184 



On Tussac Grass. 



It appears, from my own experience in Lewis, that the tussac 

 grass there, as in its native region the Falkland Islands, requires 

 to be within the near neighbourhood of the sea ; that is, within a 

 quarter of a mile, so as to catch the driving spray of the sea. 



James Matheson. 



Agricultural Chemistry Association^ 



8, Bank Street, Edinburgh. 

 Dear Sir, 15 September, 1847. 



I have the pleasure of enclosing the results of a comparative analysis 

 of the three specimens of Tussac Grass, which you have sent here for 

 examination — the one of last year, and the two of this season. You will 

 observe that the proportion of watery extract hitherto considered to repre- 

 sent the nutritive vakie of grass, is greater in the Tussac Grass of the 

 second than in that of the first year (1846). 



This appears most clearly in the third line of No. 1. When the pro- 

 portion of soluble matter in the dried plant is compared, that which you 

 gave us last year was less succulent, or dryer than that we received this 

 year, as the proportion of water in the two will show you. Hence 

 the proportion of matter extracted by water from the grass of last 

 year appears greater ; though in reality, when compared in the dry 

 state, water extracts more from the whole plant of this year. You will 

 see also, however, that the under portion contains very much more soluble 

 matter than the upper part. I would draw your attention further to No. 2, 

 in which are embodied results not hitherto obtained from any other grass, 

 and which, therefore, are not comparative. 



In this table you see that potash extracts a considerable additional 

 quantity, which water does not take. This I believe is also to be included 

 in the proper nutritive matter of this grass. 



In protein, or musile-forming compounds, it is also richer : in fact, as 

 much so in the dry state as dry wheat or oats. I need not say, therefore, 

 that, according to the results, Tussac Grass ought to be very nutritive. 



Yours, &c. 



Chas. Lawson, Esq. (Signed) Jas. T. W. Johnston. 



No. 1. — Proportion of Nutritive Matter extracted by Water in two samples 

 of Tussac Grass grown on the Farm of Holm, in the Island of Lewis, 

 from Seed sent by Mr. Matheson, M.P., proprietor, to Mr. Scobie, 

 Chamberlain and Tenant of said Farm. 



100 parts of the Grass in the state it "was sent 

 to the Laboratory contain — 



Water .... 



Watery Extract 



100 parts dried at 212" contain — 



Watery Extract 



Analysed 

 by Dr. 



Fromhog, 



Sept. 1846. 



45-50 

 9-4 



17-24 



Analysed by Dr. Valcher, 

 September, 1847. 



Lower 

 Part. 



86-09 

 4-34 



Upper 

 Part. 



75-27 

 3-64 



31-17 I 14-72 



Whole 

 Plant. 



80-68 

 3-99 



22-94 



