SYNTHESIS OF THE FATS. 25 



hydrogen in the group CH NH, which in turn is structurally closely 

 related to hydrocyanic acid. In accordance with these considera- 

 tions, we thus find that arnygdalin, C 20 H 27 NO 11 , is decomposed into 

 glucose, hydrocyanic acid, and benzaldehyde, as shown in the equa- 

 tion : 



C 20 H 27 NO U + 2H 2 = 2C 6 H 13 6 + C 6 H 6 .COH + CNH. 



Solanin, C 43 N 70 NO 16 , similarly yields glucose and solanidin, C 25 - 

 H 39 NO. 



Mannides. Like the carbohydrates proper, the mannides or man- 

 nitides, w r hich also occur widely distributed in the vegetable world, 

 are likewise derived from the aldehyde radicle that is formed by 

 chlorophyl under the influence of sunlight. They differ from the 

 glucosides in yielding mannite, C 6 H 14 O 6 , instead of glucose, on 

 hydrolytic decomposition. The origin of mannite from formic alde- 

 hyde may be represented by the equation : 



6CH 2 O + 2H = C 6 H M O 6 .. 



On the other hand, mannite may result from glucose as the result 

 of the specific activity of certain cells, as is shown by the equation : 



13C 6 H 12 6 + 6H 2 = 12C 6 H U 6 + 6CO 2 . 



Synthesis of the Fats. The fats which are found in plants 

 are, like the carbohydrates, derived from carbon dioxide and water, 

 and in all likelihood are formed also synthetically through the 

 agency of the chlorophyl. The mechanism, however, by which 

 these syntheses are effected is not so clear. It is probable that they 

 result from the union of carbon dioxide and water, as shown by the 

 equations : 



(1) SC0 2 +4H 2 = C 3 H 8 O 3 +7O. 



Glycerin. 



(2) 34CO 2 + 34H a O == C I8 H 36 O 2 + 16CH 2 O 2 + 68O. 



Stearic acid. Formic acid. 



(3) C 3 H 5 (OH) 3 + 3C 18 H 35 O.OH = C 3 H 5 (O. C J8 H 35 O) 3 + 3H 2 O. 



Glycerin. Stearic acid. Stearin. 



This supposition is strengthened by the observation that during 

 certain phases in the life of some plants an actual transformation 

 of carbohydrates into fats takes place. In the fruits and leaves of 

 the olive tree, for example, a large amount of mannite gradually 

 disappears during the months of September and October, and is 

 replaced by oil. This transformation could be explained upon the 

 basis of the equations just given, or by the assumption that the oil 

 results from mannite through a loss of water and carbon dioxide, as 

 suggested by the equation : 



11C 6 H 14 6 = C 51 H 94 6 + 30H 2 + 15C0 2 . 



In any event, the system H 2 O -f- CO 2 , which gives rise to the 

 formation of formic aldehyde and glucose, must also be regarded 

 as the fundamental basis in the synthesis of fats. 



