\i\ JAMKH M. PKTRIE. 



\:v, 



NiTKATK Plants. 



Nicotianiim tabacciim* 

 Heliaiithiis annuus ... 

 Ricinus communis 

 AiiiarHntlni.s alropiirpureiist 

 Amaraiithus niberf ... 

 Portulaca olei'acea+ ... 

 J^eta vulgaris§ 



Aniarantlms pyramidalisj .. 

 Kiichyljena (Clietiopod):^ 

 Iwrago officinalis:!: 

 Papaver rheas:J: 

 'J'riticuin .sativumH 

 Solanum tuberosumll 

 Urlica dioicaU 

 A vena aativall 



Potassium nitrate, 

 large amounts, 

 large amounts, 

 large amounts, 

 large amounts, 

 large amdunts. 

 stems, 12-4 %. 

 stems, 8 "4. 

 plant, 64. 

 leaves, 6 '2. 

 plant, 4-2. 

 stems, 3"1. 

 stems, 2 8. 

 stems, I '5. 

 stems, 1 3. 

 stems, 09. 



.A if rates in Metaholism . — By cultivation and aeration of 

 the soil, nitriTication is greatly increased, with the result 

 that nitrates are most available for absorption by plants. 

 On the other hand, the soil of moors and forests is found to 

 contain hardly any nitrate ; and Baumann, in testing un- 

 worked soils, found only minute traces, too small to estimate. 

 This is probably a reason for the small amounts found by 

 Berthelot and Andre*: — In Moss, 0005% in dry material: 

 Equisctum, 0036%: Pteris aquilina, 0-30%; Pinus sylvestris, 

 0-020%. 



In their numerous experiments, these authors found that 

 nitrate occurred in only small amounts in the roots, reached 

 a maximum in the stems, and rapidly decreased to the 

 leaves, where it is apparently utilised in the synthesis of 

 organic compounds. Leaves and flowers contained least, and 

 the seeds none. These experiments also showed that plants 

 grown in nitrate-free soil gained nitrate ; and led the authors 



* Stahi,. — Fuiidumenta Chymiae, 174, p.lOo. 

 t Boutin.— C.R., 78, 1874, p.261. 



X Ukkthei.ot et Am)RK.— Annal. chim. phy8iq.(6), 8, 1886, 28. 



g Pkixkt.— Bied. Cent., 1880, 8.235. 



T Hkkthelot.— C.R., 98. 1884, 1506. 



_ t Boutin's figures (22-7%, 16%) are copied into the standard text-lwoks. 



They are really the water-soluble ash taken as wholly potassium carbonate, 



and calculated into potassium nitrate. 



* Landw. Versuclis-Stat. 33, 1887, 247. 

 10 



