184 NEGRETTI AND ZAMBEA, HOLBOEN VIADUCT, E.G., 



and in some very confined localities even more than 90, as for example in parts of the Eed 

 Sea and Indian Archipelago. But although so warm on the surface it is very much colder 

 at a few hundred fathoms below, the temperature decreasing to 35, and even less." 



s. d. 



465 Universal Hydrometer, for all fluids from -700 to 1-900 . . . 12 



466 Confectioners' Hydrometer for Ice making ... 3s. 6d. and 056 



467 Ditto ditto for Syrups (see also No. 396) . . .056 



468 Hydrometer for Brine. A saturated solution of sea salt varies between 



1-1962 and 1-205 at 60 Fahrenheit 056 



469 Hydrometer for British Wines (Roberts' scale, to 26) . . .056 



470 Ditto, for Syrups (Specific Gravity) 056 



471 Ditto, for Soap (Beaurne's) 056 



472 Ditto, for Soap Lye (Specific Gravity) 056 



473 Olaeometer, for fixed oils, such as Sperm, Linseed, Rape, &c. . .056 

 From a competent authority we quote the following gravities : 



474 Linseed Oil , . . . 0-9347 

 Almond Oil . . . . 0-9180 

 Castor Oil . . . .09611 

 Palm Oil .... 0-968 

 Oil of Turpentine . . . 0-870 



Olive Oil .... 0-9176 



Rape Seed Oil . . . 0*9136 



Colza Oil .... 0-9136 



Nut Oil 0-9260 



Whale Oil , 923 



475 Acidometer, for estimating the strength of Acids (fig. 420) . .066 



476 Acetometer (or Acetimeter), for Vinegar . . . . . .066 



" Specific Gravity if determined by a Sensitive Hydrometer is a good test of 



the strength of genuine Yinegar. The following table of Messrs. Taylor is nearly 

 correct, or sufficiently so, for commercial transactions. 



" Revenue Proof Yinegar, called by the English manufacturer "No. 24, has a 

 Specific Gravity of 



1*0085, and contains of real acid in 100 ... 5 

 1-0170 ...... 10 



1-0257 .... 15 



1-0320 .... 20 



1-0470 .... 30 



1-0580 .... 40 



DR. URE." 



It should be observed that all Malt Yinegars contain mucilage, gluten, or 

 saline particles, which would, to a certain extent, veil the indications of the 

 Hydrometer ; therefore, if precise accuracy be required, recourse must be had to 

 Chemical Tests such as will be found described in all modern Chemical Books. 



477 Barktometer Glass for Tanner's use, from to 50 . . . .076 



478 Ditto ditto, to 80, divided to i degrees 10 6 



479 Barktometer, Gilt Metal, to 80, divided to | degrees with 



Thermometer, in Mahogany Box 330 



480 Citrometer, for Lime or Lemon Juice, as used by the Commissioners 



of Customs, specific gravity scale from to 100 in two instruments 

 for greater accuracy, complete with computing rule, and a delicate 



Thermometer in a case 1 16 



Like Yinegar, Lime or Lemon Juice often contains a very large percentage of 

 mucilage, so that the indications of the Citrometer should only be regarded as 

 approximate and not absolute. We also find that by the Act of Parliament 

 August 26th, 1867, 30 & 31 Yict., cap. 124, Lime or Lemon Juice for sbip's use 

 is to contain " fifteen per centum of proper and palatable proof spirits." Chemical 

 Tests must therefore be resorted to where definite results are desired. 



481 Negretti and Zambra's Hydrometer with Thermometer in the stem 



showing density and temperature in one instrument. Fig. 481 . 1 10 



