218 On poisonous Tea-leaves. 



of any use, or that they even turn round : for, if friction were 

 inversely as the velocity, they could (as we have already seen) 

 have no disposition to move, — nav, their inertia would always 

 oblige them to remain at rest. 



Several other necessary observations I shall pass over at pre- 

 sent, and conclude with one remark on Mr. T.'s statement al- 

 ready quoted, that {coft. par.) " the depth of impression is as 

 the force." Now this again obviouslv implies, that the resistance 

 to impression is uniform, or the same at any depth, than which 

 nothing can be more absurd ; since even on a fluid, the resistance 

 increases exactly as the depth. How much more quickly must 

 it do so on a hard road ! I am, sir, 



Your most obedient servant, 



Henuy Meikle. 



XXXVII. On poisonous Tea-Leaves. By JJfr. James Millar. 



To Mr. Tilloch. 



Sir, — X. HE regular establishwients for the manufactory of imi- 

 tation tea-leaves arrested not lonff ago the attention of the 

 public; and the parties by whom these manufactories were con- 

 ducted, together with numerous venders of the factitious tea, did 

 not escape the hand of justice. The fraud of manufacturing 

 sloe and white thorn leaves into an imitation of tea, which has 

 been drunk by the puijlic as the genuine beverage of tea, is com- 

 paratively harmless, u lien compared with the fraud lately detected 

 of manufacturing real genuine unsaleable tea-dust into tea, by 

 means of a process which renders the article absolutely deleterious 

 to health. In proof of this statement, you will have the good- 

 ness to lay before the public, through the medium of your Ma- 

 gazine, the following facts. 



A poor woman, having purchased an ounce of green tea, was 

 struck by the lively blue colour which the beverage made of it 

 assumed, on pouring into it a tea-spoonful of spirit of hartshorn. 

 This person (a char-woman) being in the habit of frequently 

 partaking of tea in other houses where she went to work, and 

 being constantly in the habit of adding a tea-spoonful of harts- 

 horn to the tea-i)everage, without having observed that singular 

 appearance which her own tea-leaves produced, made a com- 

 plaint to the grocer from whose shop the tea was purchased. 

 This person, unsconscious of any deleterious admixture, having 

 paid a fair price for his commodity, took a sample of the suspected 

 tea-leaves to Mr. Accum the chemist, who analysed it, and pro- 

 nounced it to contain copper. So unexpected a result induced 



the 



