CHEMICAL BASIS OF THE ANIMAL BODY. 139 



semen has been treated with boiling alcohol. The crystals sepa- 

 rate out from this solution on concentration, and may be purified 

 by reerystallisation. 



FIG. 6. CHARCOT'S CRYSTALS. (Krukenberg.) 



The crystals are insoluble in alcohol, ether, and chloroform, 

 slightly soluble in cold and readily so in hot water. Dilute acids 

 iiiid alkalis also dissolve them readily. 



It has been stated that the crystals are in reality a compound 

 of phosphoric acid with a nitrogenous base to which the name 

 spermin 1 has been given, and the formula C 2 H 6 N(?) has been 

 assigned. This base is obtained by the addition to the crystals 

 of baryta water which forms a phosphate of barium and liberates 

 tin- base. It is soluble in water and alcohol, yielding strongly 

 alkaline solutions; it may be reconverted into Charcot's crystals 

 l>y the action of phosphoric acid. 1 This base was at one time, 

 'led as closely related to, if not identical with ethylinimine 

 < II;. NH. 2 It has however been recently shown that the two 

 substances are not identical, and it has further been stated that 

 the composition of spermin is most probably represented by the 

 formula C H 26 N4. 8 



AMIDES AND AMIDO-ACIDS. THEIR DERIVATIVES 

 AND ALLIES. 



\\IIDO-ACIDS OF THE ACETIC SERIES. 



1. Amido formic acid. NH t .COOH. 



This substance is identical with carbamic acid, one of the amiil<>- 

 il'-rivatives of carbonic acid, the first acid of the oxalic acid series. 

 It will be described under the oxalic group. 



1 Sdirr-inor, Inc. cit. 



Abel, Ber. d. d. chem. Getell. Jalirt; \\i (1888), S. 758. Ktliy- 

 liiiiniiiic appears (see next ref.) to be nothing but pipcrazinc, Hof man's dicth\ Irnc- 

 dianiiinv 



Majort a. Schmidt, Ibid. Jahrg. xxir. (1891), 8. 241. 1'ochl. 

 S. 359. 



