192 ON THE AMOUNT OF STARCH IN RICE. 



page 891, gives the quantities of water, which he found in five varieties 

 of rice freed from the husks, as my specimens were, as follows : — 



Madras rice 13.5 



Bengal rice 13.1 



Patna rice 13.1 



Carolina rice 13.0 



Carolina rice flour 14.6 



These results of Johnston's so closely come up to my own, that I am 

 induced to think the rice examined by Braconnot must have undergone 

 some drying process before examination. 



I was somewhat further confirmed in this by obtaining a much less per- 

 centage of starch than he had obtained. I did not in any way pick or prepare 

 the specimens for analysis, but endeavoured, as far as I could, to take an 

 average of each as I received it. And, perhaps, in this way I might have 

 obtained a somewhat less per-centage of starch than he did, operating pro- 

 bably upon a perfectly clean specimen; but any difference in this way would 

 not account for the much larger per-centage of starch which he got beyond 

 me. My results were as follows : — 



No. 1, First quality 76.6 



No. 2, Second „ 73.0 



'No. 3, Third „ 70.2 



No. 4, Fourth „ 69.1 



Average percentage on the four specimens 72.2 



Whereas Braconnot's results are in the one case 85.07, and in the other 

 83.8 ; but from the results of Boussingault, Horsford, and Payen, obtained 

 since Braconnot's analysis, no doubt exists that some of the nitrogen 

 and protein compounds in the rice were set down by the latter analyst as 

 starch, and Payen has made an analysis of dry rice, showing 86.9 per cent, 

 of starch. If I deduct from this the water found either by Johnston or 

 myself, this would reduce the per-centage to rather more than 73 per cent., 

 a result closely approximating to my own, and which I had obtained 

 without knowing of these results. 



I endeavoured to check my per-centages of starch by boiling the rice with 

 dilute acids, without and also with pressure, neutralising the acid, and 

 fermenting and distilling to obtain the alcohol, from the amount of which I 

 endeavoured to calculate the per-centage of starch. But the results which 

 I obtained I found to vary very much, and in no case did I get anything 

 like the per-centage of starch I got by the first process ; showing that a 

 considerable loss of starch is occasioned in its conversion into sugar by the 

 processes now in use for so doing. If some means were devised whereby 

 little loss were occasioned in this process of conversion, rice would become, 

 taking my per-centage of starch even to be the true one, a very cheap source 

 of spirit, especially applicable for manufacturing purposes. 



