BULLETIN 231] WALNUT CULTURE IN CALIFORNIA. 197 



also that the electric current may exert bleaching action of its own. At 

 all events, walnuts bleached in this manner are decidedly free from the 

 odor and taste of chlorin which characterized many of those bleached 

 by the old liquid process. In the electric process, as first applied, the 

 walnuts were immersed directly in the liquid through which the electric 

 current passed. In its present, more improved form the apparatus 

 consists of a comparatively small, porcelain jar or cell containing the 

 electrodes, through which passes a continuous stream of the salt water 

 which is mixed in a preliminary tank, passed through the cell for 

 treatment, and goes on then into a storage tank. The bleaching device 

 proper consists of a series of slightly sloping, superimposed narrow 

 trays with coarse wire netting bottoms, down which the nuts are made 

 to travel slowly by means of a shaking device. These trays are placed 

 one beneath the other, the nuts dropping from the lower end of the 

 first on to the upper end of the second, and so on, back and forth to 

 the bottom. The electrically treated salt water is discharged in a fine 

 spray over the top tray upon the nuts, and drops down through upon 

 them more or less as they travel back and forth in traversing the 

 various trays. At the lower end of the apparatus the nuts pass 

 through a spray of clear water which cleans them of the salty solution. 

 The whole apparatus is enclosed in a tight wooden box which assists 

 bleaching to some extent by retaining the chlorin gas. This electric 

 method of bleaching walnuts is still in process of development and 

 improvement, but the results thus far obtained with it show clearly that 

 it is far the most satisfactory method yet devised for bleaching walnuts. 

 The nuts after treatment have a very beautiful, attractive appearance, 

 without the dead, unnatural whiteness which is given to them by strong 

 sulphur fumes and various other substances. The quality of the nut 

 is seemingly injured not at all, as no odor remains after drying, while 

 in respect to flavor there is also no objectionable effect. The only 

 effect of this sort which can be detected is in the case of nuts which 

 were partially open when passing through the bleach, which may have 

 a slight salty flavor. On leaving the bleaching box the nuts are dis- 

 charged on to a moving elevator belt which carries them into the 

 grader. 



GRADING. 



In this operation the nuts are graded into two sizes, the first grade 

 consisting of those which do not pass through an inch square mesh 

 screen, while No. 2s are those which will pass through such a screen 

 but not through a three quarter inch square mesh. Various devices 

 for grading are in use, some consisting of a cylindrical cylinder with 

 sides composed of a wire screen of the proper mesh, while more com- 

 monly they are graded over a horizontal screen which is shaken back 



