On Plaster. 297 



a positive opinion) would have been most conformable 

 to experience ; I shall barely remark ; that it requires 

 no small degree of practice to enable any one to form 

 a tolerable estimate (for no accurate judgment has yet 

 been promulgated) of the quantity of plaster required 

 for any of the operations, (great or small,) in which it 

 is used. We know that common salt in small quanti- 

 ties is septic ; but in large portions it is the reverse. 

 Whether xh^ plaster does or does not, produce the same 

 eftects, no person has yet been sufficiently informed, to 

 be enabled to decide. I have always believed, that 

 there must be an inchoate putrescence in the subject 

 acted on, to give the plaster an impetus ; or, at least, 

 to evidence sudden and immediately perceptible ef- 

 fects. I have no doubt that it will, in due time, ope- 

 rate as a principal, be it solvent or septic ; but its pow- 

 ers are the soonest perceived, when it acts as an aux- 

 iliary. I have found its operation the most prompt, 

 when in contact with muck, or other animal or vege- 

 table manure ; in which the putrefaction had com- 

 menced ; as is most commonly the case in such sub- 

 stances, when collected, and properly arranged. 



The f.ict I wish to mention, will probably furnish 

 speculations to theorists ; and some useful information 

 for further experiment, to practical farmers ; should it 

 be deemed of importance sufficient to excite the atten- 

 tion of either. 



Two years ago, I scowered the ditches of a watered 

 meadow ; some whereof ran through boggy ground. 

 I had a great collection of tussocks, composed of aqua- 

 tic, coarse, grasses and weeds. I composted those ma- 

 terials, in the following manner ; — in two heaps. One 

 VOL. iir. p p 



