598 
Castor -Oil Seed in Cattle Foods. 
no case on record of the seeds having been intentionally given to 
stock. 
From time to time, however, cases of severe purging among 
stock, followed occasionally by death, have been brought under 
notice, and the mischief has been traced, in some of the cases at 
least, to the presence of castor-seed in one or other of the feeding 
stuffs given to the animals. 
F rom what has been said as to the quantity of these seeds which 
is required to cause illness or death to human beings, it will be readily 
understood that not many seeds need be administered to sheep or 
cattle in order to produce like effects, and should the seed exist in a 
cattle food, several pounds of which constitute a daily ration, it will 
be likewise clear that one or two seeds per pound are all that are 
necessary in order to produce harmful results, if not death. 
Such small quantities of any seed when present in a cattle food 
may, admittedly, be easily overlooked during even a careful micro- 
scopical search. In such examinations, as anyone who is accustomed 
to use the microscope will appreciate, no very large portion of a 
food can be examined at one time, and it may consequently happen 
that, if a number of samples of a food containing, say, only half a 
dozen seeds of any kind per pound, be examined, in none of these 
may the particular seed be present. In the case of castor-oil seed 
the difficulties are considerably increased, owing to the opacity of 
the seed-case and the consequer.t non-revelation of the structure. 
It has been mentioned above, that cases of severe purging and 
death of stock have been from time to time reported. It was during 
a search made for the j^urpose of ascertaining the cause of the death 
of some stock that the writer, when working in the laboi'atory of the 
Royal Agricultural Society, under Dr. Voelcker, succeeded in dis- 
covering a method by which even very small quantities of castor- 
seed in a cattle food could be separated, and not merely be recognised 
but calso weighed. 
It would be out of place to trouble the readers of this Journal 
with any full description of the technical details of the process 
employed. These are given in a paper which was laid before the 
Society of Public Analysts in June last.* It will suffice to say that 
a quantity of the suspected food is digested, first with dilute hydro- 
chloric or sulphuric acid (1 to 2 per cent.), and then with dilute 
potash or soda. By this means the husk or fibre is separated from 
the other constituents. If, then, the husk, after being washed clean, 
is subjected to the action of either sodium hypochlorite or of ordinary 
bleaching powder, it will be found that the husk of castor-oil seed 
remains perfectly unbleached, even after several days, whereas the 
husk of linseed, cotton-seed, rape, buckwheat, locust-bean, and other 
seeds which occur in feeding-cakes, will bleach entirely in three or 
four hours. The unbleached husks may be then picked out from the 
rest of the material, and can be readily recognised under the micro- 
scope, its structure being then clearly visible. It will perhaps be 
' The Analyst, vol. xvii. No. 195, July 1892, p. 121, it seq. 
