MEASUREMENT OF QUANTITY OF MATTER 



Investigation of these masses will show that all quantities 

 of matter not exceeding 201 grams, and not less than *001 

 gram, are represented to within -001 gram. It may happen 

 that a quantity of matter to be weighed differs in quantity 

 from any possible collection of the above weights ; but it will 

 differ by a quantity less than *001 gram, and this may be 

 negligible, or the balance may be unable to mark it. Some 

 balances, however, measure within smaller quantities. Larger 

 quantities are measured by larger standards ; and names are 

 given to multiples and fractions of a gram as seen in the table 

 below, which represents a portion of the metric system of 

 measurement. 



A mass of 1,000 grams is called 1 kilogram 



(equivalent to 2*2054 Ibs. avoirdupois). 

 A mass of '1 gram is called 1 decigram. 

 01 1 centigram. 



-001 1 milligram. 



For convenience in measuring quantity of length, or 

 distance between two fixed points, a scale is used. This may 

 be looked upon as corresponding with a set of weights. It is 

 a body of suitable material and form, marked so that the dis- 

 tance from any mark to the next is equal to a centimetre, or, 

 if greater accuracy is required, to '1 centimetre. Numbers 

 are written at intervals for readiness in reading the total 

 number of centimetres. If large distances have to be 

 measured, a centimetre is too small a standard ; while for 

 very small distances the centimetre has to be subdivided, in 

 the same manner as the gram is subdivided for accurate 

 weighing. The following table gives the names of lengths, 

 derived from the centimetre, according to the metric system: 



