JAPANESE ISINGLASS SO-CALLED. 



207 



Japanese 

 Isinglass 

 [so-called]. 



substance manufactured from sea-weed in China and Japan, i860. 

 induces me to offer a few additional remarks upon the same 

 subject, and also to draw attention to some specimens of the 

 substance in question. It will be most convenient to commence 

 with the specimens, of which I have two. 



1. Under the incorrect name of Japanese Isinglass, there has 

 been lately imported into London from Japan, a quantity of 

 a substance having the form of compressed, irregularly four- 

 sided sticks, apparently composed of shrivelled, semi-transparent 

 yellowish-white membrane ; they are 11 inches long by from 1 

 to 14- inch broad, full of cavities, very light (each weighing 

 about three drachms), rather flexible but easily broken, and 

 devoid of taste and smell. Treated with cold water, a stick 

 increases greatly in volume, becoming a quadrangular spongy bar 

 with somewhat concave sides 1-J- inch wide. Though not 

 soluble in cold water to any important extent, the substance 

 dissolves for the most part when boiled for some time, and the 

 solution, even though dilute, gelatinizes upon cooling. 



2. The second specimen, also from Japan (which I owe to the 

 kindness of the late John Eeeves, Esq.), resembles the preceding 

 in all its properties, but its form is very different, it being in 

 long, shrivelled strips about -J- of an inch in diameter. These 

 strips when immersed in water speedily increase in volume, 

 and are then seen to be irregularly rectangular. This substance 

 in colour is usually whiter than the preceding ; it is also more 

 readily soluble, cleaner, and altogether a more carefully manu- . 

 factured article. 



The substance under notice in all its forms is used by the 

 Europeans in China as a substitute for true isinglass, for which 

 many of its properties render it highly efficient. That which is 

 perhaps most distinctive, is its power of combining with a very 

 large proportion of water to form a jelly. This property is due 

 to the principle named by M. Payen Gelose, of which the Gelose. 

 Japanese sea-weed product mainly consists. The jelly formed 

 by boiling this sea-weed product or crude gelose in water, and 

 allowing the solution to cool, requires a high temperature for 

 fusion, differing in this respect from a jelly made of isinglass, 

 which readily fuses and dissolves in warm water. This character 

 occasions a peculiarity in the taste of culinary jellies made of 



