  
is ground  with water in the usual      
manner4 ,the madder acts in promoting   
fermentation1 but it also serves to give
 a reddish tinge to the color4  ,the    
lime is prepared by putting quicklime   
into a basket1 then dipping  it in water
 for an instant1 lifting it out again1  
and then passing it  through a sieve1 by
 which means it is reduced to a fine    
powder1 called  by the dyers ware4 ,the 
vat is first filled with water1 which is
  heated to #adj ,f41 after which the   
materials are put in1 and the whole  is 
well stirred until the woad is dissolved
 or diffused1 and it is  then left to   
stand undisturbed overnight2 at six     
o'clock the next  morning the liquor is 
again stirred up1 and five quarts more  
of lime  are added2 at ten o'clock five 
pints of lime are again thrown in1 and  
at twelve o'clock the heat is raised to 
#abj ,f41 which temperature  must be    

kept up until three o'clock1 when       
another quart of lime is  introduced4   
,the vat is now ready for dyeing4 ,when 
the process of  fermentation is         
proceeding in a regular manner1 the     
liquid1 though  muddy from insoluble    
vegetable matter in suspension1 is of a 
yellow or  olive yellow color2 its      
surface is covered with a blue froth or 
copper-colored pellicle1 and it exhales 
a peculiar ammoniacal odor2 at  the     
bottom of the vat there is a mass of    
undissolved1 matter of a  dirty yellow  
color4 ,if there is an excess of lime   
present1 the liquor  has a dark green   
color1 and is covered with a grayish    
film1 and1 when  agitated1 the bubbles  
which are formed agglomerate on the     
surface1 and  are not easily broken4    
,cloth dyed in a liquid of this kind    
loses its  color on being washed4 ,this 
state of the vat is remedied by the     
addition of bran1 and is of no serious  
consequence4 ,when1 on the other  hand1 
there is a deficiency of lime1 or1 in   

other words1 when the  fermentation is  
too active1 the liquor acquires first a 
drab1 then a  clay-like color2 when     
agitated1 the bubbles which form on its 
surface  burst easily1 and when stirred 
up from the bottom with a rake it       
effervesces slightly1 or frits1 as the  
dyers say4 ,if the  fermentation be not 
checked at this stage1 putrefaction soon
 sets in1  the liquid begins to exhale a
 fetid odor1 and when stirred evolves   
large quantities of gas1 which burns    
with a blue flame on the  application of
 a light4 ,the indigo is now totally    
destroyed1 and the  contents of the vat 
may be thrown away4 ,no further addition
 of woad is  required after the         
introduction of the quantity taken in   
first setting  the vat1 the fermentation
 being kept up by adding daily about    
four  pounds of bran with one quart or  
three quarts of lime4 ,indigo is also   
added daily for about three or four     
months4 ,the vat is then used for  the  
purpose of dyeing light shades1 until   

the indigo contained in it  is quite    
exhausted1 and its contents are then    
thrown away40    ,this author adds3     
8,woollen cloth1 before being dyed1 is  
boiled in  water for one hour1 then     
passed immediately under cold water4 ,if
 it be  suffered to lie in heaps after  
being boiled it undergoes some change1  
which renders it afterwards incapable of
 taking up color in the vat4  ,in       
dyeing1 the cloth is placed on a        
net-work of rope attached to an  iron   
ring1 which is suspended by four iron   
chains to a depth of about  three feet  
beneath the surface of the liquor4 ,the 
cloth is stirred  about in the liquor by
 means of hooks for about twenty or     
thirty  minutes4 ,it is then taken out  
and well wrung4 ,it now appears green1  
but1 on being unfolded and exposed to   
the air1 rapidly becomes blue4  ,when   
the vat has an excess of lime the cloth 
has a dark green color  when taken out4 
,it is then passed through hot water1   
and dipped again  if a darker shade is  

required40    ,the ,indian ,vat4--,this 
presents much analogy to the woad vat1  
as the  fermentation of vegetable       
matters effects the transformation of   
the  indigo-blue4 ,according to ,dr4    
,calvert1 the ,indian vat1 probably so  
called from its origin in the ,east1 is 
taking the place in ,england of  the old
 woad vat for dyeing wool and woollens4 
,he describes its  preparation as       
follows3 #h lbs4 of powdered indigo is  
added to a bath  containing #c lbs4 of  
bran1 #c lbs4 of madder1 and #ab lbs4 of
 potash1  which is maintained for       
several hours at a temperature of #bjj  
,f4 ,it  is then allowed to cool to #ajj
 ,f41 when fermentation ensues4 ,after  
about forty-eight hours the indigo is   
rendered soluble1 being reduced  by the 
decomposition of the sugar and other    
products contained in the  bran and the 
madder root during the process of       
fermentation4 ,the  distinguishing      
feature of this vat is the use of       
potash4 ,the ,indian  or potash vats are

 spoken of by the best authorities as   
more easy to  manage than the woad vat4 
,they are less subject to accidents1 and
  yield their coloring material more    
readily to the fibre1 while three  times
 as much wool can be dyed in the same   
time4 ,on the other hand1  they do not  
last so long1 and require to be renewed 
at the end of  twenty-five or thirty    
days4 ,besides1 the fibres dyed in the  
potash vat  have a darker shade than    
those dyed in the woad vat1 owing to the
  large quantity of the coloring matter 
of the madder dissolved by the  potash1 
which becomes fixed on the stuff with   
the indigo-blue4    ,the ,urine ,vat1   
but little used except for domestic     
dyeing1 is  founded upon the same       
principles as the other fermenting vats4
 ,this  excretion1 when putrefied1      
contains at the same time the           
nitrogenized  principles which work as  
ferments and the alkali in the form of  
ammonia necessary for dissolving the    
indigo4    ,according to ,dr4 ,calvert1 

improvements have been made of late     
years in  the fermenting indigo vats by 
which the expense of madder is avoided4 
,they are now prepared by adding to     
water1 at a temperature of #bjj ,f41  #b
 buckets of bran1 #bf lbs4 of soda      
crystals1 #ab lbs4 of indigo1 and #e    
lbs4 of slacked lime4 ,after five hours 
the bath is allowed to cool to  #ajj    
,f41 when fermentation ensues1 and the  
indigo is dissolved in the  alkali4     
,this is1 in fact1 the ,german vat1 soda
 taking the place of the  potash1 and   
the only fermenting material consisting 
of bran4    ,the ,german ,vat is largely
 used by the dyers in the north of      
,france1  and is considered as more     
advantageous than the ,indian vat1      
because  the employment of soda is more 
economical than that of potash1 while   
the vat can be maintained as long as two
 years4 ,the vats used by them  are     
prepared as follows3 ,the water is      
heated to a temperature of #ie1  and    
receives #bj pails of bran1 #aa         

kilograms 7about #bd lbs47 of  crystals 
of carbonate of soda1 #e4e kilograms    
7#aa lbs47 of indigo1 and  #d lbs4 of   
slacked lime4 ,after twelve hours1 the  
temperature having  been kept at #dj or 
#ej1 fermentation commences1 the liquid 
becomes of  a greenish blue color1 and  
disengages bubbles of gas4 ,indigo1     
soda1  and lime are put in from time to 
time in the proportions above           
indicated1 and also from six to eight   
pounds of molasses4 ,at the end  of the 
third day the vat is fit for use4    ,m4
 de ,kppelin1 writing in4 #ahfd1 informs
 us that the reduction of  indigo by    
means of molasses1 is at present largely
 employed in the  great establishments  
for dyeing woollen cloth at ,sedan1     
,louviers1 and  ,elbuf4    ,the vat used
 is of very large dimensions1 and from  
twenty-two to  twenty-six pounds of     
indigo are dissolved in it2 an equal    
weight of  molasses is used1 and three  
or four times the same weight of potash 
made caustic by a proportionate addition

 of lime4    ,the space reserved for    
this subject in our present paper will  
not  permit us to enter upon a          
description of the processes used in the
  ,american dye-houses4 ,this1 as well  
as the applications of indigo in        
printing1 and the uses of sulphate of   
indigo1 must be deferred to  another    
number4    ,let us1 in concluding the   
first part of our paper1 at the risk of 
repetition1 bring out in bolder relief a
 statement which presents the           
philosophy of all the various processes 
of the indigo vat1 and at the  same     
time1 a conclusive argument for the use 
of this material1 in  preference to all 
cheaper substitutes4 ,indigo cannot     
enter into a  fibre until it is         
dissolved4 ,it cannot be dissolved so   
long as it is  in a blue state4 ,when   
reduced by any of the processes above   
described  to the white state1 it is    
easily dissolved1 and can enter the     
pores of  the fibre4 ,upon exposure to  
the oxygen of the air it takes up an    

equivalent of oxygen2 it returns to the 
blue state1 and1 being then  insoluble1 
it cannot be washed away from the       
fabric1 and being  saturated with oxygen
 it cannot be changed by air or light4  
,this  theory of the application of     
indigo involves a lesson to             
manufacturers1 dealers1 and consumers1  
especially of woollen fabrics4  ,the    
theory1 as well as experience1 dating   
back to the dawn of the  textile arts in
 the ,east1 establishes that this       
material is  incalculably superior to   
any other1 in permanence at least1 for  
imparting to woollen fibre a blue color1
 or as a foundation for most  of the    
darker colors4 ,by far the largest      
proportion of all cloths are  of dark   
colors1--blue1 black1 green1 brown1     
gray1 or mixed1--and can  advantageously
 receive in all or a portion of the     
fibre constituting  them a direct dye or
 bottom for other dyes from indigo4 ,it 
may be  safely stated that1 as a whole1 
no cloths in the world are  manufactured

 from such good wool as those produced  
in the ,united  ,states4 ,we might      
expect that the shoddy goods of         
,yorkshire should be  further falsified 
by fugacious dyes2 but is it not a shame
 that our  admirable wool should be     
deprived of half its value by parsimony 
in  dyeing8 ,the slightest shortcomings 
in dyeing are revealed in wear4 ,the    
writer cannot forbear referring to an   
illustration directly before his  eyes4 
,he is wearing a garment1 reduced now to
 the retired service of  an office coat1
 made of an admirable cheviot cloth of  
,american  manufacture4 ,the cloth      
originally was selected not only for its
  excellent texture1 but as an          
illustration of philosophical principles
  applied in the formation of color4    
,the tissue was made by weaving  three  
yarns of distinct colors1--blue1 yellow1
 and red4 ,either of those  hues alone  
would have been glaring and conspicuous1
 but1 by the law of  color1 the         
combination of blue1 red1 and yellow    

makes black1 and the  new cloth at a    
distance had the effect of a dark       
mixture4 ,upon  exposure to ordinary    
wear1 the yellow and red have retained  
their  pristine hues2 the blue1 not     
being indigo dyed1 has faded2 and the   
original dark mixture1 although sound in
 fabric1 has become of a  yellowish     
brown4 ,the extra expense of a permanent
 dyeing material  forms so small a      
proportion of the whole cost of a       
finished garment1  that it ought not to 
be generally spared4 ,the reform cannot 
be made by  the manufacturers2 it must  
be made by the dealers1 and especially  
by  that class of producers which has   
risen in our day into such great        
importance1--the manufacturers of       
ready-made clothing4 ,if they would     
demand of the manufacturers1 and furnish
 to their customers cloths  more        
permanently dyed1 it would be another   
step in the direction to  which these   
establishments are tending1--the supply 
of the chief  portion of the woollen    

