xxx GENERAL SUMMARY OF SCIENTIFIC AND 



will form an almost complete materia medica. The action 

 of phenol as an antiseptic is due, without doubt, to its de- 

 structive action upon the organisms which always accom- 

 pany putrefaction. Plugge has examined the relative val- 

 ue of phenol for this purpose, and finds that from 1 to 

 1^ per cent, suffices to kill all the vegetable and animal or- 

 ganisms in a highly putrid liquid. The alcoholic fermen- 

 tation was arrested by 4 per cent., the butyric by ^^j of 

 its weight of phenol. He believes phenol takes rank far 

 above ferrous sulphate, chloride of lime, chlorine, permanga- 

 nates, mineral acids, or even quinine. In its physiological 

 action, phenol is similar to strychnine. Its vapor even is act- 

 ive. The best antidote to poisoning by it is, according to 

 Husemann, sugar-lime, made by agitating a solution of 16 

 parts of sugar in 40 of water, with 5 parts of slaked lime, fil- 

 tering and evaporating at 100. Chalk is less efficacious, and 

 oils are of no use. 



In Physiological Chemistry much excellent work has been 

 done. Bert has investigated most carefully the influence of 

 pressure-changes on life. When animals die under a pressure 

 of only 18 centimetres of mercury, he finds that this effect is 

 due entirely to a want of oxygen ; under a pressure of from 

 1 to 2 atmospheres, from a want of oxygen and the presence 

 of carbon dioxide ; of 2 to 6 atmospheres, from the presence 

 of carbon dioxide alone; of 6 to 15 atmospheres, from the 

 presence of carbon dioxide and an excess of oxygen ; and of 

 15 to 25 atmospheres, from the excess of oxygen alone. Mam- 

 malia will die when the oxygen in their arterial blood will 

 not balance a pressure of 3^ per cent, of this gas in the at- 

 mosphere, or when the carbon dioxide in their venous blood 

 is sufficient to balance 28 to 30 per cent, of it in the air. In- 

 asmuch as the pressure of oxygen depends, first, on its per- 

 centage, and, second, on its pressure, the latter may be re- 

 duced to 6 centimetres with safety, if the amount of oxygen 

 be increased; or may be raised to 23 atmospheres if jn'operly 

 diluted with nitrogen. Bert thinks aeronauts might go high- 

 er if they would take oxygen to inhale, and divers go deeper, 

 without danger, if they would add nitrogen to their air. 

 Aubert has investigated the caffeine question again. By an 

 improved method of extraction, he shows that raw Java beans 

 contain 0.709 to 0.849 per cent, of caffeine. By much roast- 



