CHEMICAL ANALYSIS. 125 



It Avill be seeu that the Schumacher is about five days in advance of the 

 Clawson ; that the growth of each kind j^roceeds by a somewhat uneven pro- 

 gression, the increase of growtli bearing some rehition to the preceding daily 

 temperature, because the specimens wore gathered in the morning. 



The falling oil* in the seventh cutting of Clawson is curious, and I can 

 offer no explanation. After the complete ripening of the grain there is a 

 sensible decrease, showing that the common impression among farmers that 

 there is diminished production of grain when harvesting is delayed too 

 long, is well founded. This loss is not from careless handling of the grain 

 or from drying by over-ripening. The loss is a real one, though not large. 



CHEMICAL ANALYSIS. 



The wheat was powdered by prolonged beating in an iron mortar, and sift- 

 ing this in a wire sieve of 38 meshes to the inch, and this process repeated 

 till the entire quantity taken had passed through the sieve. The amount of 

 water in each specimen was determined by prolonged heating in the steam 

 bath and cooling in a sulphuric acid desiccator till there was no further loss 

 of weights, and the entire loss of weight was taken as water. The results 

 of all analyses and other estimations are based upon water-free material. 



The ash was determined by prolonged burning in a shallow platinum dish, 

 kept at a low red heat till the ash burned white, and the ash was weiglied 

 with its natural contents of carbonic acid. The percentage of ash is given 

 in Table I, which shows a regular decline as the grain develops by forma- 

 tion of ash-free carbhyd rates. 



The cellulose was estimated by boiling in water containing Ij per cent 

 sulphuric acid, then with water and repeating process; then with 1|- percent 

 caustic potash solution — then boilinsr with water and washing the crude 

 cellulose with alcohol and other, following lEennebergh's method. The crude 

 cellulose was then dried in water bath to constant weight; then incinerated 

 and the wei'^ht of ash deducted, when the residual weight was taken as 

 cellulose. No estimate was made of the small amount of nitrogen which it 

 contained. The cellulose was of a light brown color. 



The percentage of cellulose regularly decreased from the earliest forma- 

 tion of the grain up to the time of ripening, the amount being greater in 

 the first cuttings of Clawson than in those of Schumacher, because of its 

 more imuiature condition. After ripening there is an increase of cellulose, 

 showing that over-ripening is attended by a loss of nutritive material, if we 

 consider dense cellulose as indigestible. The increase of cellulose seems to 

 be in intimate relation to the process of hardening exhibited in dead 

 ripening. 



The nitrogen was determined in the usual way by combustion with soda 

 lime, and the amount of albuminoids estimated by multiplying the nitrogen 

 by 6.4. The percentage of nitrogen is given in Table I, and the estimated 

 amount of albuminoids in the dry substance is given in Table II. 



