170 REPORT — 1861. 



greatly more soluble in water than the same material dried, burnt, and then 

 finely ground. 



In the next place, I have experimented upon bones in various forms and 

 conditions, as will be seen by the following data. 



Shank-bones of ox, coarsely ground and long soaked in water before 

 the experiment was begun. This bone-dust was very hard and close in texture. 

 The first pint, which was evaporated to dryness and further treated as stated 

 above, was removed from the bone-dust after the water had been in contact for 

 3 days. After that time 1 pint contained -06 grs., or -48 grs. per gallon, of 

 phosphate of lime left for 12 days in contact with bone-dust; the 2nd pint 

 produced '10, or "80 per gallon. 



^ . , , , , f 1st pint gave '46, or 3*68 per gallon. 



Commercial bone-bust i ^ i • - r-n a ctA n 



V.V/ c V. a u^u^ uix -y 2,j(i pint gave '53, or 4*24! per gallon. 



A very porous sample of commercial bone- j .^^ ^^ ^.^^ ,^^^^ 



dust, 7000 grs. of solution gave J ' f & • 



Amount of phosphate of lime 

 dissolved 

 by 7000 grs. of sohition ; by 1 gallon. 



Boiled bones (the refuse of glue-makers) '59 or 5*90 



Boiled bones (the same sample, after it had 1 



become quite rotten by keeping 10 weeks j- -62 or 6'20 



in water) < 



The pith of ox horns (sloushs rather de- 1 , • , ^^ ^ „„ 



composed) ^ | 1 pmt gave "67 or 5-36 



It has been noticed already some years ago, by Professor Wohler, that 

 rotten bones yield to water more phosphate of lime than fresh ones. My 

 experiments fully confirm this observation, and they moreover show that 

 the more porous the bone, the more readily it yields phosphate of lime to 

 water. 



I may mention here that, some time ago, I examined the tank-water con- 

 taining the drainings and washings of the kennels at Harlow. The 

 drainings were highly offensive to the smell, although not much discoloured. 

 An imperial gallon, filtered perfectly clear, on evaporation furnished 36*86 

 grs. of solid residue, and in this residue I found '44 of phosphate of iron and 

 4*28 grs. of phosphate of lime, thus showing that phosphate of lime is soluble 

 to a considerable extent in water charged with putrefying animal matter. 



Phosphate of magnesia, and phosphate of magnesia and ammonia, are con- 

 siderably more soluble than phosphate of lime, as will be seen by the follow- 

 ing determinations : — 



Amount dissolved by 

 1 pint. by 1 gallon. 



Exp. grs. grs. 



Phosphateofraagnesia(3MgOi,P05), burnt 1 1st -87 6-96 



and finely ground J 2nd '89 7-12 



The same in moist condition j 1^*, ^'P 1*"2* 



l2ndl-80 14-48 



Phosphate of magnesia and ammonia(2MgO, \ 1st 1-62 12'96 



/2: 



PO5, NHp), in moist condition j 2nd 1-68 13-50 



In the next place, I give the amount of phosphate of lime dissolved by 

 distilled water from the following phosphatic materials :— 



In 1 pint. In 1 gallon. 



Exp. grs. grs. 



Peruvian guano i l^*- '^^ 2*46 



I2nd -33 2-64 