clothing of the people4 ,the            
manufacturers would  gladly aid them2   
for it is the growing sentiment of      
,american  manufacturers that all their 
productions should be1 in the proverbial
  phrase adopted from the dye-house1 as 
expressing the highest                  
excellence1--true blue4                 
,,bibliography4    ,citations of        
authorities having been but partially   
made in the  preceding article1 the     
writer1 for the purpose of giving his   
sources  of information1 and for the    
convenience of those who wish to pursue 
the subject further1 appends a list of  
the more important works which  he has  
consulted3--    ,schutzenberger's ,trait
 des ,matires ,colorantes1 t4 ii4 7the  
most  recent and best modern authority72
 ,bancroft's ,philosophy of  ,permanent 
,colors1 vol4 i42 ,edinburgh            
,encyclopdia2 ,berzelius1  ,trait de    
,chimie1 t4 vi2 ,chevrueil1 ,leons de   
,chimie ,applique   ,teinture1 t4 iii42 
,dumas1 ,chimie ,applique aux ,arts1 t4 

viii2  ,wurtz1 ,dictionnaire de ,chimie1
 #ahgb1 art4 ,indigo2 ,indigo et son    
,emploi1 par ,de ,kppelin2 ,annales du  
,gnie ,civil1 #ahfd1 t4 iii42  ,lectures
 of ,dr4 ,grace ,calvert1 ,chemical     
,news1 ,aug4 #i and #bc1 #ahgb2         
,o',neill's ,dictionary of ,dyeing and  
,printing2 ,napier's ,chemistry         
,adapted to ,dyeing2 ,muspratt's        
,chemistry ,applied to the ,arts1       
articles ,indigo and ,dyeing2 ,ure's    
,dictionary of ,manufactures1 ed4  of   
#ahfj2 ,proceedings of ,royal ,society1 
vol4 xvi42 ,proceedings of  ,literary   
and ,philosophic ,society of            
,manchester1 vol4 iv42 ,mc,culloch's    
,dictionary of ,commerce1 ed4 #ahfi2    
,dictionnaire ,universel du  ,commerce1 
c41 ed4 #ahfa2 ,south ,carolina         
,production4--,ramsay's  ,history2      
,drayton's ,south ,carolina2 ,silliman's
 ,journal1 vol4 xviii4  ,a more complete
 bibliography is given in               
,schutzenberger's work4      ,,part     
,,ii4    ,,part ,,ii4    ,we entered    

upon the subject of indigo1 which we    
have treated at some  length in our last
 issue1 as much in the interest of the  
people as of  manufacturers1 for we were
 deeply impressed with the conviction   
that  no improvement in our             
manufacturing processes would confer    
more  benefit upon the masses than      
imparting stability of color to the     
clothing of the people4 ,when one has a 
deep conviction upon a subject1  upon   
which others have equal opportunities   
for judging1 he may be sure  that he is 
not alone in his impressions4 ,he is    
moved by one of those  waves of thought 
which1 operating simultaneously upon    
many minds1  gives that uniformity to   
public opinion at which we so often     
wonder4  ,we are gratified to find1 from
 responses to our last article1 that we 
are not alone in our conviction of the  
importance of reviving 8true  blue0     
dyes4 ,the head of a mercantile house1  
the extent of whose  clientle in mills  
both of wool and cotton is hardly       

surpassed1 has  assured us that we have 
not overstated the reform in dyeing     
which we  have advocated4 ,he had long  
shared in our convictions4 ,pointing to 
the  throng of men in the crowded       
street1 where we were conversing1 he    
remarked that there was hardly a man in 
the crowd whose clothing would  not have
 been improved by indigo dye4 8,the     
failure to use indigo  dyes10 he        
emphatically said1 8costs the laboring  
people of this  country millions of     
dollars every year4 ,the fault is not to
 be charged  to our own manufacturers   
alone2 for the blue coat which ,i wear1 
and  which ,i bought in ,paris1 annoys  
me by the crocking caused by its        
aniline dye40 ,in one very large mill of
 which he is director as well  as       
selling agent1 he is putting his        
principles in practice4 ,all the  heavy 
blue cloths intended for popular        
consumption are faithfully  dyed1 and   
each bears a stamp1 8,warranted indigo  
dyed40 ,the ready-made  clothing        

establishments which largely consume    
these goods have already  found their   
advantage in purchasing them1 and a     
similar stamp is  attached to each      
article made from this cloth4    ,some  
of our most celebrated cotton fabrics   
have won and still retain  their        
reputation by the use of indigo dyes4   
,the ginghams are a signal              
illustration4 ,the blue check is formed 
by weaving cotton yarns dyed  blue in   
the cold indigo vat with undyed yarns4  
,these goods can be  washed indefinitely
 without change4    ,another            
illustration is the famous ,a4,b4,a4    
,amoskeag tickings1 an  article of such 
excellence that the question of the     
right to use  trade-mark ,a4,b4,a4 gave 
rise to the leading ,american case in   
this  branch of law4#c ,a prominent     
feature in these goods was and still is 
the permanence of the dye in the blue   
stripe1 produced by the cold  indigo    
vat4 ,still another illustration is the 
blue and white 8shirting  stripe0 first 

made by ,mr4 ,samuel ,batchelder1 at the
 ,hamilton ,mills1  now so generally    
adopted for sailors' shirts4 ,the indigo
 dye enables  the color to resist the   
roughest possible usage4                
----------------------------------------
---------------------    #c ,see the    
case stated at length in our article on 
,trade-marks1    ,bulletin1 vol4 i4 p4  
#ajb4                                   
----------------------------------------
---------------------    ,to recur to   
the application of indigo dyeing to wool
 and woollens4 ,we  have been unable1   
although we have written more than fifty
 letters of  inquiry upon the subject1  
to learn of any peculiarity or          
improvements  in the ,american processes
 of wool dyeing with indigo4#d ,our     
dyers are  for the most part foreigners4
 ,for this reason1 or because the art of
  indigo dyeing has long since reached  
perfection in the best  establishments  
abroad1 they rigidly pursue the old     
,european methods4  ,the best dyers     

regard the successful management of the 
warm fermenting  vats for wool as the   
highest test of their art4 ,we have     
already spoken  of the complicity of the
 phenomena in fermentations4 ,practical 
dyers  endow the fermenting vat with a  
sort of personality4 8,an indigo vat10  
says one to us1 8is more like a sick man
 than any thing in the world3  you have 
to watch it as you would a sick patient1
 and give it physic  or ferments to stir
 up the system and purify it40 #e ,the  
diagnosis of  a sick vat requires that  
sort of instinctive knowledge which     
experience gives to the practised       
physician4 ,the impatience of our  young
 ,americans will not permit them to     
serve the long apprenticeship  necessary
 to acquire the proper experience4 ,the 
artisans not  thoroughly trained will   
naturally prefer the dyes and processes 
introduced by modern science1 which     
require but little skill in their       
application4 ,it is a curious fact that 
the influence of the national           

government has been largely instrumental
 in preserving the old system  of indigo
 dyeing4 ,thanks to the                 
,quartermaster-,general's ,bureau1 or   
the  man of science1 ,general ,meigs1   
who presides over it1 indigo dyed       
cloths have been persistently insisted  
upon for the army4 ,the late war  gave a
 new impulse to indigo dyeing4 ,a       
skilled dyer1 whom we have  consulted1  
was constantly employed in ,connecticut1
 on a tour of  professional inspection  
of a dozen or more different            
establishments  making army goods4 ,no  
doctor1 he says1 ever found in hospital 
practice  more complications of disease 
than he found in the ailing vats4 ,among
  other difficulties there was a        
deficiency of imported woads1 although  
the cultivation of excellent woad       
immediately sprung up in  ,connecticut4 
,in the mean time carrot and rhubarb    
tops were used as  substitutes for the  
fermenting material of the woad4        
,carrot-tops grown  expressly for that  

purpose brought as high as twenty-five  
cents per  pound4 ,since the war the    
requisitions for indigo dyed woollen    
goods  have not relaxed1 and the art is 
not likely to be lost4                  
----------------------------------------
---------------------    #d ,a reply by 
,mr4 ,d4 ,r4 ,whitney1 an extensive     
indigo importer1    to a letter of      
inquiry1 enables us to correct some     
errors in our    former article1 under  
the head of 8commerce in indigo40 ,the  
value    of export from ,india in       
#ahfb-fc1 stated in dollars1 through a  
typographical error1 should have been   
pounds sterling2 thus1    instead of    
#b1abf1had1 read #b1abf1had4 ,it is     
stated in our first    article that the 
telegrams show a decline of price of    
indigo in    the ,indian trade of from  
#ej to #ge per cent2 8per cent0 should  
read 8rupees10 which would make a       
decline of from #be to #cj per    cent4 
,the reason for the decline1 as stated  
by ,mr4 ,whitney1 is    the unusually   

large crop of this year4 ,the average   
crop of indigo    in ,bengal is about   
#ajj1jjj maunds4 ,the crop of this year 
is    #ace1jjj maunds1 about #cj to #ce 
per cent above the average4             
,according to ,mr4 ,whitney1 the        
consumption of ,bengal indigo in the    
,united ,states was #b1deh cases of #bgj
 lbs4 to a case on an    average1 in    
#ahga2 and in #ahgb1 #a1hjb cases4      
,guatemala indigo1    #c1acb serroons in
 #ahga1 and #b1egh serroons in #ahgb4   
#e ,see notes on 8sickness0 of vats in  
,appendix4                              
----------------------------------------
---------------------    ,with the real 
difficulties which attend the process1  
it is hard for  indigo dyeing to sustain
 itself in the face of cheap substitutes
 of  easy application1 such as the      
,nicholson blue4 ,it is exceedingly     
difficult to piece dye with indigo and  
preserve a uniform hue upon the  cloth4 
,hence indigo dyes are generally given  
in the wool4 ,the wool  absorbing the   

foreign material of the dye is more     
difficult to work in  the operations of 
carding and spining4 ,in other words1 a 
finer and  costlier wool is required4 ,a
 great desideratum therefore is a means 
of piece dyeing with indigo so as to    
preserve a perfect uniformity of  hue   
throughout the piece4 ,this1 we are     
happy to say1 has been recently         
successfully accomplished by one of the 
largest and most faithful of  our       
cloth-making establishments4 ,it would  
be premature1 before the  patents are   
secured for this invention1 to explain  
the ingenious and  expensive apparatus  
devised for this purpose1 which         
constitutes in  fact a battery of vats  
so arranged that the operation may be   
continuous4 ,the experiments authorize  
the statement that bottom dyes  of      
indigo1 so desirable for a great variety
 of colors1 can be applied  with no     
other additional cost than that of the  
dyeing material4 ,when  this            
establishment1 as it proposes1 stamps   

upon the cards which  designate goods1  
already so admirable in material and    
texture1  8,warranted indigo dyed10 we  
shall regard it as an era in the        
,american  card-wool manufacture4       
,the old ,european woad vat process is  
that used in all our  establishments4   
,mr4 ,henderson of the ,washington      
,mills1 whose  experience as a practical
 dyer of wool is exceptionally large1   
informs  us that he has found no work so
 instructive upon this process as       
,napier's 8,chemistry of ,dyeing0       
7published by ,henry ,carey ,baird1 of  
,philadelphia1 #ahfi74 ,napier's        
description of the process is extracted 
from ,dumas's 8,lectures on ,dyeing40   
,the appreciation expressed by so       
competent a judge induces us to reprint 
,dumas's description in an  appendix to 
this article4    ,that we may give at   
least a general view of the whole       
subject1 we will  proceed to consider   
indigo in some relations not yet        
adverted to4    ,in ,part ,i4 of our    

