August 11, 1911J 



SCIENCE 



173 



yet. Two illustrations may prove of in- 

 terest. Paraffin oil, sp. gr. 0.88, may be 

 used to discriminate between 0.08 and 0.09 

 per cent, of water in chloroform, but it 

 does not show the presence of a smaller 

 amount. We were not aware of any test 

 having been devised to show the presence 

 of less than 0.05 per cent, of water in 

 chloroform until we found that clean crys- 

 tals of calcium carbide would answer most 

 satisfactorily. 



Carbon tetrachloride boils at + 78.1° C. 

 and has a specific gravity of 1.63 ; chloro- 

 form boils at -f 61.2° C. and has a specific 

 gravity of 1.4989. A binary mixture con- 

 taining 7.8 per cent, carbon tetrachloride 

 boils at -(- 62° C. From what has been said 

 of the presence of the variables, alcohol 

 and water, in anesthetic chloroform and 

 their influence upon the physical properties 

 of chloroform, it will be quite evident that 

 determinations of these physical constants 

 can be of little real value, and their appli- 

 cation in general practise, even in well 

 equipped laboratories, is quite out of the 

 question. All our efforts to secure a 

 method applicable on a laboratory scale to 

 detect likely amounts of carbon tetra- 

 chloride in chloroform have been unsuc- 

 cessful. To be sure carbon tetrachloride 

 possesses anesthetic properties, but it must 

 exert its own specific physiological effect 

 and the anesthetist should know the drug 

 he uses. 



Among the anesthetic mixtures, the com- 

 bination of chloroform vapor with oxygen 

 was used shortly after the introduction of 

 chloroform as an anesthetic, and it has re- 

 cently been reintroduced into practise. 

 Hence it was important to investigate the 

 changes which anesthetic chloroform under- 

 goes when a current of oxygen is conducted 

 through it. Dr. J. T. Gwathmey^^ has re- 



^ The speaker has been collaborating with Dr. 

 Gwathmey, who has directed the clinical observa- 

 tions. 



cently stated that oxygen increases the 

 value of all inhalation anesthetics as re- 

 gards life. 



Several experiments were carried out 

 in order to determine whether the passage 

 of a current of oxygen through anesthetic 

 chloroform brings about decomposition 

 of the anesthetic. Anesthetic chloroforms 

 containing 0.56 to 1.0 per cent, of alcohol 

 and 0.03 to 0.05 per cent, of water were 

 used. The conditions were such, except 

 that the temperature was about -)- 20° C, 

 as obtain during administration by the 

 Gwathmey method, his apparatus being 

 used. The oxygen was allowed to flow at 

 such rates through 3^ to 4 ounces of the 

 anesthetic that about one-half remained 

 in the vaporizer after 3|- to 10-J- hours. In 

 one experiment the chloroform vapor was 

 passed through water, as is Dr. Gwath- 

 mey 's practise, and subsequently con- 

 densed. The examination of the residue 

 and condensed chloroform showed the 

 following : 



Acidity (acetic acid) : 



Chloroform used None. 



Residue in container . . . 0.00015 g. in 100 c.c. 



Condensed chloroform . . None. 

 Sulphuric acid test: 



Chloroform used Negative. 



Eesidue in container . . . Marked reaction. 



Condensed chloroform . . Negative. 



Therefore it was concluded that the 

 oxidation products of alcohol are not car- 

 ried over when the chloroform-oxygen 

 stream is conducted through water, and 

 that these are concentrated in the residue. 

 By this method of administration the pa- 

 tient is protected from the objectionable 

 decomposition products even if they had 

 developed. Furthermore, the vapors of 

 the anesthetic so applied are saturated 

 with water, hence can not exert that des- 

 iccating effect upon the mucous mem- 

 branes they would if not moisture-laden. 



