2S8 ON EXPECTORATED MATTER. 



Opaque ropy (g). The filtered residuary liquid (/) uith muriate of 

 baryt gave immediately a copious precipitation — with lime 

 water there was milkiness produced, and subsequently a 

 white precipitation which did not disappear on adding a 

 small proportion of acetous acid — prussiate of potash occa- 

 sioned a greenish blue colour without precipitation — succi- 

 Tiate of ammonia produced a milky liquid — no effect was 

 observed from tartaric acid — There being a precipitation 

 with caustic or puie ammonia, as well as with potash, and 

 with the carbonates of the alkalis, it was supposed magnesia 

 was present: and the dissolution of this precipitate in mu- 

 riatic acid, and in acetous acid, gave no precipitate with 

 oxalic arid. Some of the muriatic dissolution, previously 



' to precipitation with oxalate of ammonia [/), being evapo- 



lated to dryness, the residue wus ignited; but if magnesia 

 was present, as well as lime, it was in too small quantity to 

 be distinguishable from the lime, by composing sulphate. 

 The precipitate now under examination was certainly not 

 mere magnesia, for it melted into an opaque globule under 

 the blowpipe ; it was not phosphate of lime, for with sul- 

 phuric acid a somewhat bitter and sour substance was com- 

 pounded, which afforded a precipitate with ammonia, but 

 none with oxalate of ammonia. It was a phosphate not 

 only on account of its fusibility, but because a curdy ap- 

 pearance was occasioned by the mixture just mentioned 

 with sulphuric acid, on adding it to lime water. Neither 

 •Was it soluble, like phosphate of lime, in phosphoric acid. 

 The quantity of this precipitate was too minute for decisive 

 experiments, but from those related, it seems probable that 

 it was phosphate of magnesia, which was dissolved, as will 

 appear presently, in phosphoric acid, and precipitated by 

 ammonia. 



{h). The residuary liquid [g], after the precipitation by 

 oxalate of ammonia, being evaporated to dryness, was easily 

 ascertained to be phosphate of ammonia, with indications of 

 a minute proportion of sulphate. 



(i). It remains only to notice the indissoluble matter in 

 muriatic acid ( f]% 1 found it to grow soft, and the parts to 

 cohere under the blowpipe, and with a little potash it rea- 

 4)ly melted into an opaque globule. 



8. Tq 



