SOLl'I'.ILITV (tl- I'lloSJ'HOKK OXIUK. J(V^ 



per criit. 

 Material ca|)al)lc of passiiii,^ thr<)nj;li a i mm. 



sieve 9.^-^^^> 



Pliosjilioric oxide : 



Total 13.80 



Citrate-soluble I.V47 



Water-soluble 4.11 



Lime i-49 



Potash i.6<) 



Nitrogen 10.94 



The methods adopted for analysint:; these mixtures were as 

 follows : 



20 u;rams of the fertiliser were extracted with distilled water 

 for half an hour in a shakinjj; machine, tilled up to 1,000 c.c., 

 well mixed and tiltered. In an ali(juot i)art of the filtrate the 

 water-soluble phosphoric oxide was precipitated direct by means 

 of ammonium citrate and ma.sjnesium mixture in the ordinary 

 way. 



By this method each of the five mixtures was anaKsed after 

 standing for three hours, for twenty- four hours, one week, two 

 weeks and three weeks, thorough mixture, as already stated, 

 being again made before each testing. The following percen- 

 tages of water-soluble phosphoric oxide were thus found in the 

 various mixtures : 



Original Comi)osition after slanditig idi- — 

 Com- ^5 24 1 2 .? 

 position, hours, hours, week, weeks, weeks. 

 Superphosphate alone I/.^.t — — — — — 

 ( a) Superphosphate and Sul- 

 phate of Ammonia .. 8.68 8.58 8.67 8.71 i^/y) ^.^} 

 ( b ) Superpliospliate and Sul- 

 phate of Potasli 8.08 iS.65 8.6.; "f^.G^ 8.74 8.64 



< c ) Superphospliate and Kai- 



nit 8.68 8.6j ^.76 8.62 8.76 8.69 



< d ) Superpliospliate and Gov- 



ernment Guano '0.7J 10. oc o..=;.j 0.22 Q.08 8.47 



(e) Superphosphate and Rone- 

 meal 8.68 8.40 8.52 ■/.i<2 7.41 — 



The first column of figures shows the calculated amounts 

 of water-soluble phosphoric oxide in the mixtures, the other 

 columns being obtained, as already stated. b\- direct analysis. 



For comparison I append a .series of results obtained by 

 Professor G. Gray, of the Canterbury .Agricultural College, Lin- 

 coln, New Zealand,* from mixtures made up on similar lines 

 to those above mentioned, and also cotisistitig (^f equal parts of 

 their respective constituents: 



* Transactions of the Australa.«:ian Assn. for the Adv. of Science. 

 Dunedin (1904). 



