AGRICULTURAL CHEMISTRY — AGROTECHNY. 115 



Micro-organisms of maple sap. — II, Discussion of physical and chemical 

 data secured on maple sirups obtained from saps inoculated with micro- 

 organisms, C. H. Jones (Vermont Sta. Bui. 167, pp. 419-474, Pls. 2).— This 

 portion of the bulletin deals with the analyses of the maple sirups discussed 

 in the abstract above, and included 128 samples collected during 3 successive 

 sugar seasons. 



Tbe average moisture content of the 26 samples collected in 1909 was 33.67, 

 maximum 38.88, and minimum 29.44 per cent; of the 60 samples in 1910 the 

 average was 38.01, maximum 47.6, and minimum 32.46 per cent; and of the 42 

 samples in 1911 the average was 30.39, maximum 38.97, and minimum 26.76. 

 The remaining determinations made were color, flavor, score, sucrose, invert 

 sugar, total ash, soluble ash, and malic acid value. 



The summary of averages showed " the color averages 7.5, corresponding 

 closely to first grade. The darkest color was obtained in the samples located 

 in the ' sour sap, kept ' group. This group also showed the highest depreciation 

 from the control as regards color. The lightest color was secured In samples 

 grouped under the captions ' tin buckets ' and ' control.' The flavor averages 

 2.9, corresponding to a quality just below medium. The finest flavor was ob- 

 tained in samples grouped under the term ' tin buckets ' and ' control,' rating 

 as 1 and 1.4, respectively ; the poorest sample in this respect was located in the 

 group denominated 'last run, sour,' which included several buddy sirups. Ex- 

 cluding the samples rating 5 and 6 in flavor (buddy) from the color and flavor 

 averages, the average color and flavor figures thus revised fbr the remaining 

 116 samples are 7.5 and 2.6, resi^ectively, equivalent to an average score of 719. 



" The average moisture content for the entire 128 samples was 34.63 per 

 cent. This was practically the moisture percentage of a standard 11-lb. to the 

 gallon sirup. The average sucrose figures, 61.44 per cent, and the invert sugar 

 percentage, 1.6 per cent, agree quite closely with the averages 62.64 aud 1.49 

 per cent secured by H. Bryan [E. S. R., 24, p. 266] in an examination of 

 395 samples from al'l parts of the United States where maple products are 

 made." 



" The invert sugar present in the sirups shows extremes, calculated to a 

 moisture-free basis, of 0.12 and 28.35 per cent. Invert sugar results from the 

 hydrolysis or inversion of sucrose, caused by yeasts, molds, bacteria, acids, etc. 

 Thirty-two sirups, or a quarter part of the entire number of samples, carried 

 less than 0.6 per cent of invert sugar on a moisture-free basis, while 57 samples, 

 or 45 per cent, contained less than 1 per cent. Hence it seems fair to conclude 

 that an invert sugar content in maple sirup of much more than 1 per cent 

 can only be due to careless methods in handling or to delay in boiling the 

 sap, or to the subsequent fermentation of the finished product." 



"The average total ash figure on a moisture-free basis was 0.93 per cent, 

 and extremes are 0.74 and 1.44 per cent. The minimum figures occur In the 

 * last run, sour ' group and include considerable number of buddy sap samples. 

 . . . Twenty-eight samples were deficient in total ash in amounts varying from 

 0.02 to 0.18 per cent The deficiencies mainly occur among samples in the con- 

 trol groups. Eleven samples were low in insoluble ash, but the shortages were 

 very slight, varying from 0.01 to 0.03 per cent, the latter figure occurring but 

 once. There were 12 deficiencies in malic acid values, many of them being 

 very small and ranging from 0.01 to 0.16 per x;ent." 



" The average insoluble ash percentage was well over the standard in every 

 group, the minimum being 0.29, the maximum 1.01, and the average 0.59 per 

 cent. 



" The malic acid value was likewise above the standard limit with a minimum 

 of 0.71, a maximum of 1.21, and an average of 0.9 per cent. . . . The ash and 



