May i, 1882.] 
THE TROPICAL AGRICULTURIST. 
989 
The 
but 
land 
the 
laid 
triet 
Hi 
that their sentiment on this score 
age of by unscrupulous merchants, 
.nures that which really contains 
experienced chemists have in recent 
persuade Scotch farmers that they 
aiselvcs about the sources of the 
nia they use as manures, provid- 
n the 
by Hi. 
Witl 
chemis 
properly suggest! 
they are — nitro- 
Next camo dis 
portion of tho 
great deal of sti 
had no claim to 
of Kcllii.- nitro- 
bio phosphate a 
practice is still common 
n combination with solu- 
quilc 
pwards of ammonia, he 
rjuirc whether it was de- 
tho less bone he is able 
lo fragments of bone in 
sfactory thing to a farmer 
hut they aro really an 
ve been imperfectly dis- 
somc other phosphate of 
id phosphate in bone is 
than any other dissolved 
bones is slower in action 
phatc analysed showed a 
ag about 30 per cent of 
only about £<1 15s. per 
ptions, the samples were 
lalysis. One sample from 
rshire, costing £4 os. per 
, that it was still about 
e. A sample from Easter 
I sustained in phosphates, 
xmmonia. Almost all the 
ent short, and some were 
tho guarantee, represent- 
ton. One sample from 
.out half the guaranteed 
valued at £3 8s. Gd. less 
thoso mixtures which arc palmed oil' a ^ ,li..„.iml Wins, 
but have not much trace of bone, should by chemists 
and manufacturers be designated lntro-superphosphate. 
Dr. Aitken's conclusion is that fanners pay too dearly 
for then' bit of sentiment in favour of the tercu "bone 
manures." Great difficulty is experienced by chemists 
in determining whether samples arc made from pure 
bones or not, unless tho mixture of the substitute for 
bonos has been unskilfully made, and then the distinc- 
tion is quite easily traced. Sixteen of the samples of 
so-called dissolved bones which came under the chemist's 
notice could not have boon puro bones dissolved in 
sulphuric acid. They had too low a composition for 
that, and had been evidently manufactured t'r.mi cheaper 
material ; while the average value of the samples con- 
forming to genuine dissolved hones was £7 '.Is. per ton. 
That of tho mixed samples, calculated ou the basis of 
composition, was only £5 8s., and their average selling 
price was £(5 17s. per ton; so that farmers were paying 
at least 2 ( Js. per ton too much for the manure. With 
several of the samples there was an overcharge of 
por ton, or about 26 per cent. Dr. Aitki n finds that, 
if the Caithness Association has paid C7 per ton for 
a manure called vitrinlated bones, whose value is £5 
per ton, tho Strathearn Society in Perthshire has paid 
£7 8s. for a manure whoso value is £5 2s.; and tho 
Lanarkshire Association lias actually paid £8 10s. for u 
manure whoso value, reckoned at the highest, is only 
£5 6s. por ton. The Curse of Oowrio Society paid £9 
5s. por ton for BO-OOllod dissolved bones, which were 
only value for £7 2s. 
In Scotland, more perhaps than in any other pail of 
tho Kingdom, formers have almost a slavish adherence 
o tho WOld "bono" iu nuimucs. Dr. Aitkeu 001 ;;iu • 
01 guano iusboi\eu in siupitunc aeia snowed very un- 
favourable results. Then' composition indicated an over- 
charge in price of about 50s. per ton. One sample of 
dissolved Peruvian guano from the Strathcam district 
of Perthshire, sold at £11 8s. per ton, was value for 
only about £6 6s. The application of sulphuric acid 
to Peruvian guano is discouraged by Dr. Aitken, and 
seomingly is not a cheap means of applying fertilisers 
to the soil. 
Tho so-called special manures, however — such as potato 
manure, turnip manure, oat manure, grass manure, Ac. 
— gave a yet more unsatisfactory result. Taking the 
turnip manures first, Dr. Aitken found that for these 
about £1 per ton more was paid than the corresponding 
value of dissolved bones could have been obtained for. 
Potato manures are still more deficient. Calculated on 
tho same scalo as tho composition of dissolved boneB, 
it was found that the potato manures which cost on 
the average £'J 7s. por ton were only value for £7 Is., 
showing an overcharge of £2 Us. per ton. One potato 
manure from tho Carso of Gowrio had been valued at 
£3 8s. per ton below its selling priee; another from 
Strathearn, sold at £11 per ton, had only value for 
about £6 15s. So-called barley manure in Strathcam 
has been yet more disappointing. One sample, costing 
£9, was at most worth no more than £1 17s. per ton, 
indicating an overcharge of uearly one-half. A few of 
tho special manures aro up to, and ouo or two over, 
tho guarantee; but tho greater proportion have been 
charged far over value. Tho average overcharge Dr. 
Aitkeu found to bo about £8 per ton. 
Those results should read an invaluable lesson to 
fanners who persist in hnyiug special mixture*., instead 
of purchasing the standard manures mid niixiug for 
tlu.uiM.hct-. The whole of the btuiidurd luuuuxva. for 