notes we have treated only of the       
application of  this substance in dyeing
 by means of reduction through the      
indigo vat4  ,indigo may be applied by  
means of reduction in the printing of   
fabrics1 as well as in dyeing them4 ,a  
true scientific arrangement  would      
compel us next in order to consider this
 other application of  indigo by means  
of reduction4 ,but the more natural and 
practical order  is to pursue the       
subject of dyeing1 and to consider next 
the  applications of the derivatives    
from indigo in dyeing proper4           
,,sulphuric ,,derivatives1--,,saxon     
,,blue1 ,c4    ,the powerful action of  
sulphuric acid upon indigo1 and the     
bright and  lively blue color thereby   
produced1 had been observed by chemists 
long  ago2 but no person appears to have
 applied this color upon cloth1  until  
it was done about the year #agdj1 by    
,counsellor ,barth1 at  ,grossenhein1 in
 ,saxony4 ,the vividness of the dye1 and
 the facility  with which it was        

applied1 brought it into great vogue    
under the name  of ,saxon blue1 from its
 origin4 ,its popularity in former times
 is  evinced by the words of the old    
song1 8,the ,blue ,bells of             
,scotland30--      8,in what clothes1 in
 what clothes is your ,highland laddie  
clad8    ,his bonnet's of the ,saxon    
blue1 his waistcoat of the plaid40#f    
----------------------------------------
---------------------    #f ,first sung 
by ,mrs4 ,jordan1 about the year #agii4 
----------------------------------------
---------------------    ,the ,saxon    
blue consists simply of a solution of   
indigo1 the ,guatemala  blue indigo     
being preferred1 in sulphuric acid      
suitably diluted with  water4 ,the      
result of this reaction is not a single 
chemical substance1  but two acids      
giving different tints1 one called      
sulpho-purpuric  acid or phenicine1 and 
the other sulpho-indigotic acid2 the    
first  giving to wool a reddish-violet  
color1 and the other a pure blue4 ,a    

third compound has been indicated by    
,berzelius1 the nature of which  has not
 been determined4 ,whether one or the   
other of the two named  acids1 or the   
two combined1 shall be produced by the  
reaction between  the sulphuric acid and
 the indigo1 depends upon the duration  
of the  contact1 the temperature of the 
mixture1 and the nature and proportion  
of the acid used4    ,persoz gives the  
following general receipt3--      8#a   
part by weight of indigo1 finely rubbed4
     #a               ,nordhaussen acid4
     #a               ordinary sulphuric
 acid4  ,leave for forty-eight hours1   
then heat until a drop turned into      
water will dissolve without producing a 
precipitate4 ,leave to cool1  and dilute
 with water till the strength is brought
 to #ah ,beaum40    ,napier says that he
 has found the following method of      
preparing  sulphate of indigo1 in       
quantities for use1 very satisfactory3  
8,the  indigo is reduced to an          
impalpable powder1 and completely dried 

by  placing it on a sand bath or flue   
for some hours at a temperature of      
about #aej ,f4 ,for each pound of indigo
 six pounds of highly  concentrated     
sulphuric acid are put into a large jar1
 or earthen pot1  furnished with a      
cover4 ,this is kept in as dry a place  
as possible1  and the indigo is added   
gradually in small quantities4 ,the     
vessel is  kept closely covered1 and    
care taken that the heat of the solution
  does not exceed #bab;,f4 ,when the    
indigo is all added1 the vessel is      
placed in such a situation that the heat
 may be kept up at about  #aej;,f41 and 
allowed to stand1 stirring occasionally1
 for forty-eight  hours4 ,these         
precautions being attended to1 we have  
uniformly found  that any failure       
occurring was clearly traceable to the  
impurity of  the indigo or weakness of  
the acid used40    ,the processes for   
producing and separating the two acids  
derived from  the combination of sulphur
 and indigo are minutely given by       

,berzelius1  in vol4 i4 of his 8,trait  
de ,chemie10 who states this curious    
fact  illustrative of the peculiar      
affinities of wool with certain dyeing  
substances4 ,wool or flannel thoroughly 
scoured1 when immersed in the  blue     
solution of indigo with sulphuric acid1 
acts as a base3 it  combines gradually  
with the acid blue1 and becomes itself  
colored of a  deep blue4 ,when saturated
 with color1 it is withdrawn4 ,fresh    
wool is  introduced until the bath      
yields no more color4 ,if sublimed or   
perfectly pure indigo is used1 there    
remains in the bath nothing but  free   
sulphuric acid4 ,the wool thus plays the
 part of a base with which  the blue    
acids combine4 ,the dyed wool is        
afterwards washed and treated  in feeble
 alkaline bath 7ammonia71 which         
redissolves the blue4 ,this  method of  
purifying the ,saxon blue is still      
practised by ,french  manufacturers4    
,the combination of indigo with         
sulphuric acid1 sometimes improperly    

called sulphate of indigo1 is known by  
the dyers here and in ,england  under   
the name of chemic4 ,the name of chemic 
blue or green is also  given the dyes   
formed from the indigo extract hereafter
 spoken of4 ,it  is largely used for    
making certain greens required in       
,scotch plaids4    ,the old ,saxon blue 
or simple solution of indigo with       
sulphuric acid is  now seldom prepared  
by the manufacturers themselves4 ,it is 
now  generally prepared for them1 and   
furnished commercially under the name   
of indigo extract4 ,the finer qualities 
used for fine dyeing and  printing are  
known under the name of carmines of     
indigo1 neutral  extract1 soluble       
indigo1 ceruline1 c4    ,the production 
of indigo carmines1 which are simply    
alkaline  sulphindigotates or           
sulpho-purpurates1 is founded upon their
  insolubility in a liquid charged with 
a salt4    ,if1 for example1 we dissolve
 one part of indigo in four parts of    
fuming acid1 and dilute the liquid with 

sixty or eighty times its  weight of    
water1 it will contain1 besides the     
sulphindigotic acid1  an excess of      
sulphuric acid4 ,by adding one part of  
crystals of soda so  as to neutralize   
the bath1 there will be formed not only 
sulphindigotate of soda1 but sulphate of
 soda3 as the former is  insoluble in   
the saline liquid1 the presence of the  
sulphate of soda  causes the            
precipitation of the sulphindigotate in 
deep blue  floccules4 ,these are        
collected on woollen filters and washed 
to remove  the sulphate of soda and a   
green coloring material1 probably a     
modified chlorophyl1 which the paste    
often contains1 and which has the       
singular property of fixing itself on   
silk1 but not on wool4    ,the carmines 
are divided according to their richness 
in indigo into  simple carmine 7#d4if   
per cent of indigo1 water #hi1 saline   
materials  #eg71 double carmine 7#aj4b  
per cent indigo1 water #he1 salts #d-h71
  triple carmine 7#ab4d per cent indigo 

water1 #gc4g1 salts #ac4i74 ,a  species 
of solid carmine known as ,boiley blue  
or purple is in high  repute in ,france4
    ,the carmines may be tested by      
dyeing a specimen of wool in an         
acidulated bath to which cream of tartar
 has been added4 ,the presence  of the  
green matter1 so objectionable to       
silk-dyers who make much use  of these  
carmines1 is detected by rubbing a small
 quantity of the  carmine on a piece of 
glazed paper1 which1 when the color     
dries1 gives  a color varying from blue 
to a rich copper color3 if any green    
coloring matter is left1 it shows itself
 by a green aureola around the  blue    
color4 ,the method of applying the      
carmines in dyeing wool and  silk1--for 
they are not adapted to cotton          
fabrics1--as given by ,m4 de  ,kppelin1 
is as follows3--    ,the operation is   
conducted in small wooden vats1 provided
 with  openings for manipulation1 and   
pipes for inducting steam to heat the   
baths to the proper temperature4 ,it    

consists of two parts1 that of          
mordanting and dyeing4 ,the former is   
thus conducted4    ,for each kilogram of
 tissue which has been previously       
scoured and  bleached1 there are        
provided #bjj grammes of cream of tartar
 and #bej  grammes of alum4 ,these are  
dissolved in the bath of water of the   
vat1  the temperature is raised to      
boiling heat1 and the tissue is immersed
  in the bath f of an hour while it is  
worked over through the opening  for    
manipulation4 ,the pieces are then taken
 from the bath1 to which is  added a    
solution of the carmine in water        
containing a quantity of  coloring      
matter proportionate to the intensity of
 the blue sought for4  ,the solution    
ought to be prepared with care and      
passed through a silk  sieve1 so that   
the small insoluble grains which might  
have been left  through bad fabrication 
may be left on the sieve4 ,after the    
pieces  have been manipulated in the    
colored bath1 so as to exhaust the color

  and obtain the required blue1 they    
should be rapidly washed in running     
water and dryed in the shade4 ,silk     
stuffs are dyed in the same way2  but   
the alum should be previously applied   
cold by means of a saturated  solution  
of alum1 in which the stuffs should be  
immersed for an hour4      ,,colors     
,,not ,,fast4    ,in regard to all the  
combinations of indigo with sulphuric   
acid1  including the carmines1 it must  
be observed that their application  does
 not constitute true indigo dyeing3 the 
colors are not fast4 ,it is  not pure   
indigotine which is fastened on the     
tissues as in the vat  dyeing1 but      
another compound of indigo with the     
sulphur4 ,berzelius  observes that 8the 
color of soluble indigo is fully as     
alterable and  fugacious as that of the 
colors extracted by the decoction of    
vegetable materials4 ,by a long exposure
 to the sun the indigo blue is          
destroyed3 it becomes green during      
evaporation1 and changes its  nature40  

,the carmines as well as the sulphur    
acids are easily  decolorized by        
reducing agents1 such as hydrogen and   
sulphuretted  hydrogen1 although they   
gradually assume their original color   
when  exposed to the atmosphere4 ,we are
 informed by some of the older  dealers 
that imported cloths and merino stuffs  
known as 8,saxony0 were  formerly       
largely sold in our shops1 but that1    
notwithstanding their  attractiveness to
 purchasers1 they were objectionable on 
account of  the instability of their    
color4      ,,application ,,of ,,indigo 
,,in ,,printing ,,stuffs4    ,our notes 
would be incomplete without some        
reference to the uses of  indigo in     
printing fabrics4 ,in pursuing this     
branch1 we are  embarrassed on the one  
hand by the consideration that the      
subject is  too technical for the       
general reader1 and on the other by the 
consciousness that it would be          
presumption in us to attempt to         
instruct those skilled in the art4 ,it  

may not1 however1 be without  benefit in
 producing a higher appreciation of     
science for the general  reader to      
observe how science comes in play1 even 
in the printing of a  single color2     
while to the skilled reader our notes   
may possibly be of  value as a vehicle  
for conveying some receipts taken from  
works not  easily accessible4           
,,printing ,,stuffs ,,of ,,wool ,,and   
,,silk1 ,,and ,,stuffs ,,with ,,cotton  
,,warps4    ,this branch of our subject 
is directly allied to the one last      
considered1 the application of the      
compounds of sulphur and indigo2  for   
indigo is applied to printing wool and  
silk principally in the  form of indigo 
carmines4 ,these applications are less  
numerous than  they were formerly1 since
 they have been replaced by ,prussian   
blue1  and more recently by the aniline 
blues1 which are now generally used4    
,when the carmines are used1 it is for  
making sky blues1 and they enter  into  
the composition of some greens and      

browns4 ,the salts of alumina  and      
vegetable acids are used to fix the     
indigo carmine upon tissues of  wool and
 silk4 ,some receipts recommended by ,m4
 de ,kppelin1 himself a  practical      
printer1 are given in a note4#g         
----------------------------------------
---------------------    #g ,,blue ,,no4
 #a4    ,indigo carmine                 
#djj grammes4    ,alum                  
#ajj        ,oxalic acid                
#aej        ,boiling water              
#a litre    ,gum water prepared in      
proportion of      #a kilogram to the   
litre            #a litre      ,,green  
,,no4 #a4    ,gum water as above        
#ab litres4    ,cuba lac                
#ab       ,alum                         
#a kilogram1 #ejj grammes4    ,oxalic   
acid                          #b        
,indigo carmine                       #d
         ,,bouillon ,,for ,,the ,,greens
 ,,and ,,blues4    ,boiling water       
#ab litres4    ,alum                    
#fjj grammes4    ,oxalic acid           

