(382 
assertion that albumin and gelatin give the reaction is erroneous. On 
the contrary, egg albumen impedes or prevents the oxidase reaction on 
guaiacum, as does alsomuch tannin. Itmay be added here that among 
other substances silver nitrate also yields a blue coloration, especially 
in presence of a very small amount of ammonia. Such blue reactions 
are not restricted to certain limits of temperature as the reactions of 
oxidizing enzyms are. 
Still more attention to control tests must be paid when materials 
which are not fresh are to be tested; for, while the fresh tobacco leaf 
never contains nitrites, sweated tobacco may contain them. This must 
be considered when the tests are made with sweated tobacco. (See on 
this point also page 55 of this report.) 
The following tests were made with samples, not collected personally, 
but received by mail. 
Tobacco cured but not sweated. 
A.—_SAMPLES FROM MARYLAND. 
[The samples were grown in 1898 on the farm of the Maryland Agricultural Experiment Station. 
Only the last mentioned was from another locality. ] 
Date. Sample. Oxidase. Peroxidase. Remarks. 
1899. 
Mar. 13 | Connecticut seed leaf..-. 
(a) Lowland plot -..--- INONG® ser syeteeosiisiers -.| Moderate ..... 
| (b) aU plandsploteeecace||eeee GO eases eee eee Lraceeeneeere C 
130 |eEaibanawsee de seenaases eee Moderate 22-22 2:5- <2 Minch sees Cured without artificial 
153 Sinan Senile ss eecccese Less than Habana-.|...---..... Seren heats 
BIB EA aK 2) Wires eo a cecimeeneooS INONGE2 See Ses oasec Mucha sees aes 
ie} | ep yrs sedoagaacasaudds Moderaterne see ees seer CORES. 
18 | Maryland broad leaf..... Slights235-2 2 eer Moderate ...-. 
IGS Wai geaniey ssseeconsesesese< Mod erates nese Imibense@meaaeee 
18 | Sumatra seed.--....-.--- INONGN 2 Steteewecoees Moderate ...-. 
18 | Connecticut broad leaf--.-|.---- OM se ee eseeeioe AWENOOS coaas oss All subjected to the flue- 
183 MEabanayseed=aasseaeeaene|se Gn) Paasdasencooas Moderate .....|| curing process. 
UG | JRO seotceooseseeosolosous (i sesemeenoecel|s Fra Onan 
Apr. 4 | Maryland tobacco ..-....|.-..- os tee ssissne fee oe doze tae ae 
B.—_SAMPLES FROM KENTUCKY. (CROP OF 1898.) 
Mar. 13 | White burley lugs...---- INO) sossacee eee Moderate -...- Single-leaf cured. 
IB lesaae dO; 2 ee ceeace cot eeece Mioderatees=s--r eee Much easss22 Cured on stalk. 
20 | Burley grade red leaf... NOME cadscosspcaocde itbletee sees | Do. 
C.—SAMPLES FROM PENNSYLVANIA. (CROP OF 1898.) 
Mar. 20 | Pennsylvania Habana | Moderate ......-...- Mmncheeaaseeee Seed wrapper. 
seed. 
20) | sHabanarseedieeeeenceeeee TPAC Cuan see ee aoe Moderate ..... Seed filler. 
20 | Pennsylvamia seed leaf..| Moderate --.-..--.-.].---- donee seca Wrapper. 
20 Seed leakacesein neice cere loser GO. a cesoirteeee eal Ree On eee Filler. 
