HYDRAULICS AND HYDROSTATICS. 229 



Fig. 244. The Oleometer. (Fig. 244.) The point indicating 

 pure sperm oil, is and S on the top of the stem ; 

 that of whale oil, 100 and W. The temperature is 

 graduated at 60 degrees, and for every five degrees 

 colder you will deduct two marks ; and for every five 

 degrees warmer, add two marks. After you get the 

 correct graduation, then all variations will show you 

 the per centage of whale oil. Each mark on the 

 stem is two per cent. Price, $2.00. 



The Urinometer. (Fig. 244.) This small instru- 

 ment is intended to ascertain the strength or acidity 

 of the urine, and thereby determine the comparative health 

 of the body, particularly with reference to the disorder called 

 diabetes, or the involuntary discharge of urine. 



The graduated side of the scale is marked with degrees, 

 by which the comparison may be made on the reverse side ; 

 at the upper part is marked the letter W, being the point at 

 which the instrument rests when immersed in pure water. 

 The next division, marked by the letter H, is the point at 

 which it rests when immersed in urine when the body is in 

 good health ; the letter S is marked to signify strong, but a 

 less degree of health ; and the last division, the point at 

 which the instrument rests when the disorder of diabetes 

 has taken place, and its progress, may be ascertained by the 

 surface of the fluid marking an increased degree on the 

 scale. 



This instrument is accompanied with a small glass vessel 

 for containing the urine, one half ounce of which is sufficient 

 to float the instrument therein ; the whole is packed in a 

 small round case about four inches long. Price, $2.00. 



Urinary Cabinet. (Fig. 245, next page.) The cabinet 

 consists of urinometer in case, graduated glass for containing 

 the urine, bottles for acids, spirit lamp, test tubes, watch 

 glasses, dropping tube, thermometer, test papers, &c., com- 

 plete, as represented in the cut ; forming a useful and im- 

 portant apparatus for the medical practitioner, and the 

 whole of a size that may be conveniently carried in the 

 pocket. Price, $8.00. 



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