50 CHEMICAL STATICS 



fluid is then syphoned off and the precipitate is washed in the 

 same volume of alcohol as that employed in the precipitation. 

 This washing is repeated, again employing the same volume of 

 alcohol, and the precipitate is allowed to steep in this alcohol for 

 about 24 hours, in order to remove all adherent or combined 

 acetic acid. The alcohol is then syphoned off and the precipitate 

 is washed in the same volume of ether (distilled over sodium). 

 This washing is repeated. The ether is then syphoned off and 

 the thick suspension of protein in ether thus obtained is rapidly 

 poured into a hardened filter, the filter and the contained sus- 

 pension of protein in ether being at once transferred to an incu- 

 bator and the filtration continued over sulphuric acid at 40 degrees 

 (to avoid condensation of atmospheric moisture on the filter). 



After the completion of filtration, the ether which has filtered 

 off is removed from the incubator, and the precipitate is allowed 

 to dry for 24 hours. The protein is then obtained in the form 

 of chalky cakes which are very readily broken up into impal- 

 pable powder. This powder is passed through a fine sieve and 

 conserved in a glass stoppered bottle. 



It is found inadvisable to work with fewer than six dozen eggs 

 at one time as, otherwise, the amount of precipitate which is 

 finally obtained is so small that the danger of excessive caking 

 and partial decomposition, in drying, due to the deposition of 

 traces of moisture upon the filter, is very great. 



Twenty-four dozen eggs of average size yield about 40 grams of 

 ovomucoid. 



About a gram of ovomucoid, prepared in this manner, was 

 dissolved in about 100 cc. of iV/2 hydrochloric acid, and this 

 solution was boiled until 30 cc. of fluid had distilled over. This 

 distillate was then tested for acetic acid. It contained a trace 

 of an acid of the fatty series, sufficient to yield a slight coloration 

 with ferric chloride, but insuSicient to yield a precipitate of ferric 

 hydrate on boiling, or to yield the ethyl acetate test.* 



Ovomucoid is a gluco-protein, and yields, on boiling with 

 strong acid, about 30 per cent of glucosamin (47) (40) (18) (42) 

 which, according to Steudel (42), is contained in the molecule not 

 in the form of glucosamin but in the form of an antecedent which 

 yields glucosamin on treatment with strong acids. 



* The solutions of ovomucoid prepared in this manner have themselves a 

 distinct odor of ethyl acetate. 



