256 
Indian Forest Becords. 
Imperial Forest Chemist, who reports on it as follows : — 
“ The sample of mangrove cutch shows little resemblance with cutches 
of Acacia and Gambier. It does not answer the general tests for cutches. 
It is entirel}' soluble in cold water, while good cutch is almost entirely 
insoluble in cold water. It has no crystalline principle like catechin and 
appears to be a sort of tannic acid w'hich in dilute solutions gives a very 
dirty green colour with a dilute solution of ferric chloride, while 
catechu-tannin gives in dilute solutions a fine green colour. It has been 
tried by IMessrs. R. B. Brown and Hummel for dyeing and they report 
on it favom-ably as a dyeing agent. I cull the following remarks from 
the reports of the Imperial Institute, London, for the year 1903 : — 
“ ‘ The Mangrove Cutch behaved dm-ing the dj-eing process very simi- 
larly to the Bull-cutch, the chief difference being that in the first oper- 
ation the cotton is stained a very much more reddish-shade than that given 
by any other cutch examined. These dyeing experiments show that the 
Bull and the Mangrove cutches may be considered as belonging to 
group II, indeed they may be placed at the head of this class, since after 
twice dyeing they give much darker colours than any of the rest.’ 
“Asa tanning agent it is not so favonrable as it produces very inferior 
leather of red colour. However, it is very much recommended for produc- 
ing sole leather as the latter tanned by it is comparatively more tight and 
durable. 
Aniline dyes .' — Dyers have now almost ceased using cutch in favour 
of aniline colours, and it is only the continued development of the fishing 
industry which has saved the cutch trade from extinction. The follow'- 
ing extract, from the jommal of the Society of Chemical Industry, affords 
information on the subject : — 
“ Catechu ; Substitutes for — , and then’ application in Calico Printing. 
G. Grieder, Farber Zeit. 1901, 12, (1), 7 — 9. Catechu, wLich was formerly 
largely employed in dyeing and printing of cotton fabrics, has been largely 
replaced in the former industry by these substantive colom’s, which acquire 
the requisite fastness by an after treatment with metallic salts, or by 
coupling with diazotised paranitraniline. In calico printing it has been 
superseded by alizarins or other colours which are fixed by metallic oxides 
on steaming. In the printing of hosiery fabrics, such as flannelette, it is 
still employed to a considerable extent in Russia, Italy, Germany and 
Austria, on account of its ch<'apness and fastness. 
