This scum, which is from two to six inches thick, and of a pasty consistency, being swallowed by cattle when drinking, acts poisonously and rapidly causes death. The symptoms of the poisoning are stupor and unconsciousness, falling and remaining quiet (as if asleep), unless touched, when convulsions are induced, the head and neck being drawn back by a rigid spasm, subsiding before death. The poison causes the death of sheep in from one to six or eight hours; of horses, in from eight to twenty-four hours; of dogs, in from four to five hours; and of pigs in three or four hours. A _post mortem_ shows the plant is rapidly absorbed into the circulation, where it must act as a ferment, and causes disorganization. As the cattle will not touch the puddle where the plant scum has collected and become putrid, all they take is quite fresh, and the poisoning is therefore not due to drinking a putrescent fluid full of bacteria, as was suggested. When the scum collects and dries on the banks it forms a green crust. When, however, it is left in wet pools it rapidly decomposes, emitting a most horrible stench, like putrid urine; but previous to reaching this stage it gives out a smell like that of very rancid butter. A blue pigment exudes from this decomposing matter, having some remarkable properties. It is remarkably fluorescent, being red by reflected and blue by transmitted light; it appears to be a product of the decomposition, and allied to the coloring matter found in some lichens. * * * * * =ASTRONOMICAL NOTES.= BY BERLIN H. WRIGHT. PENN YAN, N. Y., Saturday, August 10, 1878. The following calculations are adapted to the latitude of New York city, and are expressed in true or clock time, being for the date given in the caption when not otherwise stated. PLANETS. H.M. H.M. Mercury sets 8 03 eve. | Saturn Rises 8 89 eve. Venus rises 2 42 mo. | Saturn in meridian 2 58 mo. Jupiter in meridian 10 52 eve. | Neptune rises 10 27 eve. FIRST MAGNITUDE STARS H.M. H.M. Alpheratz rises 6 54 eve. | Regulus sets 7 29 eve. Algol (var.) rises 8 34 eve. | Spica sets 9 24 eve. 7 stars (Pleiades) rise 10 53 eve. | Arcturus sets 0 08 mo. Aldebaran rises 0 17 mo. | Antares sets 11 24 eve. Capella rises 9 40 eve. | Vega in meridian 9 15 eve. Rigel Rises 2 23 mo. | Altair in meridian 10 27 eve. Betelgeuse rises 2 08 mo. | Deneb in meridian 11 19 eve. Sirius rises 4 24 mo. | Fomalhaut rises 9 34 eve. Procyon rises 3 59 mo. | REMARKS