8 Prof. W. J. Pope and Mr. S. J. Peachey. A New [Apr. l>0, 



and, after a few hours standing at the ordinary temperature, methy Istann- 

 iodoform crystallises in large straw-coloured prisms ; the separation of 

 the latter is rendered more complete by the addition of petroleum 

 ether, and, after filtration, the stanniodoform derivative is purified by 

 crystallisation from ether or light petroleum. It crystallises in long 

 needles or prisms closely resembling iodoform in colour and melts at 

 8284 ; it gradually volatilises at 100 and, when slowly heated, 

 distils without decomposition. It is odourless and dissolves very readily 

 in alcohol, acetone and benzene. The following analytical results were 

 obtained : 



0-3083 gave 0'0254 C0 2 and 0*0172 H 2 0. C = 2-24. H = 0-62. 

 0-2964 required 17*5 x 6'0169 AgN0 3 for titration. I = 74*4. 



Theory for Sn(CH 3 )I 3 . C = 2-33. H = 0-58. I = 74-0. 



Metliylstannoxylic Acid, CH 3 .SnO.OH. 



Methy Is tanniodoform is insoluble in cold water, but dissolves in 

 boiling water giving a solution from which the iodoform derivative can- 

 not subsequently be crystallised ; as this behaviour should be attribu- 

 table to the occurrence of hydrolysis in the following sense, CH 3 .SnIs + 

 3H 2 = CH 3 .Sn(OH) 3 + 3HI, methylstanniodoform was evaporated on 

 the water bath with an aqueous solution of three molecular proportions 

 of soda ; as evaporation proceeded a white precipitate of methylstann- 

 oxylic acid was deposited, the reaction being represented by the 

 following equation : 



CH 3 .SnI 3 + 3NaHO = CH 3 .SnO.OH + 3NaI + H 2 0. 



After washing with water, solution in acetic acid and precipitation with 

 ammonia, the substance gave the following analytical results : 



0-3887 gave 0*0990 C0 2 and 0*0822 H,0 and 0'3532 SnOo. C = 6'94. 



H = 2-36. Sn = 71-60. 

 0-3396 gave 0-0869 C0 2 , 0-0800 H 2 arid 0-3024 SnO- 2 . C = 6*97. 



H = 2-63. Sn = 70-16. 



CH 3 .SnOOH requires C = 7*18. H = 2-41. Sn = 71*24. 



By the action of methyl iodide on sodium stannite, G. Meyer* 

 obtained a white powder in which he made one determination of tin, 

 and which he considered to be probably the acid which we now de- 

 scribe. On repeating Meyer's preparation we found that the substance 

 obtained is identical with the methylstannoxylic acid prepared from 

 methylstanniodoform. To the very scanty description given by 

 Meyer we would add the following. 



The acid is conveniently prepared by dissolving stannous chloride 

 * * Berichte,' vol. 16, p. 1439. 



