32 KEPOET OF OFFICE OF EXPERIMENT STATIONS. 



as Avell suited for the study of certain fundamental problems of 

 plant life as it is for the study of similar problems of animal life. 

 Plans are already under consideration for experiments on a variety 

 of such problems, with the object of securing data needed in projects 

 which the Department of Agriculture has under investigation. 



The apparatus can be used in similar ways in studying such prob- 

 lems as the changes which take place when meat or cheese or other 

 farm products are cured or ripened and factors which influence these 

 changes — problems which are of commercial interest as well as of 

 agricultural, domestic, and scientific importance. 



The small respiration calorimeter has been so constructed that 

 with a little modification of the metal-walled respiration chamber it 

 can be used for experiments with small animals as subjects should 

 cooperative work between bureaus of the department make this de- 

 sirable. As is the case in the respiration-calorimeter experiments 

 with men as subjects, ample provision can be made for the comfort 

 of the animals in such experiments, in order that the results may be 

 normal. 



It would be particularly useful to study by these or similar methods 

 the influence of heat and of the moisture and carbon-dioxid effect of 

 the air upon eggs during incubation by a hen and by artificial 

 methods, and also to study in detail the respiratory and energy 

 changes of incubating eggs. 



This new calorimeter work has been spoken of in recent publica- 

 tions.^ 



A micro-calorimeter for use in the experimental study of very 

 small quantities is being installed. With it some of the details of 

 fruit-ripening problems now under investigation can be advanta- 

 geously studied as well as other questions. This piece of apparatus 

 materially extends the possibilities of studying agricultural problems 

 by calorimetric methods, but involves little that is new in the way of 

 equipment since the recording and controlling devices already in use 

 with the larger calorimeters serve for this kind of work also. 



During the fiscal year a technical bulletin, entitled " Calcium, Mag- 

 nesium, and Phosphorus in Food and Nutrition," has been published, 

 as well as a series of 15 colored food and diet charts. A Farmers' 

 Bulletin on the care of milk and its use in the home has been issued 

 in cooperation with the Bureau of Animal Industry. A circular on 

 food customs and diet in American homes has been published, as well 

 as two articles already referred to, which have appeared in the Year- 

 book of the department, and numerous summaries, which have 

 appeared in annual reports and similar publications. There has also 



1 Experiment Station Record, 24 (1911), pp. 601-606; U. S. Dept. .\gr., OfBce Expt. 

 Stas. Circ. 116. 



