B L O 



B L O 



trie is large, of handfome growth, with abruptly pinnate, 

 ample, fmooth, entire leaves, and copious, fmall, white 

 Jloiuers, in compound, axillary panicles. Somtfoiuers have 

 iinperfeft Jlamens, others an abortive germen. Nedary a 

 glandular notched ring, furrounding the bafe of the germen 

 or its rudiment. C(7/>/i//f elliptic -oblong, three-lobed, flefhy, 

 varieg.3ted with red and yellow, about the fize of a goofe 

 egg. Seeds globular, as big as cherries, dark brown, po- 

 liced, each h.-df funk in a white, turbinate, lobed and corru- 

 gated tunic, of the fubftance of firm fuet, larger than the 

 feed, and attached laterally to the central partition of each 

 valve. 



BLIGHT,!. 25, add— See Aphis. 

 BLISTERS, Fluid of, in Chemijlry. See Fluids, 

 Animal. 



BLOCKLEY. Add — It contains i6i8 inhabitants. 

 BLOOD, Chemical Properties of. The chemical pro- 

 perties of the blood have been lately inveiligated with con- 

 iiderable fuccefs by Drs. Marcet and Bollock, Brande, Ber- 

 zelius, and others ; with a fummarj' view of whofe experi- 

 ments we (hall here prefent our readers. 



Of the fenim. — The fpecific gravity of the ferum of blood 

 has been ilated to lie between 1028 and 1029.5. The 

 opinion of De Haen that it contains gelatine, was firft {hewn 

 to be erroneous by Dr. Boftock in this country, and about 

 the fame time by Berzelius in Sweden. The principle for- 

 merly termed gelatine has been varioufly reprefented and 

 named by different chemifts. Thus Dr. Boftock en- 

 deavoured to prove that it was a fpecies of mucus, Mr. 

 Brande that it was merely an alkaline folution of albumen ; 

 Dr. Marcet terms it muco-extraSive matter. Dr. Pearfon an 

 animal oxyd, the French chemifts ozmazome, &c. ; but it is to 

 Berzelius that we owe the knowledge of its real nature. 

 We infert, nearly in his own words, the following account of 

 his aiialyfis of the ferum of the blood, as an excellent model 

 for the analyfis of all albuminous fluids. 



One thoufand parts of ferum were evaporated to drynefs 

 till it could be eafily reduced to powder. In this ftate the 

 refiduum weighed 95 parts, and confifted of a yellowilh femi- 

 tranfparent mafs, refembling amber. "Of this mafs," fays 

 he, " I digerted lo grammes in cold water. The albu- 

 minous portion became foftened and gelatinous. I feparated 

 by the filter the liquid from the infoluble part, and waftied 

 the latter repeatedly in boiling water. The undiffblved 

 albumen dried on the filter weighed 6.47 grammes, and did 

 not give up its earthy phofphate by fubfequent digeftion in 

 muriatic acid. 



" The folution which paffed the filter wss evaporated to 

 drynefs, during which thick membranes formed at the fur- 

 face of the folution, and the folution gelatinized before it 

 was perfeftly dry. I digefted this refidue in alcohol 

 whilft it was ftill gelatinous ; the fpirit affumed a yellow 

 colour, and on evaporation left an alkaline deliquefcent mafs, 

 weighing .92 grammes. This confifted of foda holding 

 albumen in folution, of muriate of foda and muriate of pot- 

 afli, of laftate of foda, and of an animal matter which always 

 accompanies the laftate. This animal matter has a brown- 

 i(h-yellow colour, is eafily foluble both in water and alcohol, 

 and is precipitated by tannin and fubmuriate of lead. ■ It is 

 conftantly formed, as has been ftated, in conjunction with the 

 laftic acid only ; and its prefence may be taken as a fure indi- 

 cation of the prefence of that acid. 



" The portion not diflblved by alcohol, when digefted with 

 water, left a frefti refidue of albumen, weighing i .95 grammes. 

 The watery folution could not be made to gelatinize, and 

 did not contain the fmalleil quantity of gelatine. Befides 



7t 



the alkali, it contained an animal matter, eafily precipitated 

 by tannin and by oxymuriate of mercury, and which appeared 

 to me to be extracted from the albumen by the boiling of 

 the water, and to be analogous to the fubftance obtained by 

 boiling fibrin in water." See Fibrix. 



Berzelius found only a flight trace of the phofphoric 

 acid, and none of the fulphuric in the ferum of ox blood ; 

 rooo parts of which, according to him, confift of 



Water - 

 Albumen 

 Subftances folubl 

 •viz. laftate of 



e in alcohol,) \ 



foda, and ex-, -6. 175' 



traftive matter - . y f 



Muriate of foda and potafli - 2.565 y 



Soda and animal matter only foluble in | 



water ----- j 



Lofs .-.•-. 



905 

 79-99 



"•74 



1.52 



4-75 



One thoufand parts of the ferum of human blood con- 

 fift of, 



According to Berzelius, 



Water 



Albumen . - - . . 



Subftances foluble in alcohol, "uiz. muriate 1 

 of potalh and foda - - 6 > 



Laftate of foda and animal matter 4 j 



Subftances foluble in water, I'iz. foda, 1 

 phofphate of foda, and a little animal V 

 matter ..... ^ 



Lofs ...... 



905.0 

 80.C 



Berzelius remarks on Dr. Marcet's analyfis, " A more per- 

 feft agreement cannot be expefted in the analyfis of fub- 

 ftances fo liable to incidental differences, particularly in the 

 quantity of water, which in the blood depends fo much on 

 the proportion hi liquid taken into the ftomach. It is clear 

 that Dr. Marcet's extradive matter is impure laftate of foda ; 

 and I muft alfo obferve, that the fulphate of potalh and 

 earthy phofphates found by him in the afhes of ferum are pro- 

 bably, for. the reafons above-mentioned, formed by the pro- 

 cefs of combuftion." See Albumex. 



Of the colouring matter or red particles of the blood. — ,■ 

 An opinion long prevailed among chemifts, that blood owed 

 its red colour to iron. Badia appears to have been the firft 

 who pointed out the exiftence of this metal in blood ; but 

 its prefence was more fatisfaftorily demonftrated by Meng- 

 hini, whofe experiments were repeated and verified by fub- 

 fequent 



