95
In volumes,which by fixing
give
Carbon 4; hydrogen 8; azote 4; oxygen 2;- 4; - 2;
12 ;
4:
*J>ich is 4 vol. of carbonic acid, and 8 of ammonia; equivalent to ordinary carbonate°f-ammonia. The fermentation of urea plays an important part in the reciprocal officest Vegetable and animal existence. By its conversion into carbonate of ammonia, ureaDe comes a food fit for plants; and by the intervention of the mucous ferment which urinec °atains, that conversion Is effected. Thus the urea constitutes a neutral and innocu-° u s substance while it remains in the bladder, but is changed into a volatile, alkaline,*hd acrid substance, when it is acted upon by the air. Yeast added to pure urea mixed"^th water, exercises no action on it in the course of several days; but when added to'jpine, it soon causes decomposition, with the formation of carbonate of ammonia, and^engagement of carbonic acid. The deposite on chamberpots ill-cleaned acts as a veryPowerful ferment on urine, causing the complete decomposition of fresh urine in oneffi of the time that would otherwise be requisite.
Nitrous Fermentation, as exhibited in the formation of nitric acid from the atmosphere,n d consequent production of nitrates in certain soils, has been with much probabilityr aced to the action of ammonia on oxygen, as the intermedium or ferment.
Caseous and putrid Fermentations.— Curd is converted into cheese, when after being,° a gulated by rennet, it is left to itself under certain conditions; and this constitutes the.Pc distinctive character of caseum. In the production of cheese there is evidently theP'ervention of a peculiar ferment which is gradually formed, and the decomposition ofp curd into new products.
°r animal and vegetable matters to run into putrefaction, they must be in contact'th air and water, at a certain temperature; viz., between the freezing and boiling0ll Us of water. The contact of a putrid substance acts as a fqrment to fresh animalPd Vegetable matters. The reagents which counteract fermentation in general stop* s ° Putrefaction. In this process, myriads of microscopic animalcules make their ap-e Ptance, and contribute to the destruction of the substances.
p -u._ dispute having taken place between some distillers in Ireland and officers oft ^.Pise, concerning the formation of alcohol in the vats or tuns by spontaneous fermen-4 tj on, without the presence of yeast, the Commissioners of Excise thought fit to cause» e Se| dcs of experiments to be made upon the subject, and they were placed under myf 0 >al superintendence. An experiment was made on the 6th of October, with the°wing mixture of corn :—
- lOOlbs. 5 oz.
- 21 7
- 20 12
nJ hc! bruised corn was wetted with 26 gallons of water at the temperature of 160° F.,tip ’ after proper stirring, had 8 gallons more of water added to it at the average tem-the re of 194°. The mash was again well stirred, and at the end of 45 minutes^bole was covered up, having at that time a temperature of 138 F. Three hours8 hr, , H 16 gallons of wash only were drawn off; being considerably less thanUs have been obtained, had the apparatus been constructed somewhat differently,^ all be presently pointed out. The gravity of that wash was 1 060, or, in the lan-Sali ?e of the distiller, 60°. After a delay of two hours more, twenty additional<Pa of water at the temperature of 200° were introduced, when the mash was wellof ' e d, and then covered up for two hours, at which period 23 gallons of fine worts^Pacific gravity 1-042 were drawn off. An hour afterward 12 gallons of water atof ,, "hire added to the residual grains, and in an hour and a half 11 gallons of wortin le density 1-033 were obtained. Next morning the several worts were collected
Total, 3 Bushels, weighing -
- 142
8
s l>e,
hew
hffic ,
„ htash tun. They consisted of 48 gallons at the temperature 80°, and of a] 9l ’hen? r u Vlty 0465 when reduced to 60°. Being set at 80°, fermentation soonf? 18 , in f 5 lu tw ° days the specific gravity had fallen to 1-0317, in three days tonr le h to L da y s t0 1-013 > and in five da y s t0 I*° 12, the temperature having at last‘3-3 j '« F. The total attenuation was therefore 34§°, indicating the production
th by fp .i 18 of proof spirit, while the produce by distillation in low wines was 3-22;4 shced ctlfi cation in spirits and feints it was 3-05. The next experiment was com-it ealW 011 J he 12th of October, upon a similar fixture of corn to the preceding.£1’ iv a „ „, of w °rts of 1'043 specific gravity were set at 82° in the tun, which nextVe d ays t e , nuated t0 ] ' 0418 j in two days to 1-0202, in three days to 1-0125, and int0 T0105, constituting in the whole an attenuation of 32p, which indicates