the largest proportion of alkaloid at or just before the time of flowering. 

 When the fruit is ripened and the plant commences to dry, the whole 

 plant shows a much smaller proportion of active substance. This 

 seems also to be the case with the Egyptian plant. Dunstan gives 

 the alkaloidal content of the leaves as reaching 1-4 per cent, 

 but I have found as much as two per cent in the dry matter of the 

 green leaves collected at the time of flowering. There are, however, 

 difficulties in dealing with the fresh plant at this stage of its growth 

 owing to the large water content. The plant, when growing in well 

 watered soil, may at the time of flowering contain as much as ninety- 

 five per cent of water. This makes the process of drying difficult and 

 tedious. Artificial drying at this stage is impossible, as the plant 

 becomes converted into a mere pulp. Besides this, to heat the plant 

 while it contains a large quantity of water would be fatal, as the whole 

 of the alkaloid would be destroyed. The plant must be dried slowly 

 in the sun, with frequent turning until the moisture is reduced to at 

 most twenty per cent ; after this stage is reached a gentle heat may 

 be applied and the plant thoroughly dried, so that it may be readily 

 ground. 



An attempt was made to obtain the alkaloid by expressing the 

 juice from the fresh plant. The presence of the alkaloid could readily 

 be detected in the fresh juice and a quantity of a litre or so was evap- 

 orated in a partial vacuum (100 mm. Hg.); no trace of alkaloid could 

 be detected in the concentrated liquor. The whole of the alkaloid 

 appeared to have been hydrolysed and converted into tropic acid, a 

 substance of no value. 



The usual method of obtaining the alkaloid from these plants is to 

 extract the dry and finely ground material with cold alcohol. If this 

 is done by percolation a great quantity of alcohol is necessary, and 

 it is therefore better to adopt some method of continuous extraction. 

 The only obstacle to the employment of the extraction method is that 

 the process must be carried out at reduced pressure. If this is done, 

 the alcohol will boil at a temperature of about 50 C. To obtain such 

 a reduction in the boiling point it is necessary that the pressure in 

 the apparatus should not exceed 200 millimetres of mercury. 

 It is of interest to note that in the course of extraction a considerable 

 amount of potassium chloride is dissolved out by the alcohol, and 

 unless this is occasionally removed from the boiler serious " bumping " 



