28 a EXPERIMENT STATION. [Jan. 



they being used in the respiration of the fruit. Measurements 

 of the rate of exhalation of carbon dioxide by the fruit showed 

 that it followed the law of acceleration of chemical action with 

 rise in temperature. Further studies on a number of varieties 

 are in progress. 



Studies of the residual effects of liming the different plots of 

 Field A to which various fertilizers have been applied for a 

 series of years has shown that the true acidity remains nearly 

 constant for several years, although the lime content steadily 

 decreases. Ammonium sulfate accelerates the leaching of 

 calcium, while nitrate of soda serves to lessen such an effect. 

 Ammonium sulfate produces a noticeably higher hydrogen ion 

 concentration in the soil moisture than any other common 

 fertilizer material. 



An experiment in the protein requirement of growing calves 

 has been in progress at the request of the agricultural committee 

 of the Council of National Defense. The experiment was begun 

 in January, 1918, with eight calves, and was completed in 

 July. Four of the calves received the high, and four the low, 

 protein diet. A number of digestion experiments were made 

 as the experiment progressed. The tabulated data showed that 

 the calves on the high protein diet made a slightly better 

 growth than those on the low protein diet, although observa- 

 tions failed to detect any differences. The experiment is now 

 being repeated. 



Digestion and metabolizable energy experiments with horses 

 have been in progress during five months of each year 

 since 1916, and the following feedstuffs studied: English hay, 

 alfalfa, corn bran, wheat bran, brewers' grains, corn meal, 

 whole corn, and rations composed of corn, oats, bran and 

 brewers' grains. It is hoped that sufficient data will soon be 

 accumulated to warrant the publication of a bulletin on the 

 subject. 



Digestion trials have been completed with sheep on velvet 

 bean meal, carrots, barley screenings, and a number of pro- 

 prietary feed mixtures. The results will be published as soon 

 as circumstances warrant. 



Two experiments have been completed with corn bran as a 

 component of a grain mixture for dairy cows. The results of 



