1888-89.] Siueet Substance called Manna. 499 



tears. Some botanical books state that it possesses the 

 same properties as the officinal manna from Fraxinus Ormts. 

 But the Alhagi manna is plainly a quite different substance. 

 It dissolves in alcohol, giving crystals of cane sugar, and it 

 appears to consist largely of this sugar. There is, however, 

 mannite present in it also, as shown by the violet colour of 

 the solution obtained by dissolving the manna in water, 

 then adding a few drops of sulphate of copper and a little 

 caustic potash. But the mannite is evidently small in 

 quantity, whereas this substance forms from 40 to 60 per 

 cent, of officinal manna. 



Report on Temperatures and Open-Air. Vegetation at the Royal 

 Botanic Garden, Edinhurgh, from July 1888 to June 

 1889. By Robert Lindsay, Curator of the Garden. 



July 1888. — This was one of the most inclement summer 

 months we have had any experience of. From the begin- 

 ning of the month until its close there was an almost entire 

 absence of real summer weather. A long spell of cloudy 

 skies, with frequent heavy falls of rain and thunderstorms, 

 completed the record of the month. The lowest night 

 temperature was 35°, which occurred on the 1st and 31st of 

 the month ; and the highest was 52°, on the 14th. The 

 lowest day temperature was 54°, on the 15th; and the highest 

 75°, on the 19th. On the rock-garden 276 species and well- 

 marked varieties came mto flower, amongst which were 

 Campamda Raineri, C. Waldsteiniana, Cyananthus lohatus, 

 Decaspora thymifolia, Dianthus carthusianorum, JSdraianthus 

 dalinaticus, Ujnlobiuni obcordatum, Galax aphylla, Gentiana 

 arvernensis, Kniphofla caidescens, Leivisia rediviva, Lilium 

 Krameri, Lithosjjermum graminifolium, Mazus pumilio, Oro- 

 hanche elatior, 0. rubra, Primida Warei, Saxifraga fimbriata, 

 Spraguea umbellata, Statice Smvaroivi, Tropmolum poly- 

 phyllum, Veronica Bidtvilli, V. cupressoides, V. glavxio- 

 cceridea. 



AugvM. — The weather during August was slightly better 

 than that of the previous month ; still it was cold and 

 unsettled. The lowest night temperature was 36°, which 

 occurred on the 19th ; and the highest 58°, on the 1st. 



