APl'HNDI X. 



LABORATORY EXERCISES. 



Exercise I. Prepare a 1 per cent. (0.8 per cent.) Holution of 



scrum :i.ll)iiiniu, scrum globulin, :iu<l <;'' albumin in dilute saline 

 solution. Dcicrminc the coagulation-point of cadi, after acidifying 

 N/i<//i(/t/ with very dilute; acetic arid. To this cud, place the alhu 

 miuoiis solution in a test-tube, of which it should fill about one- 

 third lo one half; damp this, immersed in :i beaker with \v:i.lcr, :md 

 fasten a thermometer in the albuminous solution so that the. hull, 

 nearly readies the hol.lom. Heat with a small flame and note the 

 temperature :it which coagulation just lupins; continue to hc:i.|, ;md 

 finally l>nil the solution ; note ihe chan^in;.' :ippc;i.r:inr.r of llie pn-- 

 ripitale. ('ollect some; of this and atlcmpt to di.,-.olvc it in w.'iier 

 or dilute saline, solution ; then try concentrated acid ;md alkali with 



the application of heat. 



Study the. hchavior of an :dl>uminous solution on heating in the 

 presence of an excess of dilute acid and alkali and in the |.r< enrc 

 and absence of salt (page .'JO). 



Exercise II. 1. Prepare a dilute solution of serum :dlmmin; 

 render it, feebly acid with acetic acid; coagulate it by boiling; 

 render the solution strongly .'icid with hydrochloric, acid, heat, and 

 note that, the coagulated albumin dissolves; on cooling add an 

 alkali until then-action is only favnlJy acid, and heat, a^ain : coagu- 

 lation does not, occur. 



'2. Render a solution of serum-albumin strongly alkaline with 

 sodium hydrate and boil : coagulation does not occur; then add 

 aretic acid to a feebly acid reaction and heal ajjain : no coagulation 



occurs* 

 Exercise III. Prepare solutions of serum-albumin, serum- 



dobuHn, oawcVn, egg-albumin, and test the behavior- of the. \\\ 

 lions to sodium chloride, ma'ne mm sulphate, and ammonium 

 Btllphate by salting the solutions to saturation ; let the precipitates 

 -land over night and examine the filtrates the next day ; test with 

 the bin ret test, (page; .'>.">) to ascertain whether the precipitation is 

 complete. 



hetcrmirie the upper and lower limits of precipitation of the 

 different albumins in neutral solutions with a saturated neutral 

 aqueous solution of ammonium sulphate, as described (pa^<- l^A). 



Exercise IV. Prepare dilute arjucous solutions of scrum albumin, 



