[ 457 ] .^J' T T Af r^rl- ~ 



LXIX. On the Products of the Destructive Distillation of Animal 

 Substances. — Part II. By Thomas Anderson, M.D."^ 



I PROPOSE in the followmg pages to communicate to tlie 

 Society tlie progress of my investigation of the products of 

 the destructive distillation of animal substances, the first part of 

 which was published in the 16th volume of the Transactions. 

 Since that period, partly owing to my numerous avocations, and 

 partly to the inherent difficulties of the subject, less progress has 

 been made than I had hoped or expected, but still I have accu- 

 mulated some facts of considerable interest, which I think de* 

 serving of the attention of the Society. 



It may be remembered that, in the paper just referred to, I 

 announced the discovery, among those products, of picoline, 

 which I formerly obtained from coal-tar, and of a new base, to 

 which I gave the name of Petinine ; and I entered pretty fully 

 into the method adopted for the preparation of these substances, 

 and of certain other bases, the existence of which I merely indi- 

 cated, without at the time attempting to characterize them. On 

 proceeding to the more minute investigation of these bases, I 

 soon found that the quantity of material at my disposal was 

 much too small to admit of satisfactory or complete results, al- 

 though I had employed for their preparation above 300 pounds 

 of bone-oil. I found it necessary, therefore, to begin ab initio 

 with the preparation of the bases from another equally large 

 quantity of the oil ; and after going through the whole of the 

 tedious processes described in my previous paper, with the ex- 

 penditure of the labour of some months, I found my object again 

 defeated by deficiency of material. After various experiments, 

 which, though they led to no definite or conclusive results, served 

 to familiarize me with the nature and relations of the products 

 obtained, I made up my mind once more to begin again ; and 

 being resolved on this occasion not to be foiled in the same way 

 as before, I used for my new preparation no less than 250 gal- 

 lons of crude bone-oil, the weight of which was somewhat above 

 a ton. The result of this process, though involving an immense 

 amount of labour, has been satisfactory, not only in supplying 

 me with a large amount of material, but has also enabled me to 

 obtain many substances, some of them possessed of very remark- 

 able properties, which had escaped my observation when ope- 

 rating on a smaller scale. 



' The employment of so large a quantity of material has, as might 

 be expected, led to some modification of the process described in 

 the first part of this paper, which, though convenient enough on 



* From the Transactions of the Royal Society of Edinburgh, vol. xx. 

 part 2; read 21st April 1851. Part I. appeared in the September Number 

 of this Journal for 1848. 



