22 



DR. BASTIAN ON THE 



numerous trials, have found it best in this series not to provide 

 liquor potassse sufficient to neutralize the quantity of fluid in 

 the unboiled state, but to make use of liquor potassse in a 

 closed tube to the extent of two thirds or three fourths of this 

 amount— the former being, on the v^hole, the safest proportion*. 

 An illustration will make the mode of procedure at this stage 

 clearer. If the urine to be employed has an acidity of 12 minims 

 of liquor potassse to the ounce, then 1 ounce of it should be placed 

 in each experimental vessel (retort or flask of about 2 ounces 



Fig. 6. 



Retort used in experiment, as described in text. 



capacity) ; and with it a liquor-potassse tube containing 8 minims 

 of this fluid should be also inserted, with its narrowed and bent 

 extremity downwards. If, on the other hand, the urine had an 

 acidity of 8 minims of liquor potassae to the ounce, and only tubes 

 containing this amount of liquor potassse were at the time avail- 

 able for use, we should then have to place in each experimental 

 vessel 1 J ounce of the urine and one of these 8-minim tubes. 

 When properly charged, the neck of the retort or flask is to be 

 * There is reason to believe tliat conditions other than the acidity of the 

 fluid may subsequently have to be taken into accovmt, since, although | may 

 seem quite favourable for one specimen, in another f of the amount of liquor 

 potassse which would have been requisite for full neutralization before boiling 

 appears to produce more speedy results. Such or analogous differences may have 

 to be ascertained also in regard to the urine of different individuals. 



