THE PRUNE 39 



is to say a germicide that destroys any micro- 

 organisms that enter it. 



But unless the prune has at least 15 per cent 

 of sugar in its pulp, it will take too long to desic- 

 cate it sufficiently to give the sugar the right 

 degree of concentration. And unless the condi- 

 tions are very exceptional, even when the plum 

 has a sugar content of more than 20 per cent, it 

 still will not dry rapidly enough to escape fer- 

 mentation unless its skin cracks in just the right 

 way. 



A difference of the hundredth of an inch in the 

 average interval between the cracks may make 

 all the difference between a satisfactory prune 

 and a nearly useless one. 



Of course in the pure dry air of many re- 

 gions of California, under a cloudless sky, a very 

 sweet prune will often dry perfectly without the 

 aid of the alkali bath ; but it would not do for the 

 prune raiser to depend upon these conditions as 

 a general thing. He must control his prune, for 

 he cannot control the weather. 



DIFFICULTIES IN SCHOOLING THE PRUNE 



It is obvious, then, that the plant developer 

 must always bear in mind the two particular 

 features of the fruit's education he has to con- 

 tend with. 



