( 3(51 ) 
XII. — Annual Report of the Consulting Chemist for 1883. 
Bj Dr. Augustus Voelcker, F.R.S. 
In presenting the usual Annual Report to the Chemical Com- 
mittee I have the pleasure of reporting continued satisfactory 
progress in the Chemical Department of the work of the 
Society. 
The number of analyses made for Members during the last 
year has been greater than in any previous one. The total 
number of samples received for analysis in the course of the 
year terminating the 1st of December, 1883, amounted to 1453, 
and exceeded those of the preceding year by fifty. 
Of this large number of samples analysed in the Society's 
Laboratory, nearly 500 were oil-cakes and feeding-meals, as will 
be seen by the appended summary (p. 368), which gives a detailed 
enumeration of the materials which were sent for analysis. 
Hard-pressed and Indigestible Linseed- and Decorticated 
Cotton-Cakes. — Several cases were brought under mv notice in 
which the use of linseed-cake was suspected to have done injury 
to stock. A careful examination of the suspected cakes, how- 
ever, showed that no ingredients prejudicial to health were 
present, nor that the cakes in question were mouldy or in a 
condition of incipient decomposition. The linseed-cakes com- 
plained of were, however, without exception, very hard pressed 
— some as hard as a board, and on analysis proved to be greatly 
deficient in oil. Owing to the improved machinery which of 
late years has been introduced pretty generally in the American 
and in not a few English oil-mills, linseed is much more 
thoroughly crushed and harder pressed than in former years, 
and is thereby deprived more efficiently of its oil. Of all 
the constituents of food, ready formed oil or fat unquestion- 
ably is the most valuable. Linseed-cake comparatively speak- 
ing poor in oil is consequently less valuable than cake richer 
in that substance. In round numbers 1 lb. of fat goes as far as 
2^ lbs. of starch or sugar in fulfilling similar functions in the 
animal economy. Apart from the greater feeding and fattening 
value of linseed-cakes rich in oil, such cakes possess the further 
advantage of being softer and more readily broken up into 
small bits than hard-pressed cakes, which, as a rule, are de- 
ficient in oil ; and when broken up as usual by a cake-breaker, 
the latter have proved in practice so indigestible as to endanger 
the health of stock, or to prevent their thriving as much as 
they will do when fed upon really good soft linseed-cakes 
rich in oil. In illustration of the fact that linseed-cakes, 
although made from perfectly pure and sound linseed, at the 
