GUANO.
135
(of 9) and placing it in an apparatus for estimating the quantity of carbonic acid given°ff in dissolving carbonate of lime. The apparatus, either fig. 1 or 2, described in mylittle Treatise on Alkalimetry, will serve that purpose well. I have rarely obtained^ore than h gr. of carbonic acid from the insoluble residuum of 100 gr. of good guano,°ud that corresponds to less than lj per cent, of oxalate of lime in the guano. Some-times no effervescence at all is to be perceived in treating the washed residuum withfctid after ignition.
15. The carbonate of ammonia in guano is readily determined by filtering the solution°f it in cold water, and neutralizing the ammonia with a test or alkalimetrieal acid.(See the Treatise on Alkalimetry, above referred to.)
10. Besides the above series of operations, the following researches must be made toc omplete our knowledge of guano. The insoluble residuum (of 10) which has beendeprived by two successive operations of its uric acid and ammonia, may contain azo-•-i2ed organic matter. It is to be therefore well dried, mixed with 5 times its weight ofthe usual mixture of hydrate of soda and quicklime, and subjected to gentle ignition ina glass or iron tube closed at one end, and connected at the other with an ammoniacondensing apparatus. The amount of ammonia being estimated by a proper ammoniaJoeter, represents the quantity of azote, allowing 14 of this clement for 17 of ammonia,being the potential ammonia corresponding to the undefined animal matter. In a samplePeruvian guano 1 obtained o per cent, of ammonia from this source.
17. The whole quantity of ammonia producible from guano is to be determined bygently igniting 25 gr. of it well dried, and mixed with ten times its weight of the mix-ture of hydrate of soda and quicklime (2 parts of the latter to 1 of the former). TheAmmonia disengaged is condensed and measured, as described above.
18. The ready-formed ammonia is in all cases determined by distilling a mixture of100 oT it with 50 gr. of slaked lime, condensing the disengaged ammonia, and esti-mating it exactly by the meter.
19. The relation of the combustible and volatile to the incombustible and fixed con-stituents of guano, is determined by igniting 100 gr. of it in a poised platinum capsule,^ue loss of weight denotes the amount of combustible and volatile matter, includingl he moisture, which is known from a previous experiment.
20. The insoluble matter is digested in hot water, thrown upon a filter, dried, and^sighed. The loss of weight is due to the fixed alkaline salts, which, after concentra-tln g their solutions, are investigated by appropriate tests : 1, nitrate of barytes for the^Iphates; 2, nitrate of silver for the chlorides and sulphates; and 3, soda-chloride ofUatiuum, for distinguishing the potash from the soda salts.
21. The insoluble matter (of 20) is digested with heat in dilute nitric or hydro-bloric acid, and the whole thrown upon a filter. The silica which remains on the*Oer is washed, ignited, and weighed. The lime, magnesia, and phosphoric acid, may
determined as already pointed out.
22. I have endeavored to ascertain if muriate of ammonia be present in guano, byev apo r ating its watery solution to dryness, and subliming the residuum, but I havejmver obtained a satisfactory portion of sal ammoniac; and therefore I am inclined tolll ink there is little of it. The quantity of chlorine to be obtained from guano is too in-^onsid era bie to lead to a suspicion of its presence, except in combination with sodium
Potassium. Phospjiate of soda is also a doubtful product—but if present, it maybeCoined from the saline matter (of 20), by acidulating it with nitric acid; precipita-first with nitrate of barytes, next with nitrate of silver, taking care to use no ex-!p Ss of these two re-agents, then supersaturating the residuum with ammonia, and ad-acetate of magnesia, when the characteristic double phosphate of this earth should. *» in case phosphate of soda be present.
the preceding train of researches, all the constituents of this complex product may9 exactly disentangled and estimated; but they manifestly require much care, patience,^e, an d dexterity, and also a delicate balance, particularly in using the appropriate‘ Pparatus for generating the potential ammonia, and for measuring the whole of thisoiatile substance separated in the several steps of the process. It may be easily im-j-'ined how little confidence can be reposed in many of the analyses of guano, framed.
Q ® ar 5 too often with the view of promoting the sale of an indifferent or even spuriousJ c le of commerce.
a I shall now give in detail my analytical results upon three different samples ofSouth American guano ; and next the general results upon three samples oij; lc an and Chilian guanos :—
j,, Guano from Bolivia , imported by the Mary and Anne. This sample was takenp 5 ttyself, as an average out of several bags in the lighter, before the cargo was landed.Wtn yellow brown color, dry, partly pulverulent, partly concreted, in small lumps,
8 ” a few small fragments of granite interspersed, and which, being obvious, wereParated prior to the analysis. Specific gravity of the pulverulent portion without