66 THE SIMPLER NATURAL BASES 



acetaldehyde, (CH 3 ) 3 : N(OH) . CH 2 . CHO, which was first prepared 

 by Berlinerblau [1884] by the action of trimethylamine on mono- 

 chloracetal and subsequent hydrolysis, and later by Fischer [1893] 

 by the methylation of acetalamine. The platinichloride has the com- 

 position [(CH 3 ) 3 N . CH 2 . COH^PtCl,, . 2H 2 O ; the water of crystallisa- 

 tion is given off at 105. The constitution of this base is quite certain, 

 for Fischer [1894] oxidised it to betaine and accordingly suggested 

 for it the name betaine aldehyde. In an abstract of a dissertation 

 by Nothnagel [1893], E. Schmidt [1904, I, p. 47, under choline] 

 quotes a report by Hans Meyer, who found that the anhydro-muscarine 

 of Berlinerblau (= betaine aldehyde of Fischer) does not arrest the 

 action of the frog's heart in doses of 10 mg., nor does it produce vagus 

 inhibition in the mammalian heart in doses of several centigrams. It 

 causes salivation and sweating, however, and kills by respiratory par- 

 alysis. Betaine aldehyde differs also chemically from muscarine, but on 

 the other hand natural muscarine and Schmiedeberg and Harnack's 

 pseudo-muscarine are chemically very similar, according to Schmidt and 

 Nothnagel. The platinichlorides of both bases have the composition 



[(CH 3 ) 3 N . CH 2 . CH(OH) 2 ] 2 PtCl 6 . 2H 2 O 



and do not lose water at 100. The physiological differences observed 

 by Boehm were however also found by Hans Meyer ; pseudo-muscarine 

 in doses of O' 1-0*05 m g- paralyses the intra-muscular nerve-endings of 

 a frog ; natural muscarine does not. The cardiac effect of the natural 

 base, even in doses of 6 mg., is counteracted by atropine, but this is 

 not so with flseudo-muscarme. Natural muscarine does not affect the 

 pupil of birds, but maximal myosis is produced by a I per cent, solu- 

 tion of flseudo-muscarine. 



Schmidt has suggested that the physiological differences may be 

 due to stereo-isomerism, but in this case the relationship cannot be 

 that between an optically active and a racemic modification, for then 

 the one variety could not be 10-15 times as active as the other. 



Further investigation of the chemical properties of natural muscarine 

 is very desirable, but the base is unfortunately difficult to obtain in 

 sufficient quantity. Schmiedeberg's process of isolation was a compli- 

 cated one, and Harmsen [1903] calculates from physiological data 

 that Schmiedeberg only isolated about 6 per cent, of the muscarine 

 present in the fungus. According to Harmsen 100 grm. of fresh 

 fungus (=5 grm. of dried material) contain about 16 mg. of mus- 

 carine. The amount seems, however, to be very variable, as does also 

 the amount of choline which accompanies the muscarine. The chief 

 difficulty in isolating natural muscarine is the separation from choline. 