#gej        ,gum water                  
#ab         ,,sky ,,blue ,,for ,,woollen
 ,,stuff ,,with ,,cotton ,,warp4        
,first solution4--,boiling water      #d
 litres4                      ,cyanuret 
of iron and potash    #hjj grammes4     
,second solution4--,boiling water     #b
                         ,tartaric acid 
#cjj          ,third solution4--,cold   
water         #c       ,sulphuric acid  
#cjj          ,pour in the first        
solution1 then the second and third1    
agitating the    color with a spatula   
after each new addition4      ,the      
following mixture is afterwards applied 
to the stuff3--      ,gum water         
#ab litres4    ,water                   
#f       ,blue ,no4 #a for wool         
#c                                      
----------------------------------------
---------------------    ,in printing   
tissues of wool with cotton warp1 the   
carmines are not  used alone4 ,they are 
combined in certain proportions with    
cyanites of  iron and potash1 to obtain 

upon the cotton a blue color of equal   
intensity with that produced by the     
carmines upon wool4 ,it is also         
necessary to previously mordant the     
fabrics by means of a solution of  oxide
 of tin or caustic soda which is        
precipitated on the fibres by  passing  
through a bath of water1 to which       
sulphuric acid has been added4          
,,applications ,,of ,,indigo ,,in       
,,printing ,,cotton ,,fabrics4          
,before entering upon methods used in   
large establishments1 it may not  be    
without interest to observe the         
processes still used in ,java for       
printing calicoes1 which the natives    
prefer to any imported from  ,europe4   
,in ,java there are no factories1 and   
the women in each family  make and dye  
or print all the cotton cloths required 
for their own  consumption4 ,they apply 
by means of a brush or pencil1 which    
they use  with great skill1 to the      
cotton tissue which they wish to cover a
 thin  coating of wax mixed with a      

little resin1 the wax being applied to  
all  the parts where the design1 which  
has been first traced upon the  cloth1  
requires that the fabric should remain  
uncolored4 ,they then  immerse the stuff
 several times in an indigo vat until   
they have  obtained the desired tint4   
,the stuff is afterwards washed and     
dried  for a new application of the wax1
 carefully applied with a pencil as     
before4 ,the cloth is then immersed in a
 bath of a different color1  made with  
madder or catechu1 but always of some   
dye which is perfectly  stable2 and the 
operation is repeated according to the  
number of  colors desired4 ,by these    
successive applications of wax and      
immersions  into different vats1 they   
succeed in producing very complicated   
and  harmonious colors1 while no        
,european goods compare with them in    
stability of dye4    ,in the ,european1 
and our own manufacture1 the blue       
bottoms upon  vegetable fibres1 made by 
immersion in the indigo vat1 are        

combined  with white impressions1 or    
others variously colored1 by two        
distinct  methods4 ,sometimes there is  
printed upon the cloth before dyeing in 
the indigo vat a preparation called a   
reserve or resist1 which  prevents the  
indigotine from being deposited in the  
places where it is  applied4 ,sometimes1
 on the contrary1 the indigo1 which has 
been  uniformly fixed upon the fabric1  
is destroyed in certain places marked   
out by printing upon them certain       
chemical agents1 called discharges4     
,the reserves are mechanical1 resisting 
the penetration of the dye1  such as wax
 and pipe clay1 or chemical4 ,the last1 
through these acid  or oxidizing        
properties1 cause the precipitation of  
the indigotine  before it has touched   
the fibre or penetrated into its pores4 
,such are  the salts of copper and      
bi-chlorate of mercury4 ,other bodies   
perform  the part both of mechanical and
 chemical reserves4 ,the salts of zinc  
or alumina1 for instance1 which are     

frequently used1 produce at the  same   
time a deposit of indigo white and a    
gelatinous covering of  hydrated oxide  
of zinc or aluminium4 ,the composition  
of a good reserve  is declared to be    
principally a question of good          
proportions of the  constituent parts1  
varying with the strength of the vat and
 the  intensity of the blue which is    
desired to be reserved4 ,the first      
condition is that it hardens immediately
 after immersion in the vat3  if it     
softens1 on the contrary1 it will cause 
the running of the  color4 ,in other    
words1 the acidity of the impression    
should be  proportionate to the strength
 and alkaline character of the vat4 ,the
  white reserve1 that most generally    
used1 is composed of pipe clay1  gum1   
verdigris1 and sulphate of copper4 ,the 
styles of work produced by  dipping with
 reserves are generally of a cheap and  
low class4 ,the  system is clumsy and   
expensive1 and is only tolerated because
 of the  want of a method of directly   

applying indigo1 which will yield the   
deepest shades4    ,certain styles1     
formerly in great vogue1 called ,lapis1 
and forming  one of the richest branches
 of the cotton-printing industry1 are   
founded upon the use of reserves2 and in
 these styles1 by very simple  means    
which we shall not attempt to describe1 
different colors  produced from madder1 
catechu1 c41 are produced upon the      
fabric so  perfectly surrounded by blue 
that the eye cannot detect the slightest
  want of continuity4 ,this fabrication 
has the greatest perfection in  ,russia4
 ,the imitation cashmere fabrics of     
cotton imported from that  country1     
formerly much in fashion for            
dressing-gowns1 are specimens of  this  
fabrication4 ,the great stability of the
 colors is a remarkable  feature of     
these goods4    ,the system of resists  
or reserves possesses the inconveniences
 of not  producing impressions of great 
firmness1 and of requiring very strong  
vats4 ,when the strength of the vat is  

partially exhausted1 they may be  thrown
 aside4 ,these inconveniences are       
obviated by the system of  discharges   
7enlevages74 ,in this system the cloths 
are vat dyed of a  uniform blue4 ,the   
strength of the vat is of less          
importance1 and it  can be used until   
the indigo is quite exhausted4 ,the     
means of  destroying the indigo which   
has been fixed upon the fibre are       
founded  on the use of active oxidizing 
agents1 which transform the insoluble   
indigotine into soluble isatine4 ,the   
agent generally used is chromic  acid4  
,as this acid cannot be incorporated    
with the thickening to be  printed1 as  
the thickening would produce oxide of   
chrome1 the cloth is  passed through a  
strong solution of chromate of potash1  
and dried in  the shade4 ,the required  
pattern is then printed on the cloth    
with a  mixture whose principal elements
 are acids which are susceptible of     
setting free the chromic acid on the    
tissue1 which then acts upon the  indigo

 producing a white pattern4 ,the acid   
generally employed for  freeing the     
chromic acid is oxalic acid1 thickened  
with ,british gum1  dextrine1 or starch1
 with the addition of pipe clay4 ,to    
prevent  running1 nitric1 sulphuric1 or 
tartaric acid are sometimes used4#h     
----------------------------------------
---------------------    #h             
,schutzenberger gives the following     
receipts3--      ,,preparation ,,for    
,,discharge4      ,water                
#b litres4    ,yellow chromate          
#ejj grammes4      ,,white ,,discharge  
,,on ,,blue ,,bottom4      ,tartaric    
acid                                 #c 
kilograms4    ,oxalic acid              
#bej grammes4    ,burnt starch          
#d kilograms4    ,nitric acid           
#ejj grammes4    ,water                 
#d litres4      ,de ,kppelin gives the  
following3--      ,,white ,,discharge   
,,on ,,blue4      ,water                
#b litres4    ,starch                   
#a kilogram1 #hjj grammes4    ,oxalic   

acid                                    
#ejj grammes4    ,tartaric acid         
#bej grammes4    ,sulphuric acid        
#cge grammes4      ,the pieces1 having  
been dyed blue1 are then placed in a    
solution of    bichromate of potash in  
water1 which is prepared in the ratio of
 #ej to    #fj grammes to the litre1    
according to the intensity of the blue4 
,the    pieces thus prepared must be    
dried away from direct solar light or   
too    much heat4 ,in fact1 under the   
action of these agents1 the bichromate  
would be decomposed and the tissue      
altered4 ,the pieces are often    rolled
 up to prevent this effect4 ,after the  
pieces are printed1 they    are passed  
into a vessel containing water and      
holding chalk in    suspension in       
sufficient quantity to give it a milky  
aspect4 ,the    temperature of the bath 
is raised to #fj ,r4 ,the excess of acid
 of the    color applied is saturated by
 the chalk1 and the excess of bichromate
    of potash with which the tissue is  

impregnated is dissolved in the    bath4
 ,the pieces are afterwards washed and  
passed through slightly    soapy water4 
----------------------------------------
---------------------    ,by the method 
of discharges the white designs upon    
blue are brought  out with a            
distinctness which it is impossible to  
obtain by resists1  while the most      
delicate work of the graver can be      
exactly reproduced  upon the tissue4    
,,application ,,of ,,indigotine ,,by    
,,printing4    ,the first step in the   
art of printing indigotine upon calicoes
 was the  application of what is called 
pencil blue4 ,instead of immersing the  
fabrics in an indigo vat1 the indigo    
white formed in a very strong  indigo   
vat was thickened and applied locally to
 certain places on the  cloth4 ,the     
preparation was painted upon the cloth  
by means of pencils  made of willow     
sticks1 the ends of which were broomed  
up into a kind  of brush4 ,the style was
 hence called pencil blue4 ,the methods 

now used  to apply white indigo locally 
are of two kinds4 ,the china blue       
process1 and the solid blue process1    
sometimes called fast or  precipitated  
blue4 ,the china blue process derives   
its name from the  resemblance of its   
color to the blue on the old china ware4
 ,it has  great depth of tint1 and      
permanency4 ,it is scarcely used now1   
except  for certain articles requiring  
great depth of color1 such as certain   
furniture goods1 and by the ,germans and
 ,swiss for the manufacture of  calicoes
 for exportation to ,india4    ,we do   
not venture to condense the descriptions
 at our hand of the  processes for      
applying the china blue and the solid   
blue1 and  translate those furnished by 
chemists of high authority4 ,after the  
method indicated by ,darwin in his      
recent works1 we present them in        
smaller type1 with the perhaps          
unnecessary suggestion that they may be 
passed over by the general reader4      
,china blue4--,the theory of this       

printing blue1 says ,schutzenberger1  is
 very simple4 ,the indigo1 reduced to an
 impalpable powder and  thickened1 is   
printed by a plate or roller4 ,after    
drying1 the tissue  seems dyed blue1    
more or less deep1 according to the     
proportion of  coloring material used2  
but it is only a blue of application1   
which  can be removed with the          
thickening1 by the slightest washing4   
,the  object is now to reduce and       
redissolve the indigotine in place to   
enable it to penetrate the fibre at the 
end of a consecutive  oxidization1 and  
without producing a running of the color
 or altering  the purity and            
distinctness of the contours of the     
design4 ,i owe to ,m4  ,ed4 ,schwartz   
some valuable hints upon the fabrication
 of this style1  which is also described
 with much care and details in the      
treatise on  printing by ,m4 ,persoz4   
,the reduction of the indigo is obtained
 by alternate passages of the  printed  
tissue into vats containing1--the first1

 quicklime slacked2 the  second1        
sulphate of iron2 the third1 soda4 ,the 
operation is terminated  by a passage   
through a bath of sulphuric acid1 which 
removes the oxide  of iron and          
precipitates the indigo white by        
hastening its oxidation4    ,the success
 depends upon the composition of the    
color printed1 and  above all upon the  
strength of the vats of immersion and   
the duration  of the treatment4    ,the 
operator uses six vats1--for instance1  
two lime vats1 provided each  with #ab  
kilograms of lime2 a copperas vat at #gj
 ,beaum2 a caustic soda  vat marking    
#adj ,beaum2 a sulphuric acid vat with  
#ejj grammes of acid  7par mesure       
d'eau72 and finally a vat of pure water4
    ,the receipts for printing are3--   
#a4 ,,the ,,blue ,,preparation4         
,ground indigo                          
#d kilograms4    ,acetate of iron       
#aj litres4    ,sulphate of iron        
#a kilogram4    ,water                  
#aj litres4    ,gum ,senegal            

