264 



cave. Then one melts some paraffine on a small metallic spatula and 

 lets it flow along tlie inner side of the neck nn the surface of tiie 

 liquid. In this way it is possible to fill up the wiiole upper part of 

 the neck with paraffin, witliout any difficulty and with a startling 

 result. No air bubble ought to be present between the liquid and 

 the paraffin, but no difficulties will arise, should a bubble be present, 

 provided its volume is small compared with that of the carbon dioxide, 

 evolved by the fermentation. Once the paraffin solidified, the 

 4''' reading is made. 



After this the apparatus can be sealed definitively, for which sealing- 

 wax was used, as paraffine shrinks, when it solidifies and easily gets 

 loose from the glass. The application of the sealing-wax is as 

 follow. At the outer side of the round upper part of the neck, 

 a ring of paraffin is taken away with a small knife. Care should 

 be taken, not to damage the stop of paraffin, which seals off the liquid 

 in the neck. Now on a small metallic spatula some sealing-wax is 

 liquefied by heating and the melted wax is put on the part of the 

 neck, from which the paraffin had been taken away. Not before the 

 wax is well fixed on the glass, a drop of liquefied wax is put on 

 the paraffin stop. Now the whole closure can be perfected by adding 

 more sealing-wax. ^ 



This done, one puts the apparatus in the thermostat of 30° C, 

 fixing it in the position of figure 2. The fermentation will be com- 

 pletely finished within 6 hours'). This time past, the apparatus is 

 taken from the thermostat and fastened in such a position, that the 

 mercury in the capillary tube and in the reservoir are on about 

 tlie same level. Two hours are quite sufficient to have the apparatus 

 cooled to the temperature of the air. The 5''' reading is then made, 

 but not before the mercury in the tube and in the reservoir is 

 carefully placed on the same level. This can be done, as already 

 indicated, by means of the small auxiliary apparatus, described in 

 § 1. As the same time the temperature of the air and the barometer 

 are read. Now all data, necessary for the calculation of the analysis 

 are known. 



In the experiments, dealcd with in § 5 of this communication, 

 the preparation of the yeast took place in the morning; the micro- 

 saccharimeters were put into the thermostat at about 3 o'clock in the 

 afternoon and were taken out of the thermostat in the evening of 

 the same day. The last reading was made next morning. 



1) Till now, we did not yet study the fermenlalion of raffinose with this appa- 

 ratus, il seems possible, that this sugar will ask a longer time to ferment couipletely. 



