150 



STATE rOMOLOGICAL SOCIETT. 



your h:ind, changes as \re\\ known to science and capable of as exact quantita- 

 tive statement as the local changes of the planets in the solar svstem. Forty- 

 four years ago, Liebig and his fellow workers discovered certain links in those 

 chemical changes, in the products of the almond family, and the discovery was 

 an era in chemical science. 



The chemistry of the covered seed is of interest not only for the quality of 

 the compounds found in it, but, quite as much, for the history of these com- 

 pounds, the chemical changes of seed and fruit ripening in the plant. These 

 changes differ in their general character from otlicr cluangcs of plant cliemistry, 

 coincitling more nearly with the changes of aninuil chemistry. Taking for 

 study the ri[)ening of seeds wilh succulent coverings — the fruits — the proper 

 subject of this article, — we nuiy undertake to compare fruit ripening with 

 vegetable nutrition on the one hand and witli animal nutrition on the other 

 liand, as follows : 



ly Vegetable Nutrition'. 



1. Oxj'gen is given to the 

 air. 



2. Carhonic acid 

 from the air. 



is taken 



3. The service of ])laiit- 



grceu is required. 



4. Simple compounds are 



clianged to those more 

 comi)Iex. 



5. The expended power of 



the 6UU is stored. 



6. Heat is absorbed. 



7. The clianges repr(>sont re- 



ductions and syntheses, 

 difficult to the chemist, 

 uiul hindered by atmos- 

 pheric conditions. 



8. Opposed to fermenta- 



tions, and to otlier chan- 

 ges classed under the 

 term organic decompo- 

 sition. 



In FmiT Kipening. 



Oxygen is taken from the 

 air. 



Carbonic acid is given to 

 the air. 



The service of plant-green 

 is dismissed. 



Complex compounds are 

 changed to those more 

 simple. 



The stored up power of the 

 sun is expended. 



Heat is liberated. 



The clianges represent com- 

 bustions and dissociations, 

 and are mostly favored by 

 atmospheric conditions. 



The changes include a great 

 nimibcr of distinct fer- 

 mentations, some of which 

 are spontaneous in the air 

 or occur in cooking food. 



0. The important compouiuls of the vegetable kingdom 

 — cellulose, starch, sugar, and many acids and other 

 products — are common to the fruit and other parts 

 of the phuit. 



In AMMAL Nl'TRITION. 



Oxygen is taken from the 

 air. 



Carbonic acid is given to the 

 air. 



Complex compounds are 

 changed to those more 

 simple. 



The stored up power of the 

 sun is expended. 



Heat is liberated. 



The clianges represent com- 

 bustions and dissociations, 

 such as are favored by at- 

 mospheric conditions. 



Some of the changes are al- 

 lied to fermentations, but 

 are mostlj' not liable to 

 occur without the living 

 body. 



Only a few animal products 

 are found in the vegetable 

 kinffdom. 



Fruit ripening, then, coincides with vegetable nutrition in acting with the 

 same substances, and coincides with animal nutrition in moving in the same 

 direction. 



To inquire, now, somewhat in detail, into the more obvious of the changes 

 which constitute fruit rip3ning, wo may examiuo the proportion and formation 

 of the following five classes of Fuuix Products: 



