Skey, — Osomose, as the Cause of Sasjjension of Clay in Water, 485 



Lastly : I get a decided attraction (apparently) of camphor for caraphor 

 when this substance occupies the surface of water upon which it 

 has rotated for a time sufiicieut to give a surface about half 

 charged with the camphor compound, 



Aet, LXXXII. — On Osowose, as the Cause of the j^ersistent Suspension of 

 Clay in Water. By William Skey, Analyst to the Geological Survey 

 of New Zealand. 



[Read before the Wellington PJulosopMcal Society, 9th Novemher, 1878.] 

 That certain waters can and do persistently suspend clay is a fact which 

 has been known from time immemorial, and the fact has also been known 

 for a time nearly as long that when alum is added to water thus employed, 

 the clay thereof is first coagulated, then precipitated, leaving the bulk of 

 the water quite clear. This effect of alum has always been attributed to 

 the fact that in a relatively large quantity of water it partially decomposes, 

 producing a nearly insoluble basic salt which, as it precipitates, carries the 

 clay down with it, entangled therewith, an effect which is therefore simjDly a 

 mechanical one. In the year 1868, however, I showed* that the same 

 effect could be produced chemically. I then brought under public notice 

 the fact ''that several neutral salts having their component -parts so strongly 

 combined among themselves as to render their decomposition by clay-water 

 impossible, are individually capable of 'precipitating clay from suspension in 

 water.'" I further showed that such precipitates re-acquire a property of 

 persistent diffusion, if well washed in pure water;! and I then main- 

 tained, and do still maintain, that these salts thus affect clay so suspended 

 solely by the exercise of their affinities for water, by which means the clay 

 is partially de-hydrated, and so has its density increased to such an extent 

 that gravity soon markedly asserts its influence, causing the observed 

 coagulation. 



* London Chemical News, No. 435. 

 t My claim as the discoverer of this effect of neutral salts has, to use a digger's 

 phrase, been '-jumped" by several investigators working independently of each other, 

 but all, of course, in happy ignorance of the fact, that it was already properly "pegged 

 out." One of these (Dr. Sterry Hunt, formerly of the Geological Survey of Canada), has 

 even unconsciously followed me so closely and so far as to make the same application of 

 the knowledge of this property of such salts as I did — viz., to the explanation of the 

 cause of the freedom of the oceanic waters from clayey matters, 



