421 Composition and Practical Value of Native Guano. 
ammonia, or just about the same amount wliich I found in three 
of the five samples of native-guano. Farmyard manure on an 
average contains nearly 1 per cent, of phosphate of lime, or about 
less than four of the five samples of native guano. A couple of 
shillings' worth of bone-dust, however, would supply the defici- 
ency of phosphate of lime in a ton of farmyard manure. Bear- 
ing in mind, however, that common dung contains an appreciable 
amount of salts of potash, which in the preparation of the ABC 
mud passes into the clarified sewage, and that in virtue of the 
rotten straw, dung exercises a beneficial mechanical effect upon 
the land to which it is applied, both of which give it a certain 
value that is not possessed by the Native guano, I believe 1 am not 
overstraining a point by stating it as my deliberate opinion 
that a ton of four of the five samples of Native ABC guano 
analysed by me, is barely worth as much as a ton of common 
farmyard manure. 
Unless dung can be bought at about 5s. per ton when it has to 
be carted some miles, it is unavailable for practical purposes. 
It consequently follows that the above mentioned estimated values 
of the different samples of Native Guano are stated about three 
times as high as their respective real practical values ; and that, 
at any rate, four of the five samples are practically worthless, 
if the manure has to be carted a distance beyond 10 miles from 
the place where it is manufactured. 
11, Salisbury-square, Fleet-street, E.C. 
July, 1870. 
XXXIII. — Quarterh/ Reports of the Chemical Committee on 
Adulterated Manures and Feeding Stuffs. 
Maech. 
The Committee recommend that the following report by Dr. 
Voelcker be published in the minutes of the Council meeting. 
I. Composition of a sample of so-called bone manure, sent by 
Mr, S. Bacon, jun., Ratclifi" Culey, Atherstone. 
Water 20-19 
*Organic matter 21'61 
fMonobasic phospliatc of lime '74 
Free sulphuric acid 3'78 
Oxide of iron aud alumina '69 
Sulphate of lime (<rypsum) 47*G7 
Magnesia and alkaline salts '78 
Insoluble siliceous matter 4-54: 
100-00 
* Containing nitrogen 1-11 
Equal to ammonia , .. .. 1*34 
t Equal to bont'-phosphate rendered soluble .. 1-17 
