February 13, 1885.] 



SCIENCE. 



131 



G. L. Higby gave an average specific gravity 

 of 1.0295. Two samples of a Jersey cow's 

 milk sent by the commissioner of agriculture 

 marked 1.033. The milk from Mr. W. Blair, 

 of a cow fed principally on ensilage, twenty- 

 two samples, gave specific gravity 1.0318; 

 same cow fed 'chop food,' fifteen analyses, 

 1.310. It is a very common practice to re- 

 move the cream, and then add water until the 

 milk is reduced to its original density. For 

 this reason the use of the lactometer for deter- 

 mining the purity of milk may lead to serious 

 error. It is also true that perfectly genuine 

 milk may vary greatly in density. The first 

 of the milking is alwa} T s poorer in cream, and 

 therefore denser, than the last. Unless, there- 

 fore, the conditions under wmich the sample of 

 milk is obtained are known, the number ex- 

 pressing its density is not conclusive in respect 

 to its genuineness. 



The volume of cream which a given milk will 

 afford depends on many conditions. Trans- 

 portation, shape of vessel, temperature, and 

 time allowed for cream to rise, are the chief 

 causes which affect the cream volume. A re- 

 markable decrease in the volume of cream has 

 also been noticed in milk samples purchased 

 in open market. Thirteen samples bought in 

 open market showed a percentage of cream 

 of seven. Thirty-four samples bought of the 

 dairyman, and known to be genuine, gave fif- 

 teen per cent of cream hy volume. This curi- 

 ous phenomenon will certainly be of interest 

 to milk-bu3'ers. 



The fat in a milk is not always in proportion 

 to the volumetric percentage of cream : there- 

 fore the determination of the fat (ether ex- 

 tract) gives a better index of the butter-making 

 value of the milk than is afforded by the vol- 

 ume of the cream alone. In a hundred and 

 seven analyses the average percentage of fat 

 was nearly five. 



The sugar is the most constant constituent 

 of milk. Over two hundred analyses show an 

 average percentage of sugar of milk of four 

 and six-tenths. Its determination optically is 

 quick and accurate. It is the safest single cri- 

 terion by which to judge of the purity of the 

 sample. 



The caseine of milk is composed of several 

 albuminoids. No attempt at separation of 

 these bodies has been made. The average 

 percentage of albumens in American milks is 

 markedly less than in those of other countries. 

 In the analyses made, the average per cent 

 is nearly three and a half. These analyses 

 show that the milks of the United States are 

 better adapted for butter than for cheese mak- 



ing. They are characterized in general by a 

 large percentage of fat and sugar, and a lower 

 content of albumen, than the milks of Europe. 

 It is the intention of the bureau to extend these 

 analyses so as to determine the localities of 

 the country where the best milks are produced, 

 to note the influence of change of season on 

 the composition of the milk, and to carefully 

 study the characteristics of the milk of differ- 

 ent breeds of cows, and the influence of vari- 

 ous foods thereon. 



Much of the value of analytical work on 

 milk which is clone in this country is lost on ac- 

 count of the many different methods of analy- 

 sis employed. These different methods render 

 it impossible to compare the work of various 

 analysts. The bureau hopes also, \>y a patient 

 trial of all the most approved methods, to be 

 able to unite the analysts of the country on 

 that procedure which a large experience may 

 pronounce the best. H. W. Wiley. 



NOTICE OF SOME RECENTLY DISCOV- 

 ERED EFFIGY MOUNDS. 



So few earthworks resembling animals in 

 their shape are known beyond the limits of 

 Wisconsin, that I send you an account of 

 several which I have discovered during the 

 past two seasons, the majority of which are 

 situated south of St. Paul, twentj'-five of them 

 being in this state. 



In the diagrams accompanying this article, 

 I have shown the outlines of a few of the most 

 interesting of these Minnesota effigy mounds, 

 and here give a short description of each, with 

 its surroundings. They are all reduced to the 

 same scale, 1 : 500. 



No. 1 is situated near the village of La 

 Crescent, and probably represents a frog. Its 

 greatest length is ninet} 7 -eight feet. The body 

 is two feet high, and the head eighteen inches. 

 Near it is a bird-effigy ; and within a quarter 

 of a mile there are five other bird- effigies, with 

 sixt3 T -nine round mounds and embankments. 

 The frog is on a terrace about fifty feet above 

 the Mississippi River ; and part of the mounds 

 are on the lower terrace, which is about thirty 

 feet above the river. 



No. 2 is on the town site of Hokah. It is 

 situated on a terrace some seventy feet above 

 Root River. From the extremity of the snout 

 to the tip of the tail, its length in a right line 

 is just sixty-two feet and a half, and the 

 body is a foot and a half in height. There 

 are two bird-effigies on a terrace some ten feet 

 below this one. Formerly there existed sev- 



