The Boston cooking-school cook book

by boiling with water, muscle, skin, cartilage, bone, tendon, ligament, or membrane of animals. By this process, collagen of connective tissues is dissolved and converted into gelatin. Gelatin is insoluble in cold water, soluble in hot water, but in boiling water is decomposed, and by much boiling will not solidify on cooling. When subjected to cold water it swells, and is called hydrated gelatin. Myosin is the albuminoid of muscle, collagen of tendons, ossein of bones, and chondrin of cartilage and gristle. Gelatin, although highly nitrogenous, does not act in the system as other nitrogenous foods, as a large quantity passes out unchanged. =Fat= is the white or yellowish oily solid substance forming the chief part of the adipose tissue. Fat is found in thick layers directly under the skin, in other parts of the body, in bone, and is intermingled throughout the flesh. Fat as food is a great heat-giver and force-producer. _Suet_ is the name given to fat which lies about the loins and kidneys. Beef suet tried out and clarified is much used in cookery for shortening and frying. =Mineral Matter.= The largest amount of mineral matter is found in bone. It is principally calcium phosphate (phosphate of lime). Sodium chloride (common salt) is found in the blood and throughout the tissues. =Water= abounds in all animals, constituting a large percentage of their weight. The color of meat is due to the coloring matter (hæmoglobin) which abounds in the red corpuscles of the blood. The distinctive flavor of meat is principally due to peptones and allied substances, and is intensified by the presence of sodium chloride and other salts. The beef creature is divided by splitting through the backbone in two parts, each part being called _a side of beef_. Four hundred and fifty pounds is good market weight for a side of beef. The most expensive cuts come from that part of the creature where muscles are but little used, which makes the meat finer-grained and consequently more tender, taking less time for cooking. Many of the cheapest cuts, though equally nutritious, need long, slow cooking