CHEMICAL SCIENCE. 273 



loQL against GOO/., besides eating nothing when not at work, occupying 

 less space, and economizing an immense outlay in casualties by disease, 

 cost of attendance, and daily food. The author then alluded to Mr. 

 Romanic's steam cultivator, and to Mr. Usher's steam, plough, both of 

 which he thought might yet be made sufficiently powerful to work thirty 

 or forty acres, or even 100 acres, a day. The former machine would, if 

 required, deposit the seed and roll the land at one and the same time ; and 

 when not cultivating, it would be available for driving the threshing-ma- 

 chine, mill-stones, irrigating pumps, chaff and turnip-cutters, cake-breakers, 

 &c., requisite on most improved farms. It was also intended to work a 

 reaper at harvest. The new American threshing-machine was considered 

 to be an implement that would supersede all ours in cost, utility, lightness, 

 durability, and general enconomy ; but instead of working it by horse 

 power, as had been proposed by their Yankee friends, he had attached a 

 small portable steam engine of four-horse power to the machine, and 

 proved its advantage over a relay of eight horses. 



ON THE SEWERAGE OF MANUFACTURING TOWNS. 



The analysis, made by Dr. "\Vrightson, of a natural deposit from the 

 sewerage of Birmingham, formed near the embouchure of several sewers 

 opening into the Rea, showed the absence of all arnmoniacal salts and the 

 scarcity of phosphates, particularly alkaline phosphates, and, at the same 

 time, the presence of a large quantity of protoxide of iron, also of zinc, 

 copper, and other metals in the state of oxides and sulphurets. These 

 metallic salts, in the sewers, absorbed the sulphuretted hydrogen and am- 

 monia generated by decaying vegetable and animal matter, and, doubtless, 

 contributed to promote the health of the town. The deposit contained 

 when dried only I A per cent, of nitrogen (not as ammonia) and 3.5 of 

 earthy phosphates ; but about 11.7 of protoxide of iron, besides zinc, cop- 

 per, and other metals to the extent of two or three per cent. Froc. Brit- 

 ish Association. 



ON THE EQUIVALENCY OF STARCH AND SUGAR IN FOOD. 



The following is an abstract of a paper presented to the British Associa- 

 tion, 18-51, by Messrs. Lawes and Gilbert. At the meeting of the British 

 Association at Belfast the authors had given a paper " On the Composi- 

 tion of Food in Relation to Respiration and the Feeding of Animals," in 

 which they had illustrated, by reference to experiment, that, as our current 

 food-stuffs go, it was the amounts they supplied of the assimilable non- 

 nitrogenous rather than those of the nitrogenous constituents, which 

 measured both the amounts consumed by a given weight of animal, within 

 a given time, and the amount of increase obtained from a given weight of 

 food. The results, which formed the subject of the present communica- 

 tion, afforded further illustration of some of the points brought forward 



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