xiv CHEMISTRY OF THE PROTEIDS 



Observations of Bechamp, Subbotin, Pott, Chandelon, Briicke, 237 ; 

 Maly, 238 ; Siegfried, Bondzynski and Zoja, Bernert, Ehrmann, 

 v. Fiirth, 239 ; peroxy-proteic acid, 240 ; desamino and kyro-proteic 

 acids, 242. 



Ehrmann's peroxy-proteic acids, 243 ; Low's oxamide and Seemann's oxalur- 

 amide or oxalan, 244 ; Hofmeister's synthesis of urea, 244. Seemann's 

 views on the constitution of albumin-molecule and especially on the 

 union of arginin, 245-247. Volatile products of oxidation, 247. 

 Cohnheim's summary of action of alkalies on albumins, 248. Oxy- 

 protein, 249. Formaldehyde-compounds, 250. Iron-compounds, 251. 



CHAPTER VIII 



PHYSICAL PROPERTIES OF ALBUMINS 



General account, Cohnheim's views, 252-253 ; the author's views, 254-272. 

 Definition of the terms : solution, 254 ; electrolyte, hydrolyte, 256 ; 

 colloid : Graham's definition, 256 ; characteristics of colloids, 257 ; 

 polarisation-phenomena (Tyndall's test), 258 ; other phenomena in 

 support of view that colloids are electrolytes, 259 ; colloidal gold a 

 hydrate, 260 ; colloid arsenic sulphide, 260-264 ; change accompanying 

 conversion of an electrolyte into a colloid, 264 ; definition of a neutral 

 salt, 265. Acclimatisation of colloids, 266 ; so - called spontaneous 

 change, 267. Further evidence that colloids are electrolytes, 268-271. 

 Changes induced in colloids by physical and chemical means, 271-324 : 

 Setting of colloidal solutions, 273 ; conglutination by mechanical 

 means, 274 ; coagulation by altering the electrical tension between 

 colloid and solvent, 276 ; s.alting-out, 280-294 ; precipitation of colloid 

 by withdrawing hydrogen or hydroxyl-radicals, 294 ; precipitation due 

 to removal of salts, 296 ; formation of irreversible salts, 298 : alkaline 

 earths, 299, and heavy metals, 303 ; copper albuminates, 304 ; Gibb's 

 law governing di- and pluriphasic systems, 306 ; Pauli's views, 307 ; 

 author's experiments on sublimate and salt mixtures to determine laws 

 of electro-affinity, 308-315, general conclusion, 313 ; action of double 

 salt of HgCLj + NaCl, 314 ; of HgCl 2 + 2NaCl, 315; coagulation by heat, 

 316-321 ; coagulation-temperature, 321 ; formation of additive com- 

 pounds, 322 ; ' spontaneous ' coagulation, 323. 



Some properties of colloidal albumins, 324-335 ; formation of crystals, 324 ; 

 composition, 327 ; molecular weight, 328 ; heat of combustion, 329 ; 

 rotatory power, 329 ; osmotic pressure, 330 ; precipitine reactions, 331 ; 

 gold number, 333 ; power of forming emulsions, 334 ; power of clarify- 

 ing solutions, 335. 



Dissociation of albumin by acids and alkalies : acid-albumins, 336, and 

 alkali-albuminates, 337 ; jelly formation, 338. 



Other method's of denaturalisation, 340-344 : dry heat, 340 ; alcohol, 341 ; 

 acetone, alkaloidal reagents, dyes, salts of heavy metals, silver oxide, 

 342 ; osmium tetroxide, surface-action, 343. 



Properties of denaturalised albumin, 344. 



