REPORT OF THE CHEMIST 193 



SESSIONAL PAPER No. 16 



As will be seen by an examination of the tabulated data, three cows were em- 

 ployed, one of which was giving an exceedingly rich milk, the two other milks of 

 average quality. In addition to the testing of the fresh milk on three separate occa- 

 sions, milk preserved by (1) formaldehyde, (2) corrosive sublimate, and (3) potassium 

 bichromate — substances used in conjunction with composite testing by the Babcock 

 method — was examined. 



The data of the investigation include percentages of fat by Babcock test, the per- 

 centages of protein and of casein, or curd, by chemical methods and the results from 

 Hart's tester. The accuracy of the Hart test will be determined by the degree of 

 accord between its results and the percentages of casein as ascertained by chemical 

 analysis. 



Fresh Milh. — In two of the seven determinations the diiferences between the 

 chemincal results and those with the Hart's tester were less than one-tenth of one per 

 cent ; in two, between one-tenth and two-tenths, and in the remaining three cases the 

 differences ranged between two-tenths and three-tenths. It seems therefore that with 

 fresh milk the percentage of curd obtained by the test is, for all practical purposes, 

 sufficiently close to the amount actually present. Our work, however, showed that it 

 was necessary to follow the directions carefully if satisfactory results were to be 

 secured. 



Milh containing Preservatives. — We find that the presence of the preservatives 

 formaldehyde, corrosive sublimate and potassium bichromate, seriously interfered with 

 the accuracy of the test. They keep the pellet more or less loose and spongy, and thus 

 give readings considerably higher than those obtained with the same milk to which no 

 preservative has been added. Further, concordant duplicate readings were found 

 difficult to obtain — a fact that indicates the unreliability of the test made under these 

 conditions. 



WELL WATERS EROM: EARM HOMESTEADS. 



Though we received during the year 178 samples of water only 96 were submitted 

 to ' a complete sanitary water analysis.' Of the remainder, some were specially ex- 

 amined as to the presence of ' alkali ' or an excessive saline content, while many by 

 reason of the small quantity sent, dirty corks or containers, &c., had to be rejected. 



Of the 96 now reported on, 40 were from Ontario and 33 fi'om Quebec; the remain- 

 ing 19 being from the other seven provinces of the Dominion. 



As regards their quality, we adjudged 26 as pure and wholesome, 32 as suspicious 

 and probably dangerous, 26 as seriously polluted and 12 as saline. The particulars 

 of the analyses, with a condensed pronouncement as to quality, are given in the ap- 

 pended table. 



While it may be impossible to say anything new regarding the importance of pure 

 water and the danger that lurks in the barnyard well, having brought such matters 

 before our readers in every succeeding annual report ^ince the institution of the 

 Experimental Farm system, we do not apologize for again issuing a word of warning 

 to those drawing their supply from shallow wells situated in the vicinity of farm 

 buildings or of accumulations of filth. The results of twenty years' investigation have 

 shown unmistakeably that it is quite exceptional to find a water from such a source 

 free from pollution. Almost invariably in such waters the evidences of the presence 

 of excrementitious matter are clear and strong. It is well to remember that a soil 

 may become so saturated with organic filth that it can no longer perform its office of 

 purification, and that under such a condition the water that passes through it on its 

 way to the well must.be unwholesome and a menace to health. Every one ought to 

 know now-a-days that many serious disorders, prominent among which is typhoid 

 fever, are frequently conveyed by polluted water — indeed that such is by far the most 

 common means of disseminating many germ diseases and causing an epidemic. 



16—13 



