=Preparations of Blood.=--There is no doubt of the valuable nutritive properties of blood and its preparations are sometimes used as foods. There is a deep-seated prejudice against the use of blood as human food, doubtless based on older and more effective grounds than even the laws of health promulgated by Moses. Man is an animal of some refinement of character and the sight or use of blood is repugnant to his finer instincts. Sometimes blood is dried and powdered and the blood powder mixed with other food. Another method is to coagulate the blood, then remove the coagulated portion and use the residue for food purposes. This preparation, of course, contains no coagulable portions of blood, that is, the protein thereof known as fibrin. There is no reason for believing that preparations of blood will ever occupy any prominent position in the food supply, either of persons in health or of invalids. =Beef Tea.=--A very common food preparation from beef is that known as beef tea. In all essential particulars beef tea is nothing more than a rich unfiltered soup stock. Inasmuch, however, as it is constantly prescribed in many kinds of illness and is prepared under certain conditions it should be mentioned specially here in addition to the preparations already described. As in the case of meat juice, beef tea should always be prepared in the home, and immediately before using. It is a preparation which can not be properly made and kept without the addition of some preservative which renders it totally unfit for human consumption. The very choicest portion of the beef should be selected in the preparation of beef tea and it should be reduced to a fine state of comminution. The removal of the fat and tendons should be as complete as possible, as particularly the latter tend to add to the extract more of the gelatine-like principles than is desirable. The fragments should be mixed with a sufficient quantity of cold water to make the desired amount of beef tea, usually one pound of water to a pound of comminuted beef is a good proportion. The mixture should be kept cold for a considerable length of time with frequent stirrings in order to extract as much as possible of the nitrogenous matter which becomes coagulated by heating. Salt may be used not only to promote the solubility but also to give the proper taste. After the lapse of an hour or more the vessel may be covered and gradually warmed. During this warming the mass should be frequently stirred so to as promote the solution. When finally the extraction is complete, before the tea is administered it should be cooked, that is, heated to the boiling-point, by which process the soluble protein is coagulated but not hardened, and the material is rendered more palatable. The beef tea should be administered without separating the coagulated fragments of albuminous material, which is in a state easily digestible, and adds much to the nutritive value of the mixture.