21 
ON RECENT IMPROVEMENT IN MANUFACTURES. 
and within each other, the lower flame being 
the accident. 
With muriate of lime the lower flame re- 
flected by the mercury was of a decided 
yellow, but the accidental colour of a very 
faint blue; whereas, by natural light the ac- 
cidental is of a fine indigo. 
The green flame obtained by boracic acid 
in alcohol presents a very fine appearance 
with litmus and mercury. A watch glass 
should be employed supported on a ring for- 
med out of a piece of wire, and other lights 
in the room extinguished. 
Your, 
Dear Sir, very sincerely, 
Charles Tomlinson, 
' Brown Street, Salisbury, 
April 22, 1835. 
ON CALICO-PRINTING. 
By Thomas Thomson, m. d.,f.r. s. l. & e. &c., 
Regius Professor of Chemistry in the 
University of Glasgoiv. 
[We cannot, in our opinion render a greater- 
benefit to some of our Civil Surgeons who have 
much leisure time than introduce to their no- 
tice recent improvements during 1835 in the 
manufactures. They may be turned to great 
advantage.] 
Calico printing is the art of applying one or 
more colours to particular parts of cloth, so 
as to represent leaves, flowers, &c., and the 
beauty depends partly on the elegance of the 
pattern, and partly upon the brilliancy and 
contrast of the colours. The process is not 
con^neAio cotton cloth, OlS the term calico- 
printing would lead us to suppose. It is ap- 
plied also to linen, silk, and woollen cloth ; 
but as the processes are in general the same, I 
shall satisfy myself with de.scribing them as 
applied to cotton, because it is with them 
that I am best acquainted. 
The general opinion is, that this ingenious 
art originated in India, and that it has been 
known in that country for a very long period. 
From a passage in Pliny, who probably com- 
posed his Natural History about the middle 
of the first century of the Christian Era, it is 
evident that calico-printing was understood 
and pr-actised in Egypt in his time, but un- 
known in Italy. 
There exist in Egypt,” says he, a won- 
derful method of dyeing. The white cloth is 
stained in various places, not with dye-stufts, 
but with substances which have the property 
of absorbing (fixing) colours. These appli- 
cations are not visible upon the cloth ; but 
when the pieces are dipt into a hot caldron 
containing the dye, they are drawn out an in- 
stant after, dyed. The remarkable circum- 
stance is, that though there be only ond^’-flye in 
the vat, yet different colours appear on the 
cloth ; nor can the colours be again removed.''^’’ 
That this description of Pliny applies to cali- 
co-printing, will be evident to every person 
who will take the trouble to read the account 
of the processes which we are going to give , 
The colours applied to calico in India, are 
beautiful and fast. The variety of tlieir pat- 
terns, and the great number of colours which 
they understood how to fix on different parts 
of the cloth, gave to their printed calicoes a 
richness and a value of no ordinary kind. 
But, their processes are so tedious, and their 
machinery so clumsy, and they could be em- 
ployed only where labour is so cheap as to be 
scarcely any object to the manufacturer. It is 
little more than a century and a half since 
calico-printing was transferred from India to 
Europe, and little more than a century since 
it began to be understood in Great Britain. 
The European nations who have made the 
greatest progress in it, are Switzerland, 
France, especially in Alsace, some parts of 
Germany, Belgium, and Great Britain. 
In Europe, the art has been in some measure 
created anew. By the application of machi- 
nery, and by the light thrown on the proces- 
ses by the rapid improvements in chemistry, 
the tedious methods of the Indians have been 
wonderfully simplified ; while the processes 
are remarkable for the rapidity with which 
they are executed, and for the beauty and 
variety and fastness of the colours. 
I propose in this paper to give a sketch of 
the ditierent processes of calico-printing, such 
as they are at present practised by the most 
skillful printers in Lancashire, and in the 
neighbourhood of Glasgow."^ 
PRELIMINARY PROCESSES.-The 
cotton cloth, after being woven, is subjected to 
several preliminary processes, before it is fit 
for calico-printing. It will be sufficient mere- 
ly to allude to them. They are singeing and 
bleaching. Tire singeing is intended to re- 
move the fibers of cotton which protrude on 
the surface of the cloth. This is done by pas- 
sing the cloth rapidly over the surface of a 
read-hot iron cylinder, which burns off all the 
hairs, or protruding fibres of the cotton, with- 
out injuring the cloth. Of late years, an i.uge- 
nious coal-gas apparatus has been substituted 
for the red hot-iron, both in Manchester and 
Glasgow. 
The bleaching of cotton consists essentially 
of four different processes. 1. The cloth is 
boiled with lime and water ; it is then washed 
clean. 2. It is steeped for some hours in a 
solution of chloride of lime, or bleaching 
powder, as it is usually called. From this 
steep also it is washed clean. 3. It is boil- 
ed in a solution of American potash. After 
the duty ivas taken off common salt, carbonate 
of soda (and consequently caustic soda) be- 
came so cheap, that it gradually took the place 
* I think it right to state, that for all my know- 
ledge of Calico-Printing, I am indebted to my 
friend, Mr. Walter Crum, Calico-Printer, in the 
neighbourhood of Glasgow. With a liberality, 
for which 1 feel greatly indebted to him, he has 
explained his processes to me without mystery 
or reserve. 
* Plinii Hist. Nat, lib. xxxv. c. ll. 
