THE TANNING TRADE OF NEWCASTLE, ETC. 261 



elephant's tusk, or from bone, neither of which take this beautiful red 

 colour in contact with sulphuric acid. The analysis quoted above 

 shows that the greater portion of vegetable ivory is pure cellulose, 

 but the reaction produced by sulphuric acid proves that other substances 

 are present, for cellulose does not become red with sulphuric acid. 

 Mr. Connel found in 1845 that vegetable ivory contained 81.34 per 

 cent, of cellulose, and that the other substances were, gum 6.73, legu- 

 mine 3.80, albumine 0.42 (that is, 4.22 of albuminous substances) oil 

 0.73, water 9.37, and ash 0.61 = 100. Filings of vegetable ivory dried 

 at 140° to 150 Q C. give 1 per cent, of ash. 



Payen found that these filings when boiled with caustic soda took a 

 yellow colour, a point confirmed by Baumhauer, who asserts that 

 potash does not produce any colour. The reaction of sulphuric acid on 

 vegetable ivory enables one to distinguish immediately between filings 

 of this substance and bone or ivory filings. It is owing to the well- 

 known action of this acid upon albuminous substances in presence of 

 sugar, and which has been utilized by Raspail in his microscopic re- 

 searches. But whether the sugar is formed by the action of the acid on 

 the cellulose, or pre-exists already formed in the substance is of little 

 import. 



Dr. Phipson, however, inclines to the first opinion, as the colour takes 

 a little time to show itself (five or ten minutes), and as Mr. Connel did 

 not find any sugar ready formed. The white pulp of the cocoa-nut 

 presents a similar reaction with sulphuric acid ; the colour produced is 

 first pink, then red, reddish purple, and, finally, in about sixteen hours, 

 a fine violet. The colours thus produced with vegetable ivory and 

 cocoa-nut disappear gradually in contact with water, like the fine 

 reddish-brown colour produced with essence of turpentine and sul- 

 phuric acid. 



THE TANNING TRADE OF NEWCASTLE AND 

 GATESHEAD. 



BY T. C. ANGUS. 



The following is the most correct account I have been able to obtain 

 respecting the tanning trade of Newcastle and Gateshead. Some of the 

 persons engaged in the trade have an objection to supply information ; 

 but I believe the figures appended to the paper will pretty nearly repre- 

 sent the actual transactions in this branch of local trade. 



At present we have only nine tanyaids in operation in Newcastle 

 four of some magnitude, the remainder small ones. Thirty years ago, 

 Newcastle was styled the leather metropolis of the north, and buyers 

 came from all parts to purchase. Public fairs were held twice a year, 



