424 THE GLANDULAR ORGANS. 



etc. /. <?., in true nesting birds the albumen remains transparent, 

 owing to the formation of alkaline albuminates. Such albumen has 

 been termed fato-albumen. It may be produced artificially by placing 

 hens' eggs in a 10 per cent, solution of sodium hydrate fur two ur 

 three days, when a gradual diffusion of alkali occurs into the albu- 

 men. On subsequent boiling, this appears like true tata-albumen. 



Analysis of the albumen of hens 7 eggs has given the following 

 results : 



Ferci'iit. 



Water 80.00-86.68 



Solids 13.32-20.00 



Albumins 11.50-12.27 



Extractives 0.38- 0.77 



Glucose 0.10- 0.50 



Fats and soaps traces 



Mineral salts 0.30- 0.66 



Lecithins and cholesterin traces 



According to Poleck and Weber, the mineral ash has the follow- 

 ing composition, calculated for 100 parts: 



Sodium (Xa 2 O) 23.56-32.93 



Potassium (K 2 O) 27.66-28.45 



Calcium (CaO) 1.74- 2.90 



Magnesium (MgO) 1.60- 3.17 



Iron (Fe-A) 0.44- 0.55 



Chlorine (Cl) 23.84-28.56 



Phosphoric acid (P 2 O 5 ) 3.16-4.83 



Carbonic acid (CO 2 ) 9.67-11.60 



Sulphuric acid (SO 3 ) 1.32- 2.63 



Silicic acid (SiO 2 ) 28- 0.49 



Fluorine (Fl) traces 



Of these constituents, the large amount of sodium chloride is espe- 

 cially noteworthy, and shows in itself that the albumen is in reality 

 a secretory product, and does not represent a mere transudation from 

 the blood-plasma. 



One portion of the bases is in combination with the albumins of 

 the albumen, while the remainder exists in the form of sulphates, 

 phosphates, and notably carbonates. 



The slightly yellow color of albumen is referable to the presence 

 of a lipochrome, which can be demonstrated on spectroscopic exam- 

 ination. 



The Albumins. The albumins of albumen are largely represented 

 by the so-called ovalbumins ; in addition, globulins are found, as 

 also a mucoid, which is known as ovomueoid. 



Ovalbumins. According to Gautier and others, the albumen con- 

 tains three ovalbumins, which are termed -, /?-, and ^-ovalbumin, 

 respectively. They are all closely related to the common serum- 

 albumin of the blood-plasma, but differ from this in several impor- 

 tant particulars. When introduced into the circulation as such, 

 they are eliminated in the urine as foreign matter. They are pre- 

 cipitated if a sufficient amount of hydrochloric acid is added, but 

 are soluble in an excess with much greater difficulty than serum- 



