250 Mr Davidson on the Adulteration of Fixed Oils. 



is at the warmest hours of the day that hail is formed most 

 abundantly, and in Europe it falls almost constantly during 

 the day. 



It is perhaps by dwelling on these analogies, by approxi- 

 mating and comparing them, that one arriA^es at the know- 

 ledge of the laws which these phenomena obey, and at the 

 discovery of the general cause which produces them. 



The work of M. Fuster, we have seen, by the important 

 facts and useful experiments which it contains, as well as by 

 the reflections to which it gives rise, is a real service rendered 

 to medical philosophy, and to the science of clinical observa- 

 tion. 



If we have succeeded in presenting in a lucid manner a 

 summai*}' of this important work, in shewing in their true 

 light the new facts which it details, and the excellent direc- 

 tion which it cannot fail to impress on our medical studies ; 

 if we have been able to convey our own conviction into the 

 mind of oxu' colleagues, each will have already concluded with 

 us, that the work of M. Fuster merits the approbation and 

 encoui'agement of the Academy. 



On the Adulteration of Fixed Oils. By William Davidson, 

 M. D., Glasgow.* Communicated by the Society of Arts 

 of Scotland. 



The adulteration of fixed oils is of very frequent occurrence, 

 and injurious to a great extent, in many of our manufactures ; 

 but the detection of the fraud can be made only in a few in- 

 stances with certainty, and, in most cases, an examination of 

 their sensible properties is the only means we possess for form- 

 ing an opinion. The imperfect nature of our knowledge upon 

 this subject may be accounted for, partly from the intimate 

 similarity of the various .species of fixed oils in their chemical 

 character.?, and partly from the difficulty of procuring unso- 

 phisticated samples. It is, therefore, of importance that any 

 experiments upon this subject should be made known, for. 



* Read before the Society of Arts for ScoUand, 20th June 1838. 



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