M. TECHNOLOGY. 509 



final finish, that prepared entirely with eggs. 5 C,XXXYII., 

 295. 



CEMENT FOE OVENS. 



A cement for covering the joints of ovens that has been 

 found excellent in practice and does not crack, but becomes 

 very hard, may be made by mixing equal quantities of finely 

 sifted wood-ashes and crushed and sifted clay, and adding 

 some salt and sufiicient water to form it into a dough, with 

 which the cracks are coated when the oven is cold. If this 

 cement is employed instead of clay in setting new ovens they 

 will be almost indestructible. 26 C, XL, 15. 



RAPID TANNING PROCESS. 



Le Havre of the 23d ult. gives the following account of 

 some interesting experiments which took place at Havre on 

 that date in connection with the new and rapid tanning- 

 process : "A numerous concourse of merchants, brokers, 

 manufacturers, etc., assembled at the Salle Saint-Cecile to- 

 day to witness some experiments in unhairing and tanning 

 by the Montoison process. Dr. Limon, of Manchester, super- 

 intended the proceedings. A variety of skins were experi- 

 mented on, from the fresh skin of a calf just killed to the old 

 skins of sheep and goats burned and hardened by the sun 

 of the tropics. There was, of course, some difference in the 

 treatment of each kind, more time being required to unhair 

 the drj^ hard skin than that fresh from the abattoir. A short 

 time was occupied in preparing the skins for the unhairing 

 chemical by soaking them in hot water. Subsequently they 

 received two coats of a pasty liquid on the inside, and were 

 piled up, inside to inside, to undergo the action of the com- 

 position. Many questions were put in relation to the proc- 

 ess, the reply to one of these being that the skin could bear 

 the action of the composition for two entire days without 

 being at all injured. After the skins had been soaked for a 

 short time, the wool came from them absolutely intact, and 

 quite equal to that shorn from the living animal. The man- 

 ner in which the wool came away from the skin by a touch 

 of the hand created considerable astonishment. In a few 

 seconds the skins were dipped in two special baths to neu- 

 tralize the unhairing composition. The afternoon was de- 



