Gelatin The fillings of both are made by combining ground pork with gelatin cubes, and in the process of cooking, the gelatin melts, creating a soupy interior with a characteristic gelatinous stickiness. Gelatin is used for the clarification of juices, such as apple juice, and of vinegar. Isinglass is obtained from the swim bladders of fish. It is used as a fining agent for wine and beer. Besides hartshorn jelly, from deer antlers (hence the name "hartshorn"), isinglass was one of the oldest sources of gelatin. The consumption of gelatin from particular animals may be forbidden by religious rules or cultural
Swim bladder dioxide. The resulting acidity causes the hemoglobin of the blood to lose its oxygen (Root effect) which then diffuses partly into the swim bladder. The blood flowing back to the body first enters a rete mirabile where virtually all the excess carbon dioxide and oxygen produced in the gas gland diffuses back to the arteries supplying the gas gland. Thus a very high gas pressure of oxygen can be obtained, which can even account for the presence of gas in the swim bladders of deep sea fish like the eel, requiring a pressure of hundreds of bars. Elsewhere, at a