Intelligence and Miscellaneous Articles. 467 



the cardinal points of the doctrine are by no means agreed as to 

 many of the assumptions on which it is based, nor as to the 

 issues of the argument for the case. The whole subject is compa- 

 ratively new, and the men who are entitled to express an opinion 

 on it are not numerous. Ere a general concensus of opinion can 

 be arrived at much investigation and debate are necessary ; foot by 

 foot solid ground must be conquered, and it will be found, as truth 

 emerges, that it will illumine, not only much that is yet obscure in 

 the theory of climatic perturbations, but that, like all truth, it will 

 become the fertile mother of a long line of exact knowledge. 



LYI. Intelligence and Miscellaneous Articles. 



ON THE MAGNETIC ROTATION OF MIXTURES OF WATER WITH 

 SOME OF THE ACIDS OF THE FATTY SERIES, WITH ALCOHOL, 

 AND WITH SULPHURIC ACID ; AND OBSERVATIONS ON WATER 

 OF CRYSTALLIZATION *. BY W. H. PERKIN, PH.D., F.R.S. 



FROM the Author's previous work on the magnetic rotation of 

 compounds it was found that the molecular magnetic rotation 

 of water, which is taken as unity, is not the same as the sum of 

 the values of oxygen and two of hydrogen, as deduced from the 

 molecular magnetic rotation of other bodies. Thus hydrogen is 

 found to be 0-254, whilst hydrogen in hydroxy! varies from 0-194 

 in ordinary alcohol to 0-137 in monobasic acids, and is 0-261 in 

 carbonyl; so that, taking the lowest number, it gives H 2 + = 

 0-645, and taking the highest it is 0'769, 



From these facts it appeared that the determination of the mag- 

 netic relation of hydrated bodies might give numbers which would 

 show whether they contained water or whether the substances with 

 which it was mixed had combined so as to form new compounds. 

 If the former were the case the molecular rotation should represent 

 that of the compound + that of water ; if the latter, it should be 

 lower than this. For example, if formic acid were mixed with 

 water, molecular proportions being used, either H.COOH + H 2 

 or H.C(H0 3 ) might be produced. In the first case the rotation 

 should be 



Formic acid 1-671 



Water 1-000 



2-671 

 In the second, taking the highest value of H 2 -|-0, it would be 



Formic acid 1-671 



"Water 0-769 



2-340 

 which is considerably lower. 



* Discussion on the " Nature of Solution," British Association, Birm- 

 ingham Meeting, Section B. 



