IT IS A CLEANED, POWDERED AND DRIED THYROID GLAND, OBTAINED FROM DOMESTICATED ANIMALS. ON HYDROLYSIS IT YIELDS NOT LESS THAN 90% AND NOT MORE THAN 110% EACH OF THE LABELED AMOUNTS OF THYROXIN AND LIOTHYRONINE CALCULATED ON DRIED BASIS. IT IS FREE FROM IODINE IN INORGANIC FORM OR ANY COMBINATION OTHER THAN THAT PECULIER TO THE THYROID GLAND.