August 11, 1911] 



SCIENCE 



171 



to intermittent agitation for over 200 

 hours in a Spiegelberg shaking apparatus, 

 and it was learned from four samples so 

 treated that it is desirable to prevent the 

 presence of air, i. e., oxygen, being in as- 

 sociation with this anesthetic when it is to 

 be shipped in the usual manner. Monney- 

 rat devised a method of displacing air by 

 nitrogen, even making a nitrogen siphon 

 of chloroform. 



The keeping qualities of anesthetic 

 chloroform may be seriously affected by 

 the character of containers. The question 

 of keeping anesthetic chloroform in tin 

 containers has been a much agitated one 

 in the Federal War Department, and 

 within the last ten years this department 

 has decided in favor of the tin container. 



The opinion of the author is that glass 

 containers are more conducive to purity 

 for several reasons. First, in cleaning the 

 vessels any foreign matters present may be 

 readily observed and the bottles properly 

 cleaned. Second, in the ease of tins, some 

 of the flux used in soldering may be in- 

 troduced and thus impart an acid reac- 

 tion to the chloroform. Hydrochloric acid 

 accelerates the decomposition of chloro- 

 form. The introduction of this flux is 

 also a problem in ether manufacture which 

 requires the utmost care. Third, since it 

 has been stated that spirit containing 95 

 to 96 per cent, by volume of ethyl alcohol 

 is perfectly indifferent to tin, and tinned 

 metals are absolutely unattacked by 90 

 per cent, denatured spirit, the tinned 

 metals only being corroded where the tin 

 layer is broken, ^^ one would conclude that 

 acid-free chloroform,^" containing the 



" Heinzelmann, Z. Spiritusind., 27, 399. Mal- 

 mejac, hoTvever (J. Fharm. Chim., 1901, 13, 169), 

 found that a small amount of tin goes into solu- 

 tion in 95° alcohol after six months. 



^^ On the action of hydrochloric acid in chloro- 

 form on tin, see Patten, J. Physical Chem., 7, 161, 

 who found that the dry solutions act upon the 



usual amounts of alcohol and water, would 

 also be without action on tin, providing it 

 is stored in tin containers having no 

 broken or scratched surface, very carefully 

 capped, and with a minimum amount of 

 air. In order to determine this, a five- 

 pound sample of chloroform, containing 

 0.84 per cent, by volume of absolute alco- 

 hol and approximately 0.05 per cent, of 

 water, which had been stored in a tin con- 

 tainer, sealed, .for sixteen months, was ex- 

 amined for the presence of tin. This 

 sample left a residue non-volatile at 100° 

 C, amounting to 0.0220 g. per liter, but 

 none remained upon ignition and no tin 

 could be detected in the sample. The ex- 

 amination of a sample of anesthetic 

 chloroform which had been kept in a 

 sealed tin for six years also showed that 

 no tin had been dissolved. In both cases, 

 however, oxidation of the alcohol present 

 had occurred, although no decomposition 

 products of chloroform were present. 



Fourth, we have been informed by H. 

 H. Dow-" that he has "demonstrated that 

 moist chloroform in the presence of a 

 metal will slowly form traces of CH,Cl2 

 and probably . . . that it is possible to 

 distil pure, dry chloroform in a metal con- 

 tainer and produce a decomposition as 

 shown by the following formula: 



4CHC1, + Cu, = C.Clo -I- 2CH,CL + Cu,CL. 



This reaction, however, takes place so 

 slowly that it would never be noticed ex- 

 cept in the handling of a material on 

 which superlative efforts have been ex- 

 pended for years in order to get the last 

 extreme of purity." Moreover, "all 

 chloroform contains traces of CH^CL." 

 In this connection, it should also be men- 

 tioned that it is probable that all metals 

 which show anomalous anodic conductivity 



metal less violently than upon zinc or aluminum, 

 but more violently than on lead. 

 ^ Private communication. 



