CHEMICAL SCIENCE. 215 



fectly applicable to all heavy bearings, after undergoing a slight pro- 

 cess, vet when deodorized, a chemical change or motion among its 

 particles was induced, by which it gradually thickened and became 

 unfit for lubrification. This fact led me to believe that rosin oil, under 

 certain circumstances, is an unstable compound. Hence, it was 

 desirable, to put it into a stable state by removing the body or bodies 

 which caused motion to occur. This was effected, and a perfectly 

 limpid and fixed oil was obtained, quite free from the peculiar odor of 

 rosin oil. 



In reply to certain queries propounded by the committee to an 

 eminent French chemist, communications have been received, which 

 fully show that we are not belu'nd the French manufacturers of rosin 

 oil, either in quality or quantity of product ; they have brought to our 

 knowledge a new preparation from rosin oil, in a semi-solid or lardy 

 state, now much used in France, w r ith a steady annual increasing 

 demand. This preparation is a substitute for the various well known 

 substances used in a fatty or soft-solid state for greasing wheels, gear- 

 ing and heavy shafting. Following the specific directions for the pre- 

 paration of this substance, it was found that a hard body like shoe- 

 maker's wax was produced ; an almost instantaneous solidification 

 occurring. After many trials, however, wdth great modifications of 

 proportions and time, the desired* compound was produced, possessing 

 the properties described, and appearing like the samples received from 

 France. This rosin fat has been used with success on iron gearing, 

 and my opinion is favorable to its use as a substitute for tallow, and at 

 a cost much below the average price of that article. The consumption 

 of tallow at the Merrimac Cotton Mills, for the year ending Novem- 

 ber loth, 1851, was 4,500 Ibs., which may be, probably, replaced by 

 the rosin oil substitute. 



In regard to the lubricity of the oil, the committee states, that rosin 

 oil can be used for lubrification, onlv when mixed with its bulk of 



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pure sperm oil. By accurate experiments it appears that spinning 

 machinery requires more, and weaving machinery less power, when 

 rosin and sperm oil are used, than when pure sperm oil alone is 

 employed. This may be explained by reference to the kind of 

 machinery, looms consisting chiefly of cam movements. Machinery 

 falls naturally into two classes ; 1st. That with fine or light bearings. 

 2d. That with cam movements, or with heavy bearings. All machines 

 of the first class will probably require more, and all of the second 

 class less power with the mixture of rosin and sperm oil, than with 

 pure sperm only. Deducting the less power required by some 

 machines, from the greater demanded by others, the committee would 

 avoid the question, whether the cheaper mixed oil would not pay for 

 the balance of greater power, by throwing out all the fine machinery, 

 as a class to which the rosin mixed oil is inapplicable. 



Experiments made with great care, with the same dynamometer, 

 and under the same circumstances gave the following results : The 

 average from the trials on nine spinning frames, shows that 13 8-10 

 19* 



