274 OSCAR LOEW; 



gradually developed, but not in (c). iVfter live days, withering of 

 the leaves commenced in (c) and complete death had happend in nine 

 days ; while the plants in (a) and (/>) were still perfectly healthy. 



Young branches of Prunus Cerasus, 40 cm. long, were placed in 

 the same solutions and also in O'l per cent, of hydrated sodium 

 sulphate. After three days, brown spots had appeared upon all the 

 leaves kept in the amidosulphonate, and two days later all these 

 leaves were dried up ; while in the control solutions the branches still 

 remained healthy, and for a long time afterwards. 



Isolated leaves of Msculus and Moms behaved in these solutions 

 in the same way. Mr. Maeno made, under my supervision, further 

 experiments with young plants of Allium fistulosum, Soja hispida, and 

 Brassica Rapa, and in all these cases some noxious action of calcium 

 amidosulphonate became evident. In these experiments all the 

 mineral nutrients were present. 



In contrast to what precedes, algaa (Spirogyra, Mesocarpus) had 

 not suffered even in 1 per cent, solution of calcium amidosulphonate, 

 after a week ; while the ammonium salt killed them in 0*5 per cent, 

 solution, within two days.* 



That mould-fungi and bacteria can utilise amidosulphonic acid 

 as a source of nitrogen was clearly established by their development 

 in solutions containing l°/ cane-sugar ; 0'l°/o monopotassium phos- 

 phate ; 0'01°/o magnesium sulphate; and, as the only source of 

 nitrogen, 0'l°/ amidosulphonic acid, either free or as calcium salt. 

 Mr. Maeno studied the matter closely with beer-yeast, and observed 

 that, although the acid can be utilised as a source of nitrogen, it is not 

 so good lor the purpose as ammonium sulphate. 10 cc. of thin beer- 

 yeast, corresponding to 0"0613 gram dry matter, were suspended in a 



* All ammonium salts are, for these kinds of algae, noxious in this concentration. 



