340 0)i>lhe Gas Blowpipe. 



of about the tenth of an inch in diameter. In fact, I found pla- 

 tinum to be equally susceptible of rapid volatilization, whether 

 exposed in its native granular form, or in that of globules obtained 

 from the orange-coloured precipitate of the nitro-muriatic solu- 

 tion by the muriate of ammonia." 



Silliman, page 3. " Platinum was not only melted, but volati- 

 lized with strong ebullition *." 



Clark, page92. " The fusion of this metal, owing to the great 

 improvements here mentioned in the mode of using the gas blow- 

 pipe, is now become so easy that this metal melts faster than 

 lead in a common fire. It is no longer necessary to make use of 

 wire in exhibiting its fusion and combustion. The cuttings which 

 are sold by the manufacturers of platinum utensils are placed in 

 a cupel, either mounted on a stand or held in a pair of forceps. 

 The mouth of the jet is bent downwards so as to admit of a per- 

 pendicular direction of the gaseous flame upon the metal in the 

 cupel. The flame is then suflfered to act upon the platinum, about 

 a quarter of an ounce of the metal being placed in the cupel at 

 first: as soon as this begins to melt, more may be added until a 

 cupel of the common size is nearly full of the boiling metal : and 

 in this manner a mass of platinum weighing half an ounce at the 

 least may be obtained in one brilliant bullet. This, when rolled 

 out so that all air holes being removed the mass possesses a uni- 

 form density, will be found to have a specific gravity equal to 

 20*8.57. During the fusion of the metal its combustion will be 

 often if not always apparent. It will burn with scintillation, and 

 particles of the black protoxide of platinum, if care be used, may 

 be caught upon a sheet of white paper while combustion is going 

 on." 



He would here evidently wish the reader to adopt the false im- 

 pression, that the facility with which platinum may be fused is 

 owing to *' the great improvements " made fourteen or fifteen 

 vears after I had devised and used them. Will Britons tolerate 

 such conduct in their professors? 



Silliuian, last page. " The experiments which have now been 

 related in connexion with the original ones of Mr. Hare, suffi- 

 ciently show that science is not a little indebted to that gentle- 

 man for his ingenious and beautiful invention. It was certainly 

 a happy thought, and the result of very philosophical views of 

 combustion, lo suppose that a highly combustible gaseous fluid, by 

 intimate mixture with oxygen gas, must when kindled produce in- 



* The fusion and combustion and complete dissipation of platinum, gold, 

 silver, nickel, cobalt, and most of the metals, and the fusion of the principal 

 earths and of their most refractory compounrls, by the use of Professor Hare's 

 compound blowpipe, have been the finniliar and easy class experiments of 

 every course of chemistry i:i Yale College for these eight year*. — PEn.] 



tense 



