146 REPORT OF THE CHEMIST OF THE 
eighth day, while in the milk containing only carbon dioxide 
under a pressure of 70 pounds to the square inch the souring 
was not complete until the eleventh day. From these results, 
it appears that the active agent in keeping the milk from souring 
is the carbon dioxide gas under pressure. 
FOURTH EXPERIMENT: EFFECT OF TREATING PASTEURIZED MILK 
WITH CARBON DIOXIDE GAS UNDER: PRESSURE. 
Milk pasteurized at 185° F. (85° C.) before separation and 
about 24 hours old when bottled was put into bottles under a 
pressure of 70 pounds of carbon dioxide. Some untreated milk 
was kept for comparison. The bottles were kept at room tem- 
perature, about 70° F. (21° C.). The results of this work are 
given in Table III. 
TasLe JII.— SHow1nGc AMmMounr oF ACID IN PASTEURIZED MiLK AFTER BEING 
CARBONATED. 

Se ee eee = —$——————————————————————— SSA 

AGE oF MILK AFTER BorrttLine. Untreated | Carbonated 
milk. milk. 
- Days. Per ct. Per ct. 
oe: git tides BER ula ahd Bete M te eel: © Se, one cee aS WO aCe ce ‘Oc5s 0.18 
Darcie ah Sate cf sc ae tans! ce, oe te de at sults & Sho eons ae caer ne ek ance ee 0.22 0).25 
eS et Ee SEBS OFS Pe Pmt ine PON ee ee ee 0.49 0.28 
SSR ek ee Ee eR cane ees Sree Om eget De So A de a0 .72 0.30 
EPANAGE SS asi cwapwagie of s/ slg egies ¥is oopy dem Rend gohan gut Alera eel ESSA es cin a eee 0.26 
bat) ye eR RNC EAS CRA REE aS Mike banrinatr ee Ses ee fe AM PEN CT er 0.31 
CRRA Noe adr aoeorls tie oe i ha Cel are APS ete EEG © cere Crate he eae ee 0.42 
MOSER A sg ome ge ot iy mee, oe he cea ere Ae EE CE eee 1 a ee 0.59 
aie carer peas San pein Piha Bas tec ra begin ME Bea a jubch oe  Te 0.59 
Se nn aes aati Prat colander ive (ieee act shear uid) je me Uae eet eaaistiee Sis-cre =~ a0 .83 




a Coagulated and sour. 
The uncarbonated, pasteurized milk became sour in three 
days, while the carbonated portion kept nine days before sour- 
ing, even at room temperature. 
FIFTH EXPERIMENT: EFFECT OF. TREATING FRESH: MILK WITH 
CARBON DIOXIDE GAS UNDER PRESSURE. 
We next treated some fresh, whole milk with carbon dioxide 
under a pressure of 70 pounds, keeping for comparison some un- 
treated milk. These samples were kept at a temperature of 
60°-70° F. The tabulated results follow: 
