ARTIFICIAL DIAMONDS. 259 



Surely, therefore, the helplessness of the human infant can no 

 longer be regarded as an exceptional phenomenon, and all conclusions 

 based upon it by rhetoricians may be safely dismissed to dream-land, 

 whence they came. Journal of Science. 



ARTIFICIAL DIAMONDS. 



THE world of science and the world of fashion are so far removed 

 from each other that they are seldom stirred by the same event, 

 but the production of artificial diamonds has lately startled both these 

 distant realms. 



Mr. Hannay, of Glasgow, has recently exhibited before the Royal 

 Society certain crystals which are no accidental productions, but direct 

 results of a process conceived for a definite end. These have been 

 examined by analysts like Professors Maskelyne, Roscoe, and Dewar, 

 and declared to exhibit all the physical and chemical properties of true 

 diamonds. 



Mr. Hannay's gems are very small ; but whether he will hereafter 

 succeed in producing large stones, and what effect success of this kind 

 would have on the value of the diamond, we do not propose to inquire. 

 This is a question which concerns the world of fashion alone ; the 

 world of science is interested in asking by what means the crystalliza- 

 tion of carbon has at length been accomplished. 



Every one is acquainted with the various forms of the substance 

 called carbon. It constitutes a large proportion of all animal and 

 vegetable structures, and we know it best in an impure condition as 

 coke or charcoal ; but it occurs crystallized, and in a state of purity, 

 in two very different forms, viz., diamond and plumbago, or black-lead. 



Those bodies which resist all attempts of the chemist to resolve 

 them into simpler forms of matter are called elements, and among the 

 vast number of substances composing our earth some sixty-four, which 

 are for the most part metals, are simple bodies ; of these carbon is one. 



Almost every substance which is capable of existing in the solid 

 state assumes, under favorable conditions, a distinct geometrical figure. 

 This power which bodies possess of taking on definite forms is called 

 crystallization, and its most beautiful examples are found among natu- 

 ral minerals, the results of exceedingly slow changes occurring in the 

 substance within the earth. Artificial crystals may be obtained from 

 solutions, by fusion, and in the passage of bodies from the gaseous to 

 the solid condition. Thus crystals of common salt are foi'med by the 

 evaporation of brine ; many metals, as iron and bismuth, crystallize 

 on cooling after being melted ; and the vapors of some substances, 

 like iodine, for example, deposit cryst.ifls in the act of condensation. 



