KEPORT OF THE SECRETARY. 63 



scale by keeping them in carbon dioxid for a time varying with the 

 variety and the temperature. A study on a small laboratoiy scale 

 has been made of the drying of fruits in vacuum, together with an 

 absorbent for water vapor, such as unslaked lime. The fruits which 

 have been examined for the identification of their acids in order to 

 determine the changes of composition during their manufacture into 

 fruit products included many varieties of apples, pears, strawberries, 

 raspberries, blackberries, cherries, currants, gooseberries, quinces^ 

 huckleberries, apricots, and peaches. The shipping of fresh rasp- 

 berries and blueberries from New Brunswick and Prince Edward 

 Island to Boston by boat, so that they reach the factories in a badly 

 fermented state, has been investigated and conditions improved i-n 

 some cases where the factories have been moved to the Maine border. 

 The work of the Enological Section has included studies on the com- 

 position of the ripe fruit of grapes, of the fruit of grapes during 

 ripening, of grape juice, and of the fruit of apples. Studies with 

 yeast organisms comprised incubation studies to determine the fer- 

 menting power at low temperature. 



SUGAR AND SUGAR PRODUCTS. 



The investigation of the maple products industry of the United 

 States has been continued with special study of the effect of metals 

 on the appearance and composition of the sirup, the changes in com- 

 position of maple !-ugar and sirup in storage, and the effect of manu- 

 facture from sour sap. Analyses have been made of cane sirup, 

 various gra<los of cane molasses, and sorghum sirup to note the chemi- 

 cal means of differentiating these sirups from one another. About 

 1,120 samples were received for analysis during the year, some re- 

 quiring only single detenninations, but many complete examinations. 



DAIRY PRODUCTS. 



The greater part of the work on dairy products during the year 

 was on evaporated, condensed, fresh, and dry milks, cheese, and 

 butter. Milk campaigns were carried on at Providence, P. T.. Cin- 

 cinnati, St. Louis, and Philadelphia to determine the character of 

 the interstate milk shipped to those cities. It is believed that this 

 work has been of great assistance to the local authorities in their 

 campaigns for a satisfactory milk supply. 



MTCROCIIEMICAL STUDIES. 



As a result of tlie field work and the enforcement of the food and 

 drugs act regarding certain loniato products, notably pulp and 

 ketchup, almost revolutionary changes have been taking place within 

 the last few years in the methods of their manufacture. A large 



