418 J. W. HOGARTH. 



NOTE ON A COMBINED WASH-BOTTLE and PIPETTE. 



By J. W. Hogarth. 



(Communicated by Acting Professor J. A. Schofield, 



F.C.S., A.R.S.M.) 



[Bead before the Royal Society of N. S. Wales, December 7, 1904.~] 



During some chemical work in which it was desirable to 

 dissolve a precipitate, with which the work was concerned, 

 in a known volume of acid, the want was felt of a vessel 

 possessing the combined advantages of a measuring vessel 

 and wash-bottle. It was not originally intended to have 

 devoted a separate article to the description of the apparatus 

 which is described below, but because the work for the 

 time being has been stopped, it was deemed advisable to 

 now make mention of the vessel. Ordinarily when it is 

 wished to dissolve or wash a precipitate with a known 

 volume of solution, a measured quantity of the hot or cold 

 liquid is poured into the filter containing the substance to 

 be dissolved or washed, in which manner it is not possible 

 to stir up the precipitate and thereby offer as large a sur- 

 face as possible to the action of the solution, consequently 

 more liquid has to be used than is necessary to bring about 

 the desired change; this excess of solution in some cases 

 may be objectionable. If the liquid be delivered from a 

 wash-bottle the objections to a great extent are obviated, 

 but the volume of liquid used cannot conveniently be arrived 

 at, especially when the filtrate has to be quantitatively 

 treated, because any extra operation tends to introduce 

 errors into the analysis. The apparatus of which the 

 following is a description was designed to overcome the 

 above objections. 



