6 



same colour was always used. Subsequently the following 

 mode of proceeding was ressorted to. 



Of the organ under investigation sections were made 

 (by means of a razor) which may not be thinner than 

 one whole la ver of eells, as the alcaloids escape from cells 

 opened by the knife. Thèse sections are submersed and for a 

 moment gently moved in water to remove the alcaloid in 

 the rests of the opened cells. Meanwhile three watchglasses 

 eontaining the Iodine-solution, above mentioned, are pre- 

 paired. The sections are now put in the first watchglass 

 and gently stirred by means of a glass rod. If alcaloid in 

 a somewhat considérable quantity be présent a cloud will 

 appear in the otherwise clear Iodine-solution. This cloud 

 consists of alcaloid, gummy substances, starch etc. escaping 

 from the opened cells. As soon as this cloud is observed 

 the section is removed to the second watchglass, stirred 

 gently again and as soon as a cloud lias formed here also, 

 removed to the third watchglass. Generally no cloud will 

 lté formed in this glass, if unexpectedly this might yet 

 happen the section is removed to the fourth and if 

 neeessary to the fifth watchglass. 



If this mode of proceeding is not followed the substances 

 above mentioned form a cake on the section which makes 

 it unsuitable for observation under the microscope. 



in the last watchglass the sections remain for about fifteen 

 minutes; a longer sojourn in the solution does no harm 

 if one bears in mind that a long submersion causes the 

 alcaloid to flow together to oily diops, which finally may 

 form one large drop in the cell. 



Finally the section is washed with water for a moment 

 and moimted in water also. Sometimes it was deemed ad- 

 visable to submerse the section for a moment in a solution, 

 eontaining 2,5 ce. of concentrated sulfuric acid, 25 ce. 

 alcohol of 96°/ 0 a nd 72 .5 ce of water; when the quantity 



