AND FLORISTS' STOCKS 



9 



As a result of these calculations it has been found that the heat 

 produced by the respiration of fruit while it cools is directly pro- 

 portional to the length of the cooling period. The figures for cool- 

 ing periods of 3, 4, 5, 6, and 8 days are therefore set at 3, 4, 5, 6, 

 and 8 tenths (to the nearest thousand) of the figure for 10 days. 

 The specific heat has been calculated by the formula £=0.008 a -h 0.20, 

 in which S signifies the specific heat of a substance containing a per- 

 cent of water; 0.20 is the value that has been assumed to represent 

 the specific heat of the solid constituents of the substance in question 



my- 



Table 2. — Approximate amounts of heat of respiration and sensible heat to be 

 removed from certain fruits in cooling them from 60°, 70°, or 80° to 35° F. in a 

 room at 82° F., when the cooling takes place in 8, 4, 5, 6, 8, or 10 days 



Kind of fruit 



Initial 

 tempera- 

 ture 



Heat of respiration per ton of fruit during— 



Sensible 



3 days 



4 days 



5 days 



6 days 



8 days 



10 days 



heat' 



Apples: 



Winesap 



° F. 



[ 80 



{ 70 



60 



80 



70 



60 



80 



70 



60 



80 



<^ 70 



60 



f 70 



I 60 



f 80 



70 



60 



80 



\ 70 



I 60 



| 80 



{ 70 



I 60 



B. t. u. 



8,000 

 7, 000 

 6,000 

 12, 000 

 10, 000 

 8,000 

 13, 000 

 10, 000 

 7, 000 

 16, 000 

 13, 000 

 10,000 

 16, 000 

 13, 000 

 30, 000 

 24, 000 

 19. 000 

 38, 000 

 31, 000 

 25, 000 

 9,000 

 8,000 

 6,000 



B. t. u. 

 11, 000 

 9,000 

 8,000 

 16, 000 

 13, 000 

 11,000 

 18, 000 

 13, 000 

 10. 000 

 22, 000 

 17, 000 

 13, 000 

 22, 000 

 17, 000 

 39, 000 

 32, 000 

 26, 000 

 51, 000 

 42, 000 

 34, 000 

 12, 000 

 10, 000 

 9,000 



B. t. u. 



14, 000 

 12, 000 

 10, 000 

 20, 000 

 17, 000 

 13, 000 

 22, 000 

 17, 000 

 12, 000 

 27, 000 

 21, 000 

 16, 000 

 27, 000 

 22, 000 

 49, 000 

 40, 000 

 32, 000 

 64, 000 

 52, 000 

 42, 000 



15, 000 

 13, 000 

 11, 000 



B. t. u. 

 16, 000 

 14, 000 

 12, 000 

 24, 000 

 20, 000 

 16, 000 

 26, 000 

 20, 000 



14, 000 

 32, 000 

 25, 000 

 19, 000 

 33, 000 

 26, 000 

 59, 000 

 49, 000 

 39, 000 

 77, 000 

 63, 000 

 51, 000 

 18, 000 



15, 000 

 13, 000 



B. t. u. 

 22, 000 

 19, 000 

 16, 000 

 32, 000 

 26, 000 

 21, 000 

 35, 000 

 26, 000 

 19, 000 

 43, 000 

 34, 000 

 25, 000 

 44, 000 

 35, 000 

 79, 000 

 65, 000 

 51, 000 



102, 000 

 84, 000 

 68, 000 

 24, 000 

 20, 000 

 17, 000 



B. t. u. 

 27, 000 

 23, 000 

 20, 000 

 40, 000 

 33, 000 

 27, 000 

 44,000 

 33, 000 

 24, 000 

 54, 000 

 42, 000 

 32, 000 

 54, 000 

 43, 000 

 99, 000 

 81, 000 

 64, 000 

 128, 000 

 104, 000 

 84, 000 

 30, 000 

 26, 000 

 22, 000 



B. t. u. 



80, 000 

 62, 000 



Grimes Golden __ 



Peaches: 



Elberta. 



44, 000 

 80, 000 

 62, 000 

 44, 000 

 80, 000 

 62, 000 





44, 000 

 80, 000 

 62, 000 



Pears: 



Bartlett- 



44, 000 

 61,000 

 43, 000 



Strawberries: 



Chesapeake 



Howard 17. 



Oranges: 



Florida seedlings 2 



83, 000 

 64, 000 

 46, 000 

 83, 000 

 64, 000 

 46, 000 

 81,000 

 63, 000 

 45, 000 



i For any one kind of fruit at a given temperature these figures are assumed to be the same for all cooling 

 periods included in the table. 



2 The rate of respiration is practically the same for both Florida seedling oranges and California navel 

 oranges. 



Column 1 of table 2 shows the kind and variety of fruit and col- 

 umn 2 the temperature of the fruit at the time cooling started, in a 

 room held at 32° F. The next column shows the amount of heat 

 evolved by respiration if the fruit reaches 35° at the end of 3 days. 

 The next five columns show the amount of heat if cooling to 35° re- 

 quires 4, 5, 6, 8, or 10 days, respectively. The last column is the 

 sensible heat (obtained by multiplying the specific heat of the fruit 

 by the difference between initial and final temperatures and this 

 result by the number of pounds in a ton). For any one kind of 

 fruit at a given initial temperature, the specific heat is assumed to be 

 the same for all the cooling periods included in the table. 



The values given in table 2 are only approximate. However, in 

 view of the results of the investigation mentioned on page 8, it is 

 believed that the two assumptions that have been made — namely, (1) 

 that the heat of respiration is produced only by the oxidation of a 



324484°— 41 2 



