6 
Pure and Mixed Linseed-Cakes. 
results of these mcclianical analyses throw light on the re- 
markable differences in the quality of linseed-cakes professing to 
be genuine, I give them in the following list : — 
Foreign Seeds and Impurities in Samples of Linseed. 
Per cent. 
Bombay linseed 4:h 
Finest Bombay seed If 
Black Sea seed 20 
„ „ 2nd sanijilc 12 
„ 3rd „ 19 
Odessa linseed 12^ 
Morshanski seed 7 
Fine Petersburg seed 3 
Petersbiirg Kijeff (common) seed 41 
„ „ „ 2nd quality .. .. 435 
„ „ 3rd „ .. .. 70 
Medium Kiga seed 35 
Eiga crushing seed 42 
„ „ 2nd sample dOs 
No one can look on that list without feeling astonished at 
the large amount of foreign weed-seeds that occur in com- 
riiercial linseed, which is pressed and made into cakes that are 
sold as genuine linseed-cakes. In good samples of linseed seldom 
more than from 5 to 8 per cent, of foreign seeds occur. When 
gathered from foul land, the flax crop necessarily yields linseed 
contaminated to a considerable extent with the seeds from a 
variety of weeds grown amongst the flax, but probably the foulest 
fields overrun with charlock and other weeds do not produce 
linseed containing more than from 25 to 30 per cent, of foreign 
impurities. It will appear, therefore, that the 49 or 70 per 
cent, of impurities which I actually found in two of the samples 
referred to in the preceding table, could not have grown amongst 
the flax from which the seed was produced. In fact, linseed 
is frequently adulterated before it is landed in England. Most 
of the foreign seeds in linseed are smaller than the latter, and 
can be readily removed from it by sifting. This is actually 
done in producing fine samples that are sold to the makers of 
pure linseed-cake, or to oil-crushers prepared to pay a proper 
price for clean linseed. The impurities or siftings, however, 
are too valuable to be thrown away ; they have, indeed, a peculiar 
value of their own, for they are used for mixing with linseed in 
certain proportions, and producing second, third, and fourth 
qualities of Riga, Petersburg, and other varieties. ^ I have been 
