430 ALBUMINOUS COMPOUNDS. 



put a little of the mixture into four test-tubes. The Alkali 

 Albuminate is not formed immediately. To the solution in 

 the first tube add a drop of watery solution of litmus (see 

 App. 217). Then add very dilute acid till the blue color of 

 the litmus begins to change to red. No precipitate, or only a. 

 very slight one, will take" place. Boil the neutral liquid; a 

 precipitate is produced showing that much unchanged albumin 

 is still present. ~ If a precipitate falls, the presence of much 

 unchanged albumin may still be demonstrated by filtering and 

 boiling the filtrate, or adding tannin to it, when a precipitate 

 will be produced. It /s '/ u />//// fnrnn-d irJn n heat /s u]>i>lie(L 

 Ji i* noi r(i<}i//ttf<'<! />// Ixnliu'j. Gently warm the fluid in the 

 second test-tube till it boils; no precipitate forms. Let it 

 cool, add a drop of litmus to it, and neutralize. Just when 

 the blue begins to change to red the fluid will become turbid 

 from the precipitation of the alkali albuminate. Let the pre- 

 cipitate >ettle, and filter the fluid. P>oil the filtrate; no pre- 

 cipitate is formed, showing that the whole of the albumin has 

 become insoluble in water, and has been precipitated by ncu- 

 tralixalion. // i* anlubli- hi dilute r//-/Ws. Warm and neutral- 

 ize the solution in the third tube as in last experiment, then 

 add an excess of hydrochloric acid to the neutralized solution, 

 and the liquid will again become clear. On neutralizing the 

 solution a second time the preeipitat" iv-appcars. It is formed 

 at nrdiniiry (finjH-rnlurrn, fmf more tlnirly. Let the solution 

 in the fourth tube stand for some time, and then neutralize it. 

 The precipitate will be greater than in that which was neutral- 

 ized immediately after adding the potash. Filter and test the 

 amount of albumin in the filtrate by adding tannin. It will 

 vary, being greater or less, according to the shorter or longer 

 time the solution has been allowed to stand. 



* 14. Preparation of Solid Alkali Albuminate. a. 

 From CLigs. Put the white of one or two eggs in a beaker, cut 

 it up with scissors and shake it vigorously with air in a llask 

 until the membranes separate and come to the top with the 

 foam. Kilter it through a piece of linen. Add strong solu- 

 tion of can>tic potash to it drop by drop, until the whole mass 

 becomes transformed into a stiff jelly. Cut it into pieces 

 about the size of a horse-bean and throw them into a large 

 quantity of distilled water. Stir them round and round a few 

 times and then pour oil' the water, keeping back the pieces by 

 a piece of gauze stretched across the month of the beaker. 

 "Wash the albuminate with fresh water several times in order 

 to remove the free alkali until the pieces begin to turn white 

 at the edges and exhibit only a faint though distinct alkaline 

 reaction. As the albuminate is soluble in water containing 

 alkali, a good deal of it is lost in the process. When deprived 



