338 
Annual Chemical Report. 
In conjunction with this subject I have begun a laboratory 
investis:ation of the nitrification which takes place in soils, 
especially after the cultivation of certain crops. 
The number of analyses made for Members of the Society 
during the past season, as will be seen by the appended summary, 
was fully as large as in the preceding year; not less than thirty 
samples of water, and an unusually large number of limestones, 
marls, and other minerals having been received by me. 
Six cases of supposed poisoning were referred to me, and mis- 
chief was reported to have been done in several instances by 
inferior oil-cakes. Mixed and adulterated oil-cakes, I am sorry 
to report, seem still to be more abundant in the market than 
good and pure cakes. 
Decorticated American cotton-cake of good quality, notwith- 
standing the cecession of the American war, appears to be still a 
scarce article, for most of the samples sent to me for analysis 
were very old mouldy cakes, and some scarcely fit as food for 
cattle. 
The average proportion of ammonia in genuine Peruvian 
guano within the last year or two has somewhat declined, and that 
of sand slightly increased. Genuine first-class Peruvian guano 
in 1867 probably contained on an average not much above 15 per 
cent, of ammonia. 
Amongst the analyses of more general interest I may mention 
the following : — 
Composilion of Acorni. 
Proportions of Husk and Kernel. 
Husks 13-90 
Kernels 86-10 
100-00 
1 lb. of fresh acorns when bought were put aside, and weighed 
again on the 18th of November, before the analysis was made, 
when it was found that the weight was reduced to IZ^ ounces. 
The kernel when analysed was found to contain in 100 
parts : — 
Moisture 40-88 
Fatty matters 2-64 
*Albuminous compounds (flesli-forming matters) 4-39 
Starch, gum and sugar, &:c 46-74 
Woody fibre (cellulose) 3-94 
Mineral matter (ash) 1'41 
100-00 
* Containing nitrogen ' "03 
Acorns, which are much relished by sheep and pigs, are sold 
in ordinary seasons to farmers in Hertfordshire and elsewhere at 
