ANIMAL COMPOUNJ)S 321 



6. Sperm Oil is not a true oil, being a liquid wax (Section 

 70), or compound of fatty acids, principally oleic, with 

 monohydric alcohols. It is obtained from the head cavities 

 of the sperm whale. On cooling it deposits crystals of sperm- 

 aceti, a solid wax. Sperm oil is a most excellent lubricant. 

 Spermaceti is used in making candles and in medicine. 



7. Beeswax is the substance from which honey-comb is 



%j 



made, being manufactured by the bees. It is a tough, com- 

 pact mass, yellow or brownish in color. It is not greasy 

 to the touch. In composition it is a wax, containing com- 

 pounds of palmitic, cerotic, and melissic acids with mono- 

 hydric alcohols, and in addition some higher hydrocarbons. 



8. Volatile Oils are not found in animals. 



(c) Nitrogenous Compounds. — These are for the most 

 part proteins, which differ somewhat from plant proteins. 

 Most of the knowledge of proteins is derived from a study 

 of these compounds in the animal. They have been classified, 

 their properties observed and tests described, but their 

 study is too complex and technical for a work of this kind. 

 As occasion arises various proteins will be named and briefly 

 described. Other nitrogenous compounds, as amino-acids 

 and ammonium compounds, occur as transition products. 



(d) Organic Acids are not a normal part of the animal 

 body, except as by-products of metabolic activity, as, for 

 example, sarcolactic acid in active muscle, and uric acid- 

 waste material in the blood. 



(e) Compounds of the Inorganic Elements. — In the 

 plant inorganic compounds exist merely as transitory food 

 materials absorbed by the roots. The so-called inorganic 

 elements are combined organically for use by the plant 

 either as an integral part of its tissue or as a sort of helping 

 compound for tissue formation. In the animal, however, 

 inorganic compounds play a very important part. They can 

 best be taken up by elements. 



1. Compounds of Phosphorus. — Calcium phosphate, 

 Ca 3 (P0 4 ) 2 , exists in bones and teeth, and CaH 4 (P0 4 )2 in 

 the tissue fluids. In the bones and teeth it gives solidity 

 to the organs. It is associated with magnesium phosphate, 

 Mg 3 (P0 4 ) 2 . 

 21 



