HORTICULTURE. 979 



temperatures for ISOl and 1805. The bulletin also includes the opinions 

 of 11 number of i)romiiient growers on i)ineai)ple culture. 



Causes of frogging and bloating of prunes, 1^\ T. Bioletti ( Cali- 

 fornia iSta. Bui JIJ, pp. 'J, figs. :.^).— Tlic terms ''frogging" and "bloat- 

 ing" are used somewhat indiscriminately by prune dryers; but in this 

 bulletin the author seeks to limit them, and by " bloaters " those prunes 

 arc ujeaut whicli in drying swell up to half again their natural size on 

 account of a gas produced by fermentation around the pit. They 

 become hollow and are frequently split in two. The "frogs," as dis- 

 tinguished from the "l)loaters," are almost always small prunes, imper- 

 fectly developed, the failure to develop arising from various causes. 



The claim that frogging and bloating were directly attributable to 

 the practice of lye dipping led to an investigation of this and other 

 ])rocesses through which the prunes are passed prior to their drying. 

 Jn the lye process, tlie prunes before drying are ])assed through a nearly 

 boiling solution of lye and then through water. Most of the prunes as 

 they come from the lye are covered with cracks or checks. If acted 

 upon too energetically some arc quite denuded of their skin ; while if 

 not sufliciently acted upon, no breaks at all are produced. It is this 

 last class which generally result in frogs. Properly checked prunes 

 begin to dry immediately, the skin wrinkling in folds. The flesh 

 remains of a light amber color, the outside a clear purplish-brown. 

 Overtreated prunes dry up and quickly become hard. Prunes with 

 unchecked skin do not show signs of immediate drying, but remain 

 smooth and round for several days until they become a dirty brown and 

 the flesh is discolored. 



A drying establishment, where a jmckiug machine was used exclu- 

 sively, was also visited. In this process the prunes, while passing over 

 needles, were sprayed with warm water; no lye was used. The dried 

 fruit in this process is black and shiny on the outside and of a very 

 goodapi)earance. In side they are darker than in the lye-dipping process. 

 The author conducted some experiments in the laboratory, testing 

 the strength of the lye solution and the effect of ditterent dnrations of 

 immersion, giving the results of his experiments at considerable length. 

 The i)runes used in his experiments were of three lots. The first were 

 gathered from branches broken down with the weight of fruit, the sec- 

 ond from unbroken branches of a heavily laden tree, and the third 

 from trees bearing a moderate crop of fine, well-ripened fruit. 



The first lot, although immersed in a 3 per cent boiling lye solution 

 for a minute, did not check, and suflered from the cooking. The sec- 

 ond lot, some of which were treated with a (J per cent lye solution for 

 twenty seconds, checked, but not all. The third lot, which were 

 immersed in a 1.0 per cent solution for twenty to thirty seconds, gave 

 the best results. All the prunes whi<;h had failed to check turned 

 brown, and were a long time in drying, while the others dried in a few 

 days. An attempt was made to <lct«'rmine the |)resence of a mold or 

 other microorganism within tiie tissnes of the l)r()wn prunes, bnt with- 



