ZOOLOGICAL DEPARTMENT. o77 



U. S. DEPARTMENT OF AGRICULTURE, i 

 Divisiox OF Chemistry, [- 



Wcif^hiiigton, D. C. December 2o, 189:^. ) 

 Profkssok a. J. Cook: 



Dear Sik— I beg to enclose you a sheet givinfj the results of our analyses of the 

 samples of honey received from you. Somehow or other, you have omitted numbers 

 43, 51 and 52. The others are numbered as you sent them, and such information as 

 has been received in regard to them will be found on the sheet. 



The more careful examination confirms the preliminary results which I sent you in 

 my letter of the 21st of July last. There are some additional points to which I wish to 

 call your attention. 



Prof. Scovell, in looking over my analyses, called my attention to the fact that my 

 No. 9 must be wrong, as it differed so from his No. 9. (It is interesting to note that 

 this was a sample of honey dew honey. — A. J. C.) I then repeated the work with No. 

 9 and fovmd that it was exactly correct. He therefore suggested that his number and 

 mine were different samples, and at my request he sent me a sample of his No. 9, which 

 as you see is entirely different from mine. The No. 9 of Prof. Scovell polarized at 

 ;50° + 12.0; at 88° + 29.85; on inversion at .30° it polarized +5.5. You will see, there- 

 fore, that it is entirely different from the sample entered as my No. 9, and is evidently 

 one of the adulterated honeys, having either received treatment with glucose or else 

 being the product of the aphis from the pine tree. (From plant or scale lice not 

 necessarily from pine tree aphis, or even aphides — A. J. C) 



I desire to call your attention further to the samples of honey which at ordinary 

 temperatures show a plus polarization, and which do not have any notable percentage 

 of sucrose. These samples are Nos. ii, 47, 49, 50 and 56. Fifty-six, however, has quite 

 a notable proportion of sucrose. These are samples which show uniformly a low pro- 

 portion of invert sugar, away below the normal, but are not strongly enough right- 

 handed to indicate that they are mixed with glucose. I am inclined to think that these 

 give us an excellent clue for the detection of the aphis honey when taken especially 

 from the pine trees. (It would be better to omit the words '"pine tree" altogether, 

 and say simply honey dew, as most of this honey dew could not have come from pine 

 tree aphides, as there were few or no pines in the regions. — A. J. C.) 



I beg to call your attention further to this, that these honeys have uniformly a high 

 content of ash. Added to them is No. 55, which, although it polarizes to the left, has 

 an abnormally low percentage of invert sugar and an abnormally high percentage of 

 ash. I have not yet gotten data enough to make a positive assertion, but 1 believe that 

 a honey which polarizes to the right at ordinary temperatures, or even slightly to the 

 left, and which has an abnormally low jjercentage of invert sugar and abnormally high 

 percentage of ash. may be spotted at once as an aphis honey. This I make, of course, 

 guardedly and subject to subsequent correction, but you will see on studying the data, 

 how my results are borne out. For this reason I should be inclined to class the honey 

 No. 23 as a honey dew honey, because of its right-handed polarization (not very great). 

 its high percentage of ash and its abnormally lo\t percentage of invert sugar. Honeys 

 Nos. 4 and 6 both have right-handed polarizations, abnormally low percentages of invert 

 sugar, but the ash is not much above the normal. These, therefore, wovild be excluded 

 from the honey dew honeys. I admit that there are other honeys in the list which 

 have a high i)ercentage of ash, viz.. No. 39 (this was sent me from Mo. as basswood 

 honey. I questioned the fact, from the taste and appearance of the sample, as will be 

 seen by the table. If it were basswood, it was not unmixed. — A. J. C), which has so 

 high a percentage as to be suspicious. No. 36 (red honey probably from juice of ripe 

 red raspberries. — A. J. C), likewise with so high a percentage of ash as to be suspicious. 



But these honeys are strongly left-handed, and therefore could not be positively 

 condemned. 



I have added a column of polarizations at 88° temperature for this reason: Invert 

 sugar at that temperature is optically inactive and has no intiuence on the ray of polar- 

 ized light. Any polarization, therefore, which a body may have at that temperature, 

 must be due either to sucrose or other optically active bodies. If now we subtract 

 from the polarization o'f 88° the percentage of sucrose, what is left will indicate the 

 presence of dextrose and other right-handed bodies. In this way it is seen that all 

 suspicious honeys which we examined in this way have an abnormally high right- 

 handed polarization at 88°. This can also be taken as additional evidence of 

 adulteration. 



It appears to me that we are well on the road to being able to distingush louse 

 honey from true floral honey, as we are certainly able to distinguish glucose honey 

 from both. 



In regard to the percentage of whter-permit me to say that our determinations were 



48 