#f kilograms4    ,pass through a sieve2 
leave some time at rest1 and stir       
whenever used4  ,caraccas indigo is     
preferred because it can be broken into 
a finer  powder and gives a finer paste4
    #b4 ,,colors ,,for ,,roller         
,,printing ,,nos4 #a1 #b1 #c1 #d4       
,the blue preparation above             
#a1 #a1 #c1 #d4  ,acetate of iron       
containing #gjj grammes of gum per litre
 #b1 #a1 1 4  ,gum water at #fjj grammes
 per litre                      #af1 #b1
 1 4    ,these proportions can be varied
 according to the tint desired4    ,the 
piece is treated a quarter of an hour in
 the first lime vat by  giving it a     
light movement from above to below2 it  
is left a quarter  of an hour in repose 
in the sulphate of lime vat2 a quarter  
of an hour  in the second lime vat2 a   
quarter of an hour in the copperas vat2 
five  minutes in the caustic soda2 half 
an hour in the sulphuric acid1 and  then
 thoroughly rinsed4    ,to each lime vat
 there is given #b kilograms of lime per

 piece of  cloth4 ,to the vitriol vat   
there is added #ej kilograms of sulphate
 of  iron for each dozen pieces4 ,the   
soda vat is renewed after #e pieces by  
the addition of #ab kilograms of salt of
 soda1 which has first been  made       
caustic4 ,the acid vat receives #be     
kilograms of acid after #e  pieces1 and 
ought to be renewed whenever it becomes 
saline4 ,the other  vats must be cleared
 out whenever the deposit becomes too   
great for  success4    ,m4 ,ed4         
,schwartz recommends as important       
conditions1 7#a7 the perfect  causticity
 of the tissue1 and an average strength 
of #adj ,beaum2 7#b7  the neutrality of 
the sulphate of lime vat4 ,for this end 
old iron  should be boiled in it4       
,after leaving the sulphuric acid vat   
the pieces are rinsed in the  water vat1
 then in river water1 and afterwards    
should be soaked in a  sulphuric acid   
bath at #dj ,beaum1 for the purpose of  
dissolving the  last traces of the      
peroxide of iron adhering to the fibre4 

,the fabric  is then washed in water and
 finally passed through a soapy water at
  #dj ,r4    ,solid or precipitated     
blue1 ,schutzenberger's receipt4--,the  
process  consists in printing indigo    
white precipitated in a vat1 in a thick 
paste to dissolve it on the tissue by a 
passage through an alkaline  bath 7lime 
or soda71 and of reprecipitating it by  
oxidizing it as soon  as it has entered 
the fibre4    ,it is then the china blue
 process1 minus the reduction which is  
made  before printing1 and consequently 
minus the sulphate of iron vat4         
,indigo white is too alterable to be    
printed with success1 so it is          
generally precipitated in combination   
with a stannic hydrate 7hydrate  of a   
salt of tin71 which gives it body and   
preserves it from a too  rapid          
oxidation4    ,the stannic indigotate in
 paste1 or as it is generally called    
precipitate of indigo1 is prepared by   
turning into the clear portion  of a    
strong copperas vat an acid solution of 

protochlorate of tin1 and  filtering it 
upon woollen filters1--as much as       
possible away from the  air4 ,it would  
be better to prepare a strong tin vat by
 heating a  mixture of indigo1 caustic  
soda1 and protochlorate of tin1 and to  
precipitate by chlorohydric acid4#i     
----------------------------------------
---------------------    #i ,mr4 ,t4 ,p4
 ,shepard gives in his valuable         
8,receipts for ,calico    ,printing10   
published in #ahgb1 the following3--    
,,no4 #eb4 ,,indigo ,,precipitate ,,for 
,,fast ,,blue ,,and ,,green4      #aj   
pounds quicklime1 slacked with    #f    
gallons water2 then    #b pounds ground 
indigo finely rubbed in water are       
stirred in2 then add    #f pounds       
copperas dissolved in #e gallons of     
water2 then add    #e gallons hot water 
and    #ae gallons cold water4          
,stir well from time to time1 until the 
liquid has assumed a yellow    color and
 deep blue veins or streaks appear on   
its surface4 ,when this    moment       

arrives1 draw off the clear liquor1 and 
precipitate every ten    quarts of it   
with       pound tin crystals1 dissolved
 in  pound muriatic acid4      ,to the  
remainder of the mixture of lime and    
indigo1 #ae gallons of    water may be  
added1 and the whole stirred2 and when  
settled1 the    indigo may be           
precipitated from the clear liquor as   
before4 ,this    operation may be       
repeated a second time before all the   
indigo is    exhausted4      ,the indigo
 precipitate is to be collected on a    
muslin filter1 and    well squeezed out4
                                        
----------------------------------------
---------------------    ,the deposit is
 made into a paste with gum water2 a    
salt of tin is  often added to prevent  
oxidation4 ,it is important to prevent  
the  transformation of the indigo white 
into indigotine before printing4  ,this 
indigotine would not fix itself on the  
fabric4 ,moreover1 after  printing1 it  
is necessary to hasten the dissolution  

of the indigo  white to enable it to    
penetrate the fibre4 ,it is sufficient  
for this  end to pass it through milk of
 lime4 ,the stannic combination is      
immediately destroyed2 the colorable    
matter unites itself with the  lime1 and
 the color passes into a pale gray with 
apple green4 ,the  indigo white becomes 
momentarily soluble2 but the presence of
 the  excess of lime and the thickening1
 as well as the attractive affinity  of 
the thickening1 prevent any running4    
,the piece on issuing from the lime     
water is placed in running water1  when 
reoxidation commences1 which this time  
fixes the color4 ,the piece  is finally 
passed through a sulphuric acid bath to 
absorb the lime1  and washed4    ,by    
adding to the color a salt whose base   
precipitates in the milk of  lime and   
oxidizes in the running water1 and      
replacing the simple acid  bath by an   
acid bath with yellow prussite1 the     
intensity of the blue  is increased     
through the formation of ,prussian blue4

    ,although we have seen beautiful    
effects from the application of the     
solid blue of indigo on prints at our   
,pacific ,mills1 the colors  produced by
 ,prussian blue and aniline are so much 
more brilliant and  easy of application 
that the use of indigo in printing goods
 for  ordinary consumption is likely to 
decline rather than increase4 ,it  will 
be otherwise if we should ever          
manufacture for the ,east ,india        
markets4 ,here is a field still open for
 our manufacturers4 ,mr4 ,watson1  in   
his beautiful work on 8,the ,costumes of
 the ,people of ,india10  remarks that  
8,british manufacturers have hitherto   
failed to appreciate  ,oriental tastes  
and habits1 and hence supply but an     
insignificant part  of the clothing of  
the two hundred million persons that    
form the  population of what is commonly
 spoken of as ,india40 ,the great       
defect1  he observes1 is the want of    
stability of color in the cotton fabrics
  introduced1--this stability being an  

imperative demand in the ,oriental      
markets4    ,the applications of indigo 
to cotton fabric are altogether         
secondary1  in our mind1 to its         
relations to the woollen manufacture4   
,if we have  felt called upon to say a  
word in behalf of the most ancient and  
best  ally which the fibre of wool has  
ever had1 it is because the vividness   
of color of the new products of coal1   
and the fascination which the           
application of the recent discoveries of
 science always possesses1 is           
threatening the eclipse of the more     
ancient sober and solid dyes4 ,let  the 
new colors have their place as          
auxiliaries1 not as substitutes for  the
 ancient dyes4 ,let them serve to give a
 bloom#aj to goods1 but let  the        
foundation be the good old dyes which   
the experience of ages has  proved to be
 the most unalterable by light and air4 
,the recent  wonderful discovery of     
alizarine1 or artificial madder1 in coal
 tar  products1 has led practical men to

 expect too much from science4 ,the     
opinion is quite prevalent among        
manufacturers that artificial           
indigotine has already been obtained    
from the same source4 ,and some         
manufacturers are sanguine that the     
difficulties of indigo dyeing will  thus
 be resolved4 ,it is not improbable--for
 what is impossible to  modern          
chemistry8--that this result will yet be
 partially obtained4 ,but  we have      
looked over all the recent foreign      
chemical reviews1 and  personally       
consulted some of our best chemists1 and
 we can find no  authority for the      
prevailing opinion that artificial      
indigotine has  been produced4 ,if the  
production of artificial indigotine     
should be  realized1 the only benefit   
would be the possible cheapening of the 
material4 ,the difficulties of the      
indigo vat would still remain2 for  we  
cannot too often repeat1 that in the    
very difficulties of the  process1 or in
 the insolubility of blue indigotine by 

ordinary agents1  consists the          
excellence of the dye4                  
----------------------------------------
---------------------    #aj ,guernsey  
,blue4--,the darkest of the ,nicholson  
,fast ,blues4 ,on a    bottom of        
barkwood1 camwood1 madder1 or inferior  
indigo1 produces    an indigo blue which
 will stand all the acid tests the same 
as    colors made from indigo4          
,serge ,blue4--,it will be found very   
serviceable to give bloom to    goods   
dyed with indigo1 and by itself shows a 
very good indigo test    with nitric    
acid4--,instructions for ,working the   
,atlas ,works ,aniline    ,dyes4        
----------------------------------------
---------------------      ,,appendix4  
,,dyeing ,,wool ,,in ,,the ,,warm       
,,indigo ,,vat4    ,extract from        
,dumas's ,lectures on ,dyeing4    ,the  
value attached by practical wool-dyers  
to the following induces us  to publish 
it without condensation3--    ,indigo   
,blue4--,we give a solid dye of indigo  

blue to wool by plunging it  into an    
alkaline solution of indigo white1 and  
then exposing it to  contact with the   
air4 ,the solution of indigo white is   
prepared in a  vessel usually from eight
 to nine feet in depth1 and six to seven
 feet  in diameter4 ,this size is very  
convenient for the requisite            
manipulations1 and presents a large     
volume of water1 which1 when once       
heated1 is capable of preserving a high 
temperature for a long time4  ,this     
vessel should be made of wood or copper4
 ,it always bears the name  of vat4     
,these vats are covered with a wooden   
lid1 divided into two or  three equal   
segments4 ,over this lid are spread some
 thick blankets4  ,without this         
precaution the bath would come in       
contact with the  atmospheric air1 a    
portion of the indigo would absorb      
oxygen and  become precipitated4 ,there 
would also be a great waste of heat4    
,a most necessary operation1 and one    
which has to be frequently  repeated1   

consists in stirring up the deposit of  
vegetable and  coloring matter which is 
formed in the vat1 and intimately mixing
 it  in the bath4 ,for this purpose we  
employ a utensil called a rake1  which  
is formed of a strong square piece of   
wood1 set on a long  handle4 ,the       
workman takes hold of this with both    
hands1 and1 dipping  the flat surface   
into the deposit at the bottom of the   
vessel1 he  quickly draws it up until it
 nearly reaches the surface1 when1      
giving  it a gentle shake1 he discharges
 the matter again through the liquor  of
 the bath4 ,this manuvre is repeated    
until the whole of the deposit  seems to
 be removed from the bottom of the      
vessel4 ,before the tissue  is dipped   
into the dye-bath1 it should be soaked  
in a copper full of  tepid water2 it is 
then to be hung up and beaten with      
sticks4 ,in this  state it is plunged   
into the vat2 it thus introduces less   
air into the  bath1 while it is more    
uniformly penetrated by the indigo      

