Weight. — Increase of Nitrogen in certain Soils. 121 



costa ciiid dorsum ; an evenly broad fascia of white irroration 

 from i of costa to | of dorsum, resting on second line in discal 

 portion, terminating in a white spot on costa, and edged with a 

 white line from this to angle of second line : cilia grey mixed 

 with whitish, and indistinctly barred with dark fuscous irroration. 

 Hindwings grey, darker posteriorly ; indications of a cloudy 

 whitish dot towards termen below middle ; cilia grey mixed 

 with, whitish, with dark grey basal line. 



Humboldt Range, Lake Wakatipu, at 3,600 ft. (Hudson) ; 

 one specimen. This large and interesting form is allied to 

 comhinatana. Walk., but verv distinct. 



Art. VIII. — The Increase of Nitrogen in certain Soils due to 

 Nitroculture. 



By A. M. Wright, F.C.S. (Berlin), M.Am.C.S. 

 [Bead before the Philosophical Institute of Canterbury, I4th November, 1906.] 

 This paper is the record of an attempt to determine what increase 

 of nitrogen takes place in soils which have grown a leguminous 

 crop, with and without the aid of nitro-culture, and with and 

 without the addition of sulphate of potash and superphosphate. 

 The nitro-culture was obtained from the United States De- 

 partment of Agiiculture, the experiments being carried out 

 with the garden-pea grown on various soils. 



Three soils were experimented with, about 1,500 grams of 

 soil being used in each pot. 



The following are the conditions under which each soil was 

 treated and cultivated: — 



Experiment 1. The crop grown without fertiliser or nitro- 

 culture. 

 Experiment 2. The crop grown with 1 gram sulphate of 



potash added to the soil. 

 Experiment 3. The crop grown with 1 gram sulphate of 



potash and 1 gram superphosphate added to the soil. 

 Experiment 4. The crop grown with the seed inoculated 



with nitro-culture. 

 Experiment 5. The crop grown with the soil inoculated 



with nitro-culture. 

 Experiment 6. The crop grown with the seed inoculated 

 with nitro-culture and 1 gram sulphate of potash added 

 to the soil. 

 Experiment 7. The crop grown with the seed inoculated 

 with nitro-culture and 1 gram of sulphate of potash and 

 1 gram superphosphate added to the soil. 



