210 
MANAGEMENT OF DAIRY CATTLE. 
and he informs me that in a week he perceived a change in 
the richness of the milk, with an increase of butter. 
The vegetable oils are of two distinct classes : the drying 
or setting represented by linseed, the unctuous represented by 
rape-oil. They consist of two proximate elements, margerine 
and olein ; in all probability they will vary in their propor- 
tion of these, but in what degree I have not been able to 
ascertain. Though the agricultural chemists make no dis- 
tinction, as far as I am aware, between these two classes of 
oils, the practitioners in medicine use them for distinct pur- 
poses. Cod-liver oil has been long used for pulmonary com- 
plaints; latterly, olive, almond, and rape-oils are being 
employed as substitutes. These are all of the unctuous class 
of oils. Mr. Rhind, the intelligent medical practitioner of 
this village, called my attention to some experiments by 
Dr. Leared, published in the ‘ Medical Times, 5 July 21st, 
1855, with olein alone, freed from margerine, which showed a 
marked superiority in the effect; and I now learn from 
Mr. Rhind that he is at present using with success the pure 
olein, prepared by Messrs. Price and Co, from cocoa-nut oil, 
one of the unctuous class. That linseed, and others of 
the drying oils, are used in medicine for a very different pur- 
pose, it seems unnecessary to state. 
The olein of oil is known to be more easy of consumption 
and more available for respiration than margerine — a pro- 
perty to which its use in medicine may be attributable.* If 
we examine the animal fats, tallow, suet, and other fat, they 
are almost wholly of the solid class, stearine or margerine, 
closely resembling or identical with the margerine in plants ; 
whilst butter is composed of olein and margerine, combining 
both the proximate elements found in vegetable oils. 
It seems worthy of remark that a cow can yeild a far 
greater weight of butter than she can store up in solid fat ; 
numerous instances occur where a cow gives off 2 lbs. of 
butter per day, or 14 lbs. per week, whilst half that quantity 
will probably rarely be laid on in fat. If you allow a cow to 
gain 1 6 lbs. per week, and reckon 7 for fat, there will only 
remain 9 lbs. for flesh, or, deducting the moisture, scarcely 
3 lbs. (2*97) per week, equal to *42, or less than half a pound 
per day, of dry fibrine. 
The analyses of butter show a very varying proportion of 
olein and margerine fats : summer butter usually contains of 
olein 60, and margerine 40 per cent., whilst in winter butter 
these proportions are reversed, being 40 of olein to 60 of 
margerine. By ordinary treatment the quantity of butter 
* See Lehmann’s ‘ Physiological Chemistry.’ 
