G. GENERAL NATURAL HISTORY AND ZOOLOGY. 317 



geneous, translucent, soft substance. When heated it swells, 

 and, if the temperature be high enough, gives off amraoniacal 

 vapors. It is insoluble in water, but dissolves in aether, chloro- 

 form, carbon-sulphide, and benzine. Cerebrine exists in brain 

 matter, from which it is extracted by boiling alcohol. It is 

 treated with aether to remove the fatty matter, and purified 

 from leucithine and lime-phosphate byrepeated solution in 

 boiling alcohol. It is a solid, inodorous, colorless body, and 

 is but little affected by aether. 21 A, September, IS*!!, 907. 



GASES IX THE COAGULATION OF THE BLOOD. 



As the result of some recent investigations by Messrs. Mat- 

 thieu and Urbain upon the part which the gases play in the 

 coagulation of blood, these gentlemen announce that carbonic 

 acid is the agent of spontaneous coagulation ; and that, dur- 

 ing life, the obstacle to this coagulation resides in the blood 

 corpuscles, which have as their special function the fixation 

 not only of the oxygen, but also of the carbonic acid in the 

 blood. As a result, the coagulating action of this gas can 

 not be exerted in physiological conditions. The blood which 

 returns from glandular organs, especially from the kidneys, 

 is incoagulable, and contains very little carbonic acid. It" 

 the removal of carbonic acid from the blood be favored by 

 simple exosmose, coagulation will not take place ; yet, if it 

 be placed in an atmosphere of carbonic acid, coagulation 

 rapidly sets in. The clots, however, are softer than those 

 which form in air, rendering it probable that oxygen influ- 

 ences their consistence. Lastly, certain neutral salts impede 

 or prevent coagulation, but such salts fix a notable volume 

 of carbonic acid, and thus withdraw it from the blood. 15 

 A.October 21,1874,491. 



WIND PEESSUKES IN THE HUMAN CHEST. 



The new Physical Society of London seems to have ex- 

 tended its attention to the dynamics of physiological phe- 

 nomena, Dr. Stone having recently read a paper before it on 

 wind pressures in the human chest during performance on 

 wind instruments. The author's object was to ascertain, 

 first, what w T as the extreme height of a "column of water 

 which could be supported by the muscular act of expiration 

 transmitted by the lips. This was found to be about six 



