247 



table gives the relative value per gaUon of sirup containing different 

 percentages of sugar, as calculated by the authors : 



The per cents of sugar oiveu above are calculated for a fairly good siruj). The 

 relative values in the last ci/lnmn are based ou these per cents, but will be nearly the 

 same for all except the poorest of sirups. The relative value is made use of as 

 follows : A weight of 11 pounds per gallon and 33° Baum^. is taken as the stand- 

 ard. Dividing the weight of the sirup by 11 gives the number of standard gallons. 

 Multiplying the price that is to be paid for 11-pound sirup by the relative vahie 

 ligure and dividing by 100 gives the price to be paid per standard gallon. 



[The following are the general conclusions from the investigations at the station 

 ou maple sugar :] 



(1) An accurate thermometer is the sugar maker's best guide in determining how 

 to handle his sirup to make a sugar that will draw the bounty. 



(2) When sap begins to boil its temjierature is about 213° F. ; as it boils down and 

 becomes thicker the temperature at which it boils rises, until towards the end it may 

 be 235°-240° F., or even as high as 245° F. 



(3) If the sirup had nothing in it but sugar and water, at a temperature of 230° 

 F. it would test 80°, and at 253° F. it would test 90°. A degree means 1 per cent of 

 sugar. 



(4) The sirup also contains mineral matter, malate of lime ("niter" or "sugar 

 sand"), biunt sugar, and toward the end of the season various materials resemlding 

 glucose, due to the starting of the buds and the beginning of the summer's growth 

 of the tree. 



(5) These extra materials at the beginning of the season are about one sixteenth 

 the weight of the sugar, and increase until in some very poor and black "last run" 

 they may amount to 30 pounds for every 100 pounds of actual sugar xnesent. 



(6) Hence 100 pounds of a first-class sirup boiling at 228° F. instead of containing 

 80 pounds of sugar, contains about 75 pounds of sugar and enough of the other mate- 

 rials (5 pounds) to make up the 80 iiounds, the other 20 pounds being water. 



(7) 8uch a sirup will have to be heated to 231'-' F. and some more of the water 

 driven off before it will contain 80 per cent of actual sugar, and to 243° F. to con- 

 tain 90 per cent sugar. 



