294 PHYSIOLOGICAL CHEMISTRY. 



of the water-spider (maja squinado), one a red, mtellorubin, and the other a yel- 

 low pigment, mtettolutein. Both of these pigments are colored blue by nitric 

 acid containing nitrous acid, and beautifully green by concentrated sulphuric 

 acid. The absorption-bands, especially of the vitellolutein, correspond very 

 nearly with those of ovolutein. 



The mineral bodies of the yolk of the egg consist, according to 

 POLECK, of 51.2-65.7 parts soda, 89.3-80.5 potash, 122.1-132.8 

 lime, 20.7-21.1 magnesia, 14.5-11.90 iron oxide, 638.1-667.0 phos- 

 phoric acid, and 5.5-14.0 parts silicic acid in 1000 parts of the ash. 

 We find phosphoric acid and lime the most abundant, and then 

 potash, which is somewhat greater in quantity than the soda. These 

 results are not, however, quite correct, first, because no dissolved 

 phosphate occurs in the yolk (LIEBERMANN), and secondly, in 

 burning, phosphoric and sulphuric acids are produced and these 

 drive away the chlorine, which is not accounted for in the pre- 

 ceding analyses. 



The yolk of the hen's egg weighs about 12-18 grms. The 

 quantity of water and solids amounts, according to PARKES, to 

 471.9 p. m. and 528.1 p. m. respectively. Among the solids he 

 found 156.3 p. m. albumin, 3.53 p. m. soluble and 6.12 p. m. in- 

 soluble salts. The quantity of fat, according to PARKES, is 228.4 

 p. m,, the lecithin, calculated from the amount of phosphorus in 

 the organic substance in the alcohol-ether extract, was 107.2 p. m., 

 and the cholesterin 17.5 p. m. 



The white of the egg is a faint-yellowish albuminous fluid en- 

 closed in a framework of thin membranes ; and this fluid is in it- 

 self very liquid, but seems viscous because of the presence of these 

 fine membranes. That substance which forms the membranes, 

 and of which the chalaza consists, seems to be a body nearly 

 related to horn substances (LIEBERMANN"). 



The white of the egg has a specific gravity of 1.045 and always 

 nas an alkaline reaction. It contains 850-880 p. m. water, 100-130 

 p. m. albuminous bodies, and 7 p. m. salts. Among the extractive 

 bodies LEHMAN^ found a fermentable kind of sugar which 

 amounted to 5 p. m., or according to MEISSNER, 80 p. m. Besides 

 these, we find in the white of the egg traces of fats, soaps, lecithin, 

 and cholesterin. 



The white of the egg during incubation becomes transparent on boiling 

 and acts in many respects like alkali-albuminate. This albumin TARCHANOFF 

 called "tatalbumin." 