solution4  ,the cloth is now kept at a  
depth of from two to three feet below   
the  surface of the liquid1 by means of 
an open bag or piece of network  fixed  
in the interior of an iron ring1 which  
is suspended by cords1  and fixed to the
 outside of the vat by means of two     
small iron hooks2  the bag is thus drawn
 backwards and forwards without         
permitting it to  come in contact with  
the air4 ,when this operation has been  
continued  for a sufficient length of   
time1 the cloth is wrung and hung up to 
dry4    ,flock wool is also1 for the    
purpose of dyeing1 enclosed in a fine   
net1  which prevents the least particle 
from escaping1 and which is fixed in    
the bath in the same way as in the      
foregoing case4    ,the many            
inconveniences attending the use of     
wooden baths1 which  necessitate the    
pouring of the liquor into a copper for 
the purpose of  giving it the necessary 
degree of heat1 have led to the general 
employment of copper vessels4 ,these are

 fixed in brickwork1 which  extends half
 way up their surface1 whilst a stove is
 so constructed at  this elevation that 
the flame shall play around their upper 
part4 ,by  this means the bath is heated
 and kept at a favorable temperature    
without the liquor being obliged to be  
removed4    ,the potash vats are usually
 formed of conical-shaped coppers1      
surrounded by a suitable furnace4 ,these
 may be constructed with less  depth1   
inasmuch as there is less precipitation 
induced in the liquor4  ,by using steam 
for heating the vats1 we might dispense 
with the  employment of copper vessels1 
and so return to those of wood4    ,the 
vats employed for dyeing wool are known 
under the names of the  pastel vat1 the 
woad vat1 the potash vat the tartar-lee 
vat1 and the  ,german vat4    ,pastel   
,vat4#aa--,the first care of the dyer in
 preparing the vat should  be to furnish
 the bath with matters capable of       
combining with the  oxygen1 whether     
directly or indirectly1 and of giving   

hydrogen to the  indigo4 ,we must1      
however1 be careful to employ those     
substances only  which are incapable of 
imparting to the bath a color which     
might prove  injurious to the indigo4   
,these advantages are found in the      
pastel1 the  woad1 and madder4 ,this    
latter substance furnishes a violet tint
 when  brought into contact with an     
alkali1 and by the addition of indigo it
  yields a still deeper shade4          
----------------------------------------
------------------------------    #aa   
,the distinction between pastel and woad
 is not very clear4    ,schutzenberger  
says3 8,pastel1 woad1 and satis         
tinctoria is a plant    of the family of
 the crucifera4 ,it would seem1 however1
 that the term    pastel as used by the 
old ,french dyers is applied to the     
leaves of    the woad which have been   
fermented1 formed into paste1 and       
afterwards    into balls1 and which     
contain much blue coloring matter4 ,and 
the term    woad as distinguished from  

pastel is applied to the unfermented    
plant40                                 
----------------------------------------
------------------------------    ,in   
preparing the ,indian vat1 we ordinarily
 employ one pound of fine  madder to two
 pounds of indigo4 ,the madder is here  
especially useful1  by reason of the    
avidity of some of its principles for   
oxygen4    ,the pastel vat1 when        
prepared on a large scale1 ordinarily   
contains  from #ah to #bb lbs4 of       
indigo2 #aa lbs4 of madder would suffice
 for this  proportion1 but we must also 
bear in mind the large quantity of water
  which we have to charge with          
oxidizable matters4 ,i have invariably  
seen the best results from employing #bb
 lbs4 to a vat of this size4  ,bran is  
apt to excite the lactic fermentation in
 the bath1 and should  therefore not be 
employed in too large a quantity2 #g to 
#i lbs4 will be  found amply sufficient4
    ,weld1 which is often used1 is rich 
in oxidizable principles2 it turns      

sour1 and passes into the putrid        
fermentation with facility4 ,some  dyers
 use it very freely2 but ordinarily we  
employ in this bath an  equal quantity  
of it to that of the bran4 ,sometimes   
weld is not added  at all4    ,in most  
dye-houses the pastel is pounded before 
introducing it into  the vat4 ,some     
practical men1 however1 maintain that   
this operation is  injurious1 and that  
it interferes with its durability4 ,this
 is an  opinion which deserves          
attention4 ,the effect of the pastel1   
when  reduced to a coarse powder1 is    
more uniform2 but this state of         
division must render its alterations    
more rapid4 ,when the bath has          
undergone the necessary ebullition1 the 
pastel should be introduced  into the   
vat1 the liquor decanted1 and at the    
same time #g or #h lbs4 of  lime added1 
so as to form an alkaline lye which     
shall hold the indigo  in solution4     
,having well stirred the vat1 it should 
be set aside for  four hours1 so that   

the little pellets shall have time to   
become  thoroughly soaked1 both inside  
and out1 and thus be prepared for       
fermentation4 ,some think coverings are 
to be spread over the vat1 so  as to    
preserve it from contact with the       
atmosphere4 ,after this lapse  of time1 
it is to be again stirred4 ,the bath at 
this moment presents  no decided        
character2 it has the peculiar odor of  
the vegetables which  it holds in       
digestion2 its color is of a            
yellowish-brown4    ,ordinarily1 at the 
end of twenty-four hours1 sometimes even
 after  fifteen or sixteen1 the         
fermentative process is well marked4    
,the odor  becomes ammoniacal1 at the   
same time that it retains the peculiar  
smell of the pastel4 ,the bath1 hitherto
 of a brown color1 now assumes  a       
decided yellowish-red tint4 ,a blue     
froth1 which results from the  newly    
liberated indigo of the pastel1 floats  
on the liquor as a thick  scum1 being   
composed of small blue bubbles1 which   

are closely  agglomerated together4 ,a  
brilliant pellicle covers the bath1 and 
beneath we may perceive some blue or    
almost black veins1 owing to the  indigo
 of the pastel which rises towards the  
surface4 ,if the liquor be  now agitated
 with a switch1 the small quantity of   
indigo which is  evolved floats to the  
top of the bath4 ,on exposing a few     
drops of this  mixture to the air1 the  
golden-yellow color quickly disappears1 
and is  replaced by the blue tint of the
 indigo4 ,this phenomenon is due to the 
absorption of the oxygen of the air by  
the indigogen from the pastel3  in this 
state we might even dye wool with it    
without any further  addition of indigo2
 but the colors which it furnishes are  
devoid of  brilliancy and vivacity of   
tone1 at the same time that the bath    
becomes quickly exhausted4    ,the signs
 above described announce1 in a most    
indubitable manner1 that  fermentation  
is established1 and that the vat has now
 the power of  furnishing to the indigo 

the hydrogen which is required to render
 it  soluble1--that contained in the    
pastel having been already taken up2    
this1 then1 is the proper moment for    
adding the indigo1 which should  be     
previously ground in a mill4    ,we     
stated above that the liquor of the vat 
should be previously  charged with a    
certain quantity of lime2 we also find  
in it ammonia  generated by the pastel2 
but a part of these alkalies become     
saturated  by the carbonic acid gas     
along with the proper acids of the      
madder and  of the weld1 as well as by  
the lactic acid produced by the bran    
during  fermentation4 ,the ordinary     
guide of the dyer is the odor1 which1   
according to circumstances2 becomes more
 or less ammoniacal4 ,the vat  is said  
to be either soft or harsh2 if soft1 a  
little more lime should  be added to it4
 ,the fresh vat is always soft2 it      
exhales a feeble  ammoniacal odor       
accompanied with the peculiar smell of  
the pastel2 we  must1 therefore1 add    

lime to it along with the indigo2 we    
usually  employ from five to six pounds1
 and1 after having stirred the vat1 it  
is to be covered over4 ,the indigo1     
being incapable of solution except  by  
its combination with hydrogen1 gives no 
sign of being dissolved  until it has   
remained a certain time in the bath4 ,we
 may remark that  the hard indigoes1 as 
those of ,java1 require at least eight  
or nine  hours1 whilst those of ,bengal 
do not need more than six hours1 for    
their solution4 ,we should examine the  
vat again three hours after  adding the 
indigo4 ,we ordinarily remark that the  
odor is by this time  weakened2 we must 
now add a further quantity of lime1     
sometimes less1  but generally about    
equal in amount to the first portion2 it
 is then  to be covered over again1 and 
set aside for three hours4    ,after    
this lapse of time1 the bath will be    
found covered with an  abundant froth   
and a very marked copper-colored        
pellicle2 the veins  which float upon   

its surface are larger and more marked  
than they were  previously2 the liquor  
becomes of a deep yellowish-red color4  
,on  dipping the rake into the bath1 and
 allowing the liquid to run off at  the 
edge1 its color1 if viewed against the  
light1 is of a strongly  marked         
emerald-green1 which gradually          
disappears1 in proportion as the  indigo
 absorbs oxygen1 and leaves in its place
 a mere drop rendered  opaque by the    
blue color of the indigo4 ,the odor of  
the vat at this  instant is strongly    
ammoniacal2 we also find in it the      
peculiar scent  of the pastel4 ,when we 
discover a marked character of this kind
 in the  newly formed vat1 we may       
without fear plunge in the stuff        
intended to  be dyed2 but the tints     
given during the first working of the   
vat are  never so brilliant as those    
subsequently formed2 this is owing to   
the  yellow-coloring matters of the     
pastel1 which1 aided by the heat1       
become fixed on the wool at the same    

time as the indigo1 and thus give  to it
 a greenish tint4 ,this accident is     
common both with the pastel  and the    
woad vats2 it is1 however1 less marked  
in the latter4    ,when the stuff or    
cloth has been immersed for an hour in  
the vat it  should be withdrawn2 it     
would1 in fact1 be useless to leave it  
there  for a longer time1 inasmuch as it
 could absorb no more of the coloring   
principle4 ,it is therefore to be taken 
from the bath and hung up to  dry1 when 
the indigo1 by attracting oxygen1 will  
become insoluble and  acquire a blue    
color4 ,then we may replunge the stuff  
in the vat1 and  the shade will         
immediately assume a deeper tint1 owing 
to renewed  absorption of indigo by the 
wool4 ,by repeating these operations1 we
  succeed in giving very deep shades4   
,we must not1 however1 imagine that  the
 cloth seizes only on that portion of   
indigo contained in the  liquor required
 to soak it4 ,far from such being the   
case1 experience  shows that1 during its

 stay in the bath1 it appropriates to   
itself1  within certain limits1 a       
gradually increasing quantity of indigo4
 ,we  have here1 then1 an action of     
affinity1 or perhaps a consequence of   
porosity on the part of the wool itself4
    ,woad ,vat4--,these vats are        
extensively employed at ,louviers1 and  
in the  manufactories of the north of   
,france4 ,the bath is prepared in the   
same  manner as in the foregoing case2  
the finely cut root is introduced  into 
the copper along with #b lbs4 of pounded
 indigo1 #i lbs4 of madder1  and #ae    
lbs4 of slaked lime4 ,the liquor is1    
after the necessary  ebullition1 poured 
upon the woad4 ,this substance contains 
but a very  small quantity of coloring  
principle2 we must1 therefore1 add some 
indigo when preparing the vat1 so as to 
indicate the precise instant  when the  
mixture arrives at the point of         
fermentation so necessary for  imparting
 hydrogen to the coloring principle1 and
 for rendering it  soluble4 ,we must    

