288 Report of the Cltemical Committee. 
4. Field Experiments on Potatoes. 
5. On (he Compos! lion and practical value of several samples of Nativ.j 
(-Tuano prepared by tlic " A.B.C." process of the Native Guano Company, 
Analyses made for the Members of the Itoyal Agricultural Society, 
December, 1869, to December, 1870. 
Guanos (natural) {'A 
Artificial guanos 13 
Superphnspbates, dissolved bones, wlieat manures,) ^-^^ 
and similar artificial manures | '^"^ 
Cone dust 32 
liefuse manures 27 
Nitrate of soda, sulphate of ammonia, and potasb salts 31 
Marls, limestones, and other minerals 20 
Soils 14 
Oilcakes 154 
Feedint; meals 18 
Vegetable productions 13 
Disinfectants 2 
Waters 30 
Sewage 3 
Cider 1 
Treacle 3 
Examinations for poisons 3 
Total 580 
(Signed) Augustus Voelcker, F.R.S. 
XI. — Quarterly Reports of the Chemical Committee. 
December. 
Dr. Voelcker reports the case of a manure sent to him for 
analysis, by Mr. C. S. Read, M.P., under the name of Holman's 
Blood Manure. This manure was found to have the following 
composition : — 
Moisture 30-92 
♦Organic matter 22-02 
Tribasic phosphate of lime (bone iihosphate) .. .. 5-06 
Oxides of iron and alumina 5-10 
Sulphate and little carbonate of lime 18-11 
Alkaline salts and magnesia (chieHy common salt) (i-OG 
Insoluble siliceous matter 12-73 
100-00 
* Containing nitrogen .. .. .. .. I'Ol 
Equal to ammonia 2-32 
This manure was manufactured by N. R. Holman, manu- 
facturer and dealer in agricultural tillages, Newhall Mills, 
Attercliffe, and Sheffield. The price was 6?. a ton, delivered 
carriage-paid to any station within 50 miles of Sheffield. 
In a trade circular, Mr. Holman speaks of his blood manure as 
