292 



The Potatoe Disease. 



Vol. X. 



unplouglieJ meadows and pasture fields in 

 the vicinity of Philadelphia abound with 

 a species of grass so highly odoriferous as 

 to have obtained the name of Sweet-scent- 

 ed Vernal Grass. Botanists call it Anlhox- 

 anfhuin odoraium. Tlie scent somewhat re- 

 sembles that of vanilla. It grows about a 

 foot or eighteen inches high, rising above the 

 surrounding grass. Its stem is very small and 

 round, with a few long and slender leaves. 

 Its odor will alone be sufficient to distinguish 

 it from all other grasses found in our pas- 

 tures. When in blossom, the air is often 

 highly charged with its scent, and at this 

 time I seldom ride into the country without 

 gathering a handful of the grass to enjoy its 

 rich perfumes at leisure, and perhaps store it 

 away in a drawer. As it is so very forward 

 in its growth, so does it show the earliest 

 signs of decay. About the middle of June 

 the fields and meadows where ii abounds as- 

 sume a yellowish appearance from the dying 

 of the stems of the first growth. The cattle 

 press tliese aside to get a greener herbage, and 

 now the high flavor of our butter declines. 



The Sweet-scented Vernal Grass is a na- 

 tive of Europe, whence it has doubtless been 

 introduced into the vicinity of Philadelphia, 

 blended probably with other grass seeds. It 

 has long become naturalized, and now oc- 

 curs among other spontaneous herbage, dis- 

 puting the right of soil with the common 

 green grass, and never yielding possession 

 till turned under by the plough, after which 

 it clings to the unbroken fence and head- 

 rows. Though seldom, if ever regularly 

 sown here, it constitutes a part of the 

 growth of most English pastures, thriving 

 in nearly every kind of soil. The sweet 

 odor for which English meadow hay is so 

 noted, comes from the admixture of this 

 grass. It is, however, seldom, if ever sown 

 by itself, but usually mixes with the seeds 

 of other grasses adapted to the formation of 

 permanent pastures. It ranks rather low 

 on account of nutritious properties, but is 

 principally esteemed for its early growth, 

 and continuing to throw up fresh shoots till 

 the end of autumn. Indeed, the aftermath, 

 or second growth, is particularly prized for 

 grazing purposes. 



A chemical examination of the Sweet 

 scented Vernal Grass, shows that while it; 

 nutritious properties are less than those of 

 most other grasses, it is distinguished from 

 these by containing benzoic acid, or Jlowers 

 of benzoin, a substance possessing a pecu 

 liarly agreeable aromatic odor. An essen- 

 tial oil in which this resides can be distilled 

 from the grass, affording a pleasant perfume 

 It is undoubtedly this aromatic ingredient 

 that imparts to the milky secretion of the 



cow, the flavour so pleasantly manifested in 

 Philadelphia Spring-grass jjutter. When 

 we find milk so readily imbued with the 

 peculiar flavors of garlic, turnips, and other 

 substances upon which cows often feed, there 

 can be no room to doubt that a fragrant grass 

 freely eaten by cows, should likewise impart 

 its particular flavor to the milky secretion. 



If this very simple solution of the cause 

 of the high flavor of Philadelphia Spring 

 butter be true — and I have not the least 

 doubt upon the subject, you can at once per- 

 ceive that a pasture grass may be intro- 

 duced almost everywhere, which will com- 

 municate an exquisite flavor to butter. 



In London, Epping and Cambridge butter 

 are both greatly extolled for their high and 

 delicate flavor. The cows producing the 

 former, which is most esteemed, graze du- 

 ring summer in the wilJ pastures of Epping 

 Forest, and the high flavor of their butter 

 has been commonly ascribed to the wild 

 shrubs, plants, and leaves of trees which 

 they feed upon. The Cambridge butter is 

 also produced from cows that graze upon 

 natural pastures, one part of the year on 

 uplands, and the other in rich meadows. As 

 the Sweet-scented Vernal Grass is common 

 to the natural pastures of England, I doubt 

 not it may be found most abundant in those 

 of Epping, Cambridge, and other places most 

 celebrated for high-flavored butter. So far 

 as I can find by inquiry and research in 

 English books, the particular grass which 

 contributes the greater part, if not all the 

 fine high flavor to the best and most costly 

 butter, has never, as yet been identified. 

 Without such exact knowledge, this flavor 

 of butter must necessarily remain beyond 

 the control of the agriculturist, wherever 

 nature or accident has not provided the pas- 

 tures with the aromatic agent. 



I remain very respectfully yours, &c., 



G. Emerson. 



The Potatoe Disease. 



The following is an extract from a letter 

 from Professor Liebig to Walter Crun, of 

 Thornliebank, dated Giessen, 5th Novem- 

 ber, 1845. 



" The researches I have undertaken upon 

 the sound and diseased potatoes of the pre- 

 sent year, have disclosed to me the remark- 

 able fact, that they contain in the sap a con- 

 siderable quantity of vegetable casin (cheese) 

 precipitabie by acids. This constituent I did 

 not observe in my previous researches. It 

 thus appears, that from the influence of the 

 weatlier, or, generally speaking, from atmos- 

 pheric causes, a part of the albumen which 

 prevails in the potatoe has become converted 

 into vegetable casin. The great instability 



