1886. ] Microscopy. 489 
tubing, upon which is placed a common screw-clamp for regula- 
ting the outflow, supplies a dripper which is effective and quickly 
home-made in any laboratory. For the Thoma microtome it is 
also available, either by flooding the knife when this is set slant- 
ing and pushed clear of the instrument, or by frequent readjust- 
ments to compensate the progress of the object up the inclined 
plane. Either of these expedients, however, involves objections 
which are avoided by the use of the simple apparatus here figured. 
onstant pressure and flow are secured by the siphon which is 
SE 
obtained conveniently as in Fig. 1. The stopper of the flask or 
hol € may, of course, be omitted, but in the figure it has three 
a one for the siphon-tube, one for a small funnel, and one 
Binat exit of the vapor when alcohol is poured in through the 
ictal use with the Thoma microtome the end of the flexible 
tra n-tube is attached to the object-holder in such a way as to 
he it, and hence over the object, wherever it goes (Fig. 
Ras This is done by means of a bent (or straight) stiff wire (a) 
