392 Transactions.—Chemistry. 
interfere with the success of the experiment. Heat may be at once applied, 
and before the white fumes have quite disappeared the end of the delivery 
tube should be placed under water. The experiment may then be conducted 
as usual, care being taken when it is finished to withdraw the source of heat, 
and so allow the water to rush up the delivery-tube into the flask, which 
latter should not be opened till the water has ceased to flow. The phos- 
phorus in the deflagrating spoon should be more than is required to combine 
with the oxygen in the flask, which if of moderate capacity will need a piece 
about the size of a pea. 
This method of preparing phosphine will be found very useful, even in 
a well-furnished laboratory ; but its utility will be more especially felt in 
places where coal-gas is unobtainable. 
Art. LXII.—On a new Form of Burette. By T. A. Moutert. 
(Read before the Philosophical Institute of Canterbury, 13th October, 1881.] 
Plate XXXVIL., fig. 2. 
Ture being now so many forms of burettes from which to make a choice 
when about to conduct a volumetric analysis, it may appear wholly un- 
necessary to add another to the list. It will be well, however, to remember 
that one or two are practically obsolete, their form allowing of but rough 
and uncertain results. Gay Lussac’s burette, which gives far better indica- 
tions, is of too fragile a nature to be practically useful. Binks’s also, 
though less liable to breakage, is not much handierin use than the previous 
one, and with it is open to another objection, viz., special means have to be 
taken to ensure the correct reading of the level of the solution. Mohr’s 
burette, of which several modifications have been introduced, is the one now 
generally employed; but when dealing with potassium permanganate * 
cannot be used. To remedy this defect a glass stopcock has been substi- 
tated for the caoutchouc tubing, and this form has now mostly superseded 
the others previously mentioned, as it also allows of the use of Erdmann’s 
float. The glass stopcock is somewhat liable to fracture, and this form is 
not so easily cleaned as the original. 
Some years back I devised a burette, an exact description of which I 
came upon while searching in the ‘Journal of Science,’’* from which I make 
extract :-— Y 
‘A new burette has been lately used in Paris. It consists of an upright 
tube drawn out to a fine aperture below, like that of Mohr, and s 
in the same manner. The opening at the top is fitted with a perforalll 
_—-* “Quarterly Journal of Science,” vol. fi, ma. (x0.8.), 1973, p. 182. 
