652 
A METHOD OF DETERMINING THE AMOUNT OF SUGAR IN 
DIABETIC URINE. 
By Dr. Garrod. 
At a recent meeting of the “ Medical Society of London / 5 
Dr. Garrod brought before the members a plan he had 
discovered to accomplish the above object. At the same 
time he exhibited a small instrument named a Glucometer . 
It is constructed upon the fact, that glucose or diabetic 
sugar, when boiled with a solution of carbonate of potash, 
gives rise to an amber colour, and that the tint is in propor- 
tion to the quantity of sugar. The apparatus consists of a 
standard, a graduated tube of the same calibre as the stan- 
dard, and an accurately divided minim measure, the standard 
being filled with a solution of the exact tint produced by a 
known quantity (half a grain) of the diabetic sugar to the 
fluid ounce. The following is the method of using the gluco- 
meter : — A small quantity of the urine, say half a fluid 
drachm, either previously diluted or not, according to cir- 
cumstances readily ascertained, is to be accurately^measured in 
the small minim tube, and mixed with the same bulk of a 
solution of carbonate of potash of a given strength, and after 
the measure has been washed out w r ith a drachm or two of dis- 
tilled water, the whole is to be kept at the boiling point over 
a spirit-lamp for five minutes, either in a large test-tube, or, 
still better, a very small flask. After cooling, the coloured 
liquor should be transferred to the large tube, and distilled 
w 7 ater added until the tint exactly corresponds to that of the 
standard — a process which may be readily effected by hold- 
ing the tubes side by side, directing them to a moderately 
bright light. All the required data for determining the 
amount of sugar are now obtained. Suppose, for example, 
that the half drachm of urine employed in the quantitative 
analysis requires to be diluted so as to occupy six and a half 
drachms before the standard tint is obtained, such urine 
would contain six grains and a half of sugar per ounce ; for 
its bulk has been increased thirteen times, and therefore 
thirteen half grains, or six grains and a half, of sugar must 
be present. Again, suppose the urine had been diluted w r ith 
three times its bulk of w r ater before being employed in the 
glucometer, which when the urine is rich in sugar may be 
necessary, in order to prevent the graduated tube being of 
inconvenient length, then it is only required to multiply the 
amount of sugar by four to obtain the total quantity in the 
