( 400 ) 



J'iic Lii'ow ill (»r IIk' liliii coiiliiiiics for moiilhs, w licrchv ;i ('()Jisi(((M'ul)l(' 

 acctmiiiljilioii of oi'uajiic nirhoii iiiav he ()I)serv(Ml, which is not oiilv 

 visihle t(» the iiai<e(l eve hv the xi^-oroiis hacterial ^urowth, hul eau aLso 

 he proved hv (hreet wei.uhiiio-, ajid hv a e()ni])ai-isoii of the pei-iiiaii- 

 .L-anate iiiiiuhers toiiiid hefore and after the e.xpenineiit, of wJiieh some 

 iiistajices are ,i>iven heh)\v. 



As th(M-e is reason lo a(hiii( that oiir haelei-iimi is <'-eiierall\- dis- 

 tnhiited in uai'deii-soii, and was without (h)iihl always ]»j"eseiil in tiie 

 crude material used foi- the ijiocuhitioii, the failing- of the tilm-for- 

 mation in some of lh(> flasks must necesHcarily result from the chosen 

 culturi» Huid heing less favorahle to the feehler gei-ms and not allowing 

 Iheir growth. So we ol)ser\ed that water, (hsiilled in a copper apparatus, 

 caused many more failui-es than wlien dislided in glass; ^ve there- 

 fore afterwai-ds always us(mI the latter. In other cases monads, \> hicli 

 immediately de\-oured the haclei-ia, wcvv cause of the failure; l)^■ transfers 

 and by the use of pure cultures, these voi-acious organisms could 

 he rendered harndess oi- removed. When the distilled Nvater is replaced 

 hy ta[)-water, the Jiumber of llasks remaining without growth after 

 inocnlatioii \vitli the same (|uaulily of garden-soil is much smaller. 



Tf once a |tellicle has formed, transfers into the said culture li(|uid, 

 pi'ei)ared either with distilled or with tap-watei', come easily and 

 without exception to deNelopmcnt. 



2. SOUIU'K OK MTHOOKX KKQIIKKP. 



In the al»o\'e meiUiojied nutrient li(|uid we have chosen kalium- 

 nitrate as source of niti-ogen. As well, however, kaliumnitrite or 

 some anorganic ammojiium salt may he used. \'ei-y good residts were 

 obtained w ith : 



Distilled water 100 



Annnonium sul|>hale for NI1,(T) 0.01 — 0.1 



Dikaliuniphosphale 0.02 



■■Mineral solution" 1 di-op 



and with : 



Dintilled watei- 100 



Kalinnmitrite 0.01 (). I 



l)ikalinmphosphate 0.02 



"Mineral solution" 1 drop. 



As bolli Ihcsc li((uids answer to the conditions of life of the mici'obes 

 of nitritication, the h)rmation of nitrite^ or niti'ate is actualh to be 

 observed when using them, ajid when inoculating with gardeji-soil 

 or with crude cultures. With the easily produced pure cultures 



