Granite is the only mineral worthy of mention found in the county. Limestone exists in considerable quantities here and there, but as a rule it is too far from the railway routes to be profitably worked. It is, however, burned locally and applied to arable land as a manure. In the upper reaches of Strathdon, lime-kilns are numerous. By means of peat from the adjoining mosses the limestone was regularly burned half a century ago. To-day the practice is dwindling. A unique mineral deposit called Kieselguhr is found in considerable quantity in the peat-mosses of Dinnet, on Deeside. It is really the fossil remains of diatoms, and consists almost entirely of silica with a trace of lime and iron. When dried it is used as a polishing powder for steel, silver and other metals; but its chief use is in the manufacture of dynamite, of which it is the absorbent basis. It absorbs from three to four times its own weight of nitro-glycerine, which is the active property in dynamite. As found in the moss it is a layer two feet thick of cheesy light coloured matter, which is cut out into oblong pieces like peats. When these are dried, they become lighter in colour and ash-like in character. The Dinnet deposits are the only deposits of the kind in the country. Inferior beds are found in Skye. The industry employs 50 hands during the summer months, and has been in operation for 28 years. The beds show no sign of exhaustion as yet, and the demand for the substance is on the increase. 13. Other Industries. Paper, Wool, Combs. The industries apart from agriculture, work in granite, and the fisheries are mostly concentrated in and around the chief city. These, although numerous, are not carried on in a large way, but they are varied; and there is this advantage in the eggs not being all in one basket that when depression attacks one trade, its effect is only partial and does not affect business as a whole. Paper, combs, wool, soap are all manufactured. The first of these engages four large establishments on the Don and one on the Dee at Culter. Writing paper and the paper used for the daily press and magazines as well as the coarser kinds of packing paper are all made in considerable quantity. Esparto grass and wood pulp are imported in connection with this industry. Comb-making is also carried on, and the factory in Aberdeen is the largest of its kind in the kingdom.