CHAPTER VII. 



BASES OF UNKNOWN CONSTITUTION. 



THE constitution of nearly all the bases dealt with in the preceding 

 chapters is known with certainty. In addition a large number of bases 

 of unknown constitution have been described at various times. In 

 many cases even their composition has not been fully established. 

 Nevertheless some of the latter class will be included here on account 

 of their great physiological interest. It is of course impossible to say 

 whether they have a " simple constitution," but in any case the methods 

 by which their isolation may be attempted are similar to those used 

 for the other bases of this monograph. 



Spermine. 



The phosphate of this base crystallises out when semen dries, and 

 constitutes over 5 per cent, of the solids. It has been most fully in- 

 vestigated by Schreiner [1878] who prepared it in a pure condition 

 by boiling fresh human semen with alcohol, filtering off and drying 

 the precipitate so formed, extracting the latter with very dilute warm 

 aqueous ammonia and then concentrating. The phosphate is hardly 

 soluble in cold, and only a little in hot water, but soluble in dilute acids 

 and alkalies. The salt contains two atoms of nitrogen to one of phos- 

 phorus, and at 100 3H 2 O are given off; it melts at 170. 



Schreiner found that the crystals on the surface of old anatomical 

 preparations (Bottcher's crystals) are identical with spermine phosphate ; 

 he obtained them by scraping them off the surface of calves' livers and 

 hearts and bulls' testes, kept in alcohol for three months. 



It has further been suggested that the crystals discovered by Charcot 

 in the spleen, liver, and blood in cases of leucocythaemia, and also found 

 in the sputum in cases of bronchial asthma, are identical with spermine 

 phosphate, but this does not appear to be the case. 



Schreiner assigned to spermine the formula C 2 H 5 N ; Ladenburg 

 and Abel [1888] considered it to be most probably identical with 

 piperazine C 4 H 10 N 2 , which has the constitution : 



x 

 NH( 



\CH 2 .CH/ 

 106 



