ON THE AMOUNT OF STARCH IN RICE. 191 



decorations ; and the artistic grouping of them with grasses, &c, would 

 furnish another branch of employment to our large surplus female popu- 

 lation, who ought to be encouraged and educated in the manufacture of 

 many little elegancies, for which we are now entirely dependent upon the 

 foreigner. 



ON THE AMOUNT OF STARCH IN RICE. 



BY DUGALD CAMPBELL, ANALYTICAL CHEMIST TO THE BROMPTON 



HOSPITAL, ETC. 



A few weeks ago, I was called upon, professionally, to examine some 

 Pinky Madras rice, in order to ascertain what per-centage of starch it con- 

 tained ; and as there appears to be considerable obscurity upon this point 

 generally, and even among persons who use rice for manufacturing pur- 

 poses, it occurred to me that the result of my experiments, together with a 

 few remarks upon the subject generally, might not be judged valueless by 

 the readers of the Technologist. 



There were four specimens, representing four qualities, of this rice 

 examined. These I procured from a broker of the highest respectability in 

 the City. The first specimen examined was of a very superior quality ; the 

 fourth was of a low, but still of a good low quality ; the other two were 

 intermediate between these. 



The process I followed for obtaining the starch was based upon the first 

 of two processes described in the specification of a patent granted to the 

 late Mr. Orlando Jones in 1840. Only I steeped the rice, whilst whole, 

 with an additional solution of caustic soda ; and I likewise drew off the 

 water, holding the starch in suspension "from the other matters which deposit 

 much quicker than the starch," without allowing it to stand for more than 

 one-eighth of the time stated by him ; but this decanting I repeat several 

 times. I also ascertained the per-centage of water contained in each of the 

 specimens. It was, on the whole, uniform, considering that there was a 

 very apparent difference in their quality, and was as follows : — 



No. 1, First quality 13.64 per cent. 



No. 2, Second „ 13.21 



No. 3, Third „ 13.72 



No. 4, Fourth „ 13.72 



n 



Average per-centage on the four samples... 13.57 



Hitherto I had only been familiar with the results of the analyses of rice 

 by Braconnot, which are quoted in most books, and which in one case gives 

 5, and in the other 7, as the per-centage of water. I was, therefore, some- 

 what surprised on obtaining the large amount which I did ; but on looking 

 further into the subject, I found that the late Professor Johnston, in his 

 "Lectures upon Agricultural Chemistry and Geology," published in 1847, 



