322 



REPORT OF NATIONAL MUSEUM, 1899. 



The following quotation from an English writer will serve to show 

 the advantages gained by a use of talc in paper making: 



There is a decided advantage in substituting agalite for China clay, because not 

 only is there an increase of dry paper, but such is obtained by a saving of fiber, as 

 well as a decrease of the waste in the actual loading material and a lessened amount 

 of polluting matter to be dealt with. Moreover, the fibrous character of the agalite 

 causes it to yield a paper of higher class quality than is the case with China clay. 

 The extra gloss which it is possible to obtain with papers containing agalite is shown 

 in various American journals and books. 



The soapstones are suited for a considerable range of application. 

 Although so soft, they are among the most indestructible and lasting 

 of rocks, but are too slippery and perhaps of too sombre a color for 

 general structural purposes. At present the chief use of the material 

 in the United States is in the form of thin slabs for sinks and stationary 

 washtubs. At one time it was quite extensively used throughout New 

 England in the manufacture of stoves for heating purposes and to some 

 extent for fire brick, the well-seasoned stone being thoroughly fire- 

 proof. The putting upon the market of unseasoned materials or of 

 material with bad veins, which caused the stone to crack or perhaps 

 fly to fragments when subjected to high temperature, aroused a preju- 

 dice against the employment of this material, and the manufacture is 

 stated to have been to a considerable extent discontinued as a conse- 

 quence. In the manufacture of either stoves or washtubs slabs of 

 considerable size, free from segregation nodules of. quartz, pyrite, or 

 other minerals or from dry seams, are essential. As but few of the 

 now known outcrops can furnish material of this nature, the main 

 part of the business of the country is in the hands of but two or three 

 companies. The waste material from the quarries, or the entire out- 

 put in certain cases, is pulverized and used as a lubricant or white earth, 

 as is the micaceous variety. 



13. PYROPHYLLITE; AGALMATOLITE; AND PAGODITE (IN PART). 



This is a hydrous silicate of aluminum corresponding to the formula 

 H 2 O, A1 2 O 3 , 4SiO 2 . The analyses given below show the average com- 

 position of the material as it occurs in nature: 



The mineral is not known in distinct crystals, but occurs rather 

 in foliated lamellar, massive and compact forms, closely resembling 

 some forms of talc, for which its soapy or greasy feeling renders it 

 very likely to be mistaken, though its hardness (2 to 2.5) is somewhat 



