18 MR ROBERT C. MACLAGAN ON 



could get. These were subjected to analysis for sugar in the laboratory under the care 

 of Dr Huntkr Stewart. 100 grammes were digested for six hours in streaming steam 

 100 c. 



The total bulk of the decoction so made was 1500 cubic centimetres. It contained 

 •1G(>6 per cent, glucose. Another 100 grammes yielded 2 - 49 grammes glucose. These 

 results show, then, that, decocted with steam, carefully selected heather tips yield 

 practically 2\ per cent, glucose. This seemed to give colour to the traditional possibility 

 of fermenting a decoction of heather flowers. 



Seeing, however, that the bees gather their honey from the flower itself, and not 

 from the stick, a quantity of the bloom, as free as possible from all contamination with 

 woody matter or leaves, was analysed at Gran ton, under the superintendence of 

 Mr Irvine, with the astonishing result that it yielded 17 per cent, of a substance 

 which reduced Fehling's solution, and which by ordinary tests would appear to be sugar. 

 To put this practically out of doubt, a decoction was made and yeast added to ferment 

 it. The result was a negative one ; there was no alcoholic fermentation and no dis- 

 engagement of carbonic acid, so that there was no evidence of fermentable sugar being 

 present in any proportion. 



Having failed in the laboratory, it seemed advisable to have a trial made by a 

 practical brewer, and Mr Andrew Melvin of the Boroughloch Brewery willingly 

 undertook the experiment. 



I supplied him with a quantity of pure heather blooms. He extracted 4 lbs. of this 

 with 6 gallons of water. To give an idea of the bulk of the heather flower, 2 oz. very 

 nearly equalled the bulk of one and a half imperial pints. 



To the extract obtained yeast was added ; at the end of ten days a fresh supply of 

 yeast, artificial warmth being maintained and the cask well rolled. There was no 

 appearance of fermentation. I examined it myself two days later, and its condition 

 was unaltered. The fluid was of a fine dark beer colour, perhaps a little more 

 inclined to red. When drawn from the top, it was bright and showed about 1^- 

 degrees of the saccharometer, a slight shade higher than before the yeast was added, 

 which Mr Melvin suggested might have arisen from a little wort adhering to the pressed 

 yeast. 



When the extract was first made, it had a marked woody flavour, but after the treat- 

 ment above described this had entirely disappeared. This seems quite a satisfactory 

 experiment from a brewer's point of view, and proves that a fairly strong infusion of 

 carefully picked heather flowers will not ferment. This entirely agrees with the 

 Granton laboratory experiment, which we should note was made alongside a solution of 

 grape .sugar of the same proportions as the pseudo-glucose, the grape sugar fermenting 

 while the heather infusion remained unaltered. 



Mr Melvin's extract was made in a copper jacket pan. The heather was added in 

 two quantities, the brewer conducting the experiment thinking that the first quantity 

 added was not sufficient. When I examined it, it had a perceptibly worty smell. It 



