Isinglass

Isinglass is a substance obtained from the dried swim bladders of fish. It is a form of collagen used mainly for the clarification or fining of beer. It can also be cooked into a paste for specialized gluing purposes.

https://en.wikipedia.org/wiki/Isinglass

A Compendium of Domestic Medicine, 1865 Isinglass

All page numbers are recorded as (PDF #/SOURCE #)

Cookery for the Sick that includes

• An Excellent Jelly (Another) (360/339): boiled shavings of isinglass, with Jamaica Peppers, and a brown crust of bread. Makes a jelly that can be “taken in wine and water, milk, tea, or soup.”
• Coffee Milk (361/340): shaved isinglass added to ground coffee that has be boiled in milk. Used to clarify the mixture.

Imported from

• Italy
• Russia
• Germany
• Poland
• Ireland
• Brazil
• British Guiana
• Hamburg
• British India
• Singapore and Eastern Straits Settlements
• Egypt
• German East Africa
• China