1892.] The Reserve Proteid of the Asparagus Root. 131 



with the alcohol. This precipitate when suspended in water, after 

 prolonged contact with alcohol, gave a good xanthoproteic reaction. 



When the watery extract was allowed to drop into a tall jar con- 

 taining distilled water, there was no precipitation or turbidity. 

 Similarly, when some of the extract was diluted with fifteen times its 

 volume of distilled water, and a stream of C0 2 was passed through 

 the liquid for 1 6 hours, no turbidity was apparent. 



When some of the extract was subjected to dialysis in a stream of 

 running water for four days, and the dialysis afterwards continued 

 for two days in large excess of distilled water, a finely granular pre- 

 cipitate was formed iii the dialyser, which when filtered off gave no 

 xanthoproteic reaction, whilst the filtrate still coagulated at 71 C. 



The proteid was therefore soluble in distilled water, being thrown 

 down neither by dilution nor dialysis. 



Portions of the extract were shaken up to saturation for some days 

 with crystals of the following neutral salts : NaGl, MgS0 4 , MgSOi 

 and Na 2 S0 4 , 



With NaCl there was a slight precipitation of the proteid, but the 



greater part of it remained in solution. 

 With MgS0 4 there was a more copious, but still incomplete, pre- 



cipitation of the proteid: on saturating the filtrate with Na^SOi 



*no further precipitate fell. 

 With (NH 4 ) 2 S0 4 , when the saturation was continued for a month, 



the whole of the"proteid was precipitated. 



6. Salt Solution Extract. This extract was prepared by using 10 

 per cent, solution of NaCl instead of distilled water, as in the former 

 experiments. The reactions were generally the same as those given 

 by the watery extract ; but the undetermined substance, which is pre- 

 cipitable by salt, was present in much smaller quantities, and the 

 precipitates of proteid were less bulky than those given by the 

 watery extract. 



Conclusions as to the Proteid. It appears from the foregoing ex- 

 periments that the root of the asparagus contains a single reserve 

 proteid. Inasmuch as it is readily soluble in distilled water, it is 

 essentially an albumin ; at the same time, its reactions with neutral 

 salts indicate a relationship to the globulins which is not manifested 

 by the animal albumins. However, proteids other than globulins are 

 precipitated on saturation of their solutions with neutral salts ; thus 

 Schafer* and Halliburtonf have both shown that serum-albumin is 

 completely thrown down on double saturation with magnesium and 

 sodium sulphates, and Kiihne and ChittendenJ have found that the 



* ' Journal of Physiology,' vol. 3, 1882, p. 184. 



f. Ibid., vol. 5, 1884, p 178. 



J " Ueber Albumosen," ' Zeitschrift fur Biologie,' xxii. 



K 2 



