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INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 23, No. 2
4 pictures an installation of blocks a t the clinker line of a boiler furnace. Examples of the durability of these refractory blocks under ext,remely severe service conditions are shown in Figures 5 and 6. Figure 5 indicates the durability of Corhart refractory in glass-tank service, the purpose for which it was originally developed. The lighter-colored test blocks of Corhart were built into a wall of ordinary high-grade glasstank refractory. When the tank was taken out of service, the Corhart blocks were practically untouched, while the other refractory had been eaten back as shown in the picture. Figure 6 pictures the interior of a high-duty forge furnace built of Corhart blocks as it looked after three months of service, the walls showing the durability of the refractory under the severe conditions imposed by this type of work.
Isolation of Quinic Acid from Fruits' E. F. Kohman and N. H. Sanborn NATIONAL CANNERS ASSOCIATION, WASHINGTON, D. C.
Figure 5-Comparison of Corhart Blocks with Ordinary HighGrade Refractory in Glass-Tank Service
as the result of the 15 per cent shrinkage during solidification. This difficulty has now been largely overcome, and blocks as large as 18 by 18 by 48 inches weighing about 1625 pounds are cast satisfactorily. As mentioned previously, all blocks must be cast to exact dimensions because of the high cost of grinding finished pieces. Developed first for use solely in glass tanks, Corhart refractories have a number of other indicated uses, as in the lining of the hot zones of rotary kilns, in the portion of modern boiler furnaces exposed to particularly severe duty, and in metallurgical equipment such as forging furnaces. The refractories have the advantage of long life and the minimum of repairs, which must be balanced against the greater first cost as compared with less durable materials. Figure
Figure 6-Appearance
T HA4Sbeen known that certain fruits, noticeably prunes Isystem and cranberries, tend to create an acid condition in the when eaten, even though their mineral content or ash after burning may be basic. I n the case of these two fruits it has been shown that the hippuric acid to which they give rise is responsible. These fruits contain only traces of benzoic acid, however. It has recently been shown that grape juice may likewise have an acid reaction in the system, although the mineral residue is strongly basic. The cause of the acid reaction created by grape juice has not been demonstrated. The writers have recently isolated quinic acid from prunes and cranberries. The basis for the method of isolation is the solubility of the lead and calcium salts of quinic acid compared with the relative insolubility of the same salts of other organic acids, and the low solubility of the double calcium salt of quinic and acetic acids. The solubility of the lead and calcium salts is being made the basis of a quantitative chemical method for determining quinic acid with a view to making a survey of the occurrence of quinic acid in other fruits. This is particularly desirable with those more or less closely related to prunes and cranberries. Some evidence has been obtained that indicates a considerable variation in its occurrence in different members of the plum family. Although this isolation is not quantitative, there are indications that there is approximately 1 per cent of quinic acid in cranberries and prunes on the fresh basis. Inconclusive evidence also suggests that grapes may contain 8ome quinic acid. This is to be determined conclusively, if possible, by its isolation from grapes. The presence of this interesting acid in these fruits merits consideration from the standpoint of plant physiology. It is possible that it is an intermediary in the synthesis of more complex structures. The form in which quinic acid exists in these fruits is of interest and may throw light on the above question.
of Corhart Blocks after Three Months' Service in HighHeat-Duty Forge Furnace
1
Received January 5, 1931.
