BL O
BIS ( 77 )
It has been analyzed by M. John, and ap-pears to consist of
43.2 Bismuth 24.32 Lead12.1 Copper1.58 Nickel1.32 Tellurium11.58 Sulphur
94.1
Pr. Berzelius 1 states the composition of theoxyd of bismuth from the very accurate expe-riments of M. Largerhjelm, to be
Oxygen . 9.197 — 10.13
100.000 110.13
Sub-sulphal of Bismuth . Some of this saltwas prepared by decomposing the neutral sul-phat by water. The sub-sulphat, thus preci-pitated, being washed and dried on very hotsand, 100 parts of the dried salt were stronglyignited in a platina crucible till no further lossof weight was perceived. The loss was 14.5and consisted of sulphureous acid and oxygen,leaving 85.5 of oxyd of bismuth. The 14.5sulphuric acid thus decomposed, and the 85.5of oxyd each contain 8.66 parts of oxygen.
The Neutral Sulphat of Bismuth is com-posed of so much acid as contains three timesas much oxygen as that of the base with whichit is saturated. This would give the elementsof this salt to be 14.5 sulphuric acid and —f 5 - —28.5 oxyd, or
Sulphuric Acid . . S3.7
Oxyd of Bismuth . 66.3
100.0
Nitrat of Bismuth. 10 parts of this salt,crystallized, reduced to powder, and dried inthe air, were distilled in a small retort. Thenitrous acid that passed over was colourlessand not fuming, which shews the presence ofmuch water of crystallization. In the retortwere left 4.88 parts of oxyd, so that the crys-tallized nitrat well dried contains
Nitric acid and water . . 51.2
Oxyd of bismuth • . • 48.8
100.0
consists, according to Vauquelin , of 68.25 ofbismuth, and 31.75 sulphur, as mentioned in thearticle Sulphuret in this appendix.
BITFERSPATH, or Magnesian carbo-nate of Lime.
The primitive crystalline form of this sub-stance is considered by M. Hauy as preciselythe same with that of calcareous spar; hencehe considers the magnesia contained in it aspurely accidental, and on this account denomi-nates it Chaux carbonated magnesifere. Dr.Wollaston however has shown that the obtuseangle in the primitive rhomboid of calcareousspar measures 105°.5', while the same in theprimitive rhomboid of bitterspath is at least106°. 15'. The two substances may thereforebe regarded as specifically distinct.
BLOOD.
Several very important additions have beenmade to the chemical knowledge of this mostinteresting of all the animal fluids. We shallgive a short abstract of them.
It was stated as a discovery of Fourcroy andVauquelin , and confirmed by Parmentier andDeyeux, that the serum contains Gelatine , andthe particulars were mentioned under the articleBlood , (Ch. Diet. vol. 1.) It has sincebeen very amply proved however that this is amistake, and that the substance contained inserum, uncoagulated by heat, is not gelatine,though on evaporation to dryness it leaves astiff transparent mass. Dr. Bostock, who firstdetected the mistake of these eminent chemistson this subject, has the following remarks. h
He defines Gelatine or Jelhj to be ananimal substance which is liquefied by heat,becomes concrete by cold, and with tan formsa compound insoluble in water. Alter theserum has been partially coagulated by heat,the liquid that remains, (or the Serositjj,)yields a sensible precipitate when heated withcorrosive sublimate, shewing the presence ofsome albumen which has escaped the firstcoagulation by heat, after which the liquidmay be evaporated nearly to dryness withoutshewing any degree of gelatinizatior. on cooling,and without being at all altered by infusionof tan ■, both of which circumstances prove theabsence of gelatine. This was further shewnby the addition of a small portion of gelatineto the serosity, which now gave all the cha-racters belonging to this animal principle. Dr.B. however does not consider the whole of theanimal matter in the serosity to be albumenthat has escaped coagulation, but supposes a,
t> Medico-Chirurgical Transact, vol. i. aadii,