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tious were commenced ou the comparative keeping qualities of butters 

 made from sweet aud from ripeued cream. The butters were both 

 made December 14, 1SS9, at a creamery in Iowa. Until June 20, 1890, 

 the two tubs were kept together in a cellar without ice, being examined 

 about once a month; later they were placed in an ice chest, where they 

 were kept to the close of the trial, August 20. The author sums up the 

 results in the following words : "There was no \^ery marked ditterence 

 in the keeping quality of the two butters; what difference there was 

 was in favor of the sweet cream product. As to flavor, for the first two or 

 three months most of the tasters preferred the ripened cream butter, de- 

 claring that made from sweet cream to be comparatively 'flat,' 'insipid,' 

 or ' flavorless ; ' but the longer the butters were kept, eveu while both 

 were still sweet, tlie less marked became the difference between them 

 in this respect. " 



Preservatives for Jceeping milk samples for testing. — In the directions 

 for carrying out the " relative value plan " of paying for milk at cream- 

 eries ou the basis of the actual amount of butter fat as given in Bulle- 

 tin No. 9, of the station (See Experiment Station Record, Vol. II, p. 

 101), samples of each patron's milk, taken daily, are to be preserved 

 together by means of corrosive sublimate for about one week, when a 

 single test is to be made to determine the average butter value of the 

 milk of each patron during that time. In trials since made with sam- 

 ples exposed not only to the natural heat of summer, but also to the 

 heat of the greenhouse with a temperature of from 120^ to 130° Fah., 

 this preservative has given good results for the desired length of time. 

 The fact of its being a violent poison, however, makes it open to serious 

 objections, and investigations have been commenced in the hope of dis- 

 covering some other preservative to take its place. A mixture of 50 

 parts by weight of powdered borax, 10 i)arts of mercuric chloride^ and 

 1 part of anUine rose pink, thus reducing the amount of corrosive sub- 

 limate used in each composite sample to about 2 grains, has been used 

 with success. Experiments made with preservatives containing no cor- 

 rosive sublimate "while very numerous and extending throughout the 

 entire past summer, I can not regard as conclusive." Those referred to 

 are with amyl alcohol (fusel oil) 3 per cent by volume, and sodium 

 fluoride 40 to 60 grains per 200 cubic centimeters of milk. 



The Iowa Station milk test ; new form suitable for creameries. — The 

 test as originally described has been somewhat modified for use at 

 creameries. The modified method i)ermits much more rapid work and 

 the making of a larger number of tests at the same time. "A bath con- 

 sisting of a tank lined with zinc, or preferablj' lead, with a steam coil 

 in the bottom and containing a proper amount of saturated brine," is 

 suggested for heating the tubes in place of the sand bath formerly 

 recommended. The charged tubes containing the milk are supported 

 in the bath by means of a rack. The formula of the acid mixture is 

 .somewhat modified and is as fojlows : nine volumes of pure acetic acid 



