Mr. Warington on Bones taken from the Guano. 195 



hour, and no more than 0*3 1 gr. in 4f hours, while at a red 

 heat it would lose 0*60 gr. 0'60 — 0-31 = 0*29. We may 

 therefore conclude that one-half of the water is expelled at the 

 temperature above mentioned, giving another hydrate, HO, 

 2CaO + PO5 + 2HO. 



XXIV. On a curious Change in the Composition of Bones taken 

 from the Guano. By Robert Warington, Esq.* 



MY friend Mr. Edwin Quekett, put into my hands a few 

 days since, for the purpose of chemical examination, a 

 curious crystalline substance taken from the guano, as im- 

 ported from Ichaboe, and which he considered to have en- 

 tirely replaced, and thus have assumed the form of, the ori- 

 ginal bony structure. The exterior surface, in many specimens, 

 has portions of muscular fibre in a dry and pulverulent state 

 closely in contact with the substance ; small pieces of bony 

 matter are also now and then found remaining, and in some 

 cases the cylindrical part of the bone is perfectly modelled by 

 this saline deposition or infiltration. The structure is highly 

 crystalline and laminated, and in the cylindrical parts slightly 

 radiating from the sides towards the centre; its colour is nearly 

 white, with a slight shade of yellow, and generally very free 

 from foreign matter, except at the parts where the enlarged 

 or natural terminations of the bones may be supposed to have 

 been, and in these places the substance is interspersed with 

 small brown particles. It decrepitates in the flame of the 

 spirit-lamp, assumes a gray colour, gives off ammoniacal va- 

 pour, and ultimately becomes perfectly white and opake; and 

 by increasing the heat, by means of the blowpipe, it fuses and 

 communicates a pinkish purple tinge to the flame, indicative 

 of potash, and without any trace of yellow, showing its perfect 

 freedom from soda salts. It was readily dissolved in hot di- 

 stilled water, with the exception of the interspersed brown 

 particles just alluded to; solution of nitrate of barytes threw 

 down an abundant white granular precipitate insoluble in di- 

 lute nitric acid, consequently proving the presence, to a con- 

 siderable extent, of sulphuric acid ; solution of chloride of 

 calcium occasioned no change, nor did the subsequent addi- 

 tion of ammonia cause any precipitation, so that the oxalic 

 and phosphoric acids were both absent. Solution of oxalate 

 of ammonia gave no indication of the presence of lime. By 

 boiling, after adding solution of caustic potash, ammonia was 

 evolved; nitrate of silver in a dilute solution, free nitric acid 

 being present, caused no precipitation. The addition of tar- 

 * Communicated by the Chemical Society ; having been read November 

 18, 1844. On Guano, see p. 123 of the present volunae. 



