8 THE ANALYST. ON REICHERT-MEISSL’S METHOD OF BUTTER ANALYSIS, AND ITS APPLICATION FOR THE EXAMINATION OF BUTTER AND BUTTER SUBSTITUTES. BY DR. RUDOLF WOLLNY. (Continued from page 237.) THE following results were obtained by the method improved as described. The reagents were first tested, and then five blank experiments were made, 3 C.C. NaHO and 6 C.C. alcohol being treated without fat, precisely as the sample to be analysed, namely, they were boiled for 15 minutes under a reflux condenser, the alcohol distilled off in 15 minutes ; 100 C.C. of boiled distilled water were added, and the solution kept hot in a water bath for the same time, and ultimately distilled with 40 C.C. H,SO, and two small pieces of pumice; the distillate, measuring 110 c.c., was filtered, and 100 C.C.were titrated. The figure thus obtained, due to the volatile acid contained in the mda solution and to the carbonic acid unavoidably absorbed, was subtracted from the analytical results furnished by the various fats. In the second column of the subjoined table the corrected numbers are found, indicating exactly the vobtile f a t t y acids. ANALYSES MADE BY R. WOLLN~. C.C. deci-normal alkali NO. 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 Substance examined. 3 C.C. NaHO 9 9 9 , 1s 9 9 7, 9 , 9 9 77 Blank experiment 9 , 9 , 1, 9 , 9 ) 99 9 , 1 ) Beef fat Earthnut oil 9 , 2 9 9 , Sesam Oil Cotton Oil 9 9 ? f 7, ?, Oleomargarine Pure Butter 7, 7 Consumed Corrected. Calculated -A r--- - - *30 *30 -30 .no 4 5 -- - -3 5 -35 -30 *30 --.-2 5 -33 003 -33 *03 -33 .03 -33 .03 *33 .03 -3 3 .03 .44 .14 .39 .09 .39 .09 .39 .09 - - _- __ - - - - . _ - _- _- - - _ _ - - -_ - 1 - - - - __ 28.82 28.52 __ 28-93 28-63 - 28-71 28.41 - 28.93 28.63 _- 28.58 -_ 28.88 28-82 28-52 __ 28.82 28.52 - 82-77 28.47 --_THE ANALYST. 9 C.C. deci-normal alkali. NO. 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 156 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 , Substance examined. Consumed. Corrected. Pure Butter 28.82 28.52 9 , 9 9 28.88 28 58 9 9 9 9 20.45 20.1 5 2 } 9 9 9 9 ( 9 , 9 , Y, 99 ) 1.43 1.54 ;:;;} 9 , ;:;: \ 9 9 2 8.34 40 -1 9 , 9 9 ( 9 9 9 9 ,, ) 14-74 14.44 } Margarine 1 (2 per cent. Butter) -88 9 9 9 ) ( 9 , 9 9 19 ) -88 9 9 2 (4 $ 9 9 9 3 (6 99 9 , ) 1.98 9 ) ( 9 9 9 9 9 9 ) 2.04 9 9 ( 9 , 9 , ,, ) 2.70 9 , 4 (8 99 ,, ) 2.64 9 , 3 00 9 , f, (10 ? ? ,, ) 3.19 9 9 J 9 ( 9 9 9 ) .) 3.30 9 , 6 (50 7, ,, ) 14-63 14.33 9 , 7 (85 9 , ,, ) 24.64 24-34 19 ( 7 9 1, ,, ) 24.86 24.56 } 9 , 8 (90 9 , ,, ) 36.51 25.21 ?9 9 9 (?, 9 , ,, ) 26.18 25.88 } $ 9 9 (95 9 7 ,, ) 27-61 27.31 3 C.C. NaHO -17 - -2s __- .32 - ANALYSES MADE BY A. SANGER. Blank Experiment .22 - 9 9 9 ) -- 9 , P9 -22 9 9 -32 9 9 9 , 7 9 -- Oleomargarine -28 *06 9 9 9 8 -06 9 9 -28 -06 19 9 8 -06 9 , *22 -00 Pure Butter 29-25 28.93 ,? 2, 29.15 28-93 Y ? Y ? 29.1 5 28.93 9 9 9 , 28.82 38-60 9 , 9 9 28.82 28.60 9 9 ? 9 28.99 28.77 9 9 9 9 28.99 28.77 ?9 2 9 28.82 28.60 :g } ;:;; } 9 9 9 9 ( 9 9 7 9 ,, ) 2.15 1-93 } 9 9 ?, ( 9 , 99 Y9 ) 2-64 8.42 } Margarine 1 (2 per cent. Butter) *77 9 9 $ 9 ( 9 9 9 , 9 9 ) *88 9 , 2 (4 9 , ,, ) 1.54 9 , 19 ( 9 , 9 9 9 9 ) 1-49 9 9 3 (6 9 9 1, 4 (8 9 9 ,? ) 2.64 2.42 ,, ) 2.09 1.87 Calculated ’ - - - -62 1.20 1.77 2-34 2-92 14.35 24.35 25.79 27-23 *G2 1.80 1.77 2.34- - ~ THE ANALYST._. l o - C.C. deci-normal alkali. -7 ,-.----A NO. 180 181 182 183 184 185 186 187 188 Substance examined. Consumed. Margarine 5 (10 percent. Butter) 3.08 7 9 G (50 7 7 7 , ) 14.47' 9 9 7 (85 7 7 ) 24.31 7 7 9 7 t 9 9 7 7 ,, ) 3.0s 17 ? 7 ( 7 9 7 7 ,, ) 14.41 9 7 9 7 ( 9 7 7 , 7 7 ) 24.42 7 7 8 (90 7, ,, ) 26.7'4 7 9 7 9 ( ? 7 7, ), ) 25.95 9 7 9 (95 9 ) 9 7 ) 27.50 189 Cotton Oil 190 7 ) 7 ) Substance examined. Beef-fat.Oleomargarine. Earthnut oil. Sesam oil. Cotton oil. Butter mixture, 2 per cent. ?? 4 ,? 77 6 J ? ? ? 8 7 7 77 10 ?? ,? 60 j? 1, 86 ,, ?? 90 ? 7 J 7 9.5 ,, Pure butter. SUMMARY OF ANALYSES. Results by modified method. Min. 1 *03 *03 -03 *09 *55 1.13 1.68 2-34 2.86 14.19 24.09 26.52 37.28 28.41 - Max. 9 *03 *03 *03 -14 -66 1-35? 1.93 2.42 3.00 14-44 .24*66 27-31 "8.93 - 26.31 Corrected. 