202 ANALES DE LA SOCIEDAD CIENTÍFICA ARftENTINA 



dios ordinarios de cultivo en estado perfecto de pureza como si hubie- 

 sen sido « activados » por la tirosina. 



CONCLUSIONES 



I a Los líquidos tipos enviados por Bastían se hallaban infectados 

 antes de toda manipulación ; 



2 a Se ha podido comprobar la exactitud de las apreciaciones de 

 Bastían al establecer, que pueden hallarse ciertos gérmenes, en líqui- 

 dos que habían sido sometidos á temperaturas hasta ahora conside- 

 radas incompatibles con la vida ; 



3 a La interpretación que el autor da aceptando una generación 

 « de novo » no es más que un caso de resistencia á las temperaturas 

 consideradas hasta ahora como límites, problema importante, que nos 

 proponemos estudiar en el futuro. 



I have now no colloidal silica that I can send, but I am sending you some of the 

 three cheruicals wich "were emproyed by me last july for the numero 1 and numero 2 

 solutionSj wich I nape yon and your collegue will make use of. 



If you keep the sod-silicate solution long enough, and if you dissolve some of the 

 Ammon Phos and keep it long enough you wil doubttess find organisms in eaeh. Bul 

 boil sueh Solutions even once for 20' and tken subeulture theni, as prof. Hewlett did. 

 and if you find no livings organisms then, you will kuow what interpretation to just 

 ux>on the presence of living organisms within your experimental tubes. 



I have of late been opening tubes carefully, taking one sample of the deposit au 

 then inyecting abou XXXV of a recently boiled 0.05 por ciento solution of tvrosin. 

 The tubes should then be reclosed (perhaps with realing wax) and replaeed in the in- 

 cubator for 3-1 wks. If organisms were difflcult to discorer before. they will probably 

 be found to be swaruing in tbe tubes to wich tyrosin has been added. I hope you 

 may still have some inopened tubes with which you can make such triáis. 



