NATTTRE OF EXAMINATIONS MADE. 



It is rarely necessary to make all the tests given in the following 

 list, as usually a few determinations will definitely show the value of 

 a sample for a given purpose. The nature and extent of the exami- 

 nation to be made can only be determined after the receipt of the 

 sample and of a full statement from the sender as to the object of the 

 examination that is, whether the value of the paper for a given pur- 

 pose is to be determined or its agreement or disagreement with 

 certain specifications is to be established. 



At present the Leather and Paper Laboratory and the Micro- 

 chemical Laboratory are equipped to make the following physical 

 and chemical tests, classified as quantitative and qualitative: 



QUANTITATIVE TESTS. 



(1) Kind of fibers or stock, i. e., rag, esparto, spruce, ground wood, etc. 



(2) Quantity of each kind of fibers or stock as per cent of rag, of spruce, of manila, etc. 



(3) Average length of fiber. 



(4) Weight per square meter or per ream. 



(5) Thickness. 



(6) Mean breaking weight. 



(7) Mean breaking length. 



(8) Loss of strength on folding. 



(9) Mean stretch. 



(10) Loss of stretch on folding. 



(11) Transparency. 



(12) Moisture and ash. 



(13) Absorptive power of blotting paper. 



QUALITATIVE CHEMICAL TESTS. 



(1) Kind of sizing. 



(2) Character of sizing. 



(3) Kind of loading. 



(4) Reaction. 



(5) Bleaching agents. 



(6) Chlorids and sulphates. 



DESCRIPTION OF QUANTITATIVE TESTS. 



Inasmuch as strength varies with the direction of the paper, tests 

 are made on strips cut both lengthwise and across the sheet. The 

 average of these tests gives the "mean" mentioned in the following 

 descriptions. All of the strength tests are based on an atmospheric 



[Clr.84] 



(8) 



