296 THE REVIVAL OF INORGANIC CHEMISTRY. 



rnents of candidates for the doctorate, whereby the experimental 

 material for the dissertation had to be accumulated in a comparatively 

 short time, led to the assignment of topics with which the instructor 

 was familiar, and which were fairly sure of giving positive results 

 within a year or two, and, as we all know, do branch of chemistry 

 yields results so readily as the study of carbon compounds, with its 

 highly developed synthetical methods. As the Chemiker-Zeitung has 

 recently pointed out, even at the present day the full x>rofessorships in 

 German universities are almost invariably held by organic chemists, 

 while inorganic chemistry is left to subordinates. The weight of 

 authority and influence being on the side of organic chemistry, the 

 student who looks forward to a university career sees that his chances 

 of promotion are better if he follow the organic rather than the inor- 

 ganic direction. I need hardly add that the more mercenary hope of 

 obtaining a new dyestuff or a new remedy, or of replacing nature in 

 making an alkaloid, has also been a powerful incentive to many. 



Let us now consider some of the reasons which have their root in the 

 chemical peculiarities of carbon, and which render its compounds, at 

 least those which are not too complex, comparatively easy to study. 

 These conditions are not peculiar to carbon, but no other element, as 

 far as is known, presents as many of them at the same time. 



1. Carbon compounds being very generally soluble in neutral solvents, 

 frequently crystalline, and often volatile without decomposition at 

 comparatively low temperatures, are peculiarly adapted to separation 

 in a state of purity by fractional crystallization or distillation, and for 

 the same reason it is usually possible to determine their true molecular 

 weights. The very general possession of melting or boiling points 

 lying within easily observable ranges of temperature greatly facilitates 

 identification. 



2. The x^ower of carbon of uniting, atom to atom, to form chains, the 

 form and size of which can be easily regulated by known synthetic 

 methods, and the stability of which is sufficient to allow of manipula- 

 tion under easily attainable conditions, is a marked peculiarity of this 

 element. This, with the power of forming stable compounds with 

 hydrogen, is the basis of the definition of organic chemistry as " the 

 chemistry of the hydrocarbons and their derivatives." With regard to 

 self linking power, the other elements are in marked contrast. We 

 know with certainty no compounds in which two atoms of boron are 

 linked, not more than four nitrogen atoms have been arranged tandem, 

 while of silicon, the nearest relative of carbon, we know at best a half 

 dozen well-defined compounds with two atoms of this element in series, 

 and but one with three; analogues of the hydrocarbons are unknown, 

 with the exception of silico methane, and the instability of this is 

 sufficient proof that a series of silicon paraffins would be most difficult 

 to prepare, and the same would apply to all classes of silicon compounds 

 in which self-linking is a prerequisite. It does not appear probable that 



