260 Agricultural Gazette of N.S.W. [April 3, 1920. 



cero'jenes- Their presence in cream is evidence also of a proportion of volatile 

 acids (acetic and formic), so the 160,250,000 true lactose fermenters. Bad. 

 lactis acidi type, were not entirely responsible for the acidity of the creani. 

 Amongst the 770,000 gelatin liquefiers and casein digesters, were Bad. 

 prodijious, a species of the proteus gi'oup, and sarcina lutea, a liquefying 

 micrococcus and cladothrix sp. ; 19,000 micro-organisms, comprising species 

 of moulds, oidiimi and yeasts, were counted, while the 50,000 bacteria 

 causing alkalinity or no apparent change in litmus milk were both bacillary 

 and coccal forms. 



Sample Jl — Cream after Pasteurising. — The cream was collected by n)eans 

 of a sterile pipette immediately after being discharged from the outlet pipe 

 of the pasteuriser at a temperature of 180 deg. Fah. The sample was 

 neutralised to 2 per cent acidity with lime, and pasteurised by means of the 

 flash system, then cooled to 54 deg. Fah. by passing over pipe-coolers. 



It has been seen from the figures in Table I that 162,749,000 micro- 

 organisms in 1 c.c. of the cream were reduced by pasteurisation to 24,700. 

 Of these there were 200 per c.c. gelatin liquefiers of the B. Mycoides type of 

 spore-forming organisms. The remainder, 24,500 per c.c, wex'e insignificant, 

 inasmuch as only slight acidity, without noticeable taste or odour, was 

 produced by them in litmus milk in three weeks. 



Sample K\ — Cream, immediately prior to Churning. — After being pas- 

 teurised and pumped over the pipe-coolers the cream was gravitated into 

 circular holding vats, each about 6 feet in diameter and 4| feet deep, provided 

 with semi-rotary pipe brine coolers. These vats were placed in a room about 

 12 feet wide by some 40 feet in length. The walls, which were of fibro-cement, 

 were cracked, and broken, and dirty. The floor, also greasy and dirty, was- 

 of hardwood, badly jointed, and in places leaked through to the basement 

 underneath. The beading round the bottom of the walls was loose and 

 rotting, and the room was ill- ventilated and lighted, and generally in a state 

 of disrepair and uncleanliness. The vats had open tops and the contents 

 were exposed to contamination from the above conditions. No " starter " 

 was added to the cream, which, pending churning, was held over-night 

 (twenty hours) at 57 deg. Fah. Here the plates show that 1 c.c. of crean> 

 contained 1,291,500 inicro-organi.sms ; 1(S0,000 of these were found to be- 

 desirable lactose fermenters or organisms of Ba"t. ladis acidi type and 

 1,000 were acid and gas formers of the coliform gi'oup, viz., I a"t. lactis 

 cerojenes. Amongst the 543,500 gelatin liquefiers and casein digesters were 

 Bad. proteus mirahilis, Ba t. fluores"ens liqu^faciens, sarcina lutea, and a 

 oram-positive bacterium. The 367,000 producing alkalinity or no change 

 in litmus milk were Vjoth rod-shajfed and spherical forms, somj^ being 

 . chromogenic. Two thousand colonics, comprising two species of oidium and 

 3,000 yeasts, were also (counted ; 200,000 micrococci were ft)und to produce 

 acid in litmus milk, but failed to coagulate it in ten days. 



Sample L — Bu'ter in Churn heforcSaltiny. — The cream from the attemperator 

 or holding vats after cooling to 50 deg. Fah. was churned in a box churn for 

 about thirty-five minutes, and the sample of butter for plating was collected 



