LARCH SEED. 



767 



the slits between them. Under the drum large sieves are kept 

 in constant motion backwards and forwards. This apparatus of 

 Keller's is preferable to all others yet invented, as it removes the 

 seed in less than half the time taken, for instance, by the 

 Tyrolese method. 



Larch seed, when freed from the cones, is mixed with pieces of 

 wood and scales of various sizes, and any amount of dust, from 

 which it must be cleaned. The process of cleaning is therefore 

 a most difficult and tedious business, for there are in the mixture 

 pieces of scales of the same size and weight as the seeds ; up to 

 the present time, therefore, it has not been considered possible 



Fig. 338. Fig. 339. 



to obtain really clean larch seed. In order to sift the seed hand- 

 sieves are first used and then a corn-sifter. The sifting process 

 is therefore tedious and the workmen must show much patience. 

 In some places (the Tyrol, for instance) the broken-up cones are 

 placed with water in a tub ; the pieces of wood and scales sink 

 to the bottom, whilst the seeds float on the surface and are then 

 scooped off and dried, the dried seeds finally passing through a 

 corn- sifter. This wet process of cleaning is often regarded with 

 suspicion from fear of injuring the germinative power of the 

 seed, but there appears to be no ground for this, provided the 

 seeds are afterwards thoroughly dried. 



In Keller's seed-depot a small mill is used for removing the 

 wings from larch seed, the grinders being made of vulcanised 

 caoutchouc and as far apart as the leugth of the seeds ; the 

 wings are thus removed by friction. A fly-wheel working under 



