Scientific Intelligence. — Geology, 377 



wise overspread the low gneissic hills to the N.W. of the Delaware, 

 which present no traces of having ever been submerged during the 

 cretaceous or any secondary period. 



22. Mr Ayres' objections to Professor Forbes* Deep-Sea Genera. 

 — Mr Ayres remarked, that of those genera of Echinoderms, which 

 Mr Forbes regarded as deep-sea genera, two or three are found in 

 North America, in water not two hundred feet deep. Terebratula, 

 which has been generally regarded as only an inhabitant of very deep 

 water, and whose structure has been described as admirably adapted 

 to the depth at which it has been found, and which Professor Owen 

 has demonstrated, cannot exist at a depth of less than two or three 

 hundred fathoms, exists at Eastport, Me., in water so shallow that it 

 can be taken by hand. In the same locality and position, radiata are 

 found, which have heretofore been thought to be only inhabitants of 

 deep water. Some of Professor Forbes' genera are also found in less 

 than ten fathoms of water. — {American Journal of Science and 

 Art, vol. xvii., No. 49.) 



23. Artificial Silicification of Limestone. — It is some years since 

 M. Kuhlmann of Lille proposed to preserve pieces of sculpture, &c, 

 by impregnating them with a solution of silicate of potash — SiO 3 

 KO + CO 2 CaO^SiO 3 CaO + CO 2 KO. This process has been 

 used on a grand scale in certain parts of the cathedral Notre Dame. 

 The architect of the cathedral reports as follows : — 1. That the in- 

 filtration of silica made " sur les terrasses et contre-fort du choeur, 1 ' 

 in October 1852, has preserved the stone from the green moss that 

 covers stone in moist places. 2. That the gutters and flagging of 

 limestone subjected to this process present surfaces perfectly dry, 

 covered with a silicious crust. 3. That upon the stone so prepared, 

 dust and spider webs are less common than upon the stone in the 

 ordinary state. The report also states, that tender stones have been 

 rendered hard ; they have lost part of their porosity, and after being 

 washed, they dry more rapidly than stones not silicified. The pro- 

 cess has succeeded completely on all calcareous blocks, whether iso- 

 lated, or forming part of the structure, new and old. 



It is not yet known how this process will act on mortars ; but if 

 successful, the silification of an entire monument may be accom- 

 plished, and its restoration when old. The whole exterior might be 

 thus covered with a thick bed of artificial silicate of lime, and a 

 whole edifice be protected by this means from all atmospheric causes 

 of destruction.* — (American Journal of Science and Arts, 2d 

 Series, No. 49. January 1854, p. 119.) 



* This process may prove highly useful in protecting the rapid decomposi- 

 tion of some of our finer building stones, that are exposed to much damp. The 

 overseers of our finer buildings ought, undoubtedly, not to overlook this impor- 

 tant notice. 



