In addition to the alkaloid and tannin the older writers asserted that tea contained a volatile oil to the extent of 0·6 to 1 per cent., and many of the qualities and deleterious effects of tea have been traced to the presence of this substance. The latest experiments, however throw some doubts on these early results. Thus in the report of Schimmel & Co. for April, 1897, it is stated (p. 39) that “in former years we endeavoured on several occasions to distil various kinds of tea in order to introduce tea oil ... we have, however, in no case succeeded in obtaining more than mere traces of oil,” and they conclude that in the hands of the early experimenters the oil found on distillation was due to the artificial flavouring of tea which was common at that time. Schimmel & Co. in their Report for April, 1898 (p. 50) refer to a report of the Botanical Gardens in Buitenzorg for 1896. It appears that experiments were made on a large scale, thus 2500 kilograms of freshly fermented tea leaves were submitted to steam distillation and 130 cubic centimetres or 0·0052 per cent. of oil was obtained.[10] It must be remembered that this oil was only found in freshly fermented leaves and from the minute quantity I think we may conclude that tea oil if present has little or no connection with the qualities and attributes of tea, or the deleterious effects to which it may give rise. A word or two with reference to the adulteration of tea. In former times a good many samples and especially of green tea were faced; this consisted in the addition of some colouring matter as Prussian blue, turmeric, or indigo; and sometimes black tea was faced with graphite. Another practice formerly prevalent was the addition of various leaves having a resemblance to tea leaves; and then there was the use of exhausted or spent leaves. All these forms of adulteration are now happily very seldom practiced. To shew the extreme rarity of tea adulteration in this country, in the 17 years from 1887 to 1903, 7595 samples were purchased under the Food and Drugs Acts and of these only 23 were found to be adulterated. These figures include 15 cases in 1898, and according to the report of the Local Government Board for this year many were of the description known as caper tea. This is one of the China varieties and consists of small granular masses made up by the aid of gum and starch, and this lends itself to the addition of sand and stones as actually happened in the cases in question. I think that with this exception of mineral matter, tea adulteration in this country may now be said to be practically non-existant. We have glanced through the general effects of the important constituents of tea. I now propose to consider the amount of harm which can be justly attributed to this popular article of daily consumption.