SYSTEMATIC SYNTHESIS OF ELEMENTS. 161 



will vary so much in different cases, that where the preservation or 

 restoration of health is of great importance, and very difficult to accom- 

 plish, the greatest care must be taken to select the best qualities as well 

 as kinds of food. 



72. THE ORGANIC PRINCIPLES COMPOUNDED B^ 

 PLANTS, for the use of Man, are of two classes ; those 

 adapted merely to produce heat (or fatten), and those 

 adapted to nourish his Body. 



73. THE ORGANIC PRINCIPLES ADAPTED BY THE 

 PLANTS FOR CALORIFIC PURPOSES are Starch, Sugar, 

 Gum, Fat, composed of the Elements of the first group, 

 in different proportions. These, compounded under the 

 influence of the sun's rays, store up or condense, so to 

 speak, his heat, until such time as they are burned, 

 when they give out merely what they have received. 



Remark. The Calorific Organic Principles may be, and in some 

 cases are, separated from other parts of plants in which they grow, 

 and used by themselves, or mixed with other articles ; in other cases they 

 are eaten in a combined state, as they exist in the plant, when they will 

 not be distinguished by the ordinary observer. For instance : the sap of 

 cane is expressed, boiled down, and sugar obtained ; starch is also sepa- 

 rated from the other parts of potatoes, corn, wheat, etc., and used ; or, 

 the grain and potatoes are cooked and eaten in the form of bread, etc., 

 and their starch is eaten with their other components. 



74. PLANTS ALSO COMPOUND, principally in their 

 seeds, the Organic Principles necessary to serve the pur- 

 poses of nutrition to tissues abounding in Nitrogen, 

 Phosphorus, Sulphur, Oxygen, Hydrogen, and Carbon. 

 These nutritive Organic Principles also are compounded 

 under the powerful influence of the sun's rays, which are 

 stored in them until the time occurs for their power to 

 be exhibited. These are able to receive and store up more 

 than the sun's heat ; that can be done by the first group 

 of Elements : the second group can store up more, viz., 

 the chemical or actinic power ; and the entire nutritive 

 Principle, composed of both the first and second groups, 



72. What said of ? 78. What said ? How compounded? How are calorific 

 elements used? 74. What do ? How compounded? 



