486 



SCIENCE 



[N. S. Vol. XLV. No. 1168 



increase tlie amplitude of swelling in distilled 

 water, although the last matter is not entirely 

 clear. The albumen reduced the swelling of a 

 mixture containing twenty-five per cent, of 

 gelatine slightly in acid and in alkali, but 

 the swelling in water was not markedly greater. 

 This preliminary test yielded results which 

 made their extension highly desirable. Chem- 

 ical analyses of the egg-albumen were not 

 available, and as nothing was known as to the 

 salts or other substances which might be in- 

 cluded, it was desirable to secure material of 

 known origin and composition. Arrangements 

 were made with Dr. Isaac F. Harris, of Squibb 

 and Sons Laboratory, 'New Brunswick, ISTew 

 Jersey, to prepare some albumen from beans 

 (Phaseolus) and from oats (Avena) to be used 

 in the mixtures. The preparations from 

 Phaseolus were available in February, 1917, 

 and the first tests were made with the 

 "protein" extract. 



Agar and gelatine were dissolved in the 

 usual way and the temperature of the solu- 

 tion allowed to fall to a point below 40° C. 

 before the protein was stirred into it. In the 

 course of the cooling and drying cloudy masses 

 became visible which were taken to be the 

 globulin component of the protein. The dried 

 sheets came down to a thickness of .3 to .4 

 mm. Calibrated samples were tested in trios 

 under the auxograph in the usual manner. 

 Two complete series of all mixtures were made 

 and an additional measurement of the action 

 of water and alkali were obtained. The swell- 

 ings were as follows: 



Agar 90 — Protein 10 (Phaseolus) 



800.0 50.0 150.0 



800.0 75.0 150.0 



Averages: 800.0 62^ 150T0" 



Agar 99 — Protein 1 (Phaseolus) 



1,080\0 300.0 220.0 



800.0 360.0 240.0 



Averages: 940T;o 330.0 23Cro 



The protein extract from the bean was thus 

 shown to exert an infiuence on the swelling of 

 agar similar to that of egg-albumen in reduc- 

 ing the amount of swelling in acid and alkali, 

 and increasing it in distilled water. 



The next step of importance was to ascer- 

 tain the effect of some of the simpler amino- 

 acids which might be derived from the albu- 

 mens in the plant. Tyrosin and cystin were 

 available. As an example of the method the 

 first preparation of tyrosin was one in which 

 one part of this substance in solution was 

 stirred into a liquefied mass of ten parts of agar 

 at a temperature of 32° C. This was poured 

 on a glass slab, and as desiccation was carried 

 out the tyrosin began to collect as a flour-like 

 efflorescence on the surface, and apparently a 

 large part of the substance came out in this 

 way, so that the actual proportion of the 

 amino-acid in the dried plate was probably not 

 more than a fourth of the amount originally 

 used. 



The dried plate of material came down to a 

 thickness of .15 mm. and gave the following 

 results : 



SWELLING 

 Water HCl A'/lOO NaOH Ar/100 



Agar 90 — Tyrosin 10 (less ty efflorescence) 

 1,600.0% 133.3% 133.3% 



1,200.0 233.3 100.0 



Averages: 1,400.0 183.3 lf6^ 



A similar preparation of agar and cystin 

 gave the following as an average of three tests : 



Water HCl Ar/100 NaOH 2V/100 



Agar 90 — Cystin 10 

 2,333.3% 583.1% 328.6% 



A similar mixture of agar and urea (agar 

 90 parts, urea 10 parts) gave the following: 



2,173.0% 



HCl A7100 



SWELLING 



716.6% 



NaOH AT/lOO 



560.2% 



Urea, the amino-acids, gelatine, albumen, 

 and the saline soluble proteins of the bean 

 dissolved with agar and dried into thin plates 

 show a greatly enhanced imbibition in water, 

 an imbibition in hundredth-normal hydro- 

 chloric acid not more than a third of that in 



