/\'e!ntii'ii <>f u.viildtu'iis ti> synthetic processes in yeast 

 tells. l\istenr's experiment, a. 'lake I K> oi a \ea>t cake and 

 mix thoroughly in a mortar with _'< > CC. water. Add 10 cc. of thi> 

 mixture t i "f nutrient tluid. Mix tin >n Highly, and while the 



i-t i- uniformly suspended divide int<> two equal part-, a and b. 

 Mace a in a buttle pr \ ided with a oirk and exit-tube to carry 

 1 ; tin- tube -hoiild end bel< >w the >urt';n'e of water in a 

 beaker. iWtimi b >hnuld be poured int<> one <>r more wide jars or 

 di-he- t" fcirin a thin layer well exposed t air; cover loo>ely with 

 ^la-- plaie^. Place a and b aside tor 2 days or more. Then examine 

 both carefully, comparing tlu- a]i]>earance. relative turbidity, odor, 

 and d< !" ett'erve-cence. I ran-ter b to a bottle. Shake each 



|rti"ii <a and b) ; take equal (|uantitie- of each. Centrifugalize and 

 eumpare the am unt- of the >ediment. l\e>ult>? Conclu>i<>n>? 



b. .llciilinl formation in presence and absence of <>.\'\'</cn. Ar- 

 range a -imple >till b\ allo\\in^ a l R . n ; t u ] )C . from a rla>k to run to the 

 Inittoin ( ,f a narrow te-t-tube immersed in cold water. I)i-till ot'f 

 from both a and b ( usini, r a moderate tlame ) a few cc. of the 

 di-tillate. idol the di-tillate-. ( 'oinpare their >mell and ta-te. 

 \\arm each \\itb lx.( r.''- and 1I..S'),. Kestilt ? d nclusion ? 



1 -Meet i CC. of j^a- from a fermenting yeast culture in an 

 inverted te-t-tube. Te-t the .^as by introducing in'. K<)11 solution, 

 h\ mean- of a bent pipette, into the tube in contact with the <, r a-. 

 Ah-orptiiin indicate^ ( "i i . \\'hy? \\rite the eiiuati' n. 