also use a larger quantity of lime1     
since the woad  contains no ammonia     
resulting from previous decomposition1  
such as we  find to be the case with the
 pastel of the south4 ,when the vat is  
in a  suitable state of fermentation1 a 
rusty color becomes manifest1 in        
addition to the signs already described 
in speaking of the pastel vat2  besides 
the ammoniacal odor1 the bath always    
retains the peculiar  smell of the woad4
 ,the pounded indigo is now added1 and  
we proceed1 in  the manner already      
detailed1 to reduce it to a state of    
solution fit  for dyeing4    ,the vats  
prepared by means of pastel have greater
 durability than  those made with the   
woad2 but it is thought that the colors 
given by  the latter are more brilliant 
than those obtained from the former dye4
    ,modified ,pastel ,vat4--,this vat  
is about #g feet in depth1 and #f feet  
in  diameter4 ,it is made of copper1 and
 heated by steam4 ,the lid is  composed 
of three segments1 each of which is     

formed of two planks1  about an inch    
thick1 and strongly secured together by 
bolts4    ,the beating is performed in  
the usual way1 with sticks before the   
first dipping1 after having moistened   
the cloth in tepid water4 ,this         
operation is not subsequently repeated4 
,this vat is prepared with #ac lbs4 of  
indigo1 #ag lbs4 of madder1 #d  lbs4 of 
bran1 #i lbs4 of lime1 and #d lbs4 of   
potash4 ,having filled the  vat1 we heat
 it to about #bjj ,fah41 and1 as soon as
 the water is  tepid1 introduce #dda    
lbs4 of pastel4 ,the liquor becomes of a
  yellowish-brown color2 small bubbles  
appear upon its surface1  ordinarily at 
the end of four hours if the vat be     
heated by steam1 but  not until after   
eight or twelve hours where heat is     
applied by the  common fire2 in the     
latter case the mixture should be       
stirred every  three hours4 ,when the   
liquor displays the signs of            
fermentation1 we  add the               
above-mentioned ingredients1 and cover  

the vat over2 it is  then to be set     
aside1 stirring it every three hours1 or
 oftener if the  fermentative action be 
very rapid4 ,each time that it is       
stirred we are  to add from #b to #d    
lbs4 of lime2 if fermentation proceed   
quickly we  even use more1 but in the   
contrary case less4 ,after about        
eighteen  hours1 we plunge into the vat 
three pieces of common cloth1 measuring 
from twenty to twenty-five ells in      
length each2 when they have  received   
six or seven turns1 they are to be taken
 out again4 ,the  object of this is to  
remove the excess of lime from the bath4
 ,the vat  is then set aside for three  
hours1 when it is to be stirred1 and #ac
  lbs4 of indigo1 with #b lbs4 of       
madder1 added to it4 ,we now again apply
  heat to the mixture4    ,if the vat   
contains a superabundance of lime1 it   
will be unnecessary  to add more2       
otherwise we throw in a further         
quantity4 ,during the  night it should  
be covered with a cloth1 and a workman  

left to watch  it4 ,it is usually       
stirred once before the morning2 but if 
it be  deficient in lime1 it will       
require this manipulation to be more    
frequently repeated1 and also fresh lime
 added to it4 ,on the following  day the
 stirring should be continued every     
three hours1 and so on for  the next    
thirty hours1 taking care to heat the   
vat from time to time4  ,on the morning 
of the fourth day the dyeing may be     
commenced4    ,the temperature should be
 maintained at a pretty uniform point2  
if it  be too hot1 the blue takes a red 
reflection1 by reason of the madder     
contained in the liquid4 ,a vat thus    
prepared will last three months2  we may
 even work it for double that period1   
but after the third month  it appears to
 lose some of its indigo4    ,we        
maintain the power of the vat by        
introducing every night #b lbs4 of      
madder4 ,some indigo is also added twice
 or three times a week4 ,these          
additions are made in the evening4      

,after the former1 the vat is left  at  
rest for forty-two hours2 with the      
latter only for twenty-four1 at  the    
same time observing the precautions     
already indicated4 ,at the end  of three
 months1 or sooner when we wish to stop 
the working of the  vat1 we exhaust the 
indigo2 for this purpose we continue to 
charge it  every night for the space of 
a month with madder1 and dip into it    
white cloths1 or more particularly      
woollen tissues1 which become more  or  
less loaded with the indigo4 ,we must   
continue this plan until these  matters 
take up no further color4 ,the dippings 
are to be performed  twice a day at     
first1 but once only towards the        
termination4 ,many  dyers make use of   
this bath for preparing a new vat1 but  
it is better  to throw this away and    
make it up afresh with common water4    
,indian ,vat4--,these vats are of more  
simple and of more ready  construction  
than the pastel or woad vats4 ,we are to
 boil in water a  quantity of madder and

 of bran1 proportioned to the weight of 
indigo  which we wish to employ4 ,after 
two hours' ebullition1 we turn into     
this bath some tartar-lees1 which are   
also to be boiled for an hour  and a    
half or two hours1 so as to charge the  
bath with whatever  soluble matter they 
may contain2 after this ebullition the  
bath should  be allowed to cool1 and the
 indigo1 which has been previously      
ground1  is then to be introduced4      
,supposing that we wish to employ #ba   
lbs4 of  indigo1 the following would be 
the proportions used in preparing this  
vat3 #da lbs4 tartar-lees1 #ac lbs4 of  
madder1 and #e lbs4 of bran4 ,these     
vats are usually mounted in coppers of a
 conical shape2 a small fire  should be 
kept up around them1 so as to maintain a
 moderate and  uniform heat4 ,the indigo
 will usually be found dissolved at the 
end of  twenty-four hours1 often even   
after twelve or fifteen hours4 ,the     
liquor has a reddish color in the new   
vats1 and a green tint in those  which  

are in a working state4 ,the frothy     
surface1 as well as the                 
brilliant-colored pellicle1 becomes     
manifested in this as in all other      
preparations of a like kind4    ,this   
species of vat has to be renewed much   
more frequently than the  woad and      
pastel vats1 from the indigo being more 
difficult to dissolve  after a certain  
lapse of time4 ,a moderate heat should  
be maintained in  all these vats4       
,potash ,vat4--,this species of vat is  
extensively employed at ,elbuf for  the 
dyeing of wool in the flock4 ,it        
presents in all respects a perfect      
analogy with the ,indian vat2 in fact1  
the action of the tartar-lee in  the    
latter preparation depends entirely on  
the carbonate of potash  which it       
contains4 ,the ingredients used in the  
preparation of the  potash vat are bran1
 madder1 and the subcarbonate of potash 
of commerce4    ,we obtain the deep     
shades in this species of vat with      
greater celerity  than in all others1 a 

fact which undoubtedly depends on the   
greater  power which potash has of      
dissolving indigo than is possessed by  
lime4  ,experience proves that the      
potash vat has the advantage in point of
  celerity of nearly a third2 but this  
is balanced by the inconvenience        
resulting from the darker shade1 which  
we must attribute to the large  quantity
 of coloring matter of the madder       
dissolved by the alkaline  lee1 and     
which becomes fixed on the stuff with   
the indigo4    ,to render this vat in   
its most favorable state1 the indigo    
should be  made to undergo a            
commencement of hydrogenation before    
turning it into  the mixture2 for this  
purpose we prepare in a small copper a  
bath  analogous to that in the vat1 to  
which the pounded indigo is added4      
,this bath is maintained for twenty-four
 hours at a moderate heat1  taking care 
to stir it from time to time4 ,the      
indigo assumes a  yellowish color1      
becomes dissolved1 and in this state is 

turned into  the vat2 we thus avoid many
 delays and losses in its preparation1  
and  indeed it would be desirable if a  
similar plan were adopted with all      
these compounds4    ,german ,vat4--,this
 vat is of nearly similar dimensions to 
that used for  the woad1 being three    
times the size of the potash vat4 ,its  
diameter  is about #f feet1 and its     
depth #h feet4 ,having filled the copper
 with  water1 we are to heat it to #bjj 
,fah42 we then add #bj pailsful of      
bran1 #bb lbs4 of carbonate of soda1 #aa
 lbs4 of indigo1 and #ed pounds  of     
lime1 thoroughly slaked1 in powder4 ,the
 mixture is to be well  stirred1 and    
then set aside for two hours2 the       
workman should  continually watch the   
progress of the fermentation1 moderating
 it more  or less by means of lime or   
carbonate of soda1 so as to render the  
vat  in a working state at the end of   
twelve1 fifteen1 or1 at the most1       
eighteen hours4 ,the odor is the only   
criterion by which the workman is       

enabled to judge of the good state of   
the vat1 he must therefore  possess     
considerable tact and experience4    ,in
 the process of dipping we introduce #hd
 lbs41 #ajf lbs41 or even #acj  lbs4 of 
wool1 in a net bag1 similar to that used
 in the woad vat1  taking care that the 
bag is not allowed to rest against the  
sides of  the copper4 ,when the wool has
 sufficiently imbibed the color1 we     
remove the bag containing it1 and allow 
it to drain for a short time  over the  
vessel4 ,we operate in this way on two  
or three quantities in  succession2 we  
then remove the vat1 and set it aside   
for two hours2 we  must be careful1 from
 time to time1 to replace the indigo    
absorbed by  the wool1 as also to add   
fresh quantities of bran1 lime1 and     
crystallized carbonate of soda1 so as   
constantly to maintain the  fermentation
 at a suitable point4    ,the ,german   
vat differs1 then1 from the potash vat  
by the fact that the  potash is replaced
 by crystallized carbonate of soda and  

caustic lime1  which latter substance   
also gives to the carbonate of soda a   
caustic  character4 ,it presents a      
remarkable saving as compared to the    
potash  vat2 hence the frequency of its 
employment2 but it requires great  care1
 and is more difficult to manage4 ,it   
also offers considerable  economy of    
labor2 one man is amply sufficient for  
each vat4    ,the army cloth is usually 
dyed by means of the pastel vat1 which  
gives  the most advantageous results4   
,we here make use of vats about #h feet 
in depth1 and #e feet in diameter1 into 
which we introduce from #cfa  lbs4 to   
#dje lbs of pastel or of woad1 after    
previous maceration4 ,the  vat is to be 
filled with boiling water1 and we then  
add to the bath #bb  lbs4 of madder1 #ag
 lbs4 of weld1 and #ac lbs4 of bran4    
,the mixture is  to maintained in a     
state of ebullition for about half an   
hour2 we next  add a few pailsful of    
cold water1 taking care1 however1 not to
 lower  the temperature beyond #acj     

