1854.] 





The accompanying figure, which is of the natural size, will explain itself; 

 the part E B D is the drying apparatus, containing sulphuric acid and is of one 

 piece, the tube E being melted into the flask B. In making this part of the 

 apparatus I think it preferable to join E to A before blowing the bulb. The 

 apparatus which I made myself in this way, and with which I experimented, re- 

 mained sound, while of a dozen made by a professional gentleman, joining E 

 and B after the bulb was blown, six cracked at the joint. The carbonate 

 is placed in A with water, and C, with a wax stopper, contains hydrochloric 

 acid in case of insoluble sulphates, or is empty when the oil of vitriol of 

 B is employed to effect the decomposition. The tightness of the joints 

 is ascertained and the analysis carried on as in Fresenius and Wills' appa- 

 ratus. The lead glass apparatus which I constructed myself weighed, empty, 

 36 grammes, and when charged for analysis and with much sulphuric acid 

 weighed, together with the chloride of calcium tube-hook of Oertling's 

 balance which it fits, between 50 and 60 grammes. An apparatus of Ger- 

 man glass, made by a glass blower, weighed, with its cork and empty, 20 grms. 

 This apparatus unites lightness with great strength, which is at once 

 felt on handling the apparatus, which arises from the nature of the joint of 

 E with B, and from the construction of the decomposition flask A which allows 

 E to be made of a piece of stout tube. In its construction it is simpler than aay 

 that I have seen, not excepting Geissler's (Jour. f. pr., ch. LX., 35,) which has 

 one more joint, and that a ground glass one. A being entirely separate may be 

 washed and dried ready for a fresh analysis in a couple of minutes ; the sulphuric 

 acid in B will generally last for two analyses, and is ver} r easily emptied and re- 

 plenished. A small sucking tube with perforated cork fitting the capillary end 

 of the tube D, is used to bring acid on the carbonate, to draw air through at the 

 close of the analysis, and to fill and empty B with oil of vitriol. The joints are 

 the firmest possible in this apparatus, and the connections easily made, owing 

 to single tubes passing through the two cork3, which corks being very small 

 may readily be obtained of perfect quality. I have not found any error to arise 

 from the hygroscopic nature of the corks ; but if such be feared, it is easy to coat 

 their outsides with sealing wax varnish. The following are the experimental 

 results with the apparatus : 



About one gramme of perfectly pure (tested) carbonate of soda yielded, in 



