Transactions. 15 



spore {Oospore) with a hard coat, is also formed by the fungus 

 inside the leaves and stalks. These are set free by the decay of 

 the leaves and stalks, and in the spring germinate and infect new 

 plants. This being the life-history of the fungus, the remedies 

 found to be of service are easily explained. First, it is obviously 

 necessary to destroy, by burning, all dead or decaying remains. 

 Secondly, " earthing up " the tubers prevents their being infected 

 by the conidiospores. Thirdly, a remedy which has been toimd 

 thoroughly satisfactory in the case of the American grape vine 

 mildew, also caused by a Peronospora, consists in sprinkling the 

 leaves with a mixture of 8 kilogrammes of copper sulphate, 16 

 kilogrammes of chalk in about 130 litres of water. This need 

 only be sprinkled on the leaves once for all, and a broom dipped 

 in buckets of the liquid is found to be the most convenient 

 method. It is extremely probable that this would prevent the 

 spread of the potato disease, as the mixture prevents the conidio- 

 spores from forming swarm spores, and so infecting the leaf The 

 same remedy might also be used for the onion mildew, which is 

 due to another Peronospora, P. Schleideniana, and a trial is highly 

 desirable. 



II. A Strange Atmospheric Appearanc. By Mr ROBERT RoBSON, 

 Penpont. 

 On the evening of one of those splendid summer days in the 

 middle of July last, half-an-hour before sunset, a party of five of 

 us, a lady and four gentlemen, were standing in front of Penpont 

 Manse admiring the beautiful landscape directly in front of us— a 

 view which embraces the greater portion of Middle Nithsdale. 

 This view is bounded on the east and south-east by the Closeburn 

 hills and on the south and west by the hills of Keir, broken only 

 by the deep gorge at Auldgirth through which the River Nith 

 enters the valley of Lower Nithsdale. Owing to the configuration 

 of the hills and the low elevation of the manse, no view can 

 be possibly obtained of the valley beyond. It was near sunset, 

 and Sol himself seemed to cast one long, lingering look behind, 

 and, as if bestowing his parting blessing, shone forth with special 

 splendour, as he often does before sinking for the night behind 

 the hills of Tynron. One of our number drew the attention of 

 the party to the strange appearance of what at first sight seemed 

 to be the sky towards the south. Another of the party pointed 

 out the vivid outlines of a large field, with a wood to the south of 



