The article discusses the discovery and analysis of a new mineral, schultenite (PbHAsO4), which was identified from carefully selected crystal fragments. The mineral was found to have high refraction, birefringence, and dispersion. The crystallographic data agreed with previously determined artificial crystals of lead hydrogen arsenate, prepared by Baron A. de Schulten in 1904. Schultenite is suggested as the mineral name for the natural monodical crystals, and it is also known as "lead arsenate," used as an insecticide. The article mentions that other specimens of this mineral may exist in collections from the Tsumeb mines. Additionally, the article addresses the anomalous flocculation of clay, where calcium salts accelerate flocculation compared to sodium salts. The author argues that this behavior is not anomalous when compared to other ions and emphasizes the importance of using highly purified clay to ensure the accuracy of experimental results. The article also reports on persistent solar prominences observed over a period of 71 observing dates, noting their grandeur and the repeated appearances of the same formation. The author, A. F. Alfred Buss, provides detailed observations of the formation's characteristics and its changes over time. Furthermore, the article corrects an error regarding the first attempt in Great Britain to use aeroplanes for crop spraying, which actually occurred in 1922, not 1926. The experiment, conducted by Major R. F. Bartlett, aimed to control pests in a cherry orchard using a proprietary dust. Lastly, the article announces the availability of the International Code of Zoological Nomenclature, published by the Washington Biological Society, for a price of one dollar.The article discusses the discovery and analysis of a new mineral, schultenite (PbHAsO4), which was identified from carefully selected crystal fragments. The mineral was found to have high refraction, birefringence, and dispersion. The crystallographic data agreed with previously determined artificial crystals of lead hydrogen arsenate, prepared by Baron A. de Schulten in 1904. Schultenite is suggested as the mineral name for the natural monodical crystals, and it is also known as "lead arsenate," used as an insecticide. The article mentions that other specimens of this mineral may exist in collections from the Tsumeb mines. Additionally, the article addresses the anomalous flocculation of clay, where calcium salts accelerate flocculation compared to sodium salts. The author argues that this behavior is not anomalous when compared to other ions and emphasizes the importance of using highly purified clay to ensure the accuracy of experimental results. The article also reports on persistent solar prominences observed over a period of 71 observing dates, noting their grandeur and the repeated appearances of the same formation. The author, A. F. Alfred Buss, provides detailed observations of the formation's characteristics and its changes over time. Furthermore, the article corrects an error regarding the first attempt in Great Britain to use aeroplanes for crop spraying, which actually occurred in 1922, not 1926. The experiment, conducted by Major R. F. Bartlett, aimed to control pests in a cherry orchard using a proprietary dust. Lastly, the article announces the availability of the International Code of Zoological Nomenclature, published by the Washington Biological Society, for a price of one dollar.