168 



SCIENCE 



[N. S. Vol. XXXIV. No. 867 



in particular) has not received enough at- 

 tention. Opinions are divided as to the 

 value of the determination as a criterion 

 of the purity of anesthetic chloroform. 

 In the speaker's opinion, it is of no value 

 without a knowledge of the content of alco- 

 hol and water. In making a careful frac- 

 tionation of 500 g. of anesthetic chloro- 

 form made from acetone, containing 0.5 

 per cent, alcohol and 0.026 per cent, 

 water, but otherwise pure, the temperature 

 rose at once to + 55.5° C, at which point 

 part of the alcohol and water with some 

 chloroform passed over, the remainder 

 of the alcohol with part of the chloroform 

 going over between + 59.4° and + 61°. 

 The following fractions were obtained: 



Temperature 

 55.5-59.4° 

 59.4-61.0° 

 61.0-61.2° 

 Above 61.2° 



Weight of Fraction 



10 g. 

 177 g. 

 300 g. 



13 g. 



The influence of alcohol and water, 

 separately or together, on the boiling 

 point of chloroform may be seen from the 

 following table. 



BOILING POINTS OP MIXTURES OF CHLOROFORM, 

 ALCOHOL AND WATER 



Constituent 



1. Chloroform-aleohol-water 



2. Chloroform-water 



3. Chloroform-alcohol 



4. Chloroform 



5. Alcohol-water 



(95.5 per cent, alcohol) 78.15° 



6. Alcohol 78.3° 



7. Water 100.0° 



There has been not a little variety of 

 opinion among chemists as to the nature 

 and products of the decomposition of 

 chloroform, especially the changes which 

 chloroform undergoes upon exposure to 

 air; in fact, this discordance dates from 

 the introduction of chloroform as an an- 



esthetic and prevails to-day. This condi- 

 tion is ascribable to the many influencing 

 factors occasioned by the degree of purity 

 of the chloroform under examination, the 

 extent and nature of the exposure; but is 

 principally due to the failure to consider, 

 and therefrom to correctly interpret, the 

 role of the general variable, alcohol, and 

 with it the accompanying moisture. 



The products of the decomposition of 

 "pure" chloroform, according to various 

 investigators, may be thus summarized: 



Chlorine; hydrochloric "(Morson; Maisch; 



acid j Hager. 



Carbonyl chloride Eump ; Eegnault. 



_ , 1 ,, -J r Stark; Eamsay; 



Carbonyl chloride; „ , , ., -.^ 



, , , , . ' J Schoorl and Van 



hydrochloric acid | _ _ -,-, ^^ 



I den Berg; Dott. 



_ , , , , . , , , . f Brown ; Schacht 

 Carbonyl chloride; chlorine < -,„.,, . ■, . 



{ and Blitz ; Adrian. 



The formation of carbonyl chloride is 

 alone defijiitely agreed upon. 



The decomposition of chloroform has 

 been universally conceded to be an oxida- 

 tion process. It is generally accepted that 

 chloroform is unaffected by light alone, 

 and that light, although it accelerates 

 oxidation, is not a necessary factor in the 

 process; however, several investigators ap- 

 pear to have inclined to the view that light 

 favors decomposition. 



With regard to the changes which occur 

 in anesthetic chloroform, that is, chloro- 

 form containing alcohol, during exposure 

 to air and light, there also exists a decided 

 diversity of opinion, principally owing to 

 the fact that no examinations were made 

 during the course of the various investiga- 

 tions, so far as we are aware, for the pres- 

 ence of the oxidation products of alcohol 

 in such chloroform. The whole subject re- 

 quired investigation, and accordingly an 

 experimental study of the decomposition 

 of both pure and anesthetic chloroform 

 was carried out. It was also hoped to 



