Production of Isinglass on the Coasts of India. 99 



the thinner portions being purer, and containing less Albumen than 

 the others, thus three experiments gave the following results : — 



Isinlass. 



Soluble Gelatine. 



Insoluble Albumen. 



J ,000 parts 



965 



35 



Ditto 



9U9 



91 



Ditto 



928 



72 



The best pieces have comparatively little colour or smell, dissolve 

 tolerably easily in water, and form a good firm jelly, which appears 

 to have but little tendency to become mouldy. The inferior pieces 

 are somewhat coloured, unequal in appearance, dissolve with dif- 

 ficulty, and have a peculiar disagreeable smell, in great part due 

 to the presence of the oily substance before-mentioned. From the ap- 

 pearance and properties of this Isinglass, it is probable that its defects 

 are in a great measure to be attributed to a want of sufficient care in 

 its preparation, and it is evident that good Isinglass cannot be made 

 without considerable attention is paid during the processes of wash- 

 ing, beating, scraping, and drying ; all of which have a very important 

 influence on the goodness of the finished Isinglass. Some of the 

 samples of the Bengal Isinglass are unquestionably very good Isin- 

 glass, whilst others are decidedly inferior, in consequence of their 

 being but imperfectly soluble in water, and possessed of a peculiar 

 and disagreeable smell ; it, therefore, becomes important to inquire 

 into the cause of these objections, and the best way of obviating or re- 

 moving them. The imperfect solubility of some, and more especially 

 the thick pieces, is occasioned by the presence of a considerable 

 quantity of albumen or insoluble membranous matter, having most of 

 the properties of albumen, which is not only itself insoluble, but in 

 addition renders much of the Gelatine, with which it is associated, 

 likewise insoluble. It is more than probable that the greater part of 

 this albuminous substance might be readily removed by sufficiently 

 scraping the Isinglass during its preparation. Attention should also 

 be directed to the process of drying, as if not properly dried, it might 

 possibly undergo a slight change or decomposition, and become 

 partially converted into a more insoluble form of gelatine. A more 



