PROTEIDS. 



EGG-ALBUMIN. 



SERUM-ALBUMIN. 



(a.) Readily precipitated by (a.) It is also precipitated by 

 hydrochloric acid, but the pre- hydrochloric acid, but not so 

 cipitate is not readily soluble readily, while the precipitate 



is soluble in excess. 



(6.) It is not coagulated by 

 ether. 



(c.) The corresponding preci- 

 pitate is much more soluble in 

 excess of acid. 



(d.) The corresponding preci- 

 pitate is soluble in strong nitric 

 acid. 



in excess. 



(6.) A non-alkaline solution 

 is coagulated by ether. 



(c.) The precipitate with 

 nitric acid is soluble with diffi- 

 culty in excess of the acid. 



(d.) The precipitate obtained 

 by boiling is but slightly solu- 

 ble in boiling nitric acid. 



[(e.) When injected under the [(e.) When injected under the 



skin, or introduced in large 

 quantities into the stomach or 

 rectum, it is given off by the 

 urine.] 



skin, it does not appear in the 

 urine.] 



6. II. Globulins are insoluble in pure water, but are soluble 

 in weak solutions of neutral salts e.g., sodic chloride but 

 insoluble in saturated ones. The solutions in these salts are 

 coagulated by heat. They are soluble in dilute acids and 

 alkalies, yielding acid- and alkali-albumins respectively. Most 

 of them are precipitated from their saline solution by crystals 

 of sodic chloride. 



(1.) Myosin, see " Muscle." 

 (2.) Serum-Globulin. 



(a.) Neutralise 5 cc. of blood-serum with a few drops 

 of dilute sulphuric acid (0*1 per cent.), and then add 75 cc. 

 of distilled water, and allow the precipitate to settle. Pour 

 off the fluid and divide the precipitate into two portions, 

 noting that it is insoluble in water, but soluble in excess of 

 acid. 



(6.) Boil a portion of the neutralised fluid = coagulation. 