2.86 3.86 } 14.25 1 14.19 J 24.09 24.20 } 25-58 35.73 } 27.28 Mean. 3 *03 *03 S O 3 .11 -69 1.24 1.81 2.40 2-90 14.30 24.30 25.84 37-30 98.65 - Resnlts by Meissl method. Min. 4 -26 *19 *63 * i d 1-07 1 *84 3.39 2.83 3.16 16.04 24.94 26.04 2'7.76 28.93 - Max. 6 -92 1.29 1.07 -74 1.68 2.13 3 -60 3.31 3.89 15-88 2;5*3p 26.55 28.21 30.55 - Calculated. 2.92 14.35 24.3 5 25.79 27.22 I -~ )ifferences of 4 and i compared with 3.Min. Max. The soda solution used by myself had been filtered through glass-wooi, but was slightly turbid from suspended carbonate; that used by Sanger was quite clear, and the latter, therefore, found somewhat less volatile acid in the alkali used than I did. I n experiment 135 the soap solution had been allowed too become cold and had con- sequently gelatinised. The fatty acids separated from it were therefore solid and fused only towards the end of the distillation. The volatile acids obtained consumed only 20.15 C.C. instead of 28.65 C.C. It is necessary therefore that the soap solution should be decomposed when having a temperature of not less than 50 to 60° C . The correct figures of column 2 agree very well with the calculated ones.The volatile fatty acids passing into the distillate correspond therefore to the total quantities contained in the soap, and hence it is possible to calculate accurately the percentage of butter contained in mixtures, when the fluctuations of volatile acids in different butters have been ascertained by further experiments. A11 estimations hitherto made areTHE ANALYST. 11 defective, for reasons already stated. The same applies to the estimations of volatile acids in the various materials entering into the composition of butter-substitutes. The method of analysis, as modified by me, satisfies all reasonable demands which may be made, and complies with the requirements of Clause 2 of the German Margarine Bill. The object of the present investigation has so far been directed towards conducting the saponi~'ication in a manner free from sources of error ; I now proceed to the second part of the research, viz., to ascertain the conditions of distillation whereby absolutely uniform results may be obtained.This object has already been attained in materials yielding small amounts of volatile acids; but in the case of butter and mixtures con- taining a large percentage of it, differences tip to -7 C.C. have been observed. It became necessary therefore to study all conditions which might influence the result of the distillation. I n the first place, it appeared of interest to ascertain the total amount of volatile acids contained in butter, respectively how much could be obtained by repeated distillation of the decomposed soap.Experiments 191-20%-5 grms. butter-fat were saponified and decomposed as usual ; after 110 C.C. had been distilled off, 110 C.C. distilled water were added, and the like amount again distilled off; this was repeated twelve times. The distillates required the following quantities of deci-normal solution :- 1. 28-16 5. *33 9. 9 8 2. 2.20 6. *33 10. -28 3. *77 7. -3 3 11. -22 4. -50 S. -3 3 12. -32 a total of 33-05 c.c., the distillation not being quite completed even then. Similar series of experiments (203-217) were made with three other samples of butter. 1. 2. 3. Distillate 1 26.74 27.99 31.29 1, 2 2.97 2.86 3.41 9 9 4 -55 955 a 6 6 7, 3 -8% -77 1.10 9 9 5 -44 -44 -44 31-58 me1 36.90 The quantities of volatile acids obtained in the first distillate are therefore fairly proportionate to the total amounts, and no advantage could be derived for analytical purposes by repeated distillations. The molecular weight of tlie volatile acids contained in the various fractions of butter 3 were next ascertained by weighing the baryta salts. That of t,he first and main fraction was found to be 96, whilst the insoluble portion of the fatty acids passing over with the first distillate was 197, and with the further distillates 251. The soluble acids therefore chiefly consist of butyric acid, the insoluble ones correspond with palmitic acid. 100 grms. of a 5 per cent. solution of pure butyric acid were distilled and each portion of 10 C.C. of the disbillate titrated with normal soda. The various fractions consumed 10.0, 9.4, S.3, 7.3, 6.2, 5.1, 3 * S , and 2.9 c.c., the remainder in the retort, measuring about 20 C.C. using 2.0c.c. Na.130. (To be concluded.) Experiment 218.