Annual Report of tlie Consulting Chemist for 1877. 
253 
arsenic. It was thus evident that the partridges had not been 
killed by the arsenical wheat-dressing, and, on further examina- 
tion, I was able to show that both the wheat found in the field 
and the contents of the crop of the dead partridge contained 
appreciable quantities of bichloride of mercury, or corrosive 
sublimate. I am not aware that corrosive sublimate or other 
mercurial poisons have ever been employed for dressing wheat 
for the purpose of preventing smut, and it appears to me 
probable that the wheat poisoned by corrosive sublimate had 
been laid about the field with the intention of destroying the 
game. 
My attention was directed last September to a curious sub- 
stance which made its appearance on the grass in a field of 
rough pasture, in the occupation of Mr. H. B. Riddell, White- 
field House, Rothbury, Morpeth, who wrote to me on the 29th 
of September, 1877 : — 
" Sir, — I send by this day's post two Loxes containing specimens of a 
substance which has made its appearance in a field of rough pasture near this 
house. I observed it at the same place last year, but have never seen anj-- 
thing like it elsewhere ; and, though I have pointed it out to many persons, I 
have not met any one who had seen it before. I have thought, therefore, that 
it might be of interest to you. The substance first makes its appearance as a 
viscous froth, not unlike a mass of 'cuckoo-spit ;' it gradually solidifies, and 
becomes what is sent in the card-box, and after a few days dries into the 
crystalline powder, a considerable quantity of '.vhich is in the wooden box. I 
have not analysed the crystals ; but it has struck me that, as the field was 
two years ago somewhat heavily manured with nitrate of soda and superphos- 
phate of lime, the crystals might be derived from the manure. 
" Yours truly. 
" H. B. ElDDELL. 
"Dr. Voelcker." 
The examination of the white powder, to which reference is 
made in Mr. Riddell's letter, showed that, in addition to some 
gum and sugar, the bulk of the substance consisted almost 
entirely of carbonate of lime, with merely faint traces of phos- 
phoric acid, and contained no nitrate of soda whatever. 
On further inquiry, I learned from Mr. Riddell that the field 
in which the white substance appeared is poor partially-drained 
pasture on the north flank of the Simonside Hills. It rests on 
the ironstone of the coal measures, not on limestone ; but 
dykes of limestone cross the sandstone, and the springs are 
strongly impregnated with lime, chiefly as carbonate. 
The spot where the substance in question appeared is not 
thoroughly drained, though the surface is dry. It first seemed 
to grow on the grass as a glutinous foam, and gradually dried 
to a crystalline powder. The field has not been lately dressed 
with chalk or lime. 