,fah42 during the whole of this time a  
workman1 provided with a rake1 keeps    
incessantly stirring the  materials of  
the bath4 ,the vat is then accurately   
closed by means of a  wooden lid1 and   
surrounded by blankets1 so as to keep up
 the heat4 ,it  is now put aside for six
 hours2 after this time it is again     
stirred by  means of a rake1 for the    
space of half an hour2 and this         
operation  should be repeated every     
three hours until the surface of the    
bath  becomes marked with blue veins2 we
 then add from six to eight pounds  of  
slaked lime4    ,the color of the vat   
now borders on a blackish-blue4 ,we     
immediately  add the indigo in a        
quantity proportioned to the shade which
 we wish  to obtain4 ,the pastel in the 
foregoing mixture may last for several  
months2 but we must renew the indigo in 
proportion as it becomes  exhausted1 at 
the same time adding both bran and      
madder4 ,in general we  employ--        
#aa to #ac lbs4 of good indigo for #ajj 

lbs4 of fine wool4    #i to #aa lbs4 of 
good indigo for #ajj lbs4 of common     
wool4    #i to #aa lbs4 of good indigo  
for #aca yards of cloth dyed in the     
piece4    ,management of the ,vats4--,a 
good condition of the vat is recognized 
by  the following characters3 ,the tint 
of the bath is of a fine  golden-yellow1
 and its surface is covered with a      
bluish froth and a  copper-colored      
pellicle4 ,on dipping the rake into the 
bath1 there  escapes bubbles of air1    
which should burst very slowly2 when    
they  vanish quickly1 it becomes an     
indication that we must add more lime4  
,the paste which is found at the bottom 
of the vat1 green at the moment  of its 
being drawn up1 should become brown in  
4the air2 if1 however1  it remains      
green1 this is a further sign that more 
lime is required4  ,lastly1 the vat     
should exhale the odor of indigo4 ,we   
usually complete  the assurance of the  
vat being in a good state by plunging   
into it1  after two hours' respite1 a   

skein of wool1 which1 on being withdrawn
  after the lapse of half an hour1      
should present a green color1 but       
change directly to blue4 ,we then once  
more mix the materials of the  vat1 and 
two hours after it may be considered    
ready for dyeing4    ,these vats1 like  
those already described1 are provided   
with a large  wooden ring1 the interior 
of which is armed with a kind of        
network1  for the purpose of preventing 
the objects which are intended to be    
dyed coming in contact with the         
materials at the bottom of the vat2  we1
 moreover1 take the precaution of       
enclosing the wool or cloth in  bags4   
,these tissues1 when plunged into the   
bath1 should remain there  for a longer 
or shorter time1 according to the shade 
which we wish to  obtain2 one dipping1  
however1 will never suffice for this    
object2  usually we leave in the stuff  
for half an hour only2 it is then to be 
taken from the bath1 wrung1 and exposed 
to the air4 ,this operation is  repeated

 until we have succeeded in procuring   
the desired shade2 we  ordinarily suffer
 three hours to elapse between each     
dipping4 ,the heat  of the vat should   
never be allowed to fall below #acj     
,fah4 ,after each  operation the bath   
must be well stirred1 and fresh lime    
added2  generally speaking1 a pound a   
day will suffice4 ,we re-establish the  
indigo about every second day4 ,when    
once this vat is well mounted1 and  we  
are careful to examine its working1 we  
may dye from two to four  batches a day 
with it4    ,when the stuffs have       
acquired the desired shade1 they are    
first to be  washed in common water1 and
 then in a very weak solution of        
hydrochloric acid 7about one part in a  
thousand72 after this they are  again   
rinsed in pure water4    ,the ,indian   
vat is much more easily managed than the
 foregoing2 it  presents less danger of 
failure1 from the fact that it is       
quickly  exhausted1 and also from the   
fermentative process1 which is so       

difficult to govern in the pastel vat2  
this vat not having time to  change in  
character4 ,it is prepared by first     
introducing an equal  quantity of madder
 and of bran1 and a triple quantity of  
potash2 this  is to be gradually heated 
until it reaches a temperature of #afg  
,fah41  and we then add to it the       
indigo1 thoroughly agitating the matters
 for  half an hour4 ,the vat is         
maintained at a temperature of #hf to   
#ajj  ,fah41 by keeping it closely      
covered1 and at the same time the       
mixture  is to be stirred occasionally  
at intervals of twelve hours4 ,it should
  by this time present a beautiful green
 shade1 the liquor being  surmounted by 
a copper-colored pellicle and a purplish
 froth4 ,we may  now commence the       
dyeing1 following the same course as    
with the pastel  vat2 but the stirrings 
being here repeated much more frequently
 than  with the other mixture1 we can   
dye a larger quantity of wool within a  
given time4 ,when the vat ceases to give

 a brilliant blue1 we must  altogether  
renew it2 if it be merely weakened1 we  
add to it a small  quantity of freshly  
prepared liquor containing a few pounds 
of potash1  and a little less bran and  
madder4 ,in giving the dark and the     
clear  sky blues1 we must be careful to 
employ a quantity of indigo             
proportioned to the color which we wish 
to obtain1 or1 better still1  we may use
 the previously exhausted vat for the   
dark blue4    ,when exposed to the      
influence of the putrid fermentation1   
indigo is  decomposed and loses its     
color4 ,if rendered soluble1 it obeys   
the  impulse communicated to the        
azotized matters with which it is       
brought  into contact1 although1 if     
macerated in pure water at the ordinary 
temperature1 it is itself decomposed    
with great difficulty4    ,the pastel   
and the woad are very prone to the      
putrid fermentation1 by  reason of the  
large quantity of azotized matters which
 they contain1  as do all the crucifer2 

they require therefore considerable care
 in  their employment4    ,when a vat is
 mounted1 if the fermentation be allowed
 to continue  unchecked1 after the      
appearance of the blue froth and the    
other signs  already indicated1 the     
liquor will acquire a yellow color      
similar to  that of beer2 the froth will
 become white2 it will give out a stale 
smell and lose its ammoniacal odor2     
after a few days it will turn  whitish1 
and exhale a smell at first similar to  
that of putrefied  animal substances2   
then it will acquire the odor of rotten 
eggs1 and  set free sulphuretted        
hydrogen4 ,the lime in the pastel and   
the woad  vats1 and the tartar-lee and  
potash in the other mixtures1 are used  
for the purpose of preventing these     
accidents4    ,besides the oxygenated   
compound1 which is formed by the        
combination of  oxygen with the         
extractive matters of the plants held in
 digestion1  there is a production of   
carbonic acid which saturates the       

alkaline  lee1 and forms a carbonate of 
lime in the pastel vat4 ,we find this   
attached to the sides of the vat in such
 quantity that the inside of  these     
vessels becomes incrusted with it to a  
considerable depth4 ,it is  this product
 which dyers call the tartar of the vat2
 it effervesces  with acids1 and gives  
on analysis carbonic acid1 lime1 and a  
few  particles of indigo4 ,in the potash
 vat the solubility of the carbonate  of
 potash prevents its deposition2 but it 
is very probable that we  have even here
 a formation of some carbonated         
products1 perhaps in  part formed at the
 expense of the carbonic acid of the    
air4    ,the soluble extractive         
principle being the only matter which   
remains  in solution in the bath with   
the indigo1 the lime1 c41 we have formed
  deposits which1 varying both in their 
volume and in the greater or  less      
facility with which they are            
precipitated during the various  periods
 of fermentation1 lead to a more or less

 considerable waste of  time4 ,if we    
plunge a piece of woollen tissue into a 
vat which has been  recently stirred1 it
 will acquire a dark color1 and will be 
found  covered with brown stains which  
are with difficulty removed4 ,when the  
woad or paste vat has been stirred1 it  
need be left two or three hours  only   
before plunging in the stuff1 at least  
during the early months of  its working1
 inasmuch as the pastel1 being but      
slightly divided and  attenuated1 is    
readily precipitated2 but when1 by      
reason of its  extreme division1 in     
consequence of repeated operations1 it  
is thrown  down with less facility1 the 
dipping should not be performed oftener 
than three times in the day4    ,the    
,indian vat requires less time than the 
others2 we may even dye  with it an hour
 after stirring the mixture4 ,the       
potash1 being soluble1  forms no        
precipitate2 while the ligneous fibre of
 the madder and the  pellicles of the   
bran become deposited with great        

facility4 ,we can  also dip with these  
vats much oftener than with those made  
by pastel  or woad4      ,,sickness ,,of
 ,,the ,,warm ,,vat ,,for ,,dyeing      
,,wool1 ,,and ,,its ,,remedies4    ,we  
have to thank that excellent practical  
magazine1 8,the ,american  ,chemist10   
for the following notes on the          
sicknesses of the warm vat1  by ,f4 ,w4 
,kugler1 translated from ,reimann's     
,frberzeintung3--    ,in the wool indigo
 vat1 among the principal 8sicknesses0  
is the  blackening of the vat1 or       
8sharpening40 ,this arises from the     
presence  of too much lime4 ,when       
8sharpened10 the liquor1 instead of     
having a  waxy yellow color with a dense
 blue film on its surface1 has no film2 
while the liquor is a dark              
blackish-green1 and on being stirred    
shows  a gray or white scum on its      
surface1 while it emits at the same time
 a  pungent odor4 ,if the vat is only   
slightly affected1 it is sufficient  to 
add some bran and madder and to let it  

stand over night4 ,if it has  not quite 
recovered by morning1 it may be         
necessary to heat it up1  agitate it1   
and let it stand for a couple of hours1 
after which  perhaps the addition of a  
little lime will be necessary4    ,if   
the vat is much sharpened1 it is        
recommended to sink in it a bag of      
bran1 and leave it over night1 when the 
fermentation will have  restored the vat
 in a considerable degree2 but it will  
be necessary to  add lime cautiously and
 by degrees1 to bring it to a proper    
state for  working4    ,the theory of   
the souring of the vat is given4        
,butyric fermentation  takes place under
 certain circumstances1 butyric acid    
being formed2  and hydrogen is set free1
 which reduces the indigo4 ,the addition
 of  lime makes the vat too strongly    
alkaline1 and sets ammonia free1 which  
gives the pungent odor of the soured    
7verschften7 vat4  ,simultaneously the  
lime with the white indigo forms a      
difficultly  soluble compound1 which    

settles1 and thus interferes with the   
working  of the vat4 ,the excess of lime
 must be removed1 which is accomplished 
by introducing bran1 which causes a     
lactic fermentation2 and the  lactic    
acid neutralizes the excess of lime1 and
 destroys the lime  compound with indigo
 which had been formed4 ,the lime may be
  neutralized by the use of mineral     
acids1 but there is danger in that  case
 of precipitating the indigo4    ,a     
second 8sickness0 is 8becoming too      
sweet40 ,the symptoms are1--the  blue   
veins and surface film disappear on     
stirring1 the foam gives a  rustling    
sound1 the bath assumes a reddish-yellow
 color1 blue goods  placed in the bath  
lose their color1 and the vat has an    
unpleasant odor4    ,the vat when 8too  
sweet0 needs to be brought to the       
regular  temperature1 and lime to be    
added cautiously until the vat is       
brought  to its normal state4 ,it is    
safer to add an excess of lime and      
8sour0  the vat1 and then bring it back 

according to the directions under that  
head1 than to add too little1 as less   
indigo is lost4 ,to use up all  the dye 
and to dye a light blue1 as little lime 
should be present as  is consistent with
 the workings of the vat4    ,the cause 
of the 8falling away0 of the vat is a   
too active  fermentation1 which produces
 considerable lactic acid1 from which   
butyric acid forms1 setting free        
hydrogen1 thereby making white  indigo1 
which1 if the action is allowed to      
continue1 changes to a  compound from   
which the indigo cannot be recovered4   
,if lime is added1  the lactic and      
butyric acids unite with it and         
precipitate it1 while  the excess       
precipitates the white indigo1 which is 
slowly recovered1  as fermentation      
progresses1 which forms lactic acid1    
which1 taking the  place of the white   
indigo1 sets it free4 ,besides the      
sicknesses1 there  are various results  
of mismanagement1 of which the first is 
overwarming1 which causes the bath to   

turn brown1 which is the  beginning of  
the souring4    ,when the bath begins to
 sour from overheating1 some logwood    
should be  added and then bran1 and the 
vat left to itself over night4 ,the     
reason  of it is that the temperature is
 too high for the desired fermentation  
to operate4 ,the vat sometimes suddenly 
turns green1 and even when  indigo and  
the other necessary ingredients are     
added it remains of  this color4 ,this  
is called the 8breaking up of the vat40 
,the reason is  that the temperature is 
too low2 to remedy it1 it is necessary  
to add  logwood and bran1 warm it up1   
and stir1 when it should stand for some