226 ANNUAL OF SCIENTIFIC DISCOVERY. 



salt dissolved. Osmose is, indeed, eminently the phenomenon of weak 

 solutions. The same substances are likewise always chemically active 

 bodies, and possess affinities which enable them to act upon the material of 

 the earthen- ware septum. Lime and alumina were accordingly always 

 found in solution after osmose, and the corrosion of the septum appeared 

 to be a necessary condition of the flow. Septa of other materials, such as 

 pure carbonate of lime, gypsum, compressed charcoal, and tanned sole- 

 leather, although not deficient in porosity, gave no osmose, apparently 

 because they are not acted upon chemically by the saline solutions. Ca- 

 pillarity alone was manifestly insufficient to produce the liquid movement, 

 while the vis matrix appeared to be chemical action. The electrical endos- 

 mose of Porrett, which has lately been denned with great clearness by 

 Weidemann, was believed to indicate the possession of a peculiar chemi- 

 cal constitution by water while liquid, or at least the capacity to assume 

 that constitution when water is polarized and acting chemically upon other 

 substances. 



A large but variable number of atoms of water are associated together 

 to form a liquid molecule of water, of which an individual atom of oxygen 

 stands apart, forming a negative or chlorous radical, while the whole 

 remaining atoms together are constituted into a positive or basylous radi- 

 cal ; which last will contain an unbalanced equivalent of hydrogen giving 

 the molecule basicity, as in the great proportion of organic radicals. Now, 

 it is this voluminous basylous radical which travels in the electrical decom- 

 position of pure water, and resolves itself into hydrogen gas and water at 

 the negative pole, causing the accumulation of water observed there ; 

 while the oxygen alone proceeds in. the opposite direction to the positive 

 pole. Attention was also called to the fact, that acids and alkalies, when 

 in solution, are chemically combined with much water of hydration ; sul- 

 phuric acid, for instance, evolving heat when the fiftieth equivalent of 

 water is added to it. In the combination of such bodies, the disposal of 

 the water is generally overlooked. Osmose was considered as depending 

 upon such secondary results of combination ; that is, upon the large num- 

 ber or voluminous proportions of the water molecules involved in such 

 combinations. The porous septum is the means of bringing out and ren- 

 dering visible, both in. electrical and ordinary osmose, this liquid movement 

 attending chemical combinations and decompositions. Although the 

 nature and modus operandl of the chemical action producing osmose 

 remain still very obscure, considerable light is thrown upon it in the 

 application of septa of animal membrane. Ox bladder was found to 

 acquire greatly increased activity, and also to act with much greater regu- 

 larity, when first divested of its outer muscular coat. Cotton calico also, 

 impregnated with liquid albumen, and afterwards exposed to heat so as to 

 coagulate that substance, was sufficiently impervious, and formed an excel- 

 lent septum, resembling membrane in every respect. The osmometer was 

 of the usual bulb- form, but the membrane was supported by a plate of 

 perforated zinc, and the instrument provided with a tube of considerable 



