AiTGcrsT 7, 1908] 



SCIENCE 



187 



Analyses of fresh and frozen poultry and of 

 fresh and frozen beef (in the latter case the cruror 

 triceps was used on account of its leanness, size 

 and uniformity of structure) were made at inter- 

 vals for a period of one and a half years. The 

 determinations were: moisture, ash, fat, am- 

 moniacal nitrogen (by 'two specially devised 

 methods), and on the cold-water extract, total 

 solids, ash, organic solids, total nitrogen, coag- 

 ulable nitrogen, albumose nitrogen, meat-base 

 nitrogen and acidity calculated as lactic aeid. 

 From these determinations no alteration was dis- 

 covered for the period mentioned in the composi- 

 tion of either beef or poultry. These results were 

 borne out by practical cooking tests. The work 

 will be continued for an indefinite period. 

 Histology of Frozen Beef and Poultry: W. D. 



RlCHAKDSON. 



Histological examination of frozen beef and 

 poultry for a period of one and a half years failed 

 to detect any progressive alteration in the struc- 

 ture of the muscular tissues. The samples frozen 

 for a short period of time, when properly thawed, 

 appeared to have the same structure as those 

 frozen for a longer period. When muscular tis- 

 sues freeze, the water which begins to separate 

 as ice at — 0.4° C. solidifies outside the muscle 

 fibers, and by progressively accumulating between 

 the fibers as it freezes, causes them to appear 

 much smaller than normal and of irregular form, 

 in fully frozen samples, temperatures below 

 — 9° C, the ice areas are usually greater than 

 the areas of muscle fiber, either in cross or longi- 

 tudinal sections. On account of these ice areas 

 it is impossible for bacteria to penetrate into 

 frozen meats. From the laws of cryoscopy, the 

 solution which remains after the freezing out of 

 so much ice must be very concentrated, and it is 

 altogether likely, from experiments already con- 

 ducted, that microorganisms are unable to mul- 

 tiply or remain active in such a medium. On the 

 other hand, it is probable that microorganisms 

 if artificially inoculated into meats imder these 

 circumstances would certainly lose their vitality 

 and die. Experiments on this point are not yet 

 concluded. If frozen muscular tissue is thawed 

 rapidly, the normal appearance is not resumed. 

 On the other hand, if thawed sufficiently slowly, 

 a histologic picture very close to the normal is 

 obtained. 



A Method for Detecting Synthetic Color in But- 

 ter: R. W. CORNELISON. 



The clear fat is shaken with glacial acetic acid, 

 and the aeid, after being separated from the fat. 



is tested by the addition of a few drops of mineral 

 acid, particularly nitric. A pink color developed 

 in samples containing the several azo colors which 

 were tried. The color of the acetic-acid extract 

 is also noteworthy. Reactions of several vegetable 

 colors also are given. The writer makes an 

 earnest plea for the use of the true chemical 

 names of colors in place of the fanciful and much- 

 confused names in use in the trade. 

 The Composition of Milk from Dutch Belted 



Cows: Heemann C. Ltthgoe. 



The Dutch belted cattle are all jet black with 

 the exception of a broad belt of pure white en- 

 circling the body. No white is admissible in the 

 black, and the belt must be free from black. 

 There are but few herds of this breed in this 

 country, although single cows in mixed herds are 

 not uncommon. There has been examined in the 

 laboratory of food and drug inspection of the 

 Massachusetts State Board of Health the milk of 

 23 registered, and of a few unregistered, Dutch 

 belted cows. In general this milk is better than 

 that produced by the Holsteins, being character- 

 ized by a much higher fat and refraction of the 

 milk serum. The cows were milked in the pres- 

 ence of an inspector or analyst of the state board 

 of health. The analyses of the twenty-five sam- 

 ples of milk reported may be summarized as 

 follows : 



Studies on the Action of Heat on Milk: R. R. 



Renshaw and J. C. Waee. 



The following determinations ■ were made every 

 one fourth hour on milk heated at difi'erent tem- 

 peratures between 60° and 85° C. for two and 

 a half hours with and without varying amoimts 

 of formaldehyde: sugar, polarimetrically and 

 gravimetrically, acidity, alkalinity, total nitrogen 

 and total phosphorus on clarified filtrate. Lac- 

 tose in a mixed citrate-phosphate solution hav- 

 ing an alkalinity of 19° to lacmoid was not 

 changed on heating to 85°. The authors conclude 



