Scientific Proceedings. 



(145) 81 



ciently great to permit a rapid and thorough extraction of the sub- 

 stance. Chloroform containing the di-indyl compound has a red 

 color, very like that of hemoglobin. Owing to this circumstance, 

 the condensation compound in chloroform can be approximated 

 colorimetrically in a convenient manner by comparing the tint of 

 the solution with that of the orange-red glass scale of the Fleischl 

 hemoglobinometer. When more accurate results are desired, the 

 chloroform is evaporated and the residue of the di-indyl compound 

 weighed. 



It was found that the method here indicated serves for the 

 recovery of a very large percentage of indol from peptone solutions 

 or bouillon. From solutions containing a little protein, the indol 

 may be recovered almost quantitatively. The presence of a large 

 proportion of protein may cause the retention of considerable indol. 

 The distillation should be carried on directly, without steam, from 

 the acidified fluid. The presence of indol in a small fraction of 

 distillate is best ascertained by boiling the acid solution with a few 

 drops of a 2 per cent, alcoholic solution of di-methyl amido-benz- 

 aldehyde. 



Skatol forms an homologous and similar compound with the 

 naphthoquinon reagent, but this substance is violet rather than 

 blue. 



41 (87). " Anesthesia produced by magnesium salts," a pre- 

 liminary communication, with demonstrations : S. J. MELTZ- 

 ER and JOHN AUER. 



The authors exhibited to the society two guinea-pigs, which 

 were deeply narcotized by injections of magnesium sulfate. One 

 of these animals had been similarly narcotized twice before, and 

 fully recovered each time. In their physiological and toxicological 

 studies of magnesium salts, the authors found that by subcutane- 

 ous injections of certain quantities of sulfate or chlorid of magne- 

 sium, animals can be brought into a state of deep anesthesia, dur- 

 ing which any operation can be performed upon them without the 

 least resistance. If the dose of the salts is not too large, heart- 

 beat, blood-pressure and respiration remain nearly normal. It 

 was tested on dogs, cats, rabbits, guinea-pigs, white rats and frogs. 

 A gram and a half of magnesium sulfate is about the effective dose 

 for most of the animals. The chlorid has to be used in smaller 



