California Rock Salt 2jj 



duction was 494,414 tons. Carnallite contains theoretically 26.88 

 per cent, of chloride of potassium. 



If a deposit of this character should be discovered in connection 

 with one of our great salt deposits, its importance to California 

 and the Pacific Coast can scarcely be estimated. 



Mr. Hanks illustrated his essay with specimens which were ex- 

 amined under the microscope, and found to bear out well the de- 

 scriptions in the paper. The study of the specimens led to an in- 

 teresting discussion of the subject. 



Among the donations to the society's material, were two speci- 

 mens of diatomaceous earth from William Irelan, Jr., State Min- 

 eralogist. One was impregnated with asphalt, and was from the 

 mouth of Dos Pueblos creek, near Naples, in Santa Barbara 

 County, and the other was from Shasta County. The specimens 

 were referred to Mr. Riedy and Dr. Riehl for examination and 

 report. 



Edward J. Uickso7t, Recording Secretary. 



A SHARP FAMILY— THE CACTUSES.— I. 



The cactus family contains many of the most singular and 

 grotesque productions of the vegetable world. The flowers of 

 many are of the most gorgeous coloring; of others, the most deli- 

 cate and beautiful known either to botanists or horticulturists. 

 There is no end to the varied and striking forms of these plants, 

 which Paron von Humboldt declared to be 'as characteristic of 

 the new world as the heaths are of the old.' Some possess slen- 

 der, graceful stems; others resemble a load of cord-word hastily 

 thrown from a wagon — distorted in form, coarse and awkward in 

 habit. The Cereus giganteus, Engelm, has a diameter frequently 

 of three or four feet, towering to a height of thirty to sixty feet, 

 sending out branches or high 'elbows'— rising* like a huge can- 

 delabra from the sands of the desert regions where it abounds. 

 The pretty little Mamillaria micromeris, is a lop- shaped plant, 

 three-quarters of an inch in height and half an inch in diameter, 

 covered with a delicate lace-work that would be worthy of credit 

 even from fairy fingers. 



The larger portion of the species are found in exposed situations 

 in countries where no rain falls for months at a time — in the most 

 arid and desert portions of America, springing from crevices in 

 the rocks, from the sands, or from soil otherwise barren or seem-- 

 ingly sterile. 



The family is characterized by the late Dr. Engelmann, in the 

 Botany of California, as follows: 'Green, fleshy and thickened, 

 persistent, mostly leafless plants, of peculiar aspect; globular or 

 columnar, tuberculated or ribbed, or jointed and often flattened, 

 usually armed with bundles of spines from the 'areolae' , which 

 constitute the axils of the (mostly absent) leaves. Flowers with 



