motor or a small hot air engine ; the latter motive power was used by 

 us and proved highly satisfactory. 



Incineration of the sample for analysis. For this purpose an 

 ordinary platinum dish, two and three-quarters inches in diameter, is 

 used ; the special contrivance itself being limited to the cover, thus 

 enabling one to prepare and weigh out several samples in similar 

 crucibles. The subsequent sketch of the cover will show the pecu- 

 liar features of the apparatus. 



The lines a. b. simply show the outlines of the platinum dish on 

 which the cover is resting. The line c. d. shows a loose fitting 

 sheet of platinum which prevents a direct draft into the funnel 

 above ; the platinum sheet being easily removed facilitates the clean- 

 ing of the cover. The cover needs only to lie loosely on the cru- 

 cible ; small unavoidable irregularities of the edge of the dish are 

 therefore of no consequence. 



During the combustion the cover can be taken off at any time for 

 observation and stirring up of the substance. The air comes in 

 around the edge gently, uniformly and well warmed. Oxygen can 

 be mixed with the air of combustion at the proper moment in a very 

 simple manner. 



The funnel shaped cover is of pure platinum weighing about 

 twenty-six grams and its construction is of such a nature as to allow 

 of its being easily cleaned. 



Our apparatus was imported by Messrs. Eimer «Sr Amend, New 

 York City, from Heraerus &: Co., Hanau, Germany. 



