I'.ti:"] AORIcrLTUIJAL (Ml KM ISTRY AGROTECHNY. 205 



of viiriuus YoIiiiiU'tric nictlKids for tlio (IcdTiiiination of siiiiill amounts of 

 mlciimi, niaj,'ii('siuni, and pln>si)h(»riis in of;iani(! solutions such jis Idnod. 



>l<>tliods of cheniical blood analysis, RI. Uichter-Quittnke {Jiioclicm. 

 yjschr., H5 ilUlO), No. .i-.',, pp. J7'J-20.', ; 06 (1019), No. 1-3, pp. .92-705).— Two 

 pajiers are presented. 



I. Criticisin of methods for rcnioviuf/ proteins (Vol. 9.5, pp. 179-204). — The 

 removal of the blood proti-ins is considered )).v the author to be the most im- 

 portant step in l)liH)d analysis. Various methods of accomplishiuR this are dls- 

 ciissi'd from the liteiature afld from experimental data, as the result of which 

 llie following recommendations are made: 



The removal of proteins by salts of the heavy metals or by colloidal reagents 

 is suitable for .sujiar determinations, and by heat coagulation for all constituents 

 except chlorids and sugar. Dilute acids are recommended as follows: Phos- 

 photungstic acid for uric acid ; phosphomolybdic acid for residual nitrogen, 

 sugar, and uric acid; nietaphosphoric acid for chlorids; and trichloracetic acid 

 for residual nitrogen. Methyl alcohol can be used for chlorid determination 

 and dialysis for residual nitrogen. 



II. A coinpnrison of macro- aud micro-methods (Vol. 9G, pp. 92-105). — This 

 jiaper includes a summary of the requirements of a correct microanalysis of 

 blood, a criticism of the original micro method of Bang, a critical examination 

 of dilTerent micro methods for the determination of blood sugar, chlorids, and 

 residual nitrogen, and descriptions of modified methods for these determinations. 



The author is of the opinion that as blood is a colloidal solution one drop 

 is not necessarily identical with a .second drop, and consequently the use of 

 fr(Mn 1 to 3 drops as reconnnended by Bang is open to criticism as not fur- 

 nishing a representative sample. From 2 to 3 cc. is i-ecommended as the niini- 

 mum aujount which should be used. 



Extensive references to the literature are appended to both papers. 



Deteriniiiation of the fibrin, globulin, and albumin nitrogen of blood 

 plasma, G. E. Cullen and D. D. Van Slyke (Jour. Biol. Chem., Jfl {1920), No. 

 ^, pp. 587-597). — A method of determining plasma proteins is described which 

 is based upon Kjeldahl determinations of the total nitrogen, fibrin nitrogen, 

 filtrate nitrogen (consisting of albumin and nonprotein nitrogen), and the non- 

 protein nitrogen. 



The total nitrogen determinations are made on 2 cc. of plasma, containing 0..") per 

 'lit of potassium oxalate, by the regnlar Gunning-Kjeldalil method. The tibrin 

 is precipitated by calcium chlorid from 5 cc. of the plasma, and is then washed 

 free from other nitrogenous substances and determined by Kjeldahl. To 

 determine the filtrate nitrogen, the globulin and fibrin are precipitated from 5 

 cc. of the plasma with the usual half saturation with ammonium sulphate, the 

 anunonia of the ammonium suli»liate in the filtrate is removed by distillation 

 after adding magnesium oxid and alcohol, and the nitrogen is then determined. 

 The nonprotein nitnogen is determined in the filtrate obtained by precipitating 

 the i»rotein from 5 cc. of plasma in 9 volumes of 2.r> per cent trichloracetic acid. 

 The globulin nitrogen is then calculated by subtracting the sum of the filtrate 

 nitrogen and fibrin nitrogen from the total nitrogen, and the albumin nitrogen 

 hy subtracting nonprotein nitrogen from filtrate nitrogen. 



The technique for the various determinations is described in detail. 



Studies in the acetone concentration in blood, urine, and alveolar air, 

 I. — A niicroniethod for the estimation of acetone in l)lood, based on the 

 iodoform method, E. IM. P. Wu).makk {Bioeliem. Jour., 13 {1919), No. J/, pp. 

 430-y,5, li(/s. 2). — In the method d(>scribe(l, which does not require more than 

 100 mg. of blOod, the blood is drawn up from a prick in the finger or ear lobe 



I 



