220 AGRICULTURAL CHEMISTRY 



Experiment 61 . Separation of meat globulin ormyosin. Test 

 as follows four 300. portions of myosin solution, prepared by soaking 

 fresh meat in a 5 per cent, salt solution. To the first, add a few 

 drops of alum solution. To the second, add a few drops of lead 

 acetate. To the third, add salt until the solution is saturated. 

 To the fourth, apply heat. 



Questions. ( i ) What result was obtained with the alum solution 

 and what does this indicate ? (2) What did the lead acetate and 

 the salt solutions do? (3) What was used as the solvent for the 

 myosin? (4) What is myosin? (5) What are the properties of 

 myosin ? 



302. Albuminates. The albuminates are a group of 

 proteids widely distributed in both animals and plants. 

 They may be produced by the action of either dilute acids 

 or alkalies upon albumins or globulins. The albuminates 

 are insoluble in water, and when an acid albumin is 

 neutralized with an alkali, the albuminate is precipitated. 

 In like manner, an acid precipitates an alkali albumin. 

 Casein is an albuminate present in milk, and is in a semi- 

 soluble form combined with some of the mineral matter. 

 Casein is soluble in dilute alkalies, but is precipitated by 

 acids. In plants the albuminates are sometimes called 

 vegetable casein. From peas, a casein- like body can be 

 extracted. 



Experiment 62. Separation of meat albuminate or syntonin. To 

 3 cc. portions of prepared syntonin solution, add: To the first, Na 2 CO 3 

 until neutral, avoiding excess as it dissolves the precipitate ; to the 

 second, add NaOH a drop at a time until neutral ; to the third, add 

 a few drops of lead acetate. Syntonin solution is prepared by cutting 

 fresh meat into small pieces, and extracting it for four hours, in 

 water containing a few drops of HC1. 



Questions, (i) What result was obtained when each reagent 



